Croissance et activité cellulaire du Brevibacterium casei NCDO 2049 dans du perméat de lactosérum

1997 ◽  
Vol 43 (12) ◽  
pp. 1180-1188
Author(s):  
K. M. Oulé ◽  
G. Turcotte ◽  
Y. Beaulieu

Growth and cellular activity of Brevibacterium casei NCDO 2049 were studied in a whey permeate as basic culture medium. The possible inhibitory effect of the carbone substrate (undiluted or diluted permeate) on growth was investigated as well as the influence of pH of the media (controlled or not) and of the addition of nitrogen sources (organic or inorganic) or growth factors such as yeast extract or vitamin B12. Growth in undiluted permeate produced a maximal biomass (6.5 × 109 cfu/mL) that was nearly twice as much as that in diluted permeate (3.8 × 109 cfu/mL). The carbone substrate (lactose) had no inhibitory effect on growth. In undiluted permeate and an uncontrolled pH, maximal biomass was reached after 36 h of incubation, while in a pH controlled medium, twice as much time was required to obtain an equivalent biomass. In undiluted permeate and an uncontrolled pH, growth in the presence of peptone reached 22.6 × 109 cfu/mL and, in the presence of (NH4)2SO4, 12.4 × 109 cfu/mL. Adding growth factors to media with peptone resulted in the reduction of 90% of initial lactose in the presence of yeast extract and of 75% in the presence of B12 vitamin. This study indicates the possibility of reducing lactose in whey permeate when cultivating strains of the genus Brevibacterium used as maturing bacteria for certain cheese types.Key words: whey permeate, Brevibacterium casei, lactose.[Journal translation]

Author(s):  
Whallans Raphael Couto Machado ◽  
Lucas Gomes da Silva ◽  
Ellen Silva Lago Vanzela ◽  
Vanildo Luiz Del Bianchi

Abstract This study aimed to improve the physical and nutritional process conditions for the production of carotenoids by the newly isolated Rhodotorula mucilaginosa, a red basidiomycete yeast. The carotenoid bioproduction was improved using an experimental design technique, changing the process characteristics of agitation (130 rpm to 230 rpm) and temperature (25 °C to 35 °C) using seven experiments, followed by a 25-1 fractional design to determine the relevant factors that constitute the culture medium (glucose, malt extract, yeast extract, peptone and initial pH). A complete second order experimental design was then carried out to optimize the composition of the culture medium, the variables being yeast extract (0.5 to 3.5 g/L), peptone (1 to 5 g/L) and the initial pH (5.5 to 7.5), with 17 experiments. The maximum carotenoid production was 4164.45 μg/L (252.99 μg/g), obtained in 144 h in YM (yeast malt) medium with 30 g/L glucose, 10 g/L malt extract, 2 g/L yeast extract, 3 g/L peptone, an initial pH 6, 130 rpm and 25 °C, demonstrating the potential of this yeast as a source of bio-pigments. In this work, the nitrogen sources were the factors that most influenced the intracellular accumulation of carotenoids. The yeast R. mucilaginosa presented high production at a bench level and may be promising for commercial production.


2001 ◽  
Vol 67 (8) ◽  
pp. 3767-3770 ◽  
Author(s):  
Robert J. Watson ◽  
Roselyn Heys ◽  
Teresa Martin ◽  
Marc Savard

ABSTRACT Sinorhizobium meliloti is usually cultured in rich media containing yeast extract. It has been suggested that some components of yeast extract are also required for growth in minimal medium. We tested 27 strains of this bacterium and found that none were able to grow in minimal medium when methods to limit carryover of yeast extract were used during inoculation. By fractionation of yeast extract, two required growth factors were identified. Biotin was found to be absolutely required for growth, whereas previously the need for this vitamin was considered to be strain specific. All strains also required supplementation with cobalt or methionine, consistent with the requirement for a vitamin B12-dependent homocysteine methyltransferase for methionine biosynthesis.


2018 ◽  
Vol 54 (4A) ◽  
pp. 40
Author(s):  
Tran Bao Khanh

Exopolysaccharide (EPS) production ability of Lactobacillus plantarumT10 was studied. The supplement of some sugars (lactose, saccharose, and glucose) gave the positive effects on EPS production of L. plantarum T10, in which the addition of lactose 4 % resulted in the most efficiency for EPS yield (274.83 μg/mL). The addition of 0.4 % of yeast extract into culture medium with 4 % lactose provided the highest EPS yields compared to other nitrogen sources (peptone, beef extract), which were 378.32 mg/mL. The optimal conditions for EPS production of L. plantarum T10 in MRS broth with 4 % of lactose and 0.4 % yeast extract supplement were also studied. The results indicated that the highest EPS yield (417.11 mg/L) was obtained in the conditions of 106 CFU/ml initial cell density, temperature of 35 oC, pH 5.5 and 48 h incubation.


1995 ◽  
Vol 41 (7) ◽  
pp. 633-636 ◽  
Author(s):  
Stephen C. Wagner ◽  
Horace D. Skipper ◽  
Peter G. Hartel

Literature on the utilization of C sources by cowpea Bradyrhizobium strains is difficult to interpret because the media employed often contained other sources of C in addition to the C source being tested. In addition, culture incubation periods varied widely. We modified a complex medium to contain a minimal amount of yeast extract (10 mg/L); the yeast extract provided adequate growth factors but was inadequate as a C source. Eight cowpea bradyrhizobia strains were inoculated into this modified medium containing 1 of 16 different C sources for incubation periods of 7, 10, and 14 days at 28 °C. After 14 days of incubation, most of the strains grew with six hexoses (fructose, galacturonic acid, gluconate, glucose, mannitol, and rhamnose), two pentoses (arabinose and xylose), and four other compounds (malate, γ-aminobutyric acid, glutamate, and yeast extract) as C sources; no strains were able to grow on two disaccharides (lactose and trehalose) and two other C sources (citrate and nicotinic acid). Large differences in growth were observed for fructose, γ-aminobutyric acid, malate, mannitol, and rhamnose between 7 and 14 days incubation. Because of the possibility of false negatives, our data suggest that the strains should be grown in a medium low in yeast extract over a long instead of a short incubation time.Key words: bradyrhizobia, metabolism, C source, growth.


1963 ◽  
Vol 9 (2) ◽  
pp. 211-220 ◽  
Author(s):  
D. W. S. Westlake

A number of molds and bacteria were screened for their ability to degrade quercitrin. The molds, but not the bacteria, were particularly active and produced carbon monoxide. The degradation of quercitrin is dependent upon the synthesis of an inducible glycosidase (quercitrinase). This enzyme is synthesized by only a few members of the Aspergillus flavus group. Two of these strains synthesized quercitrinase and excreted it and other enzymes into the culture medium. Maximum production of quercitrinase was obtained with organic nitrogen sources such as yeast extract or phytone. Quercitrinase is induced by readily metabolized flavonols and flavonol-glycosides. The glycosidase is quite specific, liberating the rhamnose from the 3-position of quercitrin and myricitrin and the 7-position of robinin. The aglycone, quercetin, is subsequently metabolized to carbon monoxide and the depside of phloroglucinol-carboxylic acid and proto-catechuic acid. Evidence is also presented for an alternative pathway for the metabolism of the flavonol nucleus.


AMB Express ◽  
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Dayana Morales-Borrell ◽  
Nemecio González-Fernández ◽  
Néstor Mora-González ◽  
Carlos Pérez-Heredia ◽  
Ana Campal-Espinosa ◽  
...  

Abstract Culture medium composition is one of the most important parameters to analyze in biotechnological processes with industrial purposes. The aim of this study was to design of a culture medium for optimal growth of the bacterium Pseudoxanthomonas indica H32 allowing its production as biopesticide and biofertilizer. The influence of several carbon and nitrogen sources and their molar ratios on P. indica H32 growth was investigated. The effect of different micronutrients such as mineral salts and vitamin on P. indica H32 growth was determined as well. A mixture design based on Design-Expert 10.0 Software was performed to optimize the culture medium concentration. Finally, in the designed medium, an attribute of the biological mechanism of action of the P. indica H32 against nematodes, was evaluated: the hydrogen sulfide production. It was found that tested carbon/nitrogen ratios were not a significant influence on P. indica H32 growth. Growth of P. indica H32 was favored with use of sucrose, yeast extract and phosphate buffer without the addition of any tested micronutrients. An optimal concentration of 10 g/L sucrose and 5 g/L yeast extract were obtained at a cost of 0.10 $/L. In this concentration, the specific growth rate (µ) and maximal optical density (Xmax) were equal to 0.439 h− 1 and 8.00 respectively. It was evidenced that under the culture conditions used, P. indica H32 produced hydrogen sulfide. The designed medium led to a 1.08 $/L reduction of costs in comparison to LB medium. These results were critical to carry on with biotechnological development of P. indica H32 as a bioproduct.


2020 ◽  
Author(s):  
Runxia Li ◽  
Mingjie Jin ◽  
Jun Du ◽  
Shouwen Chen ◽  
Shihui Yang

Abstract Background: Microbial growth needs C, N, P, S as well as metal ions such as magnesium, which is a major cofactor for enzymes involved in various metabolic activities. Yeast extract is widely used as nitrogen supply as well as vitamins and growth factors to sustain microbial growth in the culture medium. Zymomonas mobilis is a model ethanologenic bacterium for ethanol production, and has been developing as a chassis for diverse biochemical production. Although yeast extract is routinely used to prepare rich medium (RM) for Z. mobilis, the glucose consumption and ethanol production of Z. mobilis in RM were not coupled with cell growth in some studies. Results: In this study, the effects of different nitrogen sources as well as the supplementation of additional nitrogen source into RM and minimum medium (MM) on cell growth and ethanol fermentation of Z. mobilis were investigated to understand the uncoupled cell growth and ethanol fermentation for efficient carbon utilization and optimal ethanol productivity of Z. mobilis. Our results indicated that nitrogen sources such as yeast extract from different companies affected cell growth, glucose utilization, and the corresponding ethanol production. We also quantified the concentrations of major ion elements in different organic nitrogen sources using the quantitative analytic approach of Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), and demonstrated that metal ions such as magnesium in the media affected glucose consumption, cell growth, and ethanol fermentation. The effect of magnesium on gene expression was further investigated using RNA-Seq transcriptomics, and our result indicated that the lack of Mg2+ triggered stress responses while decreasing energy-consuming metabolism. Conclusions: Our work demonstrated that concentrations of metal ions such as magnesium and molybdenum in nitrogen sources are essential for vigorous cell growth, and the difference of Mg2+concentration in different yeast extract was one of the major factors affecting the coupling of cell growth and ethanol fermentation in Z. mobilis. We also revealed that genes responsive for Mg2+ deficiency in the medium were majorly related to stress responses and energy conservation. The importance of metal ions on cell growth and ethanol fermentation suggested that metal ions should become one of the parameters for monitoring the quality of commercial nitrogen sources and optimizing microbial culture medium for economic biochemical production.


2000 ◽  
Vol 46 (11) ◽  
pp. 1046-1050 ◽  
Author(s):  
M Guadalupe Aguilar Uscanga ◽  
Marie-Line Delia ◽  
Pierre Strehaiano

The nutritional requirements of Brettanomyces bruxellensis have been investigated. Batch culture and chemostat pulse techniques were used to identify growth-limiting nutrients. The study included determination of the essential components of the culture medium and quantification of the effects of the components. Among the components tested, ammonium sulfate and yeast extract had a significant effect on glucose consumption, growth, and ethanol production. However, if the ammonium sulfate concentration is above 2 g/L, an inhibitory effect on B. bruxellensis growth is observed. The yeast extract appears to be the most important and significant component for growth. The maximum amount of synthesized biomass is proportional to the concentration of yeast extract added to the culture broth (in the tested range). Magnesium and phosphate ions are probably not essential for B. bruxellensis. These ions appear to be supplied in sufficient amounts by the yeast extract in the culture medium. Brettanomyces bruxellensis appears to have very low nutritional requirements for growth.Key words: Brettanomyces bruxellensis, nutrition, ammonium sulfate, yeast extract.


2018 ◽  
Author(s):  
Manuela Urbischek ◽  
Helena Rannickmae ◽  
Thomas Foets ◽  
Katharina Ravn ◽  
Marko Hyvönen ◽  
...  

AbstractThe media components necessary for deriving and sustaining organoids from a number of epithelial tissues such as prostate, colon, gastric, liver, pancreas, and others have been established (1). Critical components of organoid media formulations are a set of growth factors that include EGF, R-spondins and BMP signalling antagonists such as Noggin or Gremlin. The practical limitation to organoid culture and the development of new applications for the technology is the use of defined cellular activities of growth factors in media formulations, in particular Noggin/Gremlin 1 and R-spondin 1. Here we report the production of highly pure recombinant Gremlin 1 and R-spondin 1 from bacterial expression and their use for culturing organoids. We detail the workflow for their purification, determination of cellular activity, quality control and their formulation in organoid media. The protocols we provide for generation of precisely formulated, cost-effective, organoid media of defined cellular activity will enable broader access to organoid technology and engender the development of novel applications.


1971 ◽  
Vol 24 ◽  
Author(s):  
W. H. Verstraete

Some  factors affecting the L-asparaginase activity of E.  aroideae were investigated. Increasing  concentrations of glucose in the culture medium had an inhibiting effect on  the production of L-asparaginase by this microorganism. Buffering of the  culture medium in order to stabilize the pH during growth resulted in a decrease  of the L-asparaginase activity. From the different nitrogen sources examined,  tryptone, proteose peptone nr 2 and nr 3 stimulated the L-asparaginase  production. Toluene treatment of the cells practically destroyed the  L-asparaginase. Acetone dried cells showed an L-asparaginase activity  comparable with the activity of living cells.


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