scholarly journals OPTIMAL CONDITIONS FOR EXOPOLYSACCHARIDE PRODUCTION BY Lactobacillus plantarum T10

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.

2016 ◽  
Author(s):  
Wenfa Ng ◽  
Yen-Peng Ting

Microbes for environmental research should be cultured in growth media with characteristics (e.g., pH, ionic strength, and organic and ionic composition) as close to their original habitat as possible. Additionally, the medium should also enable high cell density to be obtained - needed for providing sufficient cells in subsequent experiments. This in-progress report describes the formulation of a medium with an environmentally-relevant composition (lack of complex organics), and that allows aerobic high cell density cultivation of Escherichia coli DH5α in shake flasks. The formulated medium comprises four components: a buffer system (K2HPO4: 12.54 g/L and KH2PO4: 2.31 g/L), vitamins (yeast extract: 12.0 g/L), salts (NaCl: 5.0 g/L and MgSO4: 0.24 g/L), and carbon and nitrogen sources (D-Glucose: 6.0 g/L and NH4Cl: 1.5 g/L). Notable characteristics of this medium were: high capacity phosphate buffer system (89 mM phosphate); 1:1 molar ratio between D-Glucose and NH4Cl; and yeast extract providing trace elements and a secondary carbon and nitrogen source. Growth experiments revealed that an OD600nm of 9 was attained after 24 hours of cultivation at 37 oC. Glucose and NH4Cl serve as primary carbon and nitrogen sources for this phase of growth. After 48 hours, the OD600nm reached 11, where carbohydrates, lipids and proteins in yeast extract provided the nutrients for biomass formation. Broth’s pH varied between 5.5 and 7.8 during cultivation, which was in the range conducive for E. coli growth. In comparison, the OD600nm of E. coli reached 1.4, 3.2, and 9.2 in three commonly used complex media; Nutrient Broth, LB Lennox, and Tryptic Soy Broth, respectively, over 48 hours under identical culture conditions. In addition, the formulated medium was able to maintain a large viable cell population for a longer period of time (three days) compared to Tryptic Soy Broth. Thus, preliminary data suggested that the formulated medium holds potential for use as a high cell density aerobic growth medium for Gram-negative bacteria.


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.


2018 ◽  
Vol 127 (1D) ◽  
pp. 13
Author(s):  
Trần Thị Ái Luyến ◽  
Đỗ Thị Bích Thủy ◽  
Trần Thị Văn Thi ◽  
Phan Thị Thu Huyền

<p><strong>Abstract: </strong>The effects of carbohydrate sources in various concentration (2%, 3%, 4%, 5%, 6%) and fermentation conditions (such as initial cell density, temperature, pH and incubation time) on EPS synthesis of <em>Lactobacillus fermentum </em>MC3 were also studied. The results showed that adding different sugars (including glucose, lactose and sucrose) to culture medium significantly increased the EPS production. In comparison with other concentrations, EPS amounts were maximized in the medium supplemented with 4% (w/v) of sugars. The outcome was the highest for glucose, which was 178.207 mg/L, the obtained figures for lactose and for sucrose were 148.614 mg/L and 152.272 mg/L respectively. The results indicated that EPS production by <em>L. fermentum </em>MC3 reached the maximum values in the medium supplemented with 4% (w/v) glucose at 40<sup>0</sup>C, pH 6.0, initial cell density of 10<sup>6</sup>CFU/ml for 48 h cultivation with amount of 200.728 mg/L. By methylation analysis and gas–liquid chromatography–mass spectrometry (GLC–MS), the exopolysaccharide was found to be composed of D-mannose: D-glucose: D-galactose in a molar ratio of 1 : 0.74 : 0.09.</p>


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]


Biology ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 171
Author(s):  
Jianming Zhang ◽  
Yushan Bu ◽  
Chengcheng Zhang ◽  
Huaxi Yi ◽  
Daqun Liu ◽  
...  

At present, De Man, Rogosa and Sharpe (MRS) broth is the medium of choice for promoting bacteriocin production. However, this medium is expensive and not applicable for large-scale production. Therefore, a low-cost and high-efficiency culture medium for bacteriocin Lac-B23 production by Lactobacillus plantarum J23 was developed. First, the effects of the composition of MRS broth on bacteriocin Lac-B23 production and bacterial growth were researched by a one variable at a time approach. Then, a Plackett-Burman design was used to screen significant components for production. Finally, the steepest ascent and central composite designs were used to obtain an optimum medium. The final composition of the modified MRS was much simpler than MRS broth, and the modified MRS contained only glucose, yeast extract, dipotassium phosphate, manganese sulfate monohydrate, Tween 80 and sodium acetate anhydrous. The highest bacteriocin Lac-B23 production reached 2560 activity units (AU)/mL in the modified MRS, which is nine times higher than that in MRS broth (280 AU/mL). Meanwhile, the cost per liter of the modified MRS (8.56 Ren Min Bi (RMB)/L) is 34.70% the cost of MRS broth (13.11 RMB/L), and the cost per arbitrary units of bacteriocin Lac-B23 in the modified MRS is approximately fourteen times more convenient (3.34 RMB/106 AU) than in the MRS broth (46.82 RMB/106 AU).


2017 ◽  
Author(s):  
Wenfa Ng ◽  
Yen-Peng Ting

Microbes for environmental research should be cultured in growth media with characteristics (e.g., pH, ionic strength, and ionic composition) as close to their original habitat as possible. Additionally, the medium should also enable high cell density to be obtained, which is needed for providing sufficient cells in subsequent experiments. This in-progress report describes the formulation of a medium with an environmentally relevant composition (i.e., lack of complex organics), and that allows aerobic high cell density cultivation of Escherichia coli DH5α (ATCC 53868) in shake flasks. The formulated medium comprises four components: a buffer system (K2HPO4: 12.54 g/L and KH2PO4: 2.31 g/L), vitamins (yeast extract: 12.0 g/L), salts (NaCl: 5.0 g/L and MgSO4: 0.24 g/L), and carbon and nitrogen sources (D-Glucose: 6.0 g/L and NH4Cl: 1.5 g/L). Notable characteristics of this medium were: high capacity phosphate buffer system (89 mM phosphate); 1:1 molar ratio between D-Glucose and NH4Cl; and yeast extract providing trace elements and a secondary carbon and nitrogen source. Growth experiments revealed that an OD600nm of 9 was obtained after 24 hours of cultivation at 37 oC. Glucose and NH4Cl served as primary carbon and nitrogen sources for this growth phase. After 48 hours, the OD600nm reached 11, where carbohydrates, lipids and proteins in yeast extract provided the nutrients for biomass formation. Broth’s pH varied between 5.5 and 7.8 during cultivation, which is conducive for E. coli growth. In comparison, the OD600nm of E. coli reached 1.4, 3.2, and 9.2 in three commonly used complex media; Nutrient Broth, LB Lennox, and Tryptic Soy Broth, respectively, over 48 hours under identical culture conditions. In addition, the formulated medium was able to maintain a large viable cell population for a longer period of time (three days) compared to Tryptic Soy Broth. Thus, preliminary data suggested that the formulated medium holds potential for use as a high cell density aerobic growth medium for Gram-negative bacteria.


2019 ◽  
Vol 8 (3) ◽  
Author(s):  
Donatus Tia Harfan ◽  
Diah Wulandari Rousdy ◽  
Rikhsan Kurniatuhadi

Jelantah is the residual waste of cooking oil. The disposal of untreated waste directly into the environment has the potential to promote damage such as water channels clogging and water body pollution. Form of waste treatment such as biodegradation can be done using potential bacteria such as Pseudomonas spp. which has been known for being effectively in decomposing organic waste. This study aimed to observe the ability of Pseudomonas sp. BOT4 in degrading jelantah with different nitrogen sources i.e. NaNO3 and yeast extract. This study was carried out from August to October 2018. The used cooking oil samples were homemade with deep frying method and the isolate samples were collected from used cooking oil-contaminated sewer water. Split plot design was used with time of incubation as main plots and nitrogen sources as subplots. The parameters observed were cell density and degraded oil weight. The results obtained stated that nitrogen sources of NaNO3 and yeast extract given optimum effect on cell density of Pseudomonas sp. BOT4 on day three each with OD600 value of 1,361 and 2,300. Nevertheless both nitrogen sources did not really give real effect on final weight of degraded oil, each with weight of 1,28 g dan 1,09 g.


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.


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