Search results for: candida rugosa lipase

Authors: Benarous Khedidja, Yousfi Mohamed

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Infections caused by Candida species manifest in a number of diseases, including candidemia, vulvovaginal candidiasis, endocarditis, and peritonitis. These Candida species have been reported to have lipolytic activity by secretion of lipolytic enzymes such as esterases, lipases and phospholipases. These Extracellular hydrolytic enzymes seem to play an important role in Candida overgrowth. Candidiasis is commonly treated with antimycotics such as clotrimazole and nystatin, which bind to a major component of the fungal cell membrane (ergosterol). This binding forms pores in the membrane that lead to death of the fungus. Due to their secondary effects, scientists have thought of another treatment basing on lipase inhibition but we haven’t found any lipase inhibitors used as candidiasis treatment. In this work, we are interested to lipases inhibitors such as alkaloids as another candidiasis treatment. In the first part, we have proceeded to optimize the alkaloid structures and protein 3D structure using Hyperchem software. Secondly, we have docked inhibitors using Genetic algorithm with GOLD software. The results have shown ten possibilities of binding inhibitor to Candida rugosa lipase (CRL) but only one possibility has been accepted depending on the weakest binding energy.

Keywords: marrubiin, candida rugosa lipase, docking, gold

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Authors: M. Merabet-Khelassi, Z. Houiene, L. Aribi-Zouioueche, O. Riant

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Lipases (EC.3.1.1.3) are efficient biotools widely used for their remarkable chemo-, regio- and enantio-selectivity, especially, in kinetic resolution of racemates. They offer access to a large panel of enantiopure building blocks, such as secondary benzylic alcohols, commonly used as synthetic intermediates in pharmaceutical and agrochemical industries. Due to the stability of lipases in both water and organic solvents poor in water, they are able to catalyze both transesterifications of arylalkylcarbinols and hydrolysis of their corresponding acetates. The use of enzymatic hydrolysis in aqueous media still limited. In this presentation, we expose a practical methodology for the preparation of optically enriched acetates using a Candida antarctica lipase B-catalyzed hydrolysis in non-aqueous media in the presence of alkaline carbonate salts. The influence of several parameters which can intervene on the enzymatic efficiency such as the impact of the introduction of the carbonates salts, its amount and the nature of the alkaline earth metal are discussed. The obtained results show that the use of sodium carbonate with CAL-B enhances drastically both reactivity and selectivity of this immobilized lipase. In all cases, the resulting alcohols and remaining acetates are obtained in high ee values (up to > 99 %), and the selectivities reach (E > 500).

Keywords: alkaline-hydrolysis, enzymatic kinetic resolution, lipases, arylalkylcarbinol, non-aqueous media

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Authors: Indu Bhushan Sharma, Rashmi Saraswat

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The thermotolerant, solvent stable and alkalophilic lipase producing bacterial strain was isolated from the water sample of the foothills of Trikuta Mountain in Kakryal (Reasi district) in Jammu and Kashmir, India. The lipase-producing microorganisms were screened using tributyrin agar plates. The selected microbe was optimized for maximum lipase production by subjecting to various carbon and nitrogen sources, incubation period and inoculum size. The selected strain was identified as Bacillus subtilis strain kakrayal_1 (BSK_1) using 16S rRNA sequence analysis. Effect of pH, temperature, metal ions, detergents and organic solvents were studied on lipase activity. Lipase was found to be stable over a pH range of 6.0 to 9.0 and exhibited maximum activity at pH 8. Lipolytic activity was highest at 37°C and the enzyme activity remained at 60°C for 24hrs, hence, established as thermo-tolerant. Production of lipase was significantly induced by vegetable oil and the best nitrogen source was found to be peptone. The isolated Bacillus lipase was stimulated by pre-treatment with Mn2+, Ca2+, K+, Zn2+, and Fe2+. Lipase was stable in detergents such as triton X 100, tween 20 and Tween 80. The 100% ethyl acetate enhanced lipase activity whereas, lipase activity were found to be stable in Hexane. The optimization resulted in 4 fold increase in lipase production. Bacillus lipases are ‘generally recognized as safe’ (GRAS) and are industrially interesting. The inducible alkaline, thermo-tolerant lipase exhibited the ability to be stable in detergents and organic solvents. This could be further researched as a potential biocatalyst for industrial applications such as biotransformation, detergent formulation, bioremediation and organic synthesis.

Keywords: bacillus, lipase, thermotolerant, alkalophilic

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Authors: Abdulhakeem Sulyman, Olukotun Zainab, Hammed Abdulquadri

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Lipases (triacylglycerol acyl hydrolases) (EC 3.1.1.3) are class of enzymes that catalyses the hydrolysis of triglycerides to glycerol and free fatty acids. They account for up to 10% of the enzyme in the market and have a wide range of applications in biofuel production, detergent formulation, leather processing and in food and feed processing industry. This research was conducted to study the effect of some metal ions on the activity of purified lipase produced by Aspergillus niger cultured on Vitellaria paradoxa shells. Purified lipase in 12.5 mM p-NPL was incubated with different metal ions (Zn²⁺, Ca²⁺, Mn²⁺, Fe²⁺, Na⁺, K⁺ and Mg²⁺). The final concentrations of metal ions investigated were 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 and 1.0 mM. The results obtained from the study showed that Zn²⁺, Ca²⁺, Mn²⁺ and Fe²⁺ ions increased the activity of lipase up to 3.0, 3.0, 1.0, and 26.0 folds respectively. Lipase activity was partially inhibited by Na⁺ and Mg²⁺ with up to 88.5% and 83.7% loss of activity respectively. Lipase activity was also inhibited by K⁺ with up to 56.7% loss in the activity as compared to in the absence of metal ions. The study concluded that lipase produced by Aspergillus niger cultured on Vitellaria paradoxa shells can be activated by the presence of Zn²⁺, Ca²⁺, Mn²⁺ and Fe²⁺ and inhibited by Na⁺, K⁺ and Mg²⁺.

Keywords: Aspergillus niger, Vitellaria paradoxa, lipase, metal ions

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Authors: Masoumeh Ghasemi, Afshin Farahbakhsh, Arman Farahbakhsh, Ali Asghar Safari

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In this study, lipase production has been investigated using submerge fermentation by Aspergillus niger in Kilka fish oil as main substrate. The Taguchi method with an L9 orthogonal array design was used to investigate the effect of parameters and their levels on lipase productivity. The optimum conditions for Kilka fish oil concentration, incubation temperature and pH were obtained 3 gr./ml 35°C and 7, respectively. The amount of lipase activity in optimum condition was obtained 4.59IU/ml. By comparing this amount with the amount of productivity in the olive oil medium based on the cost of each medium, it was that using Kilka fish oil is 84% economical. Therefore Kilka fish oil can be used as an economical and suitable substrate in the lipase production and industrial usages.

Keywords: lipase, Aspergillus niger, Kilka fish oil, submerge fermentation method

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Authors: Najwa Othman, Norhidayah Suleiman, Gun Hean Chong

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Palm fatty acid distillate (PFAD) is a by-product of palm oil refineries which contains valuable compounds such as phytosterols, squalene, polycosanol, co-enzyme Q10 and vitamin E (tocopherols and tocotrienols). Approximately 0.7-1.0% of vitamin E accumulates in PFAD, and it functions as antioxidants and anti-inflammatory. The objective of this research is to evaluate the effect of manipulated variables in supercritical carbon dioxide towards the recovery of tocotrienols in PFAD. The vitamin E concentrate isolated varies depending on the pre-treatment of sample and extraction techniques. In this research, tocotrienols in PFAD was concentrated by removing the extraneous matters, especially free fatty acid (FFA) and acylglycerols. Pre-treatment method such as enzymatic hydrolysis by using lipase from Candida rugosa as an enzyme was used to remove FFA and improve recovery of vitamin E. After that, treated PFAD was extracted by using supercritical fluid extraction in co-current glass beads packed column (22 cm x 75 cm i.d) at different temperatures (40-60°C) and pressures (100-300 bar) for 5 hours. After the extraction, the sample was analyzed by using high-pressure liquid chromatography (HPLC) system to quantify the tocotrienols. The results indicated that a combined pressure (200 bar) and temperature (60°C) was predicted to provide highest tocotrienols yield and the extraction yield obtained was 106.45%.

Keywords: enzymatic hydrolysis, palm fatty acid distillate, supercritical fluid extraction, tocotrienols

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Authors: D. S. V. Barbieri, R. R. Gomes, G. D. Santos, P. F. Herkert, M. Moreira, E. S. Trindade, V. A. Vicente

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The importance of yeast infections has increased in recent decades. The monitoring of Candida yeasts has been relevant in the study of groups and populations. This research evaluated 31 Candida spp. isolates from oral microbiota of 12 Brazilian schoolchildren coinfected with Streptococcus mutans. The isolates were evaluated for their ability to form biofilm in vitro and molecularly characterized based on the sequencing of intergenic spacer regions ITS1-5,8S-ITS2 and variable domains of the large subunit (D1/D2) regions of the rDNA, as well as ABC system genotyping. The sequencing confirmed 26 lineages of Candida albicans, three Candida tropicalis, one Candida guillhermondii and one Candida glabrata. Genetic variability and differences on in biofilm formation were observed among Candida yeasts lineages. At least one Candida strain from each caries activity child was C.albicans genotype A or Candida non-albicans. C. tropicalis was associated with highest cavities rates. These results indicate that the presence of C. albicans genotype A or multi-colonization by non albicans species seem to be associates to the potentialization of caries risk.

Keywords: biofilm, Candida albicans, oral microbiota, caries

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Authors: Prasanna Belur, P. R. Ashwini, Sampath Charanyaa, I. Regupathi

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Indian oil sardine (Sardinella longiceps) are one of the richest and cheapest sources of n-3 polyunsaturated fatty acids (n-3 PUFA) such as Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA). The health benefits conferred by n-3 PUFA upon consumption, in the prevention and treatment of coronary, neuromuscular, immunological disorders and allergic conditions are well documented. Natural refined Indian Sardine oil generally contain about 25% (w/w) n-3 PUFA along with various unsaturated and saturated fatty acids in the form of mono, di, and triglycerides. Having high concentration of n-3 PUFA content in the glyceride form is most desirable for human consumption to avail maximum health benefits. Thus, enhancing the n-3 PUFA content while retaining it in the glyceride form with green technology is the need of the hour. In this study, refined Indian Sardine oil was subjected to selective hydrolysis by Candida antartica lipase to enhance n-3 PUFA content. The degree of hydrolysis and enhancement of n-3 PUFA content was estimated by determining acid value, Iodine value, EPA and DHA content (by Gas Chromatographic methods after derivitization) before and after hydrolysis. Various reaction parameters such as pH, temperature, enzyme load, lipid to aqueous phase volume ratio and incubation time were optimized by conducting trials with one parameter at a time approach. Incubating enzyme solution with refined sardine oil with a volume ratio of 1:1, at pH 7.0, for 60 minutes at 50 °C, with an enzyme load of 60 mg/ml was found to be optimum. After enzymatic treatment, the oil was subjected to refining to remove free fatty acids and moisture content using previously optimized refining technology. Enzymatic treatment at the optimal conditions resulted in 12.11 % enhancement in Degree of hydrolysis. Iodine number had increased by 9.7 % and n-3 PUFA content was enhanced by 112 % (w/w). Selective enhancement of n-3 PUFA glycerides, eliminating saturated and unsaturated fatty acids from the oil using enzyme is an interesting preposition as this technique is environment-friendly, cost effective and provide natural source of n-3 PUFA rich oil.

Keywords: Candida antartica, lipase, n-3 polyunsaturated fatty acids, sardine oil

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Authors: N. Wijayati, Kusoro Siadi, Hanny Wijaya, Maggy Thenawijjaja Suhartono

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This work describes the lipase-mediated synthesis of α-pinene oxide at ambient temperature. The immobilized lipase from Pseudomonas aeruginosa is used to generate peroxyoctanoic acid directly from octanoic acid and hydrogen peroxide. The peroxy acid formed is then applied for in situ oxidation of α-pinene. High conversion of α-pinene to α-pinene oxide (approximately 78%) was achieved when using 0,1 g enzim lipase, 6 mmol H2O2, dan 5 mmol octanoic acid. Various parameters affecting the conversion of α-pinene to α pinene oxide were studied.

Keywords: α-Pinene; P. aeruginosa; Octanoic acid

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Authors: Gulcan Sahal, Isil Seyis Bilkay

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Candida species which often exist as commensal microorganisms in healthy individuals are major causes of important infections, especially in AIDS and immunocompromised patients, by means of their biofilm formation abilities. Therefore, in this study, determination of biofilm formation in different clinical strains of Candida species, investigation of strong biofilm forming Candida strains, examination of clinical information of each strong and weak biofilm forming Candida strains and investigation of some plant substances’ effects on biofilm formation of strong biofilm forming strains were aimed. In this respect, biofilm formation of Candida strains was analyzed via crystal violet binding assay. According to our results, biofilm levels of strains belong to different Candida species were different from each other. Additionally, it is also found that some plant substances effect biofilm formation. All these results indicate that, as well as C. albicans strains, other non-albicans Candida species also emerge as causative agents of infections and have biofilm formation abilities. In addition, usage of some plant substances in different concentrations may provide a new treatment against biofilm related Candida infections.

Keywords: anti-biofilm, biofilm formation, Candida species, biosystems engineering

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Authors: Heri Hermansyah, Annisa Kurnia, A. Vania Anisya, Adi Surjosatyo, Yopi Sunarya, Rita Arbianti, Tania Surya Utami

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Lipase is one of biocatalyst which is applied commercially for the process in industries, such as bioenergy, food, and pharmaceutical industry. Nowadays, biocatalysts are preferred in industries because they work in mild condition, high specificity, and reduce energy consumption (high pressure and temperature). But, the usage of lipase for industry scale is limited by economic reason due to the high price of lipase and difficulty of the separation system. Immobilization of lipase is one of the solutions to maintain the activity of lipase and reduce separation system in the process. Therefore, we conduct a study about lipase immobilization with the adsorption-cross linking method using glutaraldehyde because this method produces high enzyme loading and stability. Lipase is immobilized on different kind of resin with the various functional group. Highest enzyme loading (76.69%) was achieved by lipase immobilized on anion macroporous which have anion functional group (OH^‑). However, highest activity (24,69 U/g support) through olive oil emulsion method was achieved by lipase immobilized on anion macroporous-chitosan which have amino (NH₂) and anion (OH^-) functional group. In addition, it also success to produce biodiesel until reach yield 50,6% through interesterification reaction and after 4 cycles stable 63.9% relative with initial yield. While for Aspergillus, niger lipase immobilized on anion macroporous-kitosan have unit activity 22,84 U/g resin and yield biodiesel higher than commercial lipase (69,1%) and after 4 cycles stable reach 70.6% relative from initial yield. This shows that optimum functional group on support for immobilization with adsorption-cross linking is the support that contains amino (NH₂) and anion (OH^-) functional group because they can react with glutaraldehyde and binding with enzyme prevent desorption of lipase from support through binding lipase with a functional group on support.

Keywords: adsorption-cross linking, immobilization, lipase, resin

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Authors: Zohreh Bayat, Dariush Minai-Tehrani

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Lipases constitute one of the most important groups of industrial enzymes that catalyze the hydrolysis of triacylglycerol to glycerol and fatty acids. Muscarinic antagonist relieves smooth muscle spasm of the gastrointestinal tract and effect on the cardiovascular system. In this research, the effect of a muscarinic antagonist on the lipase activity of Pseudomonas aeruginosa was studied. Lineweaver–Burk plot showed that the drug inhibited the enzyme by competitive inhibition. The IC50 value (60 uM) and Ki (30 uM) of the drug revealed the drug bound to the enzyme with high affinity. Determination of enzyme activity in various pH and temperature showed that the maximum activity of lipase was at pH 8 and 60°C both in presence and absence of the drug.

Keywords: bacteria, inhibition, kinetics, lipase

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Authors: Khaled M. Khleifat

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An extracellular methanol and ethanol tolerant lipase producing bacterial strain K5b4 was isolated from soil samples contaminated with hydrocarbon residues. It was identified by using morphological and biochemical characteristics and 16srRNA technique as Acinetobacter species. The immobilized lipase from Acinetobacter sp. K5b4 retained more than 98% of its residual activity after incubation with pure methanol and ethanol for 24 hours. The highest hydrolytic activity of the immobilized enzyme was obtained in the presence of 75% (v/v) methanol in the assay solution. In contrary, the enzyme was able to maintain its original activity up to only 25% (v/v) ethanol whereas at elevated concentrations of 50 and 75% (v/v) the enzyme activity was reduced to 10 and 40%, respectively. Maximum lipase activity of 31.5 mU/mL was achieved after 48 hr cultivation when the optimized medium (pH 7.0) that composed of 1.0% (w/v) olive oil, 0.2% (w/v) glycerol, 0.15% (w/v) yeast extract, and 0.05% (w/v) NaCl was inoculated with 0.4% (v/v) seed culture and incubated at 30°C and 150 rpm agitation speed. However, the presence of CaCl2 in the growth media did not show any inhibitory or stimulatory effect on the enzyme production as it compared to the control experiment. Meanwhile, the other mineral salts MgCl2, MnCl2, KCl and CoCl2 were negatively affected the production of lipase enzyme. The inhibition of lipase production from Acinetobacter sp. K5b4 in presence of glucose suggesting that lipase gene expression is prone to catabolic repression.

Keywords: K5B4, methanol and ethanol, acinetobacter, morphological

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Authors: Kwanchai Ratanamanee, Pattra Ahmadi Pirshahid, Yaowaluk Khamphan, Sirinan Thubthimthad

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Obesity is a main global health problem. The obesity rated has continued to be higher and higher. It causes to serious systems, diabetes, coronary artery disease, stroke, and some types of cancer. Oristat is one of the best drugs worldwide used as a pancreatic lipase inhibitor. To develop the new therapeutic drugs from medicinal plant always explored. In this study, 24 medicinal plants were investigated for their pancreatic lipase and cholesterol esterase inhibitory effects with Fluorometer assay and oristat as a positive control. It showed that the ethanolic extract of pods of Acacia concinna (Willd.) D.C., possess pancreatic lipase and cholesterol esterase inhibitory activities of IC50 at 2.73 and 3.77 mg/ml respectively as well as oral acute toxicity of the extract (LD50) was 6,300 mg/kg body weight. The extract of A.concinna should be further investigated in animal testing. The results of pancreatic lipase and cholesterol esterase inhibitor of the extracts will lead us to utilize A.concinna for developing as obesity dietary supplement from a medicinal plant.

Keywords: Acacia concinna (Willd.) D. C., cholesterol esterase, obesity, pancreatic lipase

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Authors: P. Karpagam, Babu Joseph, P. Ashok Kumar

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The incidence of Candida infections is increasing worldwide. The serious nature of these infections is compounded by increasing levels of drug resistance. Pure cultures of the Candida sp. were obtained from clinical isolates and fresh garlic extracts were obtained by extraction techniques. The antifungal activity of garlic extract was investigated in an in vitro system. The extract (100%, 75% and 50%) showed significant antifungal activity against Candida, whereas, low concentration (25%) of the extract showed less antifungal activity against the test organism. Antifungal activities of honey and lemon juice were tested against the Candida; however, the growth was not inhibited by these extracts. On the other hand honey and lemon when combined with garlic exhibited a good antifungal activity. The study thus confirms the antifungal properties of garlic extract along with additives like honey and lemon have significant antifungal activity against isolates of Candida species.

Keywords: Candida, garlic extract, lemon, synergitic antifungal activity

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Authors: Aqsa Kanwal, Min Zhang, Faisal Sharaf, Li Chengtao

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The globe is facing increasing challenges of plastic pollution due to single-use of plastic-based packaging material. The plastic material is continuously being dumped into the natural environment, which causes serious harm to the entire ecosystem. Polymer degradation in nature is very difficult, so the use of biodegradable polymers instead of conventional polymers can mitigate this issue. Due to the good mechanical properties and biodegradability, aliphatic-aromatic polymers are being widely commercialized. Due to the advancement in molecular biology, many studies have reported specific microbes that can effectively degrade PBAT. Aliphatic polyesters undergo hydrolytic cleavage of ester groups, so they can be easily degraded by microorganisms. In this study, we investigated the enzymatic degradation of poly (butylene adipate terephthalate) (PBAT) copolymer using lipase B from Candida Antarctica (CALB). Results of the study displayed approximately 5.16 % loss in PBAT mass after 2 days which significantly increased to approximately 15.7 % at the end of the experiment (12 days) as compared to blank. The pH of the degradation solution also displayed significant reduction and reached the minimum value of 6.85 at the end of the experiment. The structure and morphology of PBAT after degradation were characterized by FTIR, XRD, SEM, and TGA. FTIR analysis showed that after degradation many peaks become weaker and the peak at 2950 cm-1 almost disappeared after 12 days. The XRD results indicated that as the degradation time increases the intensity of diffraction peaks slightly increases as compared to the blank PBAT. TGA analysis also confirmed the successful degradation of PBAT with time. SEM micrographs further confirmed that degradation has occurred. Hence, biodegradable polymers can widely be used. The effect of PBAT biodegradation on plant growth was also studied and it was found that PBAT has no toxic effect on the growth of plants. Hence PBAT can be employed in a wide range of applications.

Keywords: aliphatic-aromatic co-polyesters, polybutylene adipate terephthalate, lipase (CALB), biodegradation, plant growth

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Authors: S. Mat Radzi, N. J. Abd Rahman, H. Mohd Noor, N. Ariffin

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Ferulic acid has widespread industrial potential by virtue of its antioxidant properties. However, it is partially soluble in aqueous media, limiting their usefulness in oil-based processes in food, cosmetic, pharmaceutical, and material industry. Therefore, modification of ferulic acid should be made by producing of more lipophilic derivatives. In this study, a preliminary investigation of lipase-catalyzed trans-esterification reaction of ethyl ferulate and olive oil was investigated. The reaction was catalyzed by immobilized lipase from Candida antarctica (Novozym 435), to produce ferulate ester, a sunscreen agent. A statistical approach of Response surface methodology (RSM) was used to evaluate the interactive effects of reaction temperature (40-80°C), reaction time (4-12 hours), and amount of enzyme (0.1-0.5 g). The optimum conditions derived via RSM were reaction temperature 60°C, reaction time 2.34 hours, and amount of enzyme 0.3 g. The actual experimental yield was 59.6% ferulate ester under optimum condition, which compared well to the maximum predicted value of 58.0%.

Keywords: ferulic acid, enzymatic synthesis, esters, RSM

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Authors: David Oluwole Moses, Odeyemi Adebowale Toba, Olawale Adetunji Kola

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Candida auris, an emerging fungus, has been reported in more than 30 countries around the world since its first detection in 2009. Due to its several virulence factors, resistance to antifungals, and persistence in hospital settings, Candida auris has been reported to cause treatment-failure infections. This study was therefore carried out to determine the incidence of Candida auris in a tertiary hospital in Ekiti State, Nigeria. In this study, a total of 115 samples were screened for Candida species using cultural and molecular methods. The carriage of virulence factors and antifungal resistance among C. auris was detected using standard microbiological methods. Candida species isolated from the samples were 15 (30.0%) in clinical samples and 22 (33.85%) in hospital equipment screened. Non-albicans Candida accounted for 3 (20%) and 8 (36.36%) among the isolates from the clinical samples and equipment, respectively. Only five of the non-albicans Candida isolates were C. auris. All the isolates produced biofilm, gelatinase, and hemolysin, while none produced germ tubes. Two of the isolates were resistant to all the antifungals tested. Also, all the isolates were resistant to fluconazole and itraconazole. Nystatin appeared to be the most effective among the tested antifungals. The isolation of Candida auris is being reported for the second time in Nigeria, further confirming that the fungus has spread beyond Lagos and Ibadan, where it was first reported. The extent of the spread of the nosocomial fungus needed to be further investigated and curtailed in Nigeria before its outbreak in healthcare facilities.

Keywords: candida auris, virulence factors, antifungals, pathogen, hospital, infection

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Authors: Richard Nyanzi, Maupi E. Letsoalo, Jacobus N. Eloff, Piet J. Jooste

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Candida albicans naturally occurs in the gastrointestinal tract (GIT) of more than 50% of humans. Overgrowth of the fungus causes several forms of candidiasis including oral thrush. Overgrowth tends to occur in immunocompromised humans such as diabetic, cancer and HIV patients. Antifungal treatment is available, but not without shortcomings. In this study, inhibitory activity of five probiotic Lactobacillus strains was demonstrated against the growth of seven clinical strains of Candida albicans by co-culturing of the organisms in a maize gruel (MG) medium. Phenotypic tests, molecular techniques and phylogenetic analysis have enabled precise identification of the organisms used in the study. The quantitative pour plate technique was used to enumerate colonies of the yeasts and the lactobacilli and the Kruskal-Wallis test and ANOVA tests were employed to compare the distributions of the colonies of the organisms. The cereal medium, containing added carbon sources, was inoculated with a Candida and a Lactobacillus strain in combination and incubated at 37 °C for 168 h. Aliquots were regularly taken and subjected to pH determination and colony enumeration. Certain Lactobacillus strains proved to be inhibitory and also lethal to some Candida albicans strains. A low pH due to Lactobacillus acid production resulted in significant low Candida colony counts. Higher Lactobacillus colony counts did not necessarily result in lower Candida counts suggesting that inhibitory factors besides low pH and competitive growth by lactobacilli contributed to the reduction in Candida counts. Such anti-Candida efficacy however needs to be confirmed by in vivo studies.

Keywords: candida albicans, oral thrush, candidiasis, lactobacillus, probiotics

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Authors: Satender Saraswat, Dharmendra Prasad Singh, Rajesh Kumar Verma, Swati Sarswat

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Background and Purpose: The predominant cause of candidiasis was Candida albicans which has shifted towards non-Candida albicans Candida (NCAC) (Candida species other than the C. albicans). NCAC, earlier considered non-pathogenic or minimally virulent, are now considered a primary cause of morbidity and mortality in immunocompromised. With the NCAC spp. gaining weightage in the clinical cases, this study was conducted to determine the prevalence of NCAC spp. in different clinical specimens and to assess a few of their virulence factors. Material and Methods: Routine samples for bacterial culture and sensitivity, showing colony characteristics like Candida on Blood Agar and microscopic features resembling Candida spp. were processed further. Candida isolates were tested for chlamydospore formation, biochemical tests including sugar fermentation and sugar assimilation tests, and growth at 42oC, colony colour on HiCrome™ Candida Differential Agar, HiCandida Identification Kit and VITEK-2 Compact. Virulence factors like adherence to buccal epithelial cells (ABEC), biofilm formation, hemolytic activity, and production of coagulase enzyme were also tested. Results: Mean age of the patients was 38.46 with a male-female ratio of 1.36:1. 137 Candida isolates were recovered. 45.3% isolates were isolated from urine, 19.7% from vaginal swabs and 13.9% from oropharyngeal swabs. 55 (40.1%) isolates of C. albicans and 82 (59.9%) of NCAC spp. were identified, with C. tropicalis (23.4%) in NCAC. C. albicans (3; 50%) was the commonest species in cases of candidemia. Haemolysin production (85.5%) and ABEC (78.2%) were the major virulence factors in C. albicans. C. tropicalis (59.4%) and C. dubliniensis (50%) showed maximum ABEC. Biofilm forming capacity was higher in C. tropicalis (78.1%) than C. albicans (67%). Conclusion: This study suggests varied prevalence and virulence based on geographical locations, even within a subcontinent. It clearly demarcates the emergence of NCAC and their predominance in different body fluids. Identification of Candida to species level should become a routine in all the laboratories.

Keywords: ABEC, NCAC, non-Candida albicans Candida, Vitek-2TM compact

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Authors: Md. Z. Alam, Devi R. Asih, Md. N. Salleh

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Immobilization of lipase enzyme produced from palm oil mill effluent (POME) by the activated carbon (AC) among the low cost support materials was optimized. The results indicated that immobilization of 94% was achieved by AC as the most suitable support material. A sequential optimization strategy based on a statistical experimental design, including one-factor-at-a-time (OFAT) method was used to determine the equilibrium time. Three components influencing lipase immobilization were optimized by the response surface methodology (RSM) based on the face-centered central composite design (FCCCD). On the statistical analysis of the results, the optimum enzyme concentration loading, agitation rate and carbon active dosage were found to be 30 U/ml, 300 rpm and 8 g/L respectively, with a maximum immobilization activity of 3732.9 U/g-AC after 2 hrs of immobilization. Analysis of variance (ANOVA) showed a high regression coefficient (R2) of 0.999, which indicated a satisfactory fit of the model with the experimental data. The parameters were statistically significant at p<0.05.

Keywords: activated carbon, POME based lipase, immobilization, adsorption

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Authors: Satyendra P. Chaurasia, Aditi Sharma, Ajay K. Dalai

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The esterification of Docosahexaenoic acid (DHA) with glycerol using immobilized Mucor mie-hei lipase (MML) and Rhizopus oryzae lipase (ROL) have been studied in the present paper to synthesize triglycerides (TG) rich in DHA. Both immobilized lipases (MML and ROL), and their support materials (immobead-150 and ion-exchange resin) were characterized and compared for surface properties with BET, for chemical functional groups with FT-IR, and for particle size distribution with particle size analyzer. The most suitable reaction conditions for synthesis of DHA rich TG in biphasic solvent system were found as 1:3 (wt/wt) glycerol to DHA ratio, 1:1 (wt/wt) buffer to DHA ratio, 1:1 (wt/wt) solvent to DHA ratio at 50 ºC temperature, and 600 rpm speed of agitation with 100 mg of immobilized lipases. Maximum 95.9 % esterification was obtained with immobilized MML in 14 days reaction with formation of 65.7 wt% DHA rich TG. Whereas, immobilized ROL has shown formation of only 23.8 wt% DHA rich TG with total 78.9 % esterification in 15 days. Additionally, repeated use of both immobilized lipases was con-ducted up to five cycles, indicated 50.4% and 41.2 % activity retention after fifth repeated use of immobilized MML and ROL, respectively.

Keywords: DHA, immobilized Mucor miehei lipase, Rhizopus oryzae lipase, esterification

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Authors: C. Asha Poorna, N. S. Pradeep

Abstract:

The biological function of lipase is to catalyze the hydrolysis of triacylglycerols to give free fatty acid, diacylglycerols, mono-acylglycerols and glycerol. They constitute the most important group of biocatalysts for biotechnological applications. The aim of the present study was to identify the lipolytic activity of Streptomyces sp. From soil sample collected from the sacred groves of southern Kerala. The culture conditions of the isolate were optimised and the enzyme was purified and characterised. The purification was attempted with acetone precipitation. The isolate observed to have high lipolytic activity and identified to be of Streptomyces strain. The purification was attempted with acetone precipitation. The purified enzyme observed to have an apparent molecular mass of ~60kDa by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme showed maximum activity at 60oC and pH-8. The lipase showed tolerance towards different organic solvents like ethanol and methanol that are commonly used in transesterification reactions to displace alcohol from triglycerides contained in renewable resources to yield fatty acid alkyl esters known as biodiesel.

Keywords: lipase, Streptomyces, biodiesel, fatty acid, transesterification

Procedia PDF Downloads 291

Authors: J. M. Hung, J. S. Chan, M. I. Kuo, D. S. Chan, C. P. Lu

Abstract:

Wheat germ is a by-product obtained from wheat milling and it contains highly concentrated nutrients. Due to highly lipase and lipoxygenase activities, wheat germ products can easily turn into rancid flavor and cause a short life. The objective of this study is to control moisture content and retard lipid hydrolysis by fluidized-bed drying. The raw wheat germ of 2 kg was dried with a vertical batch fluidized bed with the following varying conditions, inlet air temperature of 50, 80 and 120°C, inlet air velocity of 3.62 m/s. The experiment was designed to obtain a final product at around 40°C with water activity of 0.3 ± 0.1. Changes in the moisture content, water activity, enzyme activity of dried wheat germ during storage were measured. Results showed the fluidized-bed drying was found to reduce moisture content, water activity and lipase activity of raw wheat germ. After drying wheat germ, moisture content and water activity were between 5.8% to 7.2% and 0.28 to 0.40 respectively during 12 weeks of storage. The variation range of water activity indicated to retard lipid oxidation. All drying treatments displayed inactivation of lipase, except for drying condition of 50°C which showed relative high enzyme activity. During storage, lipase activity increased slowly during the first 6 weeks of storage and reached a plateau for another 6 weeks. As a result, using a fluidized-bed dryer was found to be effective drying technique in improving storage stability of wheat germ.

Keywords: wheat germ, fluidized-bed dryer, storage, lipase, stability

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Authors: Zerrin Erginkaya, Gözde Konuray

Abstract:

In this study, antimicrobial effect of Greek clover was determined with usage of MIC (minimum inhibition concentration) and agar diffusion method. Moreover, pH, water activity and microbial change were determined during storage of fenugreek paste. At first part of our study, microbial load of spices was evaluated. Two different fenugreek pastes were produced with mixing of Greek clover, spices, garlic and water. Fenugreek pastes were stored at 4 °C. At the second part, antimicrobial effect of Greek clover was determined on Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Debaryomyces hansenii, Aspergillus parasiticus, Candida rugosa, Mucor spp., when the concentrations of Greek clover were 8%, 12% and 16%. According to the results obtained, mould growth was determined at 15^th and 30^th days of storage in first and second fenugreek samples, respectively. Greek clover showed only antifungal effect on Aspergillus parasiticus at previously mentioned concentrations.

Keywords: antimicrobial, fenugreek, Greek clover, minimum inhibition concentration

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Authors: Meryem Abi-Ayad, Biagio Arcidiacono, Eusebio Chiefari, Daniela Foti, Mohamed Benyoucef, Antonio Brunetti

Abstract:

Lipoprotein Lipase (LPL) is a key enzyme for lipid metabolism; its genetic polymorphism can be a candidate for modulating lipids parameters in metabolic syndrome. The objective of the present study was to determine whether lipoproteins lipase polymorphisMetS (LPL-HindIII) could be associated with moderate hypertriglyceridemia (secondary to metabolism syndrome). The polymorphism Hind III (rs320) was assessed by PCR-RFLP in 51 MetS patients and 17 healthy controls from the hospital in Tlemcen. The logistic regression analyses showed no significant association with Hind III genotype and hypertriglyceridemia (TG ≥ 1,5g/l or TG lower treatment) (P=0,455), metabolic syndrome (P=0,455), hypertension (P=0,802) and type 2 diabetes (P=0,144). In terms of plasma biomarkers, although not statistically significant, there was a difference in TG levels (P > 0,05), which was lowest among carriers of the homogenous mutant allele (H-). In this study, there was no association between the rare allele (H-) and disease protection, and between the frequent allele (H+) and disease prevalence (hypertriglyceridemia, metabolic syndrome, hypertension, type 2 diabetes).

Keywords: moderate secondary hypertriglyceridemia, metabolic syndrome, lipids, polymorphism lipoprotein lipase, HindIII(rs320)

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Authors: Evgeniya Y. Yuzbasheva, Tigran V. Yuzbashev, Natalia I. Perkovskaya, Elizaveta B. Mostova

Abstract:

Cell-surface display of lipase is of great interest as it has many applications in the field of biotechnology owing to its unique advantages: simplified product purification, and cost-effective downstream processing. One promising area of application for whole-cell biocatalysts with surface displayed lipase is biodiesel synthesis. Biodiesel is biodegradable, renewable, and nontoxic alternative fuel for diesel engines. Although the alkaline catalysis method has been widely used for biodiesel production, it has a number of limitations, such as rigorous feedstock specifications, complicated downstream processes, including removal of inorganic salts from the product, recovery of the salt-containing by-product glycerol, and treatment of alkaline wastewater. Enzymatic synthesis of biodiesel can overcome these drawbacks. In this study, Lip2p lipase was displayed on Yarrowia lipolytica cells via C- and N-terminal fusion variant. The active site of lipase is located near the C-terminus, therefore to prevent the activity loosing the insertion of glycine-serine linker between Lip2p and C-domains was performed. The hydrolytic activity of the displayed lipase reached 12,000–18,000 U/g of dry weight. However, leakage of enzyme from the cell wall was observed. In case of C-terminal fusion variant, the leakage was occurred due to the proteolytic cleavage within the linker peptide. In case of N-terminal fusion variant, the leaking enzyme was presented as three proteins, one of which corresponded to the whole hybrid protein. The calculated number of recombinant enzyme displayed on the cell surface is approximately 6–9 × 105 molecules per cell, which is close to the theoretical maximum (2 × 106 molecules/cell). Thus, we attribute the enzyme leakage to the limited space available on the cell surface. Nevertheless, cell-bound lipase exhibited greater stability to short-term and long-term temperature treatment than the native enzyme. It retained 74% of original activity at 60°C for 5 min of incubation, and 83% of original activity after incubation at 50°C during 5 h. Cell-bound lipase had also higher stability in organic solvents and detergents. The developed whole-cell biocatalyst was used for recycling biodiesel synthesis. Two repeated cycles of methanolysis yielded 84.1–% and 71.0–% methyl esters after 33–h and 45–h reactions, respectively.

Keywords: biodiesel, cell-surface display, lipase, whole-cell biocatalyst

Procedia PDF Downloads 459

Authors: Seyed Reza Aghili, Tahereh Shokohi, Lotfollah Davoodi, Zahra Kashi, Azam Moslemi, Mahdi Abastabar, Iman Haghani, Sabah Mayahi, Asoudeh A.

Abstract:

Introduction: In diabetic foot ulcers, if fungal agents such as Candida species penetrate into the cutaneous or depth of ulcer, can increase the degree of the wound and cause Candia infection and make it more difficult to heal. Material & Methods: A cross-sectional study was performed on 100 diabetic foot ulcer patients in 2020 in Sari, Iran. patient's data and wound grade were recorded in a questionnaire. Candida infection was diagnosed with direct microscopic examination and culture of samples. Colony-PCR molecular method was used for ITS region of DNA and then PCR-RFLP with Msp1 enzyme and using HWP1 specific gene to determine species of Candida agent. Results: Of 100 patients, the mean age 62.1 ± 10.8 years, 95% type 2 diabetes, 83%>10 years duration diabetes, 59% male, 66%> poor education level, 99% married, 52% rural, 95% neuropathic symptoms, 88% using antibiotics, 69%HbA1C >9%, and mean ulcer degree 2.6±1.05 were. Candida infection was seen in 13% of the deep tissue of the wound and 7% cutaneous around the wound. The predominant Candida isolated was C. parapsilosis (71.5%), C .albicans (14.3%). Fungal infections caused by mold fungi were not detected. There was a statistically significant relationship between yeast infection and gender, rural, HbA1C and ulcer degree. Conclusion: Mycological evaluations often are ignored. Candida parapsilosis is the most common infectious agent in these patients and may require specific treatment. Therefore, more attention of physicians to Candida infections particularly, early diagnosis and effective treatment can help faster recovery and prevent amputation.

Keywords: diabetic foot ulcer, candida infection, risk factors, c. parapsilosis

Procedia PDF Downloads 159

Authors: Kidane workelul, Li xu, Xiaoyang Pang, Jiaping Lv

Abstract:

Dairy products are exceptionally ideal media for the growth of microorganisms because of their high nutritional content. There are several ways that milk might get contaminated throughout the milking process, including how the raw milk is transported and stored, as well as how long it is kept before being processed. Psychrotrophic bacteria are among the one which can deteriorate the quality of milk mainly their heat resistance proteas and lipase enzyme. For this research purpose 8 selected strains of Psychrotrophic bacteria (Entrococcus hirae, Pseudomonas fluorescens, Pseudomonas azotoformans, Pseudomonas putida, Exiguobacterium indicum, Pseudomonas paralactice, Acinetobacter indicum, Serratia liquefacients)are chosen and try to determine their characteristics based on the research methodology protocol. Thus, the 8 selected strains are cultured, plated incubate, extracted their genomic DNA and genome DNA was amplified, the purpose of the study was to identify their Psychrotrophic properties, lipase hydrolysis positive test, their optimal incubation temperature, designed primer using the noble strain P,flourescens conserved region area in target with lipA gene, optimized primer specificity as well as sensitivity and PCR detection for lipase positive strains using the design primers. Based on the findings both the selected 8 strains isolated from stored raw milk are Psychrotrophic bacteria, 6 of the selected strains except the 2 strains are positive for lipase hydrolysis, their optimal temperature is 20 to 30 OC, the designed primer specificity is very accurate and amplifies for those strains only with lipase positive but could not amplify for the others. Thus, the result is promising and could help in detecting the Psychrotrophic bacteria producing heat resistance enzymes (lipase) at early stage before the milk is processed and this will safe production loss for the dairy industry.

Keywords: dairy industry, heat-resistant, lipA, milk, primer and psychrotrophic

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Authors: Seonggil Kim, Jeonghun Nam, Chae Seung Lim

Abstract:

Rapid diagnosis of fungal infections is critical for rapid antifungal therapy. However, it is difficult to detect extremely low concentration fungi in blood sample. To address the limitation, separation and concentration of fungi in blood sample are required to enhance the sensitivity of PCR analysis. In this study, we demonstrated a sheathless separation and concentration of fungi, candida cells using a viscoelastic fluid. To validate the performance of the device, microparticle mixture (2 and 13 μm) was used, and those particles were successfully separated based on the size difference at high flow rate of 100 μl/min. For the final application, successful separation of the Candida cells from the white blood cells (WBCs) was achieved. Based on the viscoelastic lateral migration toward the equilibrium position, Candida cells were separated and concentrated by center focusing, while WBCs were removed by patterning into two streams between the channel center and the sidewalls. By flow cytometric analysis, the separation efficiency and the purity were evaluated as ~99% and ~ 97%, respectively. From the results, the device can be the powerful tool for detecting extremely rare disease-related cells.

Keywords: candida cells, concentration, separation, viscoelastic fluid

Procedia PDF Downloads 165