Effects of Yeast Extract on Poly-ε-Lysine Production in Batch Culture of Streptomyces Albulus

2011 ◽  
Vol 343-344 ◽  
pp. 1023-1028 ◽  
Author(s):  
Xiong Chen ◽  
Zhi Wang ◽  
Yong Ze Wang ◽  
Fa Tang Jiang ◽  
Dong Sheng Li ◽  
...  

Yeast extract (YE) is a sole organic nitrogen source in a commonly medium 3G for Streptomyces albulus to produce poly-ε-lysine (ε-PL). In this study, five YEs from five commercial suppliers were used to evaluate their effects on the growth of Streptomyces albulus 213 and ε-PL production. YE from bakers’ yeast with the highest total nitrogen content (TN), α-amino nitrogen content (AN) or the ratio of AN/TN produced the highest yield of ε-PL, while YE from brewers’ yeast with the highest RNA content got the most dry cell weight (DCW). However, there was little correlation between TN, AN or AN/TN in YE and the yield of ε-PL. There was also weak correlation between RNA in YE and DCW. When 60% baker YE was mixed with 40% brewer YE, the yield of ε-PL reached 1.89 g/l and increased by 16% and 37% than those of baker YE and brewer YE, respectively. Furthermore, five kinds of vitamins and nine kinds of amino acids were screened to supplement baker YE. When 6 mg/l biotin, 5mg/l pantothenic acid, 0.7 g/l L-glutamine and 0.5 g/l L-arginine were mixed with baker YE in M3G, ε-PL reached maximum production respondent to 3.05 g/l that was 61.4% higher than control.

2019 ◽  
Vol 23 (2) ◽  
pp. 101-108
Author(s):  
Xin Yang ◽  
Guowei Shu ◽  
Zhangteng Lei ◽  
Guanli Du ◽  
Zemin Liu ◽  
...  

Abstract Saccharomyces boulardii (S. boulardii) has been used as a probiotic for the prevention or treatment of various human gastrointestinal diseases for many years. Thus, S. boulardii has a wide range of application prospects in medicine and food industry. The experiments were investigated with effecting of carbon sources (galactose, sucrose, fructose, maltose, lactose, glucose, and soluble starch), nitrogen sources (tryptone, casein, yeast extract, peptone, soy peptone, beef extract and malted milk; ammonium sulfate, urea, diammonium hydrogen citrate, triammonium citrate, ammonium nitrate, ammonium chloride and potassium nitrate), prebiotics (xylo-oligosaccharide, isomaltooligosaccharide, fructo-oligosaccharide, galacto-oligosaccharide, stachyose, raffinose and inulin) on the number of viable cells and dry cell weight of S. boulardii. The optimum concentration of 5 % glucose or sucrose, 2 % peptone or yeast extract, 0.4 % urea, 0.2 % fructo-oligosaccharide and 0.6 % galacto-oligosaccharide for S. boulardii grew better in medium.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Min Li ◽  
Xianyan Liao ◽  
Dongxu Zhang ◽  
Guocheng Du ◽  
Jian Chen

Polyvinyl alcohol-degrading enzymes (PVAases) have a great potential in bio-desizing processes for its low environmental impact and low energy consumption. In this study, the effect of yeast extract on PVAases production was investigated. A strategy of four-point yeast extract addition was developed and applied to maximize cell growth and PVAases production. As a result, the maximum dry cell weight achieved was 1.48 g/L and the corresponding PVAases activity was 2.99 U/mL, which are 46.5% and 176.8% higher than the control, respectively. Applying this strategy in a 7 L fermentor increased PVAases activity to 3.41 U/mL. Three amino acids (glycine, serine, and tyrosine) in yeast extract play a central role in the production of PVAases. These results suggest that the new strategy of four-point yeast extract addition could benefit PVAases production.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Abinaya Badri ◽  
Asher Williams ◽  
Adeola Awofiranye ◽  
Payel Datta ◽  
Ke Xia ◽  
...  

AbstractSulfated glycosaminoglycans (GAGs) are a class of important biologics that are currently manufactured by extraction from animal tissues. Although such methods are unsustainable and prone to contamination, animal-free production methods have not emerged as competitive alternatives due to complexities in scale-up, requirement for multiple stages and cost of co-factors and purification. Here, we demonstrate the development of single microbial cell factories capable of complete, one-step biosynthesis of chondroitin sulfate (CS), a type of GAG. We engineer E. coli to produce all three required components for CS production–chondroitin, sulfate donor and sulfotransferase. In this way, we achieve intracellular CS production of ~27 μg/g dry-cell-weight with about 96% of the disaccharides sulfated. We further explore four different factors that can affect the sulfation levels of this microbial product. Overall, this is a demonstration of simple, one-step microbial production of a sulfated GAG and marks an important step in the animal-free production of these molecules.


2021 ◽  
Vol 22 (7) ◽  
pp. 3677
Author(s):  
Zuzana Rosenbergová ◽  
Kristína Kántorová ◽  
Martin Šimkovič ◽  
Albert Breier ◽  
Martin Rebroš

Myrosinase is a plant defence enzyme catalysing the hydrolysis of glucosinolates, a group of plant secondary metabolites, to a range of volatile compounds. One of the products, isothiocyanates, proved to have neuroprotective and chemo-preventive properties, making myrosinase a pharmaceutically interesting enzyme. In this work, extracellular expression of TGG1 myrosinase from Arabidopsis thaliana in the Pichia pastoris KM71H (MutS) strain was upscaled to a 3 L laboratory fermenter for the first time. Fermentation conditions (temperature and pH) were optimised, which resulted in a threefold increase in myrosinase productivity compared to unoptimised fermentation conditions. Dry cell weight increased 1.5-fold, reaching 100.5 g/L without additional glycerol feeding. Overall, a specific productivity of 4.1 U/Lmedium/h was achieved, which was 102.5-fold higher compared to flask cultivations.


2014 ◽  
Vol 1081 ◽  
pp. 110-114 ◽  
Author(s):  
Zhen Zhu ◽  
Hua Yin ◽  
Yan An

This research adopts the pancreatin hydrolysis of silk fibroin active peptide, evaluate the antioxidant activity of hydrolysates. In the process of hydrolysis of silk fibroin, by measuring the amino nitrogen content of neutral formaldehyde titration method. Find the amino nitrogen content gradually stabilized at around 0.37g/L, and superoxide free radical scavenging rate changing with time fluctuation trend, superoxide free radical scavenging rate to a maximum of 65.03% at 220min.The use of silk fibroin hydrolysis process optimization,reaction time 160min, enzyme concentration4% , substrate concentration 20mg/ml, pH 8, temperature 38°C. The hydrolysis process under the hydrolysate on superoxide radical scavenging rate of 72.73%. The scavenging rate of hydroxyl radical is 47.24%. Red blood cell hemolysis induced by H2O2 inhibition rate was 24.30%.


Fisheries ◽  
2021 ◽  
Vol 2021 (1) ◽  
pp. 103-107
Author(s):  
Ekaterina Konopleva ◽  
Liubov Abramova ◽  
Valeria Gershunskaya ◽  
Maksim Arnautov

The aim of the work was to develop the parameters of the process of salting Pacific herring fillet with a reduced salt content, intended for children’s nutrition. For salting, food salt with a reduced sodium content, enriched with potassium, magnesium, was used. Based on the conducted studies, a rational formulation of the salting mixture was selected, consisting of 5 % salt with a reduced sodium content, 4% sugar, 0.35-0.50% citric acid. It was found that carrying out the salting process for 72-96 hours provides a low-salted fillet with a salt content of 3.5% with high organoleptic parameters, which are determined by the amino nitrogen content of 110-130 mg/100 g of the product and the buffering capacities of 40-45 degrees.


2015 ◽  
Vol 77 (31) ◽  
Author(s):  
Huszalina Hussin ◽  
Madihah Md Salleh ◽  
Chong Chun Siong ◽  
Muhammad Abu Naser ◽  
Suraini Abd- Aziz ◽  
...  

The recent study has demonstrated the effects of different nitrogen sources on vanillin production by Phanerochaete chrysosporium. Primary screening supported maximum biotransformation of ferulic acid (from lemongrass leaves hydrolysate) to vanillin by using ammonium chloride and yeast extract as inorganic and organic nitrogen source, respectively. With the 2-level factorial analysis, the optimum conditions of vanillin production from ferulic acid by P. chrysosporium was achieved at 0.192g/L with a molar yield of 24.5%.


2021 ◽  
Vol 11 (20) ◽  
pp. 9573
Author(s):  
Natalia Kujawska ◽  
Szymon Talbierz ◽  
Marcin Dębowski ◽  
Joanna Kazimierowicz ◽  
Marcin Zieliński

The study aimed to determine the effectiveness of docosahexaenoic acid (DHA) production by Schizochytrium sp. biomass fed with waste glycerol depending on the concentration of extracellular polymeric substances (EPS) in the culture medium and medium aeration effectiveness. The microalgae from the genus Schizochytrium sp. were proved to be capable of producing EPS composed of glucose, galactose, mannose, fucose, and xylose. The highest EPS concentration, reaching 8.73 ± 0.09 g/dm3, was determined at the stationary growth phase. A high EPS concentration caused culture medium viscosity to increase, contributing to diminished oxygen availability for cells, lower culture effectiveness, and reduced waste glycerol conversion to DHA. The Schizochytrium sp. culture variant found optimal in terms of the obtained technological effects and operating costs was performed at the volumetric oxygen mass transfer coefficient of kLa = 600 1/h, which enabled obtaining dry cell weight (DCW) of 147.89 ± 4.77 g/dm3, lipid concentration of 69.44 ± 0.76 g/dm3, and DHA concentration in the biomass reaching 29.44 ± 0.36 g/dm3. The effectiveness of waste glycerol consumption in this variant reached 3.76 ± 0.31 g/dm3·h and 3.16 ± 0.22 g/gDCW.


2004 ◽  
Vol 34 (4) ◽  
pp. 1219-1223 ◽  
Author(s):  
Luís Henrique de Barros Soares ◽  
Patrícia Melchionna Albuquerque ◽  
Francine Assmann ◽  
Marco Antônio Záchia Ayub

Three sources of food proteins were treated with microbial transglutaminase (EC 2.3.2.13) in order to assess changes in the physicochemical properties of reactivity, solubility, emulsification, and free amino groups of the formed polymers. Samples of lactic casein (LC), isolated soy protein (ISP), and hydrolysed animal protein (HAP), were incubated with the enzyme for one or two hours. LC and ISP showed a reduced solubility of 15% and 24% respectively, with HAP showing no alteration on solubility. Amino nitrogen content was 7%, 3% and 2% reduced for HAP, LC and ISP respectively. LC and ISP demonstrated lower emulsifying activity when they were enzymatically treated but the formed emulsions were stable, contrasting with HAP, which exhibited no changes in emulsifying properties.


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