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Introduction: Glucose oxidase (GOX) is considered a commercial enzyme in the medicine, pharmaceutical, and food industries. Optimization of the fermentation medium and conditions is important to increase heterologous GOX production. The current study aimed to optimize GOX production in a ‎recombinant strain of Yarrowia lipolytica via statistical techniques. Materials and Methods: Response surface methodology (RSM) as a statistical technique for the design of the experiment was used for the optimization of recombinant GOX production by Y. lipolytica. Then, the optimized conditions were used for the production of GOX in bioreactor cultivation. Results: GOX production was increased up to 570 U/L after optimization of the medium in flask culture which is 2 times more than the non-optimized medium. In the bioreactor culture using optimized medium containing glucose and sucrose as carbon sources, GOX production was reached 720 and 730 U/L after two and six days, respectively. Discussion and Conclusion: Results of the study provided valuable information about the statistical optimization of bioprocess development for the production of heterologous protein in Y. lipolytica.

Introduction: L-Asparaginase catalyzes the hydrolysis of L-asparagine to L-aspartic acid and ammonia. This enzyme is used for the treatment of patients with acute lymphoblastic leukemia, melanosarcoma and lymphosarcoma. It is also used in the production of acrylamide-free foods. Considering the important applications of this enzyme, the aim of this study was to introduce a new microbial source for the production of eukaryotic L-asparaginase. Materials and Methods: The quality and quantity production of L-asparaginase was investigated in four strains of yeast Yarrowia lipolytica. The quality assessment of L-asparaginase production was done on asparagine minimal agar. Quantitative assay of the enzyme was done in Czapex Dox’s medium by spectrophotometric method using Nessler’s reagent. Results: All of four strains show that they are able to produce asparaginase making a purple halo around the colony. Y. lipolytica DSM3286, DSM70562, DSM3218 and CBS6303 were produced 17/14, 11, 6/98 and 5/61 U/mL of asparaginase in Czapex Dox’s medium after 24 h, respectively. Discussion and Conclusion: Y. lipolytica DSM3286 was selected as the best asparaginase producer strain with the largest halo and the highest asparaginase production. The Y. lipolytica could be used as a potential source of L-asparaginase production.

نایسین اولین نگهدارنده غذایی تایید شده FDAاست که در مقیاس صنعتی توسط Lactococcus lactis subsp. lactisتولید می­شود. برای کاهش اثر منفی اسید لاکتیک تولید شده در متابولیسم L. lactisبر روی تولید نایسین، کشت توام این باکتری با Yarrowia lipolytica استفاده شده است. در این پژوهش برای اولین بارL. lactis به همراه Y. lipolyticaدر تخمیر بسته با استفاده از بیوراکتور آزمایشگاهی در محیط بر پایه ملاس در دمای °C30 ،­­pH شش و هوادهی vvm15/0 و دور همزن rpm100کشت داده شده­اند. میزان تولید نایسین در این شرایط IU/ml920بوده است. همچنین در تخمیر همزمان دو سویه، میزان زیست توده و تولید نایسین به ترتیب 63 درصد و 78 درصد بیشتر از کشت خالص L. lactisاست. به نظر می­رسد عوامل دیگری از جمله فعالیت پروتئازی برون سلولی مخمر که باعث تسهیل دسترسی باکتری به منابع غذایی محیط کشت می­شود، در این فرآیند موثر باشد.

Introduction:Laccases (EC 1.10.3.2; benzenediol: oxygen oxidoreductase) are copper-containing oxidases that use molecular oxygen to oxidize various aromatic and non-aromatic compounds. Laccase is applied in delignification of lignocellulosic compounds for production of bioethanol, bioremediation of industrial wastewaters especially textile, food industries, and making biosensors. Materials and methods: The Taguchi experimental design method was used for optimization of laccase production in recombinant strain Yarrowia lipolytica YL4. A L-16 Taguchi orthogonal array was used to optimize the carbon and nitrogen sources along with vitamin in four levels. Results: The results showed that glucose, ammonium chloride, yeast extract and thiamine have significant effects on the production of laccase, respectively. The laccase activity reached to 1.52 U/mL after optimization of medium which is 7.6-fold higher than un-optimized medium. Discussion and conclusion: According to the analysis of results, the Taguchi experimental design method is a successful approach to increase laccase and recombinant proteins production in Y. lipolytica.

Introduction: Lipase of the yeast Yarrowia lipolytica used in detergents, cosmetics, pharmaceuticals and food industries. This enzyme production depends on medium composition, especially carbon source. The purpose of this study was to investigate the effect of olive oil different feeding strategies on Y. lipolytica lipase production. Materials and methods: The yeast strains Y. lipolytica FDY1390 was cultured in media with different feeding strategies. Three different models were used to fed-batch feeding method. The yeast growth is monitored by direct counting method with neubauer chamber. Lipase activity was measured using titration method. Results: All three models of fed-batch feeding increased lipase toward the batch culture. Fed3 was the best model of fed-batch feeding, in which the model leads to the production of lipase activity with 526 U/ml after 120 hours and the productivity reached to 4.38 U/ h. Discussion and conclusion: The results showed that feeding patterns of fed-batch culture increase production rate of lipase production towards batch culture. The best strategy is to add olive oil as the carbon source induction substrate in medium after 48 hours of inoculation.

Introduction: Proteases are the most important industrial enzymes. These enzymes have gained much attention due to their industrial applications in eliminating the environmental pollutions and improving the industrial processes. The aims of this research were the isolation and identification of native yeasts that were able to produce the alkaline protease. Materials and methods: Several samples of soil, water and wastewater were collected from various places. The culture media used for screening of yeast spp. with potential of alkaline protease production were alkaline peptone agar and alkaline milk agar. The alkaline protease activity in potential spp. was measured using Lowry method. The effects of different culture media on the production of alkaline protease by selected yeast isolates were determined. For molecular identification of the best isolate, the DNA extraction was performed and the PCR followed using universal 18s rDNA primers. Results: Among 27 isolates with the capability of alkaline protease production, one isolate with the most enzyme activity, 525 u/ ml, was selected for further processing. The best culture medium for alkaline protease production was YPG broth. The comparison of 18s rDNA sequence from isolated yeast with the highest enzyme activity, with the genomic database available in Gen Bank, using BLAST software showed that our yeast isolate had the highest similarity with Yarrowia lipolytica. Discussion and conclusion: According to numerous applications of alkaline proteases industrially and the lack of their production in our country, the native strains could be beneficial for their production. Regarding to non-pathogenicity and high productivity of alkaline protease by our isolated yeast, Yarrowia lipolytica, this isolate could be introduced as an amenable strain for industrial production of alkaline protease.

Introduction: Lipases are a class of hydrolases which catalyze the hydrolysis of triglycerides to glycerol and free fatty acids. Lipases have become an integral part of the modern food, detergents, cosmetics and pharmaceutical industries. The aim of this study was investigation of the effect of olive oil with different commercial purity as a substrate on lipase production by Yarrowia lipolytica. Materials and methods: One percentage of olive oil with three different commercial grades Extra-virgin, Virgin and Ordinary was used as cheap substrate to produce lipase by wild-type strain Y. lipolytica DSM3286 and mutant strain Y. lipolytica FDY139. Results: Maximum lipase activity was observed 72 hours after inoculation. The wild-type strain Y. lipolytica DSM3286 produced lipase with 56 U/ml activity on Virgin olive oil, but mutant strain Y. lipolytica FDY1390 produced lipase with 300 U/ml activity on Ordinary olive oil. Discussion and conclusion: The Y. lipolytica FDY1390 produced lipase about 5.4-fold higher than the wild-type strain on Ordinary olive oil. Whereas other expensive type of olive oil, Ordinary olive oil is a cheap oil which could be used to lipase production and optimization.

Introduction: L-Asparaginase catalyzes the hydrolysis of L-asparagine to L-aspartic acid and ammonia. This enzyme is used for the treatment of patients with acute lymphoblastic leukemia, melanosarcoma and lymphosarcoma. It is also used in the production of acrylamide-free foods. Considering the important applications of this enzyme, the aim of this study was to introduce a new microbial source for the production of eukaryotic L-asparaginase. Materials and Methods: The quality and quantity production of L-asparaginase was investigated in four strains of yeast Yarrowia lipolytica. The quality assessment of Lasparaginase production was done on asparagine minimal agar. Quantitative assay of the enzyme was done in Czapex Dox’s medium by spectrophotometric method using Nessler’s reagent. Results: All of four strains show that they are able to produce asparaginase making a purple halo around the colony. Y. lipolytica DSM3286, DSM70562, DSM3218 and CBS6303 were produced 17/14, 11, 6/98 and 5/61 U/mL of asparaginase in Czapex Dox’s medium after 24 h, respectively. Discussion and Conclusion: Y. lipolytica DSM3286 was selected as the best asparaginase producer strain with the largest halo and the highest asparaginase production. The Y. lipolytica could be used as a potential source of L-asparaginase production. [ABSTRACT FROM AUTHOR]

Introduction: Laccases (EC 1.10.3.2; benzenediol: oxygen oxidoreductase) are coppercontaining oxidases that use molecular oxygen to oxidize various aromatic and non-aromatic compounds. Laccase is applied in delignification of lignocellulosic compounds for production of bioethanol, bioremediation of industrial wastewaters especially textile, food industries, and making biosensors. Materials and methods: The Taguchi experimental design method was used for optimization of laccase production in recombinant strain Yarrowia lipolytica YL4. A L-16 Taguchi orthogonal array was used to optimize the carbon and nitrogen sources along with vitamin in four levels. Results: The results showed that glucose, ammonium chloride, yeast extract and thiamine have significant effects on the production of laccase, respectively. The laccase activity reached to 1.52 U/mL after optimization of medium which is 7.6-fold higher than un-optimized medium. Discussion and conclusion: According to the analysis of results, the Taguchi experimental design method is a successful approach to increase laccase and recombinant proteins production in Y. lipolytica. [ABSTRACT FROM AUTHOR]

Microbial oil has lots of similarity to the plant's oil; the only difference between them is that microbial oil is rich in unsaturated fatty acids. This oil can be used in pharmaceutical industry for technical purposes or as edible oil in food industry. The purpose of this study was to increase lipid production and the amount of unsaturated fatty acids in oleaginous yeasts by mutagenesis. In this study, optimization of lipid production in the yeast ,Yarrowia lipolytica, was done using ultraviolet random mutation and screening was done with the inhibitory effect of cerulenin on lipid synthesis. Mutants that had normal growth in the presence of cerulenin were selected as superior strains for further investigations. Lipid production in mutants and wild strains were compared after incubation period. Then, the mutant with significant increase in lipid production was selected. The best mutant had increasing of 50% and 30% in lipid production and growth yield, respectively. Also, Linoleic acid was increased after mutation. The composition of fatty acids in the lipid profile of the evaluated yeast did not change a lot after mutation. Of course, unsaturated fatty acids were increased, so this technique was very effective to improve lipid production. Cerulenin used as an effective screening technique in this study and paved the way for the isolation of superior mutants. [ABSTRACT FROM AUTHOR]

Introduction: Lipase of the yeast Yarrowia lipolytica used in detergents, cosmetics, pharmaceuticals and food industries. This enzyme production depends on medium composition, especially carbon source. The purpose of this study was to investigate the effect of olive oil different feeding strategies on Y. lipolytica lipase production. Materials and methods: The yeast strains Y. lipolytica FDY1390 was cultured in media with different feeding strategies. Three different models were used to fed-batch feeding method. The yeast growth is monitored by direct counting method with neubauer chamber. Lipase activity was measured using titration method. Results: All three models of fed-batch feeding increased lipase toward the batch culture. Fed3 was the best model of fed-batch feeding, in which the model leads to the production of lipase activity with 526 U/ml after 120 hours and the productivity reached to 4.38 U/ h. Discussion and conclusion: The results showed that feeding patterns of fed-batch culture increase production rate of lipase production towards batch culture. The best strategy is to add olive oil as the carbon source induction substrate in medium after 48 hours of inoculation. [ABSTRACT FROM AUTHOR]

Yarrowia lipolytica is unusual yeast that has the ability to produce important metabolites such as lipase enzymes. Lipase enzyme has many applications in different industries including manufacturing of detergents, food industry, pharmacy, fuel and etc. In this paper, we studied the lipase enzyme produced by the yeast under different treatments of nitrogen sources such as yeast extract, peptone, soybean meal, sesame meal and sesame meal extracts on the medium of Czapek Dox Broth. Selected treatments of nitrogen resources include treatment solution (100%), solution (50%) containing with sesame cake extract (3.6%), solution (50%) containing with sesame cake extract (3.6%) in distilled water, solution (50%) containing with yeast extract (3.6%) in distilled water and solution (50%) containing with peptone (3.6%) in distilled water on the medium (CDB). Fermentation time levels are considered 3, 4 and 5 days. Among examined treatments, Treatment solution (50%) containing with sesame cake extract (3.6%) on the medium (CDB) showed the highest lipase activity (91.5900±0.56241 and 67.5200 ± 0.01000 enzyme units, respectively) in the fourth day of incubation with stirring speed (120 rpm) and temperature (30 °C). The results show use of sesame cake extract increases lipase activity more than use of yeast extract and peptone at the level of 5%. Also, statistical analysis of resulted data showed use of sesame cake extract increases lipase activity significantly at 5% level in comparison with yeast extract and peptone. [ABSTRACT FROM AUTHOR]

Introduction: Proteases are the most important industrial enzymes. These enzymes have gained much attention due to their industrial applications in eliminating the environmental pollutions and improving the industrial processes. The aims of this research were the isolation and identification of native yeasts that were able to produce the alkaline protease. Materials and methods: Several samples of soil, water and wastewater were collected from various places. The culture media used for screening of yeast spp. with potential of alkaline protease production were alkaline peptone agar and alkaline milk agar. The alkaline protease activity in potential spp. was measured using Lowry method. The effects of different culture media on the production of alkaline protease by selected yeast isolates were determined. For molecular identification of the best isolate, the DNA extraction was performed and the PCR followed using universal 18s rDNA primers. Results: Among 27 isolates with the capability of alkaline protease production, one isolate with the most enzyme activity, 525 u/ ml, was selected for further processing. The best culture medium for alkaline protease production was YPG broth. The comparison of 18s rDNA sequence from isolated yeast with the highest enzyme activity, with the genomic database available in Gen Bank, using BLAST software showed that our yeast isolate had the highest similarity with Yarrowia lipolytica. Discussion and conclusion: According to numerous applications of alkaline proteases industrially and the lack of their production in our country, the native strains could be beneficial for their production. Regarding to non-pathogenicity and high productivity of alkaline protease by our isolated yeast, Yarrowia lipolytica, this isolate could be introduced as an amenable strain for industrial production of alkaline protease. [ABSTRACT FROM AUTHOR]

Introduction: Lipases are a class of hydrolases which catalyze the hydrolysis of triglycerides to glycerol and free fatty acids. Lipases have become an integral part of the modern food, detergents, cosmetics and pharmaceutical industries. The aim of this study was investigation of the effect of olive oil with different commercial purity as a substrate on lipase production by Yarrowia lipolytica. Materials and methods: One percentage of olive oil with three different commercial grades Extra-virgin, Virgin and Ordinary was used as cheap substrate to produce lipase by wild-type strain Y. lipolytica DSM3286 and mutant strain Y. lipolytica FDY139. Results: Maximum lipase activity was observed 72 hours after inoculation. The wild-type strain Y. lipolytica DSM3286 produced lipase with 56 U/ml activity on Virgin olive oil, but mutant strain Y. lipolytica FDY1390 produced lipase with 300 U/ml activity on Ordinary olive oil. Discussion and conclusion: The Y. lipolytica FDY1390 produced lipase about 5.4-fold higher than the wild-type strain on Ordinary olive oil. Whereas other expensive type of olive oil, Ordinary olive oil is a cheap oil which could be used to lipase production and optimization. [ABSTRACT FROM AUTHOR]