scholarly journals Underlying Mechanism of Uncoupled Cell Growth and Ethanol Fermentation of Zymomonas mobilis using Different Nitrogen Sources

2020 ◽  
Author(s):  
Runxia Li ◽  
Mingjie Jin ◽  
Jun Du ◽  
Shouwen Chen ◽  
Shihui Yang
Keyword(s):  
Cell Growth ◽  
Metal Ions ◽  
Ethanol Production ◽  
Yeast Extract ◽  
Stress Responses ◽  
Ethanol Fermentation ◽  
Culture Medium ◽  
Nitrogen Sources ◽  
Glucose Consumption ◽  
Biochemical Production

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.

The influence of the initial concentrations of glucose and yeast extract on the ethanolic fermentation by Pachysolen tannophilus

1990 ◽  
Vol 55 (3) ◽  
pp. 854-866 ◽  
Author(s):  
Rodríguez V. Bravo ◽  
Rubio F. Camacho ◽  
Villasclaras S. Sánchez ◽  
Vico M. Castro
Keyword(s):  
Cell Growth ◽  
Ethanol Production ◽  
Yeast Extract ◽  
Culture Medium ◽  
Ethanolic Fermentation ◽  
Pachysolen Tannophilus ◽  
Significant Component ◽  
Batch Cultures

The ethanolic fermentation in batch cultures of Pachysolen tannophilus was studied experimentally varying the initial concentrations of two of the components in the culture medium: glucose between 0 and 200 g l-1 and yeast extract between 0 and 8 g l-1. The yeast extract appears to be a significant component both in cell growth and for ethanol production.

scholarly journals Experimental Design to Improve Cell Growth and Ethanol Production in Syngas Fermentation by Clostridium carboxidivorans

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 59 ◽  
Author(s):  
Carolina Benevenuti ◽  
Alanna Botelho ◽  
Roberta Ribeiro ◽  
Marcelle Branco ◽  
Adejanildo Pereira ◽  
...  
Keyword(s):  
Cell Growth ◽  
Ethanol Production ◽  
Yeast Extract ◽  
Biomass Gasification ◽  
Culture Collection ◽  
Medium Composition ◽  
Syngas Fermentation ◽  
The Cost ◽  
Clostridium Carboxidivorans ◽  
Peptone Yeast Extract Glucose

Fermentation of gases from biomass gasification, named syngas, is an important alternative process to obtain biofuels. Sequential experimental designs were used to increase cell growth and ethanol production during syngas fermentation by Clostridium carboxidivorans. Based on ATCC (American Type Culture Collection) 2713 medium composition, it was possible to propose a best medium composition for cell growth, herein called TYA (Tryptone-Yeast extract-Arginine) medium and another one for ethanol production herein called TPYGarg (Tryptone-Peptone-Yeast extract-Glucose-Arginine) medium. In comparison to ATCC® 2713 medium, TYA increased cell growth by 77%, reducing 47% in cost and TPYGarg increased ethanol production more than four-times, and the cost was reduced by 31%. In 72 h of syngas fermentation in TPYGarg medium, 1.75-g/L of cells, 2.28 g/L of ethanol, and 0.74 g/L of butanol were achieved, increasing productivity for syngas fermentation.

scholarly journals Evaluation of the process conditions for the production of microbial carotenoids by the recently isolated Rhodotorula mucilaginosa URM 7409

2019 ◽  
Vol 22 ◽  
Author(s):  
Whallans Raphael Couto Machado ◽  
Lucas Gomes da Silva ◽  
Ellen Silva Lago Vanzela ◽  
Vanildo Luiz Del Bianchi
Keyword(s):  
Experimental Design ◽  
Yeast Extract ◽  
Culture Medium ◽  
Nitrogen Sources ◽  
Process Conditions ◽  
Malt Extract ◽  
Rhodotorula Mucilaginosa ◽  
Process Characteristics ◽  
Initial Ph ◽  
Microbial Carotenoids

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.

scholarly journals OPTIMAL CONDITIONS FOR EXOPOLYSACCHARIDE PRODUCTION BY Lactobacillus plantarum T10

2018 ◽  
Vol 54 (4A) ◽  
pp. 40
Author(s):  
Tran Bao Khanh
Keyword(s):  
Lactobacillus Plantarum ◽  
Cell Density ◽  
Yeast Extract ◽  
Culture Medium ◽  
Nitrogen Sources ◽  
Optimal Conditions ◽  
Exopolysaccharide Production ◽  
Initial Cell ◽  
Positive Effects ◽  
Mrs Broth

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.

Understanding and Efficiently Manipulating Environmental Stress Caused by Metal Ions to Improve Ethanol Fermentation

2021 ◽  
Author(s):  
Boontiwa Ninchan ◽  
Chollada Sirisatesuwon ◽  
Kittipong Rattanaporn ◽  
Klanarong Sriroth
Keyword(s):  
Metal Ions ◽  
Ethanol Production ◽  
Ethanol Fermentation ◽  
Production Efficiency ◽  
Sucrose Solution ◽  
Ion Concentration ◽  
Strong Inhibitor ◽  
Ion Removal

The inconsistent quality of molasses directly influences ethanol production, particularly due to contamination by metal ions that causes severe problems and reduces production efficiency. This research focused on calcium (Ca2+), potassium (K+), and magnesium (Mg2+) ions that are common in molasses. The key objective was to understand clearly the effect of ions on ethanol fermentation and Saccharomyces cerevisiae performance. Individual ions and ion mixtures were studied in sucrose solution and in molasses. The results showed that severe stress could be ordered as Ca2+>K+>Mg2+ and the adverse effect was greater when the ion concentration increased. Ca2+ was a strong inhibitor while trace amounts of Mg2+ produced a positive effect. To achieve the greatest efficiency in ethanol production using molasses in the substrate preparation, Ca2+ should not exceed 0.18% (w/w) prior to fermentation and the final sugar concentration should be 20–25% (w/v), as adjusting the addition of sucrose will result in a suitable yeast medium. Pretreatment and dilution were the best practices for ion removal, with Ca2+ being clearly decreased. Furthermore, determination of the composition and ion concentration in molasses are essential initial steps that must be routinely applied to ensure that the knowledge gained and the efficient techniques investigated can both be used to improve ethanol production.

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
Keyword(s):  
Growth Factors ◽  
Yeast Extract ◽  
Culture Medium ◽  
Nitrogen Sources ◽  
Inhibitory Effect ◽  
Vitamin B ◽  
Cellular Activity ◽  
Whey Permeate ◽  
The Media ◽  
Influence Of Ph

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]

scholarly journals Unexpected Link between Metal Ion Deficiency and Autophagy in Aspergillus fumigatus

2007 ◽  
Vol 6 (12) ◽  
pp. 2437-2447 ◽  
Author(s):  
Daryl L. Richie ◽  
Kevin K. Fuller ◽  
Jarrod Fortwendel ◽  
Michael D. Miley ◽  
Jason W. McCarthy ◽  
...  
Keyword(s):  
Metal Ions ◽  
Aspergillus Fumigatus ◽  
Stress Responses ◽  
Metal Ion ◽  
Nitrogen Sources ◽  
Hyphal Growth ◽  
Wild Type ◽  
Serine Threonine Kinase ◽  
Gene Encoding ◽  
Carbon And Nitrogen

ABSTRACT Autophagy is the major cellular pathway for bulk degradation of cytosolic material and is required to maintain viability under starvation conditions. To determine the contribution of autophagy to starvation stress responses in the filamentous fungus Aspergillus fumigatus, we disrupted the A. fumigatus atg1 gene, encoding a serine/threonine kinase required for autophagy. The ΔAfatg1 mutant showed abnormal conidiophore development and reduced conidiation, but the defect could be bypassed by increasing the nitrogen content of the medium. When transferred to starvation medium, wild-type hyphae were able to undergo a limited amount of growth, resulting in radial expansion of the colony. In contrast, the ΔAfatg1 mutant was unable to grow under these conditions. However, supplementation of the medium with metal ions rescued the ability of the ΔAfatg1 mutant to grow in the absence of a carbon or nitrogen source. Depleting the medium of cations by using EDTA was sufficient to induce autophagy in wild-type A. fumigatus, even in the presence of abundant carbon and nitrogen, and the ΔAfatg1 mutant was severely growth impaired under these conditions. These findings establish a role for autophagy in the recycling of internal nitrogen sources to support conidiophore development and suggest that autophagy also contributes to the recycling of essential metal ions to sustain hyphal growth when exogenous nutrients are scarce.

MICROBIOLOGICAL DEGRADATION OF QUERCITRIN

1963 ◽  
Vol 9 (2) ◽  
pp. 211-220 ◽  
Author(s):  
D. W. S. Westlake
Keyword(s):  
Carbon Monoxide ◽  
Carboxylic Acid ◽  
Aspergillus Flavus ◽  
Yeast Extract ◽  
Organic Nitrogen ◽  
Culture Medium ◽  
Alternative Pathway ◽  
Nitrogen Sources ◽  
Maximum Production ◽  
Aspergillus Flavus Group

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.

scholarly journals Design of a culture medium for optimal growth of the bacterium Pseudoxanthomonas indica H32 allowing its production as biopesticide and biofertilizer

AMB Express ◽  
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Dayana Morales-Borrell ◽  
Nemecio González-Fernández ◽  
Néstor Mora-González ◽  
Carlos Pérez-Heredia ◽  
Ana Campal-Espinosa ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Yeast Extract ◽  
Culture Medium ◽  
Nitrogen Sources ◽  
Optimal Growth ◽  
Culture Conditions ◽  
Medium Composition ◽  
Mineral Salts ◽  
Molar Ratios ◽  
Biotechnological Processes

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.

scholarly journals ESTUDO DA FERMENTAÇÃO SUBMERSA NÃO AERADA POR SACCHAROMYCES CEREVISIAE PARA DETERMINAÇÃO DOS PARÂMETROS DE CONSUMO DE GLICOSE E PRODUÇÃO DE GLICEROL E ETANOL

2014 ◽  
Vol 39 (1) ◽  
pp. 91
Author(s):  
Maria Elisa Marciano Martinez ◽  
Patrícia Carvalho dos Reis ◽  
Douglas Alves Santos ◽  
Willibaldo Schmidell Netto
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Growth Factor ◽  
Cell Growth ◽  
Osmotic Stress ◽  
Ethanol Production ◽  
Glucose Consumption ◽  
Glycerol Production ◽  
High Coefficient ◽  
Maximum Production ◽  
Growth Factor Production

A study of non-aerated submerged fermetation by Saccharomyces cerevisiae was carried out evaluating the effect of pH on the coefficients: (I) of Pirt equation; and (II) of Garden model. In the tests performed, increasing the pH slowed glucose comsumption, and, cell growth and ethanol production decreased with increasing pH from 4.5 to 9.0. Specifically, with regard to ethanol, the high coefficient values associated with the growth from the non-associated growth factor production associated indicate growth. However, for maximum production of glycerol there was a decrease in the coefficient values associated with growth and an increase in coefficient values not associated with the growth. Glucose consumption for cellular maintenance was significant (0,2gglucose / ((gcell.h)) to pH 7.0 and 7.5, where there was a greater production of glycerol. In conclusion it was possible to observe the existence of a relationship between the saline and osmotic stress in the metabolism of Saccharomyces cerevisiae by increasing the maintaining glucose consumption, and glycerol production disassociation cell growth, indicating the intra and extracellular glycerol accumulation.

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