L-Methionine (L-Met) is a sulfur-containing amino acid, which is one of the eight essential amino acids to human body. In this work, the fermentative production of L-Met with genetically engineered Escherichia coli W3110-BL in a 5-L fermentor was enhanced through supplement of Ca2+ into the fermentation medium. With the addition of 30 g/L calcium carbonate (CaCO3), the titer of L-Met and yield against glucose reached 1.48 g/L and 0.09 mol/mol glucose, 57.45% higher than those of the control, respectively. The flux balance analysis (FBA) revealed that addition of CaCO3 strengthened the tricarboxylic acid cycle and increased the intracellular ATP concentration by 39.28%. The re-distribution of carbon, ATP, and cofactors flux may collaborate to improve L-Met biosynthesis with E. coli W3110-BL. The regulation of citrate synthase and oxidative phosphorylation pathway was proposed to be important for overproduction of L-Met. These foundations provide helpful reference in the following metabolic modification or fermentation control for further improvement of L-Met biosynthesis.

/pdf/calcium-carbonate-addition-improves-l-methionine-13eeqehdom.pdf

Calcium Carbonate Addition Improves L-Methionine Biosynthesis by Metabolically Engineered Escherichia coli W3110-BL.

Microorganisms, fermentation processes, and the resultant metabolic products are a key driving force in biotechnology and, in particular, in food biotechnology. The quantity and/or quality of final manufactured food products are directly related to the efficiency of the metabolic processes of producer microorganisms. Food BioTech companies are naturally interested in increasing the productivity of their biotechnological production lines. This could be achieved via either indirect or direct influence on the fundamental mechanisms governing biological processes occurring in microbial cells. This review considers an approach to improve the efficiency of producer microorganisms through the use of several types of substances or complexes affecting the metabolic processes of microbial producers that are of interest for food biotechnology, particularly fermented milk products. A classification of these supplements will be given, depending on their chemical nature (poly- and oligosaccharides; poly- and oligopeptides, individual amino acids; miscellaneous substances, including vitamins and other organic compounds, minerals, and multicomponent supplements), and the approved results of their application will be comprehensively surveyed.

https://www.mdpi.com/1420-3049/28/3/1413/pdf?version=1675316189

Biologically Active Supplements Affecting Producer Microorganisms in Food Biotechnology: A Review

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.

/pdf/effect-of-carbon-sources-nitrogen-sources-and-prebiotics-on-3izv97w5et.pdf

Effect of Carbon Sources, Nitrogen Sources and Prebiotics on Growth of Saccharomyces Boulardii

In this paper,the culture medium of Lactobacillus plantarum for bacteriocin production was optimized.The results showed that the culture medium had an important effect on germ formation and production of bacteriocin,in which carbon source was significant.Overall,5% molasses,0.5% yeast extract,2% tryptone,0.4% KH2PO4,0.1% MgSO4.7H2O,0.5% CaCO3,0.05% MnSO4and 0.3% Tween 80 were the optimal combination of culture medium.

Culture Medium Optimization of Lactobacillus Plantarum for Bacteriocin Production

This work aimed to establish the conditions that improve the viability of Lactobacillus fermentum K73 during and after the electrospinning process. A mixture of experimental designs were performed to select the formulation (gelatin and bacterial culture) that improves the probiotic viability after blending and under simulated gastrointestinal conditions. A Box–Behnken design was performed to improve the encapsulation yield and survival during the electrospinning process. For the Box–Behnken design, the factors were soy lecithin and bacteria culture concentration at the blend and collector distance for electrospinning. It was hypothesized that soy lecithin improved the electrospinnability, acting as a surfactant in the mixture and allowing lower voltage to be used during the process. The selected volume ratio of the gelatin (25%)/bacterial culture mixture was 0.66/0.34. The physicochemical parameters of the selected blend were in the recommended range for electrospinning. The conditions that improved the encapsulation yield and survival during electrospinning were 200 g/L of bacterial culture, 2.5% (w/v) soy lecithin, and 7 cm collector distance. The experimental encapsulation yield and survival was 80.7%, with an experimental error of 7.2%. SEM micrographs showed the formation of fibers with gelatin/bacterial culture beads. Encapsulation improved the viability of the probiotic under simulated gastrointestinal conditions compared to free cells.

Electrospinning Microencapsulation of Lactobacillus fermentum K73 Using Gelatin as the Main Component of a Food-Grade Matrix

In present study, the effects of carbon sources (glucose, lactose, sucrose, galactose, maltose and soluble starch) and nitrogen sources (casein peptone, whey protein, soy peptone, yeast, tryptone, beef extract and peptone) on activity of cell envelope proteinases (CEP), specific activity, protein content, OD₆₀₀ value and pH in MRS broth fermented by Lactobacillus plantarum LP69 were investigated by individual factor experiment. The results indicated that carbon and nitrogen sources have significant influence on the activity of CEP and specific activitys of L. plantarum LP69, glucose, maltose, casein peptone and peptone are superior to other selected carbon and nitrogen sources. The optimum concentrations of glucose, maltose, casein peptone and peptone for L. plantarum LP69 are 2%, 2%, 1% and 1%; the activity of CEP are 19.52U/mL, 21.13U/mL, 13.49U/mL and 20.61U/mL, respectively.

/pdf/effects-of-carbon-and-nitrogen-sources-on-activity-of-cell-wz8lfftxwl.pdf

Effects of Carbon and Nitrogen Sources on Activity of Cell Envelope Proteinase Produced by Lactobacillus plantarum LP69

Background Cell-envelope proteinases (CEPs) can improve the texture and organoleptic characteristics of dairy products, and may also cause the release of bioactive peptides, which contribute to improving the hostrs health. Thus, the CEPs with high activity produced by L. plantarum has great potential in the development of functional dairy products. Methods A single factor experiment was used to investigate the effects of prebiotics (inulin, stachyose, isomaltooligosaccharide, xylooligosaccharides, galactooligosaccharides and fructooligosaccharides), inorganic salts (Na2HPO4, NaH2PO4, K2HPO4, KH2PO4, CH3COONa and C6H14N2O7) and amino acids (arginine, leucine, serine, lysine, alanine and glutamic acid) on the activity of cell envelope proteinases (CEPs), specific activity, protein content, OD600 value and pH in MRS broth fermented by Lactobacillus plantarum LP69. Results The optimum concentration of inulin (0.7%), isomaltooligosaccharide (0.5%), Na2HPO4 (0.4%), CH3COONa (0.4%), leucine (20 mg/L), serine (20 mg/L) for L. plantarum LP69 was estimated with the activity of CEP in the range 17.36n21.47 U/mL, protein content in the range 19.18n22.53 mg/mL, specific activity in the range 0.77n1.12 U/mg. Conclusions Inulin, isomaltooligosaccharide, Na2HPO4, CH3COONa, leucine and serine are superior to other selected substances, and have a significant influence on the CEP activity and specific activity of L. plantarum LP69. This would provide a reference for further optimization of CEP-producing media of L. plantarum LP69.

/pdf/effect-of-prebiotics-inorganic-salts-and-amino-acids-for-3xambi1zax.pdf

Effect of prebiotics, inorganic salts and amino acids for cell envelope proteinase production from Lactobacillus plantarum LP69.

In order to select the most important nutrients that influence the production of cell-envelope proteinase (CEP), Plackett–Burman design was employed to assess the effects of glucose, maltose, peptone, casein peptone, inulin, isomaltooligosaccharide, Na2HPO4, CH3COONa, leucine, and serine on the activity of CEP, protein content, specific activity, optical density (OD600) value and pH in MRS broth fermented by Lactobacillus plantarum LP69. The results revealed that Na2HPO4, inulin, casein peptone and leucine significantly affect (P<0.05) the production of CEP. Additionally, Na2HPO4, inulin and leucine were negatively correlated with the enzyme activity and the specific activity, while casein peptone was positively correlated with the enzyme activity and the specific activity.

https://www.gup.ugal.ro/ugaljournals/index.php/food/article/download/2683/2374

Screening of the main nutrients for cell envelope proteinases production by Lactobacillus plantarum LP69 using Plackett-Burman design

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Meng Zhang

Author Tools

Chat about Author

Papers

Effects of Carbon and Nitrogen Sources on Activity of Cell Envelope Proteinase Produced by Lactobacillus plantarum LP69

Effect of prebiotics, inorganic salts and amino acids for cell envelope proteinase production from Lactobacillus plantarum LP69.

Screening of the main nutrients for cell envelope proteinases production by Lactobacillus plantarum LP69 using Plackett-Burman design