Search results for: enzymatic fermentation

Authors: Joseph A. Bentil, Anders Thygesen, Lene Langea, Moses Mensah, Anne Meyer

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The study investigated the saccharification potential of in-house enzymes produced from a white-rot basidiomycete strain, Polyporus ciliatus CBS 366.74. The in-house enzymes were produced by growing the fungus on mono and composite substrates of cocoa pod husk (CPH) and green seaweed (GS) (Ulva lactuca sp.) with and without the addition of 25mM ammonium nitrate at 4%w/v substrate concentration in submerged condition for 144 hours. The crude enzyme extracts preparations (CEE 1-5 and CEE 1-5+AN) obtained from the fungal cultivation process were sterile-filtered and used as enzyme sources for enzymatic hydrolysis of hydrothermally pretreated corn stover using a commercial cocktail enzyme, Cellic Ctec3, as benchmark. The hydrolysis was conducted at 50ᵒC with 50mM sodium acetate buffer, pH 5 based on enzyme dosages of 5 and 10 CMCase Units/g biomass at 1%w/v dry weight substrate concentration at time points of 6, 24, and 72 hours. The enzyme activity profile of the in-house enzymes varied among the growth substrates with the composite substrates (50-75% GS and AN inclusion), yielding better enzyme activities, especially endoglucanases (0.4-0.5U/mL), β-glucosidases (0.1-0.2 U/mL), and xylanases (3-10 U/mL). However, nitrogen supplementation had no significant effect on enzyme activities of crude extracts from 100% GS substituted substrates. From the enzymatic hydrolysis, it was observed that the in-house enzymes were capable of hydrolysing the pretreated corn stover at varying degrees; however, the saccharification yield was less than 10%. Consequently, theoretical glucose yield was ten times lower than Cellic Ctec3 at both dosage levels. There was no linear correlation between glucose yield and enzyme dosage for the in-house enzymes, unlike the benchmark enzyme. It is therefore recommended that the in-house enzymes are used to complement the dosage of commercial enzymes to reduce the cost of biomass saccharification.

Keywords: enzyme production, hydrolysis yield, feedstock, enzyme blend, Polyporus ciliatus

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Authors: Salwa Karboune, Amanda Waglay

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Recent studies indicate that health-promoting functional ingredients and nutraceuticals can help support and improve the overall public health, which is timely given the aging of the population and the increasing cost of health care. The development of novel ‘natural’ functional ingredients is increasingly challenging. Biocatalysis offers powerful approaches to achieve this goal. Our recent research has been focusing on the development of innovative biocatalytic approaches towards the isolation of protein isolates from potato by-products and the generation of peptides. Potato is a vegetable whose high-quality proteins are underestimated. In addition to their high proportion in the essential amino acids, potato proteins possess angiotensin-converting enzyme-inhibitory potency, an ability to reduce plasma triglycerides associated with a reduced risk of atherosclerosis, and stimulate the release of the appetite regulating hormone CCK. Potato proteins have long been considered not economically feasible due to the low protein content (27% dry matter) found in tuber (Solanum tuberosum). However, potatoes rank the second largest protein supplying crop grown per hectare following wheat. Potato proteins include patatin (40-45 kDa), protease inhibitors (5-25 kDa), and various high MW proteins. Non-destructive techniques for the extraction of proteins from potato pulp and for the generation of peptides are needed in order to minimize functional losses and enhance quality. A promising approach for isolating the potato proteins was developed, which involves the use of multi-enzymatic systems containing selected glycosyl hydrolase enzymes that synergistically work to open the plant cell wall network. This enzymatic approach is advantageous due to: (1) the use of milder reaction conditions, (2) the high selectivity and specificity of enzymes, (3) the low cost and (4) the ability to market natural ingredients. Another major benefit to this enzymatic approach is the elimination of a costly purification step; indeed, these multi-enzymatic systems have the ability to isolate proteins, while fractionating them due to their specificity and selectivity with minimal proteolytic activities. The isolated proteins were used for the enzymatic generation of active peptides. In addition, they were applied into a reduced gluten cookie formulation as consumers are putting a high demand for easy ready to eat snack foods, with high nutritional quality and limited to no gluten incorporation. The addition of potato protein significantly improved the textural hardness of reduced gluten cookies, more comparable to wheat flour alone. The presentation will focus on our recent ‘proof-of principle’ results illustrating the feasibility and the efficiency of new biocatalytic processes for the production of innovative functional food ingredients, from potato by-products, whose potential health benefits are increasingly being recognized.

Keywords: biocatalytic approaches, functional ingredients, potato proteins, peptides

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Authors: Uthumporn Utra, Y. N. Shariffa, M. Maizura, A. S. Ruri

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This research is to study the utilization of pumpkin and winter melon as the main substrate for kefir fermentation in the production of pumpkin and winter melon-based fermented drinks. Optimized temperature and time were chosen for fermentation of pumpkin and winter melon. Physicochemical and microbiological evaluations were conducted to the end products: P (fermented pumpkin juice) and K (fermented winter melon juice). Ethanol content was detected at low concentration of 0.9% (v/wt) in P, and 1.0% (v/wt) in K. Level of glucose and fructose increased significantly (p < 0.05) in both fermented drinks when compared to unfermented pumpkin (CP) and winter melon (CK) juices. Total phenolic content in P & K was higher than CP and CK, while %DPPH inhibition of both decreased significantly. Total Lactobacilli counts in P & K were 8.9 and 7.88 log cfu/ml respectively, while acetic acid bacteria counts were 8.62 and 7.57 log cfu/ml respectively, yeast counts were 4.71 and 5 log cfu/ml, and no E.coli was detected in all samples. Sensory evaluation yield comparable properties in P & K. This concluded that pumpkin and winter melon fermented drinks inoculated by water kefir grains could be promising source of nutrients with probiotic potency.

Keywords: fermented drinks, functional beverage, kefir, pumpkin, winter melon

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Authors: Sudkate Chaiyo, Weena Siangproh, Orawon Chailapakul, Kurt Kalcher

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In the present work, a simple and sensitive non-enzymatic electrochemical detection of glucose in disposable paper-based sensor was developed at ionic liquid/graphene/cobalt phthalocyanine composite (IL/G/CoPc) modified electrode. The morphology of the fabricated composite was characterized and confirmed by scanning electron microscopy and UV-Vis spectroscopy. The UV-Vis spectroscopy results confirmed that the G/CoPc composite formed via the strong π–π interaction between CoPc and G. Amperometric i-t technique was used for the determination of glucose. The response of glucose was linear over the concentration ranging from 10 µM to 1.5 mM. The response time of the sensor was found as 30 s with a limit of detection of 0.64 µM (S/N=3). The fabricated sensor also exhibited its good selectivity in the presence of common interfering species. In addition, the fabricated sensor exhibited its special advantages such as low working potential, good sensitivity along with good repeatability and reproducibility for the determination of glucose.

Keywords: glucose, paper-based sensor, ionic liquid/graphene/cobalt phthalocyanine composite, electrochemical detection

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Authors: Vanitha Varadharaj, Vijalakshmi Krishnamurthy

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Annona squamosa Linn, commonly known as Sugar apple, belonging to the family Annonaceae, is said to show varied medicinal effects, including insecticide, antiovulatory and abortifacient. The alkaloid and flavonoids present in Annona squamosa leaf has proved to have antioxidant activity. The present work has been planned to investigate the effect of ethanolic leaf extract of Annona squamosa leaf on Den Induced wistar albino rats. The study was carried out to analyze the biochemical Parmeters like Total Proteins, Bilirubin, Enzymatic and Non –Enzymatic enzymes, Marker enzymes and Tumor markers in serum and also the histopathological studies in liver is carried out in control and DEN induced rats. Supplementation of ELAS (Ethanolic Leaf Extract Of Annona squamosa) reduced the liver weight and also reduced the tumour incidence. Chemoprevention group showed near normal values of bilirubin when compared with the control rats. Total protein was decreased in the cancer bearing group and on treatment with the extract the levels of protein were restored. Both in pre and post treatment group, the activities of enzymatic antioxidants such as superoxide dismutase, catalase, and Glutathione peroxidase were increased but in pre treated animals it was more effective than post treated animals. The non- enzymatic antioxidants such as vitamin C and vitamin E were brought back to normal level significantly in post and pre treated animals. Activities of marker enzymes such as SGOT, SGPT, ALP, γ GT were significantly elevated in the serum of cancer animals and the values returned to normal after treatment with the extract suggesting the hepato protective effect of the extract. Lipid peroxide was found to be elevated in the cancer induced group. This condition was brought back to the normal in the pre and post treated animals with ELAS. Histological examination also confirmed the anti- carcinogenic potential of ELAS, Cancer induced groups had a triple fold increase in their AFP values when compared to other groups. DEN treatment increased the level of AFP expression while ELAS partially counteracted the effect of it. So the scientific validation obtained from this study may pave way to many budding scientists to find new drugs from Annona squamosa for various ailments.

Keywords: annona squamosa, biochemical parmeters, cancer, leaf extract

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Authors: Stephen Olusanmi Akintayo, Ilesanmi Fadahunsi

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The ability of Lactic acid bacteria (LAB) to grow and survive in milk is being exploited in industrial and biotechnological applications. Although considerable studies have been reported on the fermentation of milk, however, not so much work has been documented on the selection of LAB strains from milk of the Nigerian local cattle breeds for their starter culture potentials. A total of 110 LAB were isolated from raw milk of Sokoto gudali cattle breed. The isolates were screened for their proteolytic activities on skimmed milk media with isolates A07, F06 and A01 showing the highest zone of clearance of 18.5mm, 18.5mm, and 18.0mm respectively and were selected for the studies of their growth in different constituents of milk. A01, F06, and A07 were identified as Pediococcus acidilactici, Lactococcus raffinolactis, and Leuconostoc mesenteriodes respectively using cultural, biochemical, physiological and molecular characterization techniques. Leuconostoc mesenteriodes showed the highest growth in all the milk components that were used in this study. The three LAB species selected showed a growth range of 6.46 log cfu/ml to 10.91 log cfu/ml in lactose with Leuconostoc mesenteriodes showing the highest growth of 10.91 log cfu/ml while Pediococcus acidilactici recorded the lowest growth of 9.78 log cfu/ml. In medium containing leucine as the only amino acid, the viable counts of Pediococcus acidilactici, Lactococcus raffinolactis and Leuconostoc mesenteriodes in log cfu/ml at zero hour were 6.39, 6.36 and 6.38 respectively which increased to 9.31 log cfu/ml, 9.21 log cfu/ml, 9.92 log cfu/ml respectively after 24 hours. Similarly, in all other substrates (casein, lysine, glutamic acid, aspartic acid, stearic acid and oleic acid ) tested in this study, Leuconostoc mesenteriodes showed the highest growth. It was observed that the highest quantity of lactic acid (15.31mg/ml) was produced by Leuconostoc mesenteriodes. The same trend was also observed in the production of diacetyl and hydrogen peroxide by the three tested microorganisms. Due to its ability to grow maximally in milk components, Leuconostoc mesenteriodes shows potential as starter culture for milk fermentation.

Keywords: Leuconostoc mesenteriodes, lactic acid bacteria, Sokoto gudali, starter culture

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Authors: Yatimah Alias, Tilagam Marimuthu, M. R. Mahmoudian, Sharifah Mohamad

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The rapid growth of science and technology in energy and environmental fields has enlightened the substantial importance of the conducting polymer and metal composite materials engineered at nano-scale. In this study, polypyrrole-cobalt composites (PPy-Co Cs) and polypyrrole-nickel oxide composites (PPy-NiO Cs) were prepared by a simple and facile chemical polymerization method with an aqueous solution of pyrrole monomer in the presence of metal salt. These composites then fabricated into non-enzymatic hydrogen peroxide (H2O2) and glucose sensor. The morphology and composition of the composites are characterized by the Field Emission Scanning Electron Microscope, Fourier Transform Infrared Spectrum and X-ray Powder Diffraction. The obtained results were compared with the pure PPy and metal oxide particles. The structural and morphology properties of synthesized composites are different from those of pure PPy and metal oxide particles, which were attributed to the strong interaction between the PPy and the metal particles. Besides, a favorable micro-environment for the electrochemical oxidation of H2O2 and glucose was achieved on the modified glassy carbon electrode (GCE) coated with PPy-Co Cs and PPy-NiO Cs respectively, resulting in an enhanced amperometric response. Both PPy-Co/GCE and PPy-NiO/GCE give high response towards target analyte at optimum condition of 500 μl pyrrole monomer content. Furthermore, the presence of pyrrole monomer greatly increases the sensitivity of the respective modified electrode. The PPy-Co/GCE could detect H2O2 in a linear range of 20 μM to 80 mM with two linear segments (low and high concentration of H2O2) and the detection limit for both ranges is 2.05 μM and 19.64 μM, respectively. Besides, PPy-NiO/GCE exhibited good electrocatalytic behavior towards glucose oxidation in alkaline medium and could detect glucose in linear ranges of 0.01 mM to 0.50 mM and 1 mM to 20 mM with detection limit of 0.33 and 5.77 μM, respectively. The ease of modifying and the long-term stability of this sensor have made it superior to enzymatic sensors, which must kept in a critical environment.

Keywords: metal oxide, composite, non-enzymatic sensor, polypyrrole

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Authors: Hak-Ryul Kim, Hyung-Geun Lee, Qi Long, Ching Hou

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Structural modification of natural lipids via chemical reaction or microbial bioconversion can change their properties or even create novel functionalities. Enzymatic oxidation of lipids leading to formation of oxylipin is one of those modifications. Hydroxy fatty acids, one of those oxylipins have gained important attentions because of their structural and functional properties compared with other non-hydroxy fatty acids. Recently 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) was produced with high yield from lipid-containing oleic acid by microbial conversion, and the further study confirmed that DOD contained strong antimicrobial activities against a broad range of microorganisms. In this study, we tried to modify DOD molecules by the enzymatic or physical reaction to create new functionality or to enhance the antimicrobial activity of DOD. After modification of DOD molecules by different ways, we confirmed that the antimicrobial activity of DOD was highly enhanced and presented strong antimicrobial activities against multidrug-resistant Staphylococcus aureus, suggesting that DOD and its derivatives can be used as efficient antimicrobial agents for medical and industrial applications.

Keywords: biocatalysis, antimicrobial agent, multidrug-resistant bacteria, vegetable oil

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Authors: Vita Krungleviciute, Rasa Zelvyte, Ingrida Monkeviciene, Jone Kantautaite, Rolandas Stankevicius, Modestas Ruzauskas, Elena Bartkiene

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The environmental impact of agricultural bioproducts from the processing of food crops is an increasing concern worldwide. Currently, cereal bran has been used as a low-value ingredient for both human consumption and animal feed. The most popular bioprocessing technologies for cereal bran nutritional and technological functionality increasing are enzymatic processing and fermentation, and the most popular starters in fermented feed production are lactic acid bacteria (LAB) including pediococci. However, the ruminant digestive system is unique, there are billions of microorganisms which help the cow to digest and utilize nutrients in the feed. To achieve efficient feed utilization and high milk yield, the microorganisms must have optimal conditions, and the disbalance of this system is highly undesirable. Pediococcus strains Pediococcus acidilactici BaltBio01 and Pediococcus pentosaceus BaltBio02 from spontaneous fermented rye were isolated (by rep – PCR method), identified, and characterized by their growth (by Thermo Bioscreen C automatic turbidometer), acidification rate (2 hours in 2.5 pH), gas production (Durham method), and carbohydrate metabolism (by API 50 CH test ). Antimicrobial activities of isolated pediococcus against variety of pathogenic and opportunistic bacterial strains previously isolated from diseased cattle, and their resistance to antibiotics were evaluated (EFSA-FEEDAP method). The isolated pediococcus strains were cultivated in barley/wheat bran (90 / 10, m / m) substrate, and developed supplements, with high content of valuable pediococcus, were used for Lithuanian black and white dairy cows feeding. In addition, the influence of supplements on milk production and composition was determined. Milk composition was evaluated by the LactoScope FTIR” FT1.0. 2001 (Delta Instruments, Holland). P. acidilactici BaltBio01 and P. pentosaceus BaltBio02 demonstrated versatile carbohydrate metabolism, grown at 30°C and 37°C temperatures, and acidic tolerance. Isolated pediococcus strains showed to be non resistant to antibiotics, and having antimicrobial activity against undesirable microorganisms. By barley/wheat bran utilisation using fermentation with selected pediococcus strains, it is possible to produce safer (reduced Enterobacteriaceae, total aerobic bacteria, yeast and mold count) feed stock with high content of pediococcus. Significantly higher milk yield (after 33 days) by using pediococcus supplements mix for dairy cows feeding could be obtained, while similar effect by using separate strains after 66 days of feeding could be achieved. It can be stated that barley/wheat bran could be used for higher value feed production in order to increase milk production. Therefore, further research is needed to identify what is the main mechanism of the positive action.

Keywords: barley/wheat bran, dairy cattle, fermented feed, milk, pediococcus

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Authors: Sonia Mbarki Marian Brestic, Artemio Cerda Naceur Jedidi, Jose Antonnio Pascual Chedly Abdelly

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Monitoring the effect addition bio-amendment as compost to an agricultural soil for growing plant lolium perenne irrigated with a CdCl2 solution at 50 µM on physicochemical soils characteristics and plant production in laboratory condition. Even microbial activity indexes (acid phosphatase, β-glucosidase, urease, and dehydrogenase) was determined. Basal respiration was the most affected index, while enzymatic activities and microbial biomass showed a decrease due to the cadmium treatments. We noticed that this clay soil with higher pH showed inhibition of basal respiration. Our results provide evidence for the importance of ameliorating effect compost on plant growth even when soil was added with cadmium solution at 50 µmoml.l-1. Soil heavy metal concentrations depended on heavy metals types, increased substantially with cadmium increase and with compost addition, but the recorded values were below the toxicity limits in soils and plants except for cadmium.

Keywords: compost, enzymatic activity, lolium perenne, bioremediation

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Authors: Andres Diaz Garcia

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The successful technological development of any bioproduct, including those of the biostimulant type, requires to adequately completion of a series of stages allied to different disciplines that are related to microbiological, engineering, pharmaceutical chemistry, legal and market components, among others. Engineering as a discipline has a key contribution in different aspects of fermentation processes such as the design and optimization of culture media, the standardization of operating conditions within the bioreactor and the scaling of the production process of the active ingredient that it will be used in unit operations downstream. However, all aspects mentioned must take into account many biological factors of the microorganism such as the growth rate, the level of assimilation to various organic and inorganic sources and the mechanisms of action associated with its biological activity. This paper focuses on the practical experience within the Colombian Corporation for Agricultural Research (Agrosavia), which led to the development of a biostimulant bioproduct based on native rhizobacteria Bacillus amyloliquefaciens, oriented mainly to plant growth promotion in cape gooseberry nurseries and fruit crops in Colombia, and the challenges that were overcome from the expertise in the area of engineering. Through the application of strategies and engineering tools, a culture medium was optimized to obtain concentrations higher than 1E09 CFU (colony form units)/ml in liquid fermentation, the process of biomass production was standardized and a scale-up strategy was generated based on geometric (H/D of bioreactor relationships), and operational criteria based on a minimum dissolved oxygen concentration and that took into account the differences in the capacity of control of the process in the laboratory and pilot scales. Currently, the bioproduct obtained through this technological process is in stages of registration in Colombia for cape gooseberry fruits for export.

Keywords: biochemical engineering, liquid fermentation, plant growth promoting, scale-up process

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Authors: Valiollah Babaeipour, Mahdi Rahaie

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food supplements are rich in specific nutrients and bioactive compounds that eliminate free radicals and improve cellular metabolism. The major bioactive compounds are found in bran and cereal sprouts. Secondary metabolites of these microorganisms have antioxidant properties that can be used alone or in combination with chemotherapy and radiation therapy to treat cancer. Biologically active compounds such as benzoquinone derivatives extracted from fermented wheat germ extract (FWGE) have several positive effects on the overall state of human health and strengthen the immune system. The present work describes the discontinuous fermentation of raw wheat germ for FWGE production through the simultaneous culture process using the probiotic strains of Saccharomyces cerevisiae, Lactobacillus plantarum, and the possibility of using solid waste. To increase production efficiency, first to select important factors in the optimization of each fermentation process, using a factorial statistical scheme of stirring fraction (120 to 200 rpm), dilution of solids to solvent (1 to 8-12), fermentation time (16 to 24 hours) and strain to wheat germ ratio (20% to 50%) were studied and then simultaneous culture was performed to increase the yields of 2 and 6 dimethoxybenzoquinone (2,6-DMBQ). Since 2 and 6 dimethoxy benzoquinone were fermented as the main biologically active compound in wheat germ extract, UV-Vis analysis was performed to confirm the presence of 2 and 6 dimethoxy benzoquinone in the final product. In addition, 2,6-DMBQ of some products was isolated in a non-polar C-18 column and quantified using high performance liquid chromatography (HPLC). Based on our findings, it can be concluded that the increase of 2 and 6 dimethoxybenzoquinone in the simultaneous culture of Saccharomyces cerevisiae - Lactobacillus plantarum compared to pure culture of Saccharomyces cerevisiae (from 1.89 mg / g) to 28.9% (2.66 mg / g) Increased.

Keywords: wheat germ, FWGE, saccharomyces cerevisiae, lactobacillus plantarum, co-culture, 2, 6-DMBQ

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Authors: Muralisankar Thirunavukkarasu, Saravana Bhavan Periyakali, Santhanam Perumal

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The present study was performed to assess the effects of dietary copper (Cu) on growth, biochemical constituents, digestive enzyme activities, enzymatic antioxidant and metabolic enzymes of the freshwater prawn, Macrobrachium rosenbergii post larvae (PL). The Cu was supplemented at 0, 10, 20, 40, 60 and 80 mg kg-1 with the basal diets. Cu supplemented diets were fed to M. rosenbergii PL for a period of 90 days. At the end of the feeding experiment, 40 mg kg-1 Cu supplemented feeds fed PL showed significant (P < 0.05) improvement in survival, growth, digestive enzyme activities and concentrations of biochemical constituents. However, PL fed with 60 to 80 mg Cu kg-1 showed negative performance. Activities of enzymatic antioxidants, metabolic enzymes and lipid peroxidation in the muscle and hepatopancreas showed insignificant alterations (P > 0.05) up to 40 mg kg-1 Cu supplemented feeds fed PL. Whereas, 60 and 80 mg of Cu kg-1 supplemented feeds fed PL showed significant alterations on these antioxidants and metabolic enzymes levels. It indicates that beyond 40 mg Cu kg-1 diets were produced some toxic to M. rosenbergii PL. Therefore, the present study suggests that 40 mg Cu kg-1 can be supplemented in the diets of M. rosenbergii PL for regulating better survival and growth.

Keywords: antioxidants, biochemical constituents, copper, growth, Macrobrachium rosenbergii

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Authors: Apichai Sawisit, Sirima Suvarnakuta Jantama, Sunthorn Kanchanatawee, Lonnie O. Ingram, Kaemwich Jantama

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Escherichia coli KJ122 was engineered to produce succinate from glucose using the wild type GalP for glucose uptake instead of the native phosphotransferase system (ptsI mutation). This strain ferments 10% (w/v) xylose poorly. Mutants were selected by serial transfers in AM1 mineral salts medium with 10% (w/v) xylose. Evolved mutants exhibited a similar improvement, co-fermentation of an equal mixture of xylose and glucose. One of these, AS1600a, produced 84.26±1.37 g/L succinate, equivalent to that produced by the parent (KJ122) strain from 10% glucose (85.46±1.78 g/L). AS1600a was sequenced and found to contain a mutation in galactose permease (GalP, G236D). Expressing the galP* mutation gene in KJ122ΔgalP resembled the xylose utilization phenotype of the mutant AS1600a. The strain AS1600a and KJ122ΔgalP (pLOI5746; galP*) also co-fermented a mixture of glucose, xylose, arabinose, and galactose in sugarcane bagasse hydrolysate for succinate production.

Keywords: xylose, furfural, succinat, sugarcane bagasse, E. coli

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Authors: Marcin Zieliński, Marcin Dębowski, Mirosław Krzemieniewski

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The anaerobic degradation of substrates is limited especially by the rate and effectiveness of the first (hydrolytic) stage of fermentation. This stage may be intensified through pre-treatment of substrate aimed at disintegration of the solid phase and destruction of substrate tissues and cells. The most frequently applied criterion of disintegration outcomes evaluation is the increase in biogas recovery owing to the possibility of its use for energetic purposes and, simultaneously, recovery of input energy consumed for the pre-treatment of substrate before fermentation. Hydrodynamic cavitation is one of the methods for organic substrate disintegration that has a high implementation potential. Cavitation is explained as the phenomenon of the formation of discontinuity cavities filled with vapor or gas in a liquid induced by pressure drop to the critical value. It is induced by a varying field of pressures. A void needs to occur in the flow in which the pressure first drops to the value close to the pressure of saturated vapor and then increases. The process of cavitation conducted under controlled conditions was found to significantly improve the effectiveness of anaerobic conversion of organic substrates having various characteristics. This phenomenon allows effective damage and disintegration of cellular and tissue structures. Disintegration of structures and release of organic compounds to the dissolved phase has a direct effect on the intensification of biogas production in the process of anaerobic fermentation, on reduced dry matter content in the post-fermentation sludge as well as a high degree of its hygienization and its increased susceptibility to dehydration. A device the efficiency of which was confirmed both in laboratory conditions and in systems operating in the technical scale is a hydrodynamic generator of cavitation. Cavitators, agitators and emulsifiers constructed and tested worldwide so far have been characterized by low efficiency and high energy demand. Many of them proved effective under laboratory conditions but failed under industrial ones. The only task successfully realized by these appliances and utilized on a wider scale is the heating of liquids. For this reason, their usability was limited to the function of heating installations. Design of the presented cavitation generator allows achieving satisfactory energy efficiency and enables its use under industrial conditions in depolymerization processes of biomass with various characteristics. Investigations conducted on the laboratory and industrial scale confirmed the effectiveness of applying cavitation in the process of biomass destruction. The use of the cavitation generator in laboratory studies for disintegration of sewage sludge allowed increasing biogas production by ca. 30% and shortening the treatment process by ca. 20 - 25%. The shortening of the technological process and increase of wastewater treatment plant effectiveness may delay investments aimed at increasing system output. The use of a mechanical cavitator and application of repeated cavitation process (4-6 times) enables significant acceleration of the biogassing process. In addition, mechanical cavitation accelerates increases in COD and VFA levels.

Keywords: hydrodynamic cavitation, pretreatment, biomass, methane fermentation, Virginia fanpetals

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Authors: S. Thangapandiyan, S. Miltonprabu

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Fl (Fl) exposure engenders neurodegeneration and induces oxidative stress in the brain. The Neuroprotective role of EGCG on oxidative stress-mediated neurotoxicity in Fl intoxicated rat hippocampus has not yet been explored so far. Hence, the present study is focused on witnessing whether EGCG (40mg/kg) supplementation prevents Fl induced oxidative stress in the brain of rats with special emphasis on the hippocampus. Fl (25mg/kg) intoxication for four weeks in rats showed an increase in Fl concentration along with the decrease the AChE, NP, DA, and 5-HT activity in the brain. The oxidative stress markers (ROS, TBARS, NO, and PC) were significantly increased with decreased enzymatic (SOD, CAT, GPx, GR, GST, and G6PD) and non-enzymatic antioxidants (GSH, TSH, and Vit.C) in Fl intoxicated rat hippocampus. Moreover, Fl intoxicated rats exhibited an intrinsic and extrinsic pathway mediated apoptosis in the hippocampus of rats. Fl intoxication significantly increased the DNA damage as evidenced by increased DNA fragmentation. Furthermore, the toxic impact of Fl on hippocampus was also proved by the immunohistochemical, histological, and ultrastructural studies. Pre-administration of EGCG has significantly protected the Fl induced oxidative stress, biochemical changes, cellular apoptotic, and histological alternations in the hippocampus of rats. In conclusion, EGCG supplementation significantly attenuated the Fl induced oxidative stress mediated neurotoxicity via its free radical scavenging and antioxidant activity.

Keywords: brain, hippocampal, NaF, ROS, EGCG

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Authors: Friday A. Ogori, Ojotu M. Eke, Oneh J. Abu, Abraham T. Girgih

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B.aeqygtiaca del (Balanites aegyptiaca del) seed protein concentrate (APC) was hydrolyzed using different enzymes such as pepsin+pancreatin (PP), Alcalase (Alca), and Flavourzyme (Flav). The Alca has higher yield (100%) when compared to PP (83.23%) and Flav (62.90%). The hydrophobic amino acid and Sulphur containing amino acid (40.19%, 7.04%) in PP hydrolysate were higher compared to Alcalase (38.92%, 6.69%), Flavourenzyme (37.43%,6.35%), and APC (39.97%, 6.95%) samples. The PP has stronger DPPH, Hydroxyl radical quenching, Ferric reducing activity, and linoleic acid peroxidation activity, followed by the protein concentrate (APC) and Alcalase (Alca), while Flavourenzyme (Flav) derived hydrolysate was least in scavenging and inhibiting radical peroxidation properties. Flavourenzyme derived hydrolysate had stronger Ferric reducing antioxidant potential and metal chelating property. The result showed that the Alcalase hydrolysate has promising peptide yield, and PP hydrolysate had excellent amino acid residues and good in-vitro antioxidant potentials and could be a preferred ingredients in the nutraceutical and functional food emerging industries.

Keywords: balanites aegyptiaca del, protein concentrate, protein hydrolysates, enzymatic hydrolysis, antioxidants

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Authors: Calister Wingang Makebe, Wilson Ambindei Agwanande, Emmanuel Jong Nso, P. Nisha

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Traditional liquid-state fermentation processes of Annona muricata L. juice can result in fluctuating product quality and quantity due to difficulties in control and scale up. This work describes a laboratory-scale batch fermentation process to produce a probiotic Annona muricata L. enzymatically extracted juice, which was modeled using the Doehlert design with independent extraction factors being incubation time, temperature, and enzyme concentration. It aimed at a better understanding of the traditional process as an initial step for future optimization. Annona muricata L. juice was fermented with L. acidophilus (NCDC 291) (LA), L. casei (NCDC 17) (LC), and a blend of LA and LC (LCA) for 72 h at 37 °C. Experimental data were fitted into mathematical models (Monod, Logistic and Luedeking and Piret models) using MATLAB software, to describe biomass growth, sugar utilization, and organic acid production. The optimal fermentation time was obtained based on cell viability, which was 24 h for LC and 36 h for LA and LCA. The model was particularly effective in estimating biomass growth, reducing sugar consumption, and lactic acid production. The values of the determination coefficient, R2, were 0.9946, 0.9913 and 0.9946, while the residual sum of square error, SSE, was 0.2876, 0.1738 and 0.1589 for LC, LA and LCA, respectively. The growth kinetic parameters included the maximum specific growth rate, µm, which was 0.2876 h-1, 0.1738 h-1 and 0.1589 h-1 as well as the substrate saturation, Ks, with 9.0680 g/L, 9.9337 g/L and 9.0709 g/L respectively for LC, LA and LCA. For the stoichiometric parameters, the yield of biomass based on utilized substrate (YXS) was 50.7932, 3.3940 and 61.0202, and the yield of product based on utilized substrate (YPS) was 2.4524, 0.2307 and 0.7415 for LC, LA, and LCA, respectively. In addition, the maintenance energy parameter (ms) was 0.0128, 0.0001 and 0.0004 with respect to LC, LA and LCA. With the kinetic model proposed by Luedeking and Piret for lactic acid production rate, the growth associated, and non-growth associated coefficients were determined as 1.0028 and 0.0109, respectively. The model was demonstrated for batch growth of LA, LC, and LCA in Annona muricata L. juice. The present investigation validates the potential of Annona muricata L. based medium for heightened economical production of a probiotic medium.

Keywords: L. acidophilus, L. casei, fermentation, modelling, kinetics

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Authors: M. H. Nahaisi, N. M. Almaroum

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Laban is a Libyan traditional fermented milk product. This lactic fermentation has been known in many cities of Libya long time ago as stable, nutritious, refreshing drink especially during the summer. 16 naturally fermented milk samples were collected from different cities located in North West of Libya. The average pH, titratable acidity, fat and total solids were 4.16, 0.73%, 1.54% and 8.12 % respectively. Coliform, yeast and mold counts were 21×10⁴, 39×10⁴ and 41 ×10³ cfu/ ml. respectively. The average Lactococcus, Streptococcus, Mesophilic Lactobacillus / Leuconostoc and Thermophilic Lactobacillus counts were 99 ×10⁷, 96 ×10⁷, 93 ×10⁷ and 15 ×10⁷ cfu / ml. respectively. A total of one hundred forty two lactic acid bacteria (LAB) isolates were identified to the genus level as Lactobacillus (48.59%), Lactococcus (43.66%), Streptococcus (4.93%) and Leuconostoc (2.82%). Sugar fermentation tests have revealed that the most frequently Lactobacillus species was found to be Lactobacillus delbrueckii ssp. lactis (62.32%) followed by Lactobacillus plantarum (31.88%). Furthermore, other selected LAB isolates were identified by API 50 CH test as Lactococcus lactis ssp. lactics, Lactobacillus pentosus, Lactobacillus brevis and Leuconostoc mesenteroides ssp. cremoris.

Keywords: traditional fermented milk, laban, lactococcus, streptococcus, mesophilic lactobacillus, thermophilic lactobacillus counts

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Authors: Parastoo Motallebi, Vahid Niknam, Hassan Ebrahimzadeh, Majid Hashemi

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Wheat, the most strategically important worldwide crop, is widely grown in various countries. Based on international wheat production statistics (FAOSTAT database), the total production of wheat in 2012 was 13.8 in Iran. Fusarium culmorum is one of the principal causative agents of Fusarium crown rot (FCR), an overwhelming disease of wheat and barley which is in the early stages causing yield losses, stand reductions and rotting of root and lower stem tissues. In this study inoculation of two wheat seedlings of the susceptible cultivar Falat and the partially field-resistant cultivar Pishtaz were carried out in greenhouse conditions and root samples were taken for 6 days. The activity of peroxidase (POX) and polyphenoloxidase (PPO) enzymes were analyzed to identify possible relations between resistance and enzymatic activities. Although the POX and PPO activities in both geno types increased, this significant increase was more dominant in Pishtaz. The results showed an earlier elevation in the activity of these defense related enzymes in semi-resistant cv. Pishtaz after inoculation, suggested that the activities of POX and PPO in wheat geno types play an important role in the induction of resistance to this disease.

Keywords: Defense responses, Fusarium culmorum, Wheat

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Authors: Chengliang Xie, Jinhyun Ryu, Hyun Joon Kim, Gyeong Jae Cho, Wan Sung Choi, Sang Soo Kang, Kye Man Cho, Dong Hoon Lee

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Obesity has become a global health problem and a source of major metabolic diseases like type-2 diabetes, hypertension, heart disease, nonalcoholic fatty liver and cancer. Synthetic anti-obesity drugs are effective but very costly and with undesirable side effects, so natural products such as soybean are needed as an alternative for obesity treatment. Lactobacillus Plantarum P1201is a probiotic bacterial strain reported to produce conjugated linoleic acid (CLA) and increase the ratio of aglycone-isoflavone of soybean, both of which have anti-obesity effect. In this study, the anti-obesity effect of the fermented soybean extract with P1201 (FSE) will be evaluated compared with that of the soybean extract (SE) by 3T3-L1 cells as an in vitro model of adipogenesis. 3T3-L1 cells were treated with SE and FSE during the nine days of the differentiation, lipid accumulation was evaluated by oil-red staining and triglyceride content and the mRNA expression level of adipogenic or lipogenic genes were analyzed by RT-PCR and qPCR. The results showed that formation of lipid droplets in differentiated 3T3-L1 cells was inhibited and triglyceride content was reduced by 23.1% after treated with 1000 μg/mL of FSE compared with control. For SE-treated groups, no delipidating effect was observed. The effect of FSE on adipogenesis inhibition can be attributed to the down-regulation of mRNA expressionof CCAAT/enhancer binding protein (C/EBP-α), lipoprotein lipase (LPL), adiponectin, adipocyte fatty acid-binding protein (aP2), fatty acid synthesis (FAS) and CoA carboxylase (ACC). Our results demonstrated that the anti-obesity effect of soybean can be improved by fermentation with P1201, and P1201can be used as a potential probiotic bacterial strain to produce natural anti-obesity food.

Keywords: fermentation, Lactobacillus plantarum P1201, obesity, soybean

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Authors: Chen Zhang, Fengxue Xin, Jianzhong He

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A unique Clostridium beijerinckii species strain BGS1 was obtained from grass land samples, which is capable of producing 8.43g/L butanol and 3.21 isopropanol from 60g/L glucose while generating 4.68g/L volatile fatty acids (VFAs) from 30g/L xylan. The concentration of isopropanol produced by culture BGS1 is ~15% higher than previously reported wild-type Clostridium beijerinckii under similar conditions. Compared to traditional Acetone-Butanol-Ethanol (ABE) fermentation species, culture BGS1 only generates negligible amount of ethanol and acetone, but produces butanol and isopropanol as biosolvent end-products which are pure alcohols and more economical than ABE. More importantly, culture BGS1 can consume acetone to produce isopropanol, e.g., 1.84g/L isopropanol from 0.81g/L acetone in 60g/L glucose medium containing 6.15g/L acetone. The analysis of BGS1 draft genome annotated by RAST server demonstrates that no ethanol production is caused by the lack of pyruvate decarboxylase gene – related to ethanol production. In addition, an alcohol dehydrogenase (adhe gene) was found in BGS1 which could be a potential gene responsible for isopropanol-generation. This is the first report on Isopropanol-Butanol (IB) fermentation by wild-type Clostridium strain and its application for isopropanol and butanol production.

Keywords: acetone conversion, butanol, clostridium, isopropanol

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Authors: B. Santoso, B. Tj. Hariadi, H. Abubakar

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The aim of the experiment was to evaluate the effect of probiotic addition in concentrate on fermentation characteristics and in vitro nutrient digestibility of the grass Pennisetum purpureophoides. Two strains lactic acid bacteria (LAB) i.e Lactobacillus plantarum and Lactobacillus acidhophilus, and one strain yeast of Saccharomyces cerevisiae were used as probiotic. The probiotics was added at 2% and 4% (v/w) in the concentrate. The result showed the concentrate containing between 1.5 × 106 and 3 × 107 CFU/g of lactic acid bacteria and 3 × 103 CFU/g of S. cerevisiae. The DM, OM and NDF digestibility were higher (P<0.01) in grass substrate with concentrate than in grass alone. Addition of probiotic in concentrate increased (P<0.01) DM, OM and NDF compared to concentrate without probiotic. Total VFA and propionic acid concentrations were higher (P<0.01) in grass substrate with concentrate than in grass alone. Concentration of acetic acid decreased (P<0.01) in grass substrate with concentrate than in grass substrate alone. Addition of L. plantarum and L. acidophilus and S. cerevisiae in concentrate increased (P<0.01) propionic acid concentration. It was concluded that addition of probiotic in concentrate increased propionic concentration and in vitro nutrient digestibility.

Keywords: by-products, concentrate, digestibility, probiotics

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Authors: Patsarawadee Paojinda, Waranya Imprasittichai, Sudaratana R. Krungkrai, Nirianne Marie Q. Palacpac, Toshihiro Horii, Jerapan Krungkrai

Abstract:

Fusion of the last two enzymes in the pyrimidine biosynthetic pathway in the inversed order by having COOH-terminal orotate phosphoribosyltransferase (OPRT) and NH2-terminal orotidine 5'-monophosphate decarboxylase (OMPDC), as OMPDC-OPRT, are described in many organisms. Here, we produced gene fusions of Plasmodium falciparum OMPDC-OPRT and expressed the bifunctional protein in Escherichia coli. The enzyme was purified to homogeneity using affinity and anion-exchange chromatography, exhibited enzymatic activities and functioned as a dimer. The activities, although unstable, can be stabilized by its substrate and product during purification and long-term storage. Furthermore, the enzyme expressed a perfect catalytic efficiency (kcat/Km). The kcat was selectively enhanced up to 3 orders of magnitude, while the Km was not much affected and remained at low µM levels when compared to the monofunctional enzymes. The fusion of the two enzymes, creating a “super-enzyme” with perfect catalytic power and more flexibility, reflects cryptic relationship of enzymatic reactivaties and metabolic functions on molecular evolution.

Keywords: bifunctional enzyme, orotate phosphoribosyltransferase, orotidine 5'-monophosphate decarboxylase, plasmodium falciparum

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Authors: Jwan J. Abdullah, Greetham Darren, Gregory A, Tucker, Chenyu Du

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Solid-state fermentation (SSF) is an alternative to liquid fermentations for the production of commercially important products such as antibiotics, single cell proteins, enzymes, organic acids, or biofuels from lignocellulosic material. This paper describes the optimisation of SSF on municipal solid waste (MSW) for the production of cellulase enzyme. Production of cellulase enzymes was optimised by Trichoderma reesei or Aspergillus niger for temperature, moisture content, inoculation, and period of incubation. Also, presence of minerals, and alternative carbon and nitrogen sources. Optimisation revealed that production of cellulolytic enzymes was optimal when using Trichoderma spp at 30°C with an incubation period of 168 hours with a 60% moisture content. Crude enzymes produced from MSW, by Trichoderma were evaluated for the saccharification of MSW and compared with activity of a commercially available enzyme, results demonstrated that MSW can be used as inexpensive lignocellulosic material for the production of cellulase enzymes using Trichoderma reesei.

Keywords: SSF, enzyme hydrolysis, municipal solid waste (MSW), optimizing conditions, enzyme hydrolysis

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Authors: Masni Mat Yusoff, Michael H. Gordon, Keshavan Niranjan

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The study reports on the effect of aqueous enzymatic extraction (AEE) parameters on the Moringa oleifera (MO) oil yield and the formation of emulsion at the end of the process. A mixture of protease and cellulase enzymes was used at 3:1 (w/w) ratio. The highest oil yield of 19% (g oil/g sample) was recovered with the use of a mixture of pH 6, 1:4 material/moisture ratio, and incubation temperature, time, and shaking speed of 50 ⁰C, 12.5 hr, and 300 stroke/min, respectively. The use of pH 6 and 8 resulted in grain emulsions, while solid-intact emulsion was observed at pH 4. Upon fixing certain parameters, higher oil yield was extracted with the use of lower material/moisture ratio and higher shaking speed. Longer incubation time of 24 hr resulted in significantly (p < 0.05) similar oil yield with that of 12.5 hr, and an incubation temperature of 50 ⁰C resulted in significantly (p < 0.05) higher oil yield than that of 60 ⁰C. In overall, each AEE parameter showed significant effects on both the MO oil yields and the emulsions formed. One of the major disadvantages of an AEE process is the formation of emulsions which require further de-emulsification step for higher oil recovery. Therefore, critical studies on the effect of each AEE parameter may assist in minimizing the amount of emulsions formed whilst extracting highest total MO oil yield possible.

Keywords: enzyme, emulsion, Moringa oleifera, oil yield

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Authors: Ajay Dwivedi, M. Suresh Kumar, A. N. Vaidya

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The problem of fruit and vegetable waste management is a grave one and with ever increasing need to feed the exponentially growing population, more and more solid waste in the form of fruit and vegetables waste are generated and its management has become one of the key issues in protection of environment. Energy generation from fruit and vegetables waste by dark anaerobic fermentation is a recent an interesting avenue effective management of solid waste as well as for generating free and cheap energy. In the present study 17 vegetables were characterized for their physical as well as chemical properties, these characteristics were used to determine the hydrogen and methane potentials of vegetable from various models, and also lab scale batch experiments were performed to determine their actual hydrogen and methane production capacity. Lab scale batch experiments proved that vegetable waste can be used as effective substrate for bio hydrogen and methane production, however the expected yield of bio hydrogen and methane was much lower than predicted by models, this was due to the fact that other vital experimental parameters such as pH, total solids content, food to microorganism ratio was not optimized.

Keywords: vegetable waste, physico-chemical characteristics, hydrogen, methane

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Authors: Rajeev Ravindran, Amit K. Jaiswal

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Lignocellulose is the largest reservoir of inexpensive, renewable source of carbon. It is composed of lignin, cellulose and hemicellulose. Cellulose and hemicellulose is composed of reducing sugars glucose, xylose and several other monosaccharides which can be metabolised by microorganisms to produce several value added products such as biofuels, enzymes, aminoacids etc. Enzymatic treatment of lignocellulose leads to the release of monosaccharides such as glucose and xylose. However, factors such as the presence of lignin, crystalline cellulose, acetyl groups, pectin etc. contributes to recalcitrance restricting the effective enzymatic hydrolysis of cellulose and hemicellulose. In order to overcome these problems, pre-treatment of lignocellulose is generally carried out which essentially facilitate better degradation of lignocellulose. A range of pre-treatment strategy is commonly employed based on its mode of action viz. physical, chemical, biological and physico-chemical. However, existing pretreatment strategies result in lower sugar yield and formation of inhibitory compounds. In order to overcome these problems, we proposes a novel pre-treatment, which utilises the superior oxidising capacity of alkaline potassium permanganate assisted by ultra-sonication to break the covalent bonds in spent coffee waste to remove recalcitrant compounds such as lignin. The pre-treatment was conducted for 30 minutes using 2% (w/v) potassium permanganate at room temperature with solid to liquid ratio of 1:10. The pre-treated spent coffee waste (SCW) was subjected to enzymatic hydrolysis using enzymes cellulase and hemicellulase. Shake flask experiments were conducted with a working volume of 50mL buffer containing 1% substrate. The results showed that the novel pre-treatment strategy yielded 7 g/L of reducing sugar as compared to 3.71 g/L obtained from biomass that had undergone dilute acid hydrolysis after 24 hours. From the results obtained it is fairly certain that ultrasonication assists the oxidation of recalcitrant components in lignocellulose by potassium permanganate. Enzyme hydrolysis studies suggest that ultrasound assisted alkaline potassium permanganate pre-treatment is far superior over treatment by dilute acid. Furthermore, SEM, XRD and FTIR were carried out to analyse the effect of the new pre-treatment strategy on structure and crystallinity of pre-treated spent coffee wastes. This novel one-step pre-treatment strategy was implemented under mild conditions and exhibited high efficiency in the enzymatic hydrolysis of spent coffee waste. Further study and scale up is in progress in order to realise future industrial applications.

Keywords: spent coffee waste, alkaline potassium permanganate, ultra-sonication, physical characterisation

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Authors: Yong Geun Yun, Jong Hui kim, Sang Ho Baik

Abstract:

This study was carried out to develop a fermented dandelion (Tarazacum officinale) beverage using lactic acid bacteria with cinnamoyl esterase (CE) activity isolated from human feces. Lactic acid bacteria were screened based on bacterial survival ability in dandelion extract and CE activity. Dandelion extract fermented by Lactobacillus acidophilus F-46 (LA-F46) maintained approximately 105-106 log CFU/mL over an 8 days period. After fermented dandelion beverage (FDB) with LA-46 for 8 days at 37oC the pH was decreased from pH 7.0 to 3.5. Antioxidant activity by using DPPH radical scavenging activity of the prepared FDB was significantly increased compared to that of non-fermented dandelion beverage (NFDB). Moreover, CE activity was significantly enhanced during fermentation and showed the approximately 4.3 times increased concentration of caffeic acid up to 9.91 mg/100 mL after 8 days of incubation compared to NFDB. Therefore, it concluded that dandelion can be a good source for preparing a functional beverage and fermentation by LA-F46 enhanced the food functionality with enhanced caffeic acids.

Keywords: cinnamoyl esterase, dandelion, fermented beverage, lactic acid bacteria

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Authors: Yenny Paola Morales Cortés, Fabián Rico Rodríguez, Juan Carlos Serrato Bermúdez, Carlos Arturo Martínez Riascos

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Numerous benefits of galactooligosaccharides (GOS) as prebiotics have motivated the study of enzymatic processes for their production. These processes have special complexities due to several factors that make difficult high productivity, such as enzyme type, reaction medium pH, substrate concentrations and presence of inhibitors, among others. In the present work the production of galactooligosaccharides (with different degrees of polymerization: two, three and four) from lactose was studied. The study considers the formulation of a mathematical model that predicts the production of GOS from lactose using the enzyme β-galactosidase. The effect of pH in the reaction was studied. For that, phosphate buffer was used and with this was evaluated three pH values (6.0.6.5 and 7.0). Thus it was observed that at pH 6.0 the enzymatic activity insignificant. On the other hand, at pH 7.0 the enzymatic activity was approximately 27 times greater than at 6.5. The last result differs from previously reported results. Therefore, pH 7.0 was chosen as working pH. Additionally, the enzyme concentration was analyzed, which allowed observing that the effect of the concentration depends on the pH and the concentration was set for the following studies in 0.272 mM. Afterwards, experiments were performed varying the lactose concentration to evaluate its effects on the process and to generate the data for the adjustment of the mathematical model parameters. The mathematical model considers the reactions of lactose hydrolysis and transgalactosylation for the production of disaccharides and trisaccharides, with their inverse reactions. The production of tetrasaccharides was negligible and, because of that, it was not included in the model. The reaction was monitored by HPLC and for the quantitative analysis of the experimental data the Matlab programming language was used, including solvers for differential equations systems integration (ode15s) and nonlinear problems optimization (fminunc). The results confirm that the transgalactosylation and hydrolysis reactions are reversible, additionally inhibition by glucose and galactose is observed on the production of GOS. In relation to the production process of galactooligosaccharides, the results show that it is necessary to have high initial concentrations of lactose considering that favors the transgalactosylation reaction, while low concentrations favor hydrolysis reactions.

Keywords: β-galactosidase, galactooligosaccharides, inhibition, lactose, Matlab, modeling

Procedia PDF Downloads 347