Search results for: yeast enzymes
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 925

Search results for: yeast enzymes

835 Development of Strategy for Enhanced Production of Industrial Enzymes by Microscopic Fungi in Submerged Fermentation

Authors: Zhanara Suleimenova, Raushan Blieva, Aigerim Zhakipbekova, Inkar Tapenbayeva, Zhanar Narmuratova

Abstract:

Green processes are based on innovative technologies that do not negatively affect the environment. Industrial enzymes originated from biological systems can effectively contribute to sustainable development through being isolated from microorganisms which are fermented using primarily renewable resources. Many widespread microorganisms secrete a significant amount of biocatalysts into the environment, which greatly facilitates the task of their isolation and purification. The ability to control the enzyme production through the regulation of their biosynthesis and the selection of nutrient media and cultivation conditions allows not only to increase the yield of enzymes but also to obtain enzymes with certain properties. In this regard, large potentialities are embedded in immobilized cells. Enzyme production technology in a secreted active form enabling industrial application on an economically feasible scale has been developed. This method is based on the immobilization of enzyme producers on a solid career. Immobilizing has a range of advantages: decreasing the price of the final product, absence of foreign substances, controlled process of enzyme-genesis, the ability of various enzymes' simultaneous production, etc. Design of proposed equipment gives the opportunity to increase the activity of immobilized cell culture filtrate comparing to free cells, growing in periodic culture conditions. Such technology allows giving a 10-times raise in culture productivity, to prolong the process of fungi cultivation and periods of active culture liquid generation. Also, it gives the way to improve the quality of filtrates (to make them more clear) and exclude time-consuming processes of recharging fermentative vials, that require manual removing of mycelium.

Keywords: industrial enzymes, immobilization, submerged fermentation, microscopic fungi

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834 Effects of Brewer's Yeast Peptide Extract on the Growth of Probiotics and Gut Microbiota

Authors: Manuela Amorim, Cláudia S. Marques, Maria Conceição Calhau, Hélder J. Pinheiro, Maria Manuela Pintado

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Recently it has been recognized peptides from different food sources with biological activities. However, no relevant study has proven the potential of brewer yeast peptides in the modulation of gut microbiota. The importance of human intestinal microbiota in maintaining host health is well known. Probiotics, prebiotics and the combination of these two components, can contribute to support an adequate balance of the bacterial population in the human large intestine. The survival of many bacterial species inhabiting the large bowel depends essentially on the substrates made available to them, most of which come directly from the diet. Some of these substrates can be selectively considered as prebiotics, which are food ingredients that can stimulate beneficial bacteria such as Lactobacilli or Bifidobacteria growth in the colon. Moreover, conventional food can be used as vehicle to intake bioactive compounds that provide those health benefits and increase people well-being. In this way, the main objective of this work was to study the potential prebiotic activity of brewer yeast peptide extract (BYP) obtained via hydrolysis of yeast proteins by cardosins present in Cynara cardunculus extract for possible use as a functional ingredient. To evaluate the effect of BYP on the modulation of gut microbiota in diet-induced obesity model, Wistar rats were fed either with a standard or a high-fat diet. Quantified via 16S ribosomal RNA (rRNA) expression by quantitative PCR (qPCR), genera of beneficial bacteria (Lactobacillus spp. and Bifidobacterium spp.) and three main phyla (Firmicutes, Bacteroidetes and Actinobacteria) were assessed. Results showed relative abundance of Lactobacillus spp., Bifidobacterium spp. and Bacteroidetes was significantly increased (P < 0.05) by BYP. Consequently, the potential health-promoting effects of WPE through modulation of gut microbiota were demonstrated in vivo. Altogether, these findings highlight the possible intervention of BYP as gut microbiota enhancer, promoting healthy life style, and the incorporation in new food products, leads them bringing associated benefits endorsing a new trend in the improvement of new value-added food products.

Keywords: functional ingredients, gut microbiota, prebiotics, brewer yeast peptide extract

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833 Inhibitory Effect of Potential Bacillus Probiotic Strains against Pathogenic Bacteria and Yeast Isolated from Oral Cavity

Authors: Fdhila Walid, Bayar Sihem, Khouidi Bochra, Maâtouk Fethi, Ben Amor Feten, Hajer Hentati, Mahdhi Abdelkarim

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The presence of resistant bacteria in the oral cavity can be the major cause of dental antibiotic prophylaxis failure. Multidrug efflux has been described for many organisms, including bacteria and fungi as part of their drugs resistance strategy. The potential use of probiotic bacteria can be considered as a new alternative in the prevention or cure of oral cavity diseases. In this study, different Bacillus strains isolated from the environment were isolated and characterized using biochemical and molecular procedures. The inhibitory activity against different pathogenic bacteria and yeast strains was tested using diffusion agar assay method. Our data revealed that the tested strains have an antimicrobial effect against the pathogenic strains such as Streptococcus mutants. The inhibitory effect was variable depending from the probiotic and pathogenic strains. The obtained result demonstrated that Bacillus can be used as a potential candidates probiotic and help in the prevention and treatment of oral infections, including dental caries, periodontal disease and halitosis. Our data, partly encourage the use of probiotic strains because they do not produce acid which can contribute to faster installation decay and these are spore-forming bacteria that can withstand the stress of the oral cavity (acids, alkalis, and salty foods).

Keywords: probiotic, pathogenic bacteria, yeast, oral cavity

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832 Using Hybrid Method for Inactivation of Microorganism and Enzymes in a Berry Juice

Authors: Golnoosh Torabian, P. Valtchev, F. Dehghani

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The need for efficient nutraceutical products has been dramatically changing the approach of the industrial processes. The development of novel mild processes is highly demanded for the production of such products; especially when both quality and safety need to be guaranteed during their long shelf life. Within this research, for the first time, we investigated the effect of supercritical carbon dioxide treatment for the inactivation of microbes and enzymes in a berry juice possessing therapeutic effect. We demonstrated that a complete inactivation of microbes can be achieved at optimized conditions of treatment. However, the bottle neck of the process was represented by the unpromising inactivation of the degradative enzyme by supercritical carbon dioxide treatment. However, complete enzyme inactivation was achieved by applying two strategies: the first was optimizing juicing method by adding a mechanical step and the second strategy was addition of natural inhibitors to the juice. Overall these results demonstrate that our hybrid process has a significant effect on the inactivation of microorganism and enzymes in the fresh juice. The developed process opens the possibility for the evolution of new products with optimal nutritional and sensorial characteristics, as well as offering a competitive cost and an environmentally friendly alternative for pasteurization and extension of shelf life in a wide range of natural therapeutic products.

Keywords: hybrid method, berry juice, pasteurization, enzymes inactivation

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831 Effect of Supplementing Different Sources and Levels of Phytase Enzyme to Diets on Productive Performance for Broiler Chickens

Authors: Sunbul Jassim Hamodi, Muna Khalid Khudayer, Firas Muzahem Hussein

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The experiment was conducted to study the effect of supplement sources of Phytase enzyme (bacterial, fungal, enzymes mixture) using levels (250, 500, 750) FTY/ kg feed to diets compared with control on the performance for one thousand fifty broiler chicks (Ross 308) from 1day old with initial weight 39.78 gm till 42 days. The study involved 10 treatments, three replicates per treatment (35 chicks/replicate). Treatments were as follows: T1: control diet (without any addition). T2: added bacterial phytase enzyme 250FTY/ kg feed. T3: added bacterial phytase enzyme 500FTY/ kg feed. T4: added bacterial phytase enzyme 750FTY/ kg feed. T5: added fungal phytase enzyme 250FTY/ kg feed. T6: added fungal phytase enzyme 500FTY/ kg feed. T7: added fungal phytase enzyme 750FTY/ kg feed. T8 added enzymes mixture 250U/ kg feed. T9: added enzymes mixture 500U/ kg feed. T10: added enzymes mixture 750U/ kg feed. The results revealed that supplementing 750 U from enzymes mixture to broiler diet increased significantly (p <0.05) body weight compared with (250 FTY bacterial phytase/Kgfeed), (750 FTY bacterial phytase/Kg feed), (750FTY fungal phytase/Kgfeed) at 6 weeks, also supplemented different sources and levels from phytase enzyme improved a cumulative weight gain for (500 FTY bacterial phytase/Kgfeed), (250FTY fungal phytase/Kgfeed), (500FTY fungal phytase/Kgfeed), (250 Uenzymes mixture/Kgfeed), (500 Uenzymes mixture/Kgfeed) and (750 U enzymes mixture/Kgfeed) treatments compared with (750 FTY fungal phytase/Kgfeed)treatment, about accumulative feed consumption (500 FTY fungal phytase/Kgfeed) and (250 Uenzymes mixture/Kgfeed) increased significantly compared with control group and (750FTY fungal phytase/Kgfeed) during 1-6 weeks. There were significantly improved in cumulative feed conversion for (500U enzymes mixture/Kgfeed) compared with the worse feed conversion ratio that recorded in (250 FTY bacterial phytase/Kgfeed). No significant differences between treatments in internal organs relative weights, carcass cuts, dressing percentage and production index. Mortality was increased in (750FTY fungal phytase/Kgfeed) compared with other treatments.

Keywords: phytase, phytic acid, broiler, productive performance

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830 The Antagonistic/Synergistic Effect of Probiotic Yeast Saccharomyces boulardii on Candida glabrata Adhesion

Authors: Zorica Tomičić, Ružica Tomičić, Peter Raspor

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Growing resistance of pathogenic yeast Candida glabrata to many classes of antifungal drugs has stimulated efforts to discover new agents to combat a rising number of invasive C. glabrata infections, which deserves a great deal of concern due to the high mortality rate in immunocompromised populations. One promising strategy is the use of probiotic microorganisms, which, when administered in adequate amounts, confers a health benefit. A selected number of probiotic organisms, Saccharomyces boulardii among them, have been tested as potential biotherapeutic agents. The aim of this study was to investigate the effect of the probiotic yeast S. boulardii on the adhesion of clinical isolates of C. glabrata at different temperatures, pH values, and in the presence of three clinically important antifungal drugs, such as fluconazole, itraconazole and amphotericin B. The method used to assess adhesion was crystal violet staining. The selection of antimycotics concentrations used in the adhesion assay was based on minimum inhibitory concentrations (MICs) obtained by the preliminarily performed microdilution modification of the Reference method for broth dilution antifungal susceptibility testing of yeast (Clinical and Laboratory Standards Institute (CLSI), standard M27-A2). the results showed that despite the nonadhesiveness of S. boulardii cells, probiotic yeast significantly suppressed the adhesion of C. glabrata strains. Besides, at specific strain ratios, a slight stimulatory effect was observed in some C. glabrata strains, which highlights the importance of strain specificity and opens up further research interests. When environmental conditions are considered, temperature and pH significantly influenced co-culture adhesion of C. glabrata and S. boulardii. The adhesion of C. glabrata strains was relatively equally reduced over all tested temperature range (28°C, 37°C, 39°C and 42°C) in the presence of S. boulardii cells, while the adhesion of a few C. glabrata strains were significantly stimulated at 28°C and suppressed at 42°C. Further, the adhesion was highly dependent on pH, with the highest adherence at pH 4 and lowest at pH 8.5. It was observed that S. boulardii did not manage to suppress the adhesion of C. glabrata strains at high pH. Antimycotics on the other hand showed a greater impact, since S. boulardii failed to affect co-culture adhesion at higher antimycotics concentrations. As expected, exposure to various concentrations of amphotericin B significantly reduced the adherence ability of C.glabrata strains both in a single culture and co-culture with S. boulardii. Therefore, it can be speculated that S. boulardii could substitute the effect of antimycotics in a range concentrations and with specific type of strains. This would certainly change the view on the treatment of yeast infections in the future.

Keywords: adhesion, antimycotics, candida glabrata, saccharomyces boulardii

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829 Evaluation of Antarctic Bacteria as Potential Producers of Cellulolytic Enzymes of Industrial Interest

Authors: Claudio Lamilla, Andrés Santos, Vicente Llanquinao, Jocelyn Hermosilla, Leticia Barrientos

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The industry in general is very interested in improving and optimizing industrial processes in order to reduce the costs involved in obtaining raw materials and production. Thus, an interesting and cost-effective alternative is the incorporation of bioactive metabolites in such processes, being an example of this enzymes which catalyze efficiently a large number of enzymatic reactions of industrial and biotechnological interest. In the search for new sources of these active metabolites, Antarctica is one of the least explored places on our planet where the most drastic cold conditions, salinity, UVA-UVB and liquid water available are present, features that have shaped all life in this very harsh environment, especially bacteria that live in different Antarctic ecosystems, which have had to develop different strategies to adapt to these conditions, producing unique biochemical strategies. In this work the production of cellulolytic enzymes of seven bacterial strains isolated from marine sediments at different sites in the Antarctic was evaluated. Isolation of the strains was performed using serial dilutions in the culture medium at M115°C. The identification of the strains was performed using universal primers (27F and 1492R). The enzyme activity assays were performed on R2A medium, carboxy methyl cellulose (CMC)was added as substrate. Degradation of the substrate was revealed by adding Lugol. The results show that four of the tested strains produce enzymes which degrade CMC substrate. The molecular identifications, showed that these bacteria belong to the genus Streptomyces and Pseudoalteromonas, being Streptomyces strain who showed the highest activity. Only some bacteria in marine sediments have the ability to produce these enzymes, perhaps due to their greater adaptability to degrade at temperatures bordering zero degrees Celsius, some algae that are abundant in this environment and have cellulose as the main structure. The discovery of new enzymes adapted to cold is of great industrial interest, especially for paper, textiles, detergents, biofuels, food and agriculture. These enzymes represent 8% of industrial demand worldwide and is expected to increase their demand in the coming years. Mainly in the paper and food industry are required in extraction processes starch, protein and juices, as well as the animal feed industry where treating vegetables and grains helps improve the nutritional value of the food, all this clearly puts Antarctic microorganisms and their enzymes specifically as a potential contribution to industry and the novel biotechnological applications.

Keywords: antarctic, bacteria, biotechnological, cellulolytic enzymes

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828 Effects of Cassava Pulp Fermentation by Yeast on Meat Goats Performances and Nitrogen Retention

Authors: S. Paengkoum, P. Paengkoum, W. Kaewwongsa

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Twenty-four male growing goats were randomly assigned to a Randomized Complete Block Design. Dietary treatments were different level of feeding concentrate diet at 1.0, 1.5, 2.0, and 2.5% of body weight (BW). The results showed that average daily gain, microbial N supply, N retention of meat goats in the group of feeding level at 2.0% BW and 2.5% BW were significantly higher (P<0.05) than those goats fed with feeding levels of 1.0% BW and 1.5% BW. Based on this result the conclusion can be made that using 75% fermented cassava pulp by Saccharomyces cerevisiae as the main source of protein to completely replace soybean meal was beneficial to meat goats in terms of feed intake. The feeding concentrate at levels between 2.0-2.5% BW gives highest in the growth of meat goat in this experiment.

Keywords: cassava pulp, yeast, goat, nitrogen retention

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827 Fermentable Bio-Ethanol Using Bakers and Palmwine Yeasts: Indices of Bioavailability of Carbohydrate and Sugar from Fungal Treated Rice Husk

Authors: Ezeonu, Chukwuma Stephen, Onwurah, Ikechukwu Noel Emmanuel

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Pure strains of Aspergillus fumigatus (AF), aspergillus niger (AN), aspergillus oryzae (AO), trichophyton mentagrophyte (TM), trichophyton rubrum (TR) and Trichophyton soudanense (TS) were isolated from decomposing rice husk. Freshly processed rice husk in Mandle’s medium were heat pre-treated using an autoclave at 121oC for 20 minutes. The isolated fungi as monoculture and di-culture combinations were inoculated into each of the pre-treated rice husk with the exception of two controls. Seven days hydrolysis was followed by estimation of carbohydrate, reducing sugar and non-reducing sugar. Fungal treated rice husks were left to ferment for 7 days with introduction of both baker’s and palm wine yeast. The result obtained in the work gave the highest carbohydrate (20.53 ± 2.73 %) from rice husks treated with TS + TR di-culture. The highest soluble reducing sugar (2.66 ± 0.14 %) was obtained from rice husk treated with TM. The highest soluble nonreducing sugar (18.08 ± 2.61 %) was from AF. The introduction of yeasts from palm wine gave the highest bio-ethanol (12.82 ± 0.39 %) from AO. The highest bio-ethanol (6.60 ± 0.10 %) from baker's yeast fermentation was in AO + TS treated rice husk. There was increased availability of sugar and moderate yield of bio-ethanol, especially from palm wine yeast.

Keywords: fungi, rice husk, carbohydrate, reducing sugar, non-reducing sugar, ethanol, fermentation

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826 Bismuth-Inhibitory Effects on Bacteria and Stimulation of Fungal Growth In vitro

Authors: Sulaiman B. Ali Alharbi, Bassam H. Mashat, Naif Abdullah Al-Harbi, Milton Wainwright, Abeer S. Aloufi, Sulamain Alnaimat

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Bismuth salicylate was found to inhibit the growth of a range of bacteria and yeast, Candida albican. In general the growth of bacteria did not result in the increase in bismuth solubilisation, in contrast, bismuth solubilisation increased following the growth of C. albicans. A significant increase in the biomass (dry weight) of Aspergillus niger and Aspergillus oryzae occurred in vitro when these fungi were grown in the presence of bismuth salicylate. Biomass increase occurred over a range of bismuth compound additions, which in the case of A. oryzae was associated with the increase in the solubilisation of the insoluble bismuth compounds.

Keywords: bacterial inhibition, fungal growth stimulation, medical uses of bismuth, yeast inhibition

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825 Enzymatic Hydrolysis of Sugar Cane Bagasse Using Recombinant Hemicellulases

Authors: Lorena C. Cintra, Izadora M. De Oliveira, Amanda G. Fernandes, Francieli Colussi, Rosália S. A. Jesuíno, Fabrícia P. Faria, Cirano J. Ulhoa

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Xylan is the main component of hemicellulose and for its complete degradation is required cooperative action of a system consisting of several enzymes including endo-xylanases (XYN), β-xylosidases (XYL) and α-L-arabinofuranosidases (ABF). The recombinant hemicellulolytic enzymes an endoxylanase (HXYN2), β-xylosidase (HXYLA), and an α-L-arabinofuranosidase (ABF3) were used in hydrolysis tests. These three enzymes are produced by filamentous fungi and were expressed heterologously and produced in Pichia pastoris previously. The aim of this work was to evaluate the effect of recombinant hemicellulolytic enzymes on the enzymatic hydrolysis of sugarcane bagasse (SCB). The interaction between the three recombinant enzymes during SCB pre-treated by steam explosion hydrolysis was performed with different concentrations of HXYN2, HXYLA and ABF3 in different ratios in according to a central composite rotational design (CCRD) 23, including six axial points and six central points, totaling 20 assays. The influence of the factors was assessed by analyzing the main effects and interaction between the factors, calculated using Statistica 8.0 software (StatSoft Inc. Tulsa, OK, USA). The Pareto chart was constructed with this software and showed the values of the Student’s t test for each recombinant enzyme. It was considered as response variable the quantification of reducing sugars by DNS (mg/mL). The Pareto chart showed that the recombinant enzyme ABF3 exerted more significant effect during SCB hydrolysis, with higher concentrations and with the lowest concentration of this enzyme. It was performed analysis of variance according to Fisher method (ANOVA). In ANOVA for the release of reducing sugars (mg/ml) as the variable response, the concentration of ABF3 showed significance during hydrolysis SCB. The result obtained by ANOVA, is in accordance with those presented in the analysis method based on the statistical Student's t (Pareto chart). The degradation of the central chain of xylan by HXYN2 and HXYLA was more strongly influenced by ABF3 action. A model was obtained, and it describes the performance of the interaction of all three enzymes for the release of reducing sugars, and can be used to better explain the results of the statistical analysis. The formulation capable of releasing the higher levels of reducing sugars had the following concentrations: HXYN2 with 600 U/g of substrate, HXYLA with 11.5 U.g-1 and ABF3 with 0.32 U.g-1. In conclusion, the recombinant enzyme that has a more significant effect during SCB hydrolysis was ABF3. It is noteworthy that the xylan present in the SCB is arabinoglucoronoxylan, due to this fact debranching enzymes are important to allow access of enzymes that act on the central chain.

Keywords: experimental design, hydrolysis, recombinant enzymes, sugar cane bagasse

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824 Non Interferometric Quantitative Phase Imaging of Yeast Cells

Authors: P. Praveen Kumar, P. Vimal Prabhu, Renu John

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In biology most microscopy specimens, in particular living cells are transparent. In cell imaging, it is hard to create an image of a cell which is transparent with a very small refractive index change with respect to the surrounding media. Various techniques like addition of staining and contrast agents, markers have been applied in the past for creating contrast. Many of the staining agents or markers are not applicable to live cell imaging as they are toxic. In this paper, we report theoretical and experimental results from quantitative phase imaging of yeast cells with a commercial bright field microscope. We reconstruct the phase of cells non-interferometrically based on the transport of intensity equations (TIE). This technique estimates the axial derivative from positive through-focus intensity measurements. This technique allows phase imaging using a regular microscope with white light illumination. We demonstrate nano-metric depth sensitivity in imaging live yeast cells using this technique. Experimental results will be shown in the paper demonstrating the capability of the technique in 3-D volume estimation of living cells. This real-time imaging technique would be highly promising in real-time digital pathology applications, screening of pathogens and staging of diseases like malaria as it does not need any pre-processing of samples.

Keywords: axial derivative, non-interferometric imaging, quantitative phase imaging, transport of intensity equation

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823 Antitrypanosomal Activity of Stigmasterol: An in silico Approach

Authors: Mohammed Auwal Ibrahim, Aminu Mohammed

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Stigmasterol has previously been reported to possess antitrypanosomal activity using in vitro and in vivo models. However, the mechanism of antitrypanosomal activity is yet to be elucidated. In the present study, molecular docking was used to decipher the mode of interaction and binding affinity of stigmasterol to three known antitrypanosomal drug targets viz; adenosine kinase, ornithine decarboxylase and triose phosphate isomerase. Stigmasterol was found to bind to the selected trypanosomal enzymes with minimum binding energy of -4.2, -6.5 and -6.6 kcal/mol for adenosine kinase, ornithine decarboxylase, and triose phosphate isomerase respectively. However, hydrogen bond was not involved in the interaction of stigmasterol with all the three enzymes, but hydrophobic interaction seemed to play a vital role in the binding phenomenon which was predicted to be non-competitive like type of inhibition. It was concluded that binding to the three selected enzymes, especially triose phosphate isomerase, might be involved in the antitrypanosomal activity of stigmasterol but not mediated via a hydrogen bond interaction.

Keywords: antitrypanosomal, in silico, molecular docking, stigmasterol

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822 Effect of Yeast Selenium on CD4 T Cell and WAZ of HIV1 Positive Children in Nyamasaria in Kisumu Kenya

Authors: S. B. Otieno1, F. Were, A. Afullo, K. Waza

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Background: Multi drug resistance HIV has emerged rendering the current conventional treatment of HIV ineffective. There is a need for new treatment regime which is cheap, effective and not prone to resistance development by HIV. Methods: In randomized clinical study of 68 HIV positive children 3 – 15 years to asses the efficacy of yeast selenium in HIV/AIDS patients, 50μ yeast selenium was administered to 34 children while in matched control of 34 were put on placebo. Blood samples and weight of the both groups which were taken every 3 months intervals up to 6 months, were analyzed by ELIZA for CD4T cells, the data was analyzed by SPSS version 16, WAZ scores were analyzed by Epi Info version 6. Results: No significant difference in age { χ2 (1, 62) =0.03, p =0.853}, cause of morbidity between test and controls {χ2 (1, 65) = 5.87, p= 0.015} and on condition of foster parents {χ2 ( 1,63) = 5.57, p= 0.0172} was observed. Children on selenium showed progressive improvement of WAZ and significant difference at six months {F (5,12) = =5.758, P=0.006}, and weight gain of up to 4.1 kilograms in six months, and significant CD4 T cell count increase t= -2.943, p<0.05 compared to matched controls t = -1.258 p> 0.05. CD4 T cell count increased among all age groups on test 3-5 years (+ 267.1),5-8 years (+200.3) 9-15 years (+71.2) cells/mm3 and in matched controls a decrease 3-5 years (-71), 5-8 years (-125) and 9-13 years (-10.1) cells/mm3 . No significant difference inCD4 T cell count between boys {F (2, 32) = 1.531 p= 0.232} and between boys {F (2, 49) = 1.040, p= 0.361} on test and between boys and girls {F (5, 81) = 1.379, p= 0.241} on test. Similarly no significant difference between boys and girls were observed {F (5, 86) = 1.168, p= 0.332}.In the test group there was significant positive correlation β =252.23 between weight for age (WAZ), and CD4 T Cell Count p=0.007, R2= 0.252, F< 0.05. In matched controls no significant correlation between weight gain and CD4 T cell count change was observed at six months p > 0.05. No positive correlation β =-138.23 was observed between CD4T Cell count, WAZ, p=0.934, R2 =0.0337 F >0.05. Majority (96.78%) of children on test either remained or progressed to WHO immunological stage I. Conclusion: From this study it can be concluded that yeast Selenium is effective in slowing the progress of HIV 1 in children from WHO clinical stage I by improving CD4 T cell count and hence the immunity.

Keywords: selenium, HIV, AIDS, WAZ

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821 Histochemistry of Intestinal Enzymes of Juvenile Dourado Salminus brasiliensis Fed Bovine Colostrum

Authors: Debora B. Moretti, Wiolene M. Nordi, Thaline Maira P. Cruz, José Eurico P. Cyrino, Raul Machado-Neto

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Enzyme activity was evaluated in the intestine of juvenile dourado (Salminus brasiliensis) fed with diets containing 0, 10 or 20% of lyophilized bovine colostrum (LBC) inclusion for either 30 or 60 days. The intestinal enzymes acid and alkaline phosphatase (ACP and ALP, respectively), non-specific esterase (NSE), lipase (LIP), dipeptidyl aminopeptidase IV (DAP IV) and leucine aminopeptidase (LAP) were studied using histochemistry in four intestinal segments (S1, S2, S3 and posterior intestine). Weak proteolitic activity was observed in all intestinal segments for DAP IV and LAP. The activity of NSE and LIP was also weak in all intestines, except for the moderate activity of NSE in the S2 of 20% LBC group after 30 days and in the S1 of 0% LBC group after 60 days. The ACP was detected only in the S2 and S3 of the 10% LBC group after 30 days. Moderate and strong staining was observed in the first three intestinal segments for ALP and weak activity in the posterior intestine. The activity of DAP IV, LAP and ALP were also present in the cytoplasm of the enterocytes. In the present results, bovine colostrum feeding did not cause alterations in activity of intestinal enzymes.

Keywords: carnivorous fish, enterocyte, intestinal epithelium, teleost

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820 The Subcellular Localisation of EhRRP6 and Its Involvement in Pre-Ribosomal RNA Processing in Growth-Stressed Entamoeba histolytica

Authors: S. S. Singh, A. Bhattacharya, S. Bhattacharya

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The eukaryotic exosome complex plays a pivotal role in RNA biogenesis, maturation, surveillance and differential expression of various RNAs in response to varying environmental signals. The exosome is composed of evolutionary conserved nine core subunits and the associated exonucleases Rrp6 and Rrp44. Rrp6p is crucial for the processing of rRNAs, other non-coding RNAs, regulation of polyA tail length and termination of transcription. Rrp6p, a 3’-5’ exonuclease is required for degradation of 5’-external transcribed spacer (ETS) released from the rRNA precursors during the early steps of pre-rRNA processing. In the parasitic protist Entamoeba histolytica in response to growth stress, there occurs the accumulation of unprocessed pre-rRNA and 5’ ETS sub fragment. To understand the processes leading to this accumulation, we looked for Rrp6 and the exosome subunits in E. histolytica, by in silico approaches. Of the nine core exosomal subunits, seven had high percentage of sequence similarity with the yeast and human. The EhRrp6 homolog contained exoribonuclease and HRDC domains like yeast but its N- terminus lacked the PMC2NT domain. EhRrp6 complemented the temperature sensitive phenotype of yeast rrp6Δ cells suggesting conservation of biological activity. We showed 3’-5’ exoribonuclease activity of EhRrp6p with in vitro-synthesized appropriate RNAs substrates. Like the yeast enzyme, EhRrp6p degraded unstructured RNA, but could degrade the stem-loops slowly. Furthermore, immunolocalization revealed that EhRrp6 was nuclear-localized in normal cells but was diminished from nucleus during serum starvation, which could explain the accumulation of 5’ETS during stress. Our study shows functional conservation of EhRrp6p in E.histolytica, an early-branching eukaryote, and will help to understand the evolution of exosomal components and their regulatory function.

Keywords: entamoeba histolytica, exosome complex, rRNA processing, Rrp6

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819 Detection and Expression of Peroxidase Genes in Trichoderma harzianum KY488466 and Its Response to Crude Oil Degradation

Authors: Michael Dare Asemoloye, Segun Gbolagade Jonathan, Rafiq Ahmad, Odunayo Joseph Olawuyi, D. O. Adejoye

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Fungi have potentials for degrading hydrocarbons through the secretion of different enzymes. Crude oil tolerance and degradation by Trichoderma harzianum was investigated in this study with its ability to produce peroxidase enzymes (LiP and MnP). Many fungal strains were isolated from rhizosphere of grasses growing on a crude oil spilled site, and the most frequent strain based on percentage incidence was further characterized using morphological and molecular characteristics. Molecular characterization was done through the amplification of Ribosomal-RNA regions of 18s (1609-1627) and 28s (287-266) using ITS1 and ITS4 combinations and it was identified using NCBI BLAST tool. The selected fungus was also subjected to an in-vitro tolerance test at crude oil concentrations of 5, 10, 15, 20 and 25% while 0% served as control. In addition, lignin peroxidase genes (lig1-6) and manganese peroxidase gene (mnp) were detected and expressed in this strain using RT-PCR technique, its peroxidase producing activities was also studied in aliquots (U/ml). This strain had highest incidence of 80%, it was registered in NCBI as Trichoderma harzianum asemoJ KY488466. The strain KY488466 responded to crude oil concentrations as it increase, the dose inhibition response percentage (DIRP) increased from 41.67 to 95.41 at 5 to 25 % crude oil concentrations. All the peroxidase genes are present in KY488466, and expressed with amplified 900-1000 bp through RT-PCR technique. In this strain, lig2, lig4 and mnp genes were over-expressed, lig 6 was moderately expressed, while none of the genes was under-expressed. The strain also produced 90±0.87 U/ml lignin peroxidase and 120±1.23 U/mil manganese peroxidase enzymes in aliquots. These results imply that KY488466 can tolerate and survive high crude oil concentration and could be exploited for bioremediation of oil-spilled soils, the produced peroxidase enzymes could also be exploited for other biotechnological experiments.

Keywords: crude oil, enzymes, expression, peroxidase genes, tolerance, Trichoderma harzianum

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818 Comparative Survival Rates of Yeasts during Freeze-Drying, Traditional Drying and Spray Drying

Authors: Latifa Hamoudi-Belarbi, L'Hadi Nouri, Khaled Belkacemi

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The effect of three methods of drying (traditional drying, freeze-drying and spray-drying) on the survival of concentrated cultures of Geotrichum fragrans and Wickerhamomyces anomalus was studied. The survival of yeast cultures was initially compared immediately after freeze-drying using HES 12%(w/v)+Sucrose 7% (w/v) as protectant, traditional drying in dry rice cakes and finally spray-drying with whey proteins. The survival of G. fragrans and W. anomalus was studied during 4 months of storage at 4°C and 25°C, in the darkness, under vacuum and at 0% relative humidity. The results demonstrated that high survival was obtained using traditional method of preservation in rice cakes (60% for G. fragrans and 65% for W. anomalus) and freeze-drying in (68% for G. fragrans and 74% for W. anomalus). However, poor survival was obtained by spray-drying method in whey protein with 20% for G. fragrans and 29% for W. anomalus. During storage at 25°C, yeast cultures of G. fragrans and W. anomalus preserved by traditional and freeze-drying methods showed no significant loss of viable cells up to 3 months of storage. Spray-dried yeast cultures had the greatest loss of viable count during the 4 months of storage at 25°C. During storage at 4°C, preservation of yeasts cultures using traditional method of preservation provided better survival than freeze-drying. This study demonstrated the effectiveness of the traditional method to preserve yeasts cultures compared to the high cost methods like freeze-drying and spray-drying.

Keywords: freeze-drying, traditional drying, spray drying, yeasts

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817 Binding Studies of Complexes of Anticancer Drugs with DNA and Enzymes Involved in DNA Replication Using Molecular Docking and Cell Culture Techniques

Authors: Fouzia Perveen, Rumana Qureshi

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The presently studied twelve anticancer drugs are the cytotoxic agents which inhibit the replication of DNA and activity of enzymes involved in DNA replication namely topoisomerase-II, polymerase and helicase and have shown remarkable anticancer activity in clinical trials. In this study, we performed molecular docking studies of twelve antitumor drugs against DNA and DNA enzymes in the presence and absence of ascorbic acid (AA) and developed the quantitative structure-activity relationship (QSAR) model for anticancer activity screening. A number of electronic and steric descriptors were calculated using MOE software package. QSAR was established showing a correlation of binding strength with various physicochemical descriptors. Out of these twelve, eight cytotoxic drugs were tested on Non-Small Cell Lung Cancer cell lines (H-157 and H-1299) in the absence and presence of ascorbic acid and experimental IC50 values were calculated. From the docking studies, binding constants were calculated indicating the strength of drug-DNA and drug-enzyme complex formation and it was correlated to the IC50 values (both experimental and theoretical). These results can offer useful references for directing the molecular design of DNA enzyme inhibitor with improved anticancer activity.

Keywords: ascorbic acid, binding constant, cytotoxic agents, cell culture, DNA, DNA enzymes, molecular docking

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816 Comparison the Effect of Different Pretreatments on Ethanol Production from Lemon Peel (Citrus × latifolia)

Authors: Zohreh Didar Yaser, Zanganeh Asadabadi

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The aim of this work is to open up the structure of lemon peel (Citrus × latifolia) with mild pretreatments. The effects of autoclave, microwave and ultrasonic with or without acid addition were investigated on the amount of glucose, soluble and insoluble lignin, furfural, yeast viability and bioethanol. The finding showed that autoclave- acid impregnated sample, has the highest glucose release from lignocellulose materials (14.61 and 14.95 g/l for solvent exposed and untreated sample, respectively) whereas at control sample glucose content was at its minimal level. Pretreatments cause decrease on soluble and insoluble lignin and the highest decrease cause by autoclave following with microwave and ultrasonic pretreatments (p≤5%). Moderate increase on furfural was seen at pretreated samples than control ones. Also, the most yeast viability and bioethanol content was belong to autoclave samples especially acid- impregnated ones (40.33%). Comparison between solvent treated and untreated samples indicated that significant difference was between two tested groups (p≤1%) in terms of lignin, furfural, cell viability and ethanol content but glucose didn’t show significant difference. It imply that solvent extraction don’t influences on glucose release from lignocellulose material of lemon peel but cause enhancement of yeast viability and bioethanol production.

Keywords: Bioethanol, Lemon peel, Pretreatments, Solvent Extraction

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815 Isolation, Identification and Characterization of the Bacteria and Yeast from the Fermented Stevia Extract

Authors: Asato Takaishi, Masashi Nasuhara, Ayuko Itsuki, Kenichi Suga

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Stevia (Stevia rebaudiana Bertoni) is a composite plant native to Paraguay. Stevia sweetener is derived from a hot water extract of Stevia (Stevia extract), which has some effects such as histamine decomposition, antioxidative effect, and blood sugar level-lowering function. The steviol glycosides in the Stevia extract are considered to contribute to these effects. In addition, these effects increase by the fermentation. However, it takes a long time for fermentation of Stevia extract and the fermentation liquid sometimes decays during the fermentation process because natural fermentation method is used. The aim of this study is to perform the fermentation of Stevia extract in a shorter period, and to produce the fermentation liquid in stable quality. From the natural fermentation liquid of Stevia extract, the four strains of useful (good taste) microorganisms were isolated using dilution plate count method and some properties were determined. The base sequences of 16S rDNA and 28S rDNA revealed three bacteria (two Lactobacillus sp. and Microbacterium sp.) and one yeast (Issatchenkia sp.). This result has corresponded that several kinds of lactic bacterium such as Lactobacillus pentosus and Lactobacillus buchneri were isolated from Stevia leaves. Liquid chromatography/mass spectrometory (LC/MS/MS) and High-Performance Liquid Chromatography (HPLC) were used to determine the contents of steviol glycosides and neutral sugars. When these strains were cultured in the sterile Stevia extract, the steviol and stevioside were increased in the fermented Stevia extract. So, it was suggested that the rebaudioside A and the mixture of steviol glycosides in the Stevia extract were decomposed into stevioside and steviol by microbial metabolism.

Keywords: fermentation, lactobacillus, Stevia, steviol glycosides, yeast

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814 Design, Molecular Modeling, Synthesize, and Biological Evaluation of Some Dual Inhibitors of Soluble Epoxide Hydrolase (sEH) and Cyclooxygenase 2 (COX-2)

Authors: Elham Rezaee, Sayyed Abbas Tabatabai

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Dual inhibition of COX-2 and sEH enzymes represents one of the distinct pharmaceutical approaches for the treatment of inflammation, pain, cancers, and other diseases. The discovery of these inhibitors for treatment is a great deal of attention because of some advantages such as increased efficacy, a promising safety profile, ease of formulation, and better target engagement. In this research, based on the structure-activity relationship of COX-2 and sEH inhibitors, some amide derivatives with oxadiazole and dihydropyrimidinone rings against sEH and COX-2 enzymes were developed. The designed compounds showed high affinity to the active site of both enzymes in docking studies and were synthesized in good yield and characterized by IR, Mass, 1HNMR, and 13CNMR. All of the novel compounds exhibited considerable in-vitro sEH and COX-2 inhibitory activities in comparison with 12-(3-Adamantan-1-yl-ureido)- dodecanoic acid and celecoxib (a potent urea-based sEH inhibitor and selective nonsteroidal anti-inflammatory drug, respectively). Ethyl 6-methyl-4-(4-(4-(methylsulfonyl)benzamido)phenyl)-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate was found to be the most selective COX-2 inhibitor (COX-2/COX-1 ratio: 683) with IC50 value of 2.1 nM targeting sEH enzyme.

Keywords: COX-2, dual inhibitors, sEH, synthesis

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813 Bio-Desalination and Bioremediation of Agroindustrial Wastewaters Using Yarrowia Lipolytica

Authors: Selma Hamimed, Abdelwaheb Chatti

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The current study deals with the biological treatment of saline wastewaters generated by various agro-food industries using Yarrowia lipolytica. The ability of this yeast was studied on the mixture of olive mill wastewater and tuna wash processing wastewater. Results showed that the high proportion of olive mill wastewater in the mixture about (75:25) is the suitable one for the highest Y. lipolytica biomass production, reaching 11.3 g L⁻¹ after seven days. In addition, results showed significant removal of chemical oxygen demand (COD) and phosphorous of 97.49 % and 98.90 %, respectively. On the other hand, Y. lipolytica was found to be effective to desalinate all mixtures reaching a removal of 92.21 %. Moreover, the analytical results using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) confirmed the biosorption of NaCl on the surface of the yeast as nanocrystals form with a size of 47.3 nm.

Keywords: nanocrystallization of NaCl, desalination, wastewater treatment, yarrowia lipolytica

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812 Second Generation Biofuels: A Futuristic Green Deal for Lignocellulosic Waste

Authors: Nivedita Sharma

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The global demand for fossil fuels is very high, but their use is not sustainable since its reserves are declining. Additionally, fossil fuels are responsible for the accumulation of greenhouse gases. The emission of greenhouse gases from the transport sector can be reduced by substituting fossil fuels by biofuels. Thus, renewable fuels capable of sequestering carbon dioxide are in high demand. Second‐generation biofuels, which require lignocellulosic biomass as a substrate and ultimately producing ethanol, fall largely in this category. Bioethanol is a favorable and near carbon-neutral renewable biofuel leading to reduction in tailpipe pollutant emission and improving the ambient air quality. Lignocellulose consists of three main components: cellulose, hemicellulose and lignin which can be converted to ethanol with the help of microbial enzymes. Enzymatic hydrolysis of lignocellulosic biomass in 1st step is considered as the most efficient and least polluting methods for generating fermentable hexose and pentose sugars which subsequently are fermented to power alcohol by yeasts in 2nd step of the process. In the present technology, a complete bioconversion process i.e. potential hydrolytic enzymes i.e. cellulase and xylanase producing microorganisms have been isolated from different niches, screened for enzyme production, identified using phenotyping and genotyping, enzyme production, purification and application of enzymes for saccharification of different lignocellulosic biomass followed by fermentation of hydrolysate to ethanol with high yield is to be presented in detail.

Keywords: cellulase, xylanase, lignocellulose, bioethanol, microbial enzymes

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811 Effect of Mineral Ion Addition on Yeast Performance during Very High Gravity Wort Fermentation

Authors: H. O. Udeh, T. E. Kgatla, A. I. O. Jideani

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The effect of Zn2+, Mg2+, and Ba2+ on Saccharomyces pastorianus during very high gravity fermentation was evaluated in this study at independent and three variable combinations. Wort gravity of 21oP was prepared from barley malt, hops and water, to which the metal ions were supplemented in their combinations and subsequently pitched. After 96 h of fermentation, high wort fermentability (%F)= 29.53 was obtained in wort medium containing 900:4 ppm Mg2+ + Ba2+. Increased ethanol titre 7.3491 %(v/v) and 7.1313 %(v/v) were obtained in media containing 900:4 ppm Mg2+ + Ba2+ and 12:900 ppm Zn2+ + Mg2+. Decrease %F= 22.54 and ethanol titre 6.1757% (v/v) was recorded in wort medium containing 12:4 ppm Zn2+ + Ba2+. In media containing the individual metal ions, increased %F= 27.94 and %F= 26.03 were obtained in media containing 700 ppm Mg2+ and 2 ppm Ba2+, with increased ethanol yield of 7.8844% (v/v) and 7.6245% (v/v) respectively. Least %F of 11.75 and 10.80, and ethanol titre of 4.99 (%v/v) and 4.80 (%v/v) were obtained for 10 ppm Zn2+ and 4 ppm Ba2+ respectively.

Keywords: ethanol yield, fermentability, mineral ions, yeast stress, very high gravity fermentation

Procedia PDF Downloads 372
810 Immunoprotective Role of Baker's Yeast (Saccharomyces cerevisiae) against Experimentally Induced Aflatoxicosis in Broiler Chicks

Authors: Zain Ul Abadeen, Muhammad Zargham Khan, Muhammad Kashif Saleemi, Ahrar Khan, Ijaz Javed Hassan, Aisha Khatoon, Qasim Altaf

Abstract:

Aflatoxins are secondary metabolites produced by toxigenic fungi, and there are four types of aflatoxins include AFB1, AFB2, AFG1 and AFG2. Aflatoxin B1 (AFB1) is considered as most toxic form. It is mainly responsible for the contamination of poultry feed and produces a condition called aflatoxicosis leads to immunosuppression in poultry birds. Saccharomyces cerevisiae is a single cell microorganism and acts as a source of growth factors, minerals and amino acids which improve the immunity and digestibility in poultry birds as probiotics. Saccharomyces cerevisiae is well recognized to cause the biological degradation of mycotoxins (toxin binder) because its cell wall contains β-glucans and mannans which specifically bind with aflatoxins and reduce their absorption or transfer them to some non-toxic compounds. The present study was designed to investigate the immunosuppressive effects of aflatoxins in broiler chicks and the reduction of severity of these effects by the use of Baker’s Yeast (Saccharomyces cerevisiae). One-day-old broiler chicks were procured from local hatchery and were divided into various groups (A-I). These groups were treated with different levels of AFB1 @ 400 µg/kg and 600 µg/kg along with different levels of Baker’s Yeast (Saccharomyces cerevisiae) 0.1% and 0.5 % in the feed. The total duration of the experiment was six weeks and different immunological parameters including the cellular immune response by injecting PHA-P (Phytohemagglutinin-P) in the skin of the birds, phagocytic function of mononuclear cells by Carbon clearance assay from blood samples and humoral immune response against intravenously injected sheep RBCs from the serum samples were determined. The birds from each group were slaughtered at the end of the experiment to determine the presence of gross lesions in the immune organs and these tissues were fixed in 10% neutral buffered formalin for histological investigations. The results showed that AFB1 intoxicated groups had reduced body weight gain, feed intake, organs weight and immunological responses compared to the control and Baker’s Yeast (Saccharomyces cerevisiae) treated groups. Different gross and histological degenerative changes were recorded in the immune organs of AFB1 intoxicated groups compared to control and Baker’s Yeast (Saccharomyces cerevisiae) treated groups. The present study concluded that Baker’s Yeast (Saccharomyces cerevisiae) addition in the feed helps to ameliorate the immunotoxigenic effects produced by AFB1 in broiler chicks.

Keywords: aflatoxins, body weight gain, feed intake, immunological response, toxigenic effect

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809 Beneficial Effect of Lupeol in Diabetes Induced Oxidative Damage

Authors: Rajnish Gupta, R. S. Gupta

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Present research was aimed to investigate antidiabetic and antioxidant status of Lupeol in streptozotocin induced diabetes. Rats were divided into following groups mainly: control, diabetic, normal group as well as diabetic treated with Lupeol at 25 and 35 mg/kg b.wt./day for 21 days, diabetic group treated with glibenclamide. Tissue (pancreas, kidney and liver) as well as serum biochemical parameters were analysed for any abnormal behavior. Lupeol administration reduced diabetes onset with significant improvement in serum insulin level also strengthened by increase in β-Cell counts. A significant decrease was observed in serum glucose level. Furthermore, Lupeol treatment increased the antioxidant enzymes, glycolytic enzymes and also protein levels with a decrease in the level of thiobarbituric acid-reactive oxygen species and gluconeogenic enzymes. Present study proves that Lupeol administration significantly reinstated serum and tissue biochemical parameters and thus strengthening its antidiabetic potential.

Keywords: oxidative stress, pterostilbene, thiobarbituric acid, reactive oxygen species

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808 Beneficial Effect of Chromium Supplementation on Glucose, HbA1C and Lipid Variables in Individuals with Newly Onset Type-2 Diabetes

Authors: Baljinder Singh, Navneet Sharma

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Chromium is an essential nutrient involved in normal carbohydrate and lipid metabolism. It influences glucose metabolism by potentiating the action as taking part in insulin signal amplification mechanism. A placebo-controlled single blind, prospective study was carried out to investigate the effect of chromium supplementation on blood glucose, HbA1C and lipid profile in newly onset patients with type-2 diabetes. Total 40 newly onset type-2 diabetics were selected and after one month stabilization further randomly divided into two groups viz. study group and placebo group. The study group received 9 gm brewer’s yeast (42 μ Cr) daily and the other placebo group received yeast devoid of chromium for 3 months. Subjects were instructed not to change their normal eating and living habits. Fasting blood glucose, HbA1C and lipid profile were analyzed at beginning and completion of the study. Results revealed that fasting blood glucose level significantly reduced in the subjects consuming yeast supplemented with chromium (197.65±6.68 to 103.68±6.64 mg/dl; p<0.001). HbA1C values improved significantly from 9.51±0.26% to 6.86±0.28%; p<0.001 indicating better glycaemic control. In experimental group total cholesterol, TG and LDL levels were also significantly reduced from 199.66±3.11 to 189.26±3.01 mg/dl; p<0.02, 144.94±8.31 to 126.01±8.26; p<0.05 and 119.19±1.71 to 99.58±1.10; p<0.001 respectively. These data demonstrate beneficial effect of chromium supplementation on glycaemic control and lipid variables in subjects with newly onset type-2 diabetes.

Keywords: type-2 diabetes, chromium, glucose, HbA1C

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807 A 7 Dimensional-Quantitative Structure-Activity Relationship Approach Combining Quantum Mechanics Based Grid and Solvation Models to Predict Hotspots and Kinetic Properties of Mutated Enzymes: An Enzyme Engineering Perspective

Authors: R. Pravin Kumar, L. Roopa

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Enzymes are molecular machines used in various industries such as pharmaceuticals, cosmetics, food and animal feed, paper and leather processing, biofuel, and etc. Nevertheless, this has been possible only by the breath-taking efforts of the chemists and biologists to evolve/engineer these mysterious biomolecules to work the needful. Main agenda of this enzyme engineering project is to derive screening and selection tools to obtain focused libraries of enzyme variants with desired qualities. The methodologies for this research include the well-established directed evolution, rational redesign and relatively less established yet much faster and accurate insilico methods. This concept was initiated as a Receptor Rependent-4Dimensional Quantitative Structure Activity Relationship (RD-4D-QSAR) to predict kinetic properties of enzymes and extended here to study transaminase by a 7D QSAR approach. Induced-fit scenarios were explored using Quantum Mechanics/Molecular Mechanics (QM/MM) simulations which were then placed in a grid that stores interactions energies derived from QM parameters (QMgrid). In this study, the mutated enzymes were immersed completely inside the QMgrid and this was combined with solvation models to predict descriptors. After statistical screening of descriptors, QSAR models showed > 90% specificity and > 85% sensitivity towards the experimental activity. Mapping descriptors on the enzyme structure revealed hotspots important to enhance the enantioselectivity of the enzyme.

Keywords: QMgrid, QM/MM simulations, RD-4D-QSAR, transaminase

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806 Biomass and Lipid Enhancement by Response Surface Methodology in High Lipid Accumulating Indigenous Strain Rhodococcus opacus and Biodiesel Study

Authors: Kulvinder Bajwa, Narsi R. Bishnoi

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Finding a sustainable alternative for today’s petrochemical industry is a major challenge facing by researchers, scientists, chemical engineers, and society at the global level. Microorganisms are considered to be sustainable feedstock for 3rd generation biofuel production. In this study, we have investigated the potential of a native bacterial strain isolated from a petrol contaminated site for the production of biodiesel. The bacterium was identified to be Rhodococcus opacus by biochemical test and 16S rRNA. Compositional analysis of bacterial biomass has been carried out by Fourier transform infrared spectroscopy (FTIR) in order to confirm lipid profile. Lipid and biomass were optimized by combination with Box Behnken design (BBD) of response surface methodology. The factors selected for the optimization of growth condition were glucose, yeast extract, and ammonium nitrate concentration. The experimental model developed through RSM in terms of effective operational factors (BBD) was found to be suitable to describe the lipid and biomass production, which indicated higher lipid and biomass with a minimum concentration of ammonium nitrate, yeast extract, and quite higher dose of glucose supplementation. Optimum results of the experiments were found to be 2.88 gL⁻¹ biomass and lipid content 38.75% at glucose 20 gL⁻¹, ammonium nitrate 0.5 gL⁻¹ and yeast extract 1.25 gL⁻¹. Furthermore, GCMS study revealed that Rhodococcus opacus has favorable fatty acid profile for biodiesel production.

Keywords: biofuel, Oleaginious bacteria, Rhodococcus opacus, FTIR, BBD, free fatty acids

Procedia PDF Downloads 136