scholarly journals Modelling the Biphasic Growth and Product Formation byEnterococcus faeciumCECT 410 in Realkalized Fed-Batch Fermentations in Whey

2010 ◽  
Vol 2010 ◽  
pp. 1-16 ◽  
Author(s):  
Nelson Pérez Guerra ◽  
Paula Fajardo ◽  
Clara Fuciños ◽  
Isabel Rodríguez Amado ◽  
Elisa Alonso ◽  
...  
Keyword(s):  
Logistic Models ◽  
Product Formation ◽  
Monod Model ◽  
Fed Batch ◽  
Acid Fermentation ◽  
Total Sugars ◽  
Batch Cultures ◽  
Mixed Acid ◽  
Initial Ph ◽  
Product Accumulation

The influence of initial pH on growth and nutrient (total sugars, nitrogen, and phosphorous) consumption byEnterococcus faeciumCECT 410 was studied during batch cultures in whey. With these data, two realkalized fed-batch fermentations were developed using different feeding substrates. The shift from homolactic to mixed acid fermentation, the biphasic kinetics observed for cell growth and nitrogen consumption and the increase in the concentrations of biomass and products (lactic acid, acetic acid, ethanol, and butane-2,3-diol) were the most noteworthy observations of these cultures. Modelling the fed-batch growth ofEnt. faeciumwith the Logistic and bi-Logistic models was not satisfactory. However, biomass production was best mathematically described with the use of a double Monod model, which was expressed in terms of biomass, product accumulation, and nitrogen utilization. Product formation was successfully modelled with a modified form of the Luedeking and Piret model developed in this study.

scholarly journals The Joint Effect of pH Gradient and Glucose Feeding on the Growth Kinetics of Lactococcus lactis CECT 539 in Glucose-Limited Fed-Batch Cultures

2019 ◽  
Vol 68 (2) ◽  
pp. 269-280
Author(s):  
MÓNICA COSTAS MALVIDO ◽  
ELISA ALONSO GONZÁLEZ ◽  
RICARDO J. BENDAÑA JÁCOME ◽  
NELSON PÉREZ GUERRA
Keyword(s):  
Lactococcus Lactis ◽  
Viable Cell ◽  
Product Formation ◽  
Ph Gradient ◽  
Feeding Strategies ◽  
Fed Batch ◽  
Batch Cultures ◽  
Cell Counts ◽  
First Time ◽  
Kinetics Of

Two glucose-limited realkalized fed-batch cultures of Lactococcus lactis CECT 539 were carried out in a diluted whey medium (DW) using two different feeding media. The cultures were fed a mixture of a 400 g/l concentrated lactose and a concentrated mussel processing waste (CMPW, 101.72 g glucose/l) medium (fermentation I) or a CMPW medium supplemented with glucose and KH2PO4 up to concentrations of 400 g glucose/l and 3.21 g total phosphorus/l, respectively (fermentation II). For an accurate description and a better understanding of the kinetics of both cultures, the growth and product formation by L. lactis CECT 539 were both modelled, for the first time, as a function of the amounts of glucose (G) added and the pH gradient (VpH) generated in every realkalization and feeding cycle, by using an empirical polynomial model. With this modeling procedure, the kinetics of biomass, viable cell counts, nisin, lactic acid, acetic acid and butane-2,3-diol production in both cultures were successfully described (R2 values > 0.970) and interpreted for the first time. In addition, the optimum VpH and G values for each product were accurately calculated in the two realkalized fed-batch cultures. This approach appears to be useful for designing feeding strategies to enhance the productions of biomass, bacteriocin, and metabolites by the nisin-producing strain in wastes from the food industry.

Creation of Plasmidless and Markerless Escherichia coli Succinate Producing Strain and Evaluation of its Biosynthetic Potential during Utilization of Lignocellulosic Sugars

2020 ◽  
Vol 36 (2) ◽  
pp. 3-11
Author(s):  
O.A. Zhuravliova ◽  
Т.А. Voeikova ◽  
A.Yu. Gulevich ◽  
V.G. Debabov
Keyword(s):  
Escherichia Coli ◽  
Succinic Acid ◽  
Plant Biomass ◽  
Anaerobic Fermentation ◽  
Basic Research ◽  
Acid Fermentation ◽  
Mixed Acid ◽  
Gene Coding ◽  
Lignocellulosic Sugars ◽  
Basic Research Project

The plasmidless and markerless Escherichia coli succinate producing strain SGM2.0Pyc-int has been engineered and characterized. The strain has the inactivated main mixed-acid fermentation pathways due to the deletions of ldhA,poxB, ackA,pta, and adhE genes, constitutively expresses the genes of the aceEF-lpdA operon encoding components of pyravate dehydrogenase complex, and possesses the chromosomally integrated Bacillus subtilis pycA gene coding for pyruvate carboxylase. The capacity of the strain to synthesize succinic acid in course of dual-phase aerobic-anaerobic fermentation with lignocellulosic sugars as substrates was studied. The SGM2.0Pyc-int strain synthesized succinic acid from glucose, xylose, and arabinose with a molar yields of 1.41 mol/mol, 1.18 mol/mol, and 1.18 mol/mol, respectively, during the anaerobic production stage. The constructed strain has great potential for developing efficient processes for the succinic acid production from plant biomass-derived sugars. Escherichia coli, fermentation, arabinose, glucose, xylose, succinic acid. The work was supported by a Grant from the Russian Foundation for Basic Research (Project no. 18-29-14005).

Using Alternating Tangential Flow with Fed-Batch Cultures

2019 ◽  
Vol 39 (10) ◽  
pp. 54-56
Author(s):  
Shashi Kudugunti ◽  
Daniel Diggins ◽  
Jyoti Amatya ◽  
Jamie Peyser
Keyword(s):  
Fed Batch ◽  
Batch Cultures ◽  
Tangential Flow

scholarly journals Metabolic Profiling of Xylooligosaccharides by Lactobacilli

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2387
Author(s):  
Ilia Iliev ◽  
Tonka Vasileva ◽  
Veselin Bivolarski ◽  
Albena Momchilova ◽  
Iskra Ivanova
Keyword(s):  
Plasma Membranes ◽  
Meat Products ◽  
Lactobacillus Brevis ◽  
Degree Of Polymerization ◽  
Acid Fermentation ◽  
Carbohydrate Utilization ◽  
Beneficial Effects ◽  
Mixed Acid ◽  
Rat Liver Plasma Membranes ◽  
Different Types

Three lactic acid bacteria (LAB) strains identified as Lactobacillus plantarum, Lactobacillus brevis, and Lactobacillus sakei isolated from meat products were tested for their ability to utilize and grow on xylooligosaccharides (XOSs). The extent of carbohydrate utilization by the studied strains was analyzed by HPLC. All three strains showed preferences for the degree of polymerization (DP). The added oligosaccharides induced the LAB to form end-products of typical mixed-acid fermentation. The utilization of XOSs by the microorganisms requires the action of three important enzymes: β-xylosidase (EC 3.2.1.37) exo-oligoxylanase (EC 3.2.1.156) and α-L-arabinofuranosidase (EC 3.2.1.55). The presence of intracellular β-D-xylosidase in Lb. brevis, Lb. plantarum, and Lb. sakei suggest that XOSs might be the first imported into the cell by oligosaccharide transporters, followed by their degradation to xylose. The studies on the influence of XOS intake on the lipids of rat liver plasma membranes showed that oligosaccharides display various beneficial effects for the host organism, which are probably specific for each type of prebiotic used. The utilization of different types of oligosaccharides may help to explain the ability of Lactobacillus strains to compete with other bacteria in the ecosystem of the human gastrointestinal tract.

scholarly journals A novel process-based model of microbial growth: self-inhibition in Saccharomyces cerevisiae aerobic fed-batch cultures

2015 ◽  
Vol 14 (1) ◽  
Author(s):  
Stefano Mazzoleni ◽  
Carmine Landi ◽  
Fabrizio Cartenì ◽  
Elisabetta de Alteriis ◽  
Francesco Giannino ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Microbial Growth ◽  
Fed Batch ◽  
Batch Cultures

Ethanol production by anaerobic thermophilic bacteria: Kinetics in fed-batch cultures ofClostridium thermohydrosulfuricum

1989 ◽  
Vol 11 (6) ◽  
pp. 443-448 ◽  
Author(s):  
Fatiou Toukourou ◽  
Luiz Donaduzzi ◽  
Andr� Miclo ◽  
Pierre Germain
Keyword(s):  
Ethanol Production ◽  
Thermophilic Bacteria ◽  
Fed Batch ◽  
Batch Cultures

SUBMERGED CITRIC ACID FERMENTATION OF SUGAR BEET MOLASSES: INCREASE IN SCALE

1955 ◽  
Vol 1 (5) ◽  
pp. 299-311 ◽  
Author(s):  
R. Steel ◽  
C. P. Lentz ◽  
S. M. Martin
Keyword(s):  
Citric Acid ◽  
Scale Up ◽  
Aeration Rate ◽  
Small Scale ◽  
Acid Fermentation ◽  
Inoculum Level ◽  
Cross Sectional ◽  
Factors Affecting ◽  
Beet Molasses ◽  
Initial Ph

Factors affecting the production of citric acid in the submerged fermentation of ferrocyanide-treated beet molasses by Aspergillus niger were studied in 2.5 and 36 liter fermenters. The small fermenters were used to determine the effects of changes in sterilization technique, phosphate supplement, ferrocyanide treatment, inoculum level, initial pH, fermentation temperature, and aeration rate. The relation between ferrocyanide concentration and inoculum level was also studied. Four different samples of molasses were fermented successfully. An average yield of 8.2% citric acid (64% conversion) was obtained from 51 small-scale fermentations. Comparable yields were obtained in the large fermenters under comparable conditions. Most of the information obtained with the small fermenters was applicable to the larger-scale fermenters, but in the latter the fermentation was significantly more stable. Aeration was the main problem in the scale-up and aeration rates approximately double those calculated on a fermenter cross-sectional area basis were required for comparable results in the large fermenters.

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