scholarly journals Kinetics and Metabolism of Bifidobacterium adolescentis MB 239 Growing on Glucose, Galactose, Lactose, and Galactooligosaccharides

2007 ◽  
Vol 73 (11) ◽  
pp. 3637-3644 ◽  
Author(s):  
Alberto Amaretti ◽  
Tatiana Bernardi ◽  
Elena Tamburini ◽  
Simona Zanoni ◽  
Mariella Lomma ◽  
...  
Keyword(s):  
Growth Rate ◽  
Recursive Algorithm ◽  
Carbon Fluxes ◽  
Degree Of Polymerization ◽  
Substrate Selectivity ◽  
Carbon Distribution ◽  
Bifidobacterium Adolescentis ◽  
Fermentation Products ◽  
Batch Cultures ◽  
Ethanol Yields

ABSTRACT The kinetics and the metabolism of Bifidobacterium adolescentis MB 239 growing on galactooligosaccharides (GOS), lactose, galactose, and glucose were investigated. An unstructured unsegregated model for growth in batch cultures was developed, and kinetic parameters were calculated with a recursive algorithm. The growth rate and cellular yield were highest on galactose, followed by lactose and GOS, and were lowest on glucose. Lactate, acetate, and ethanol yields allowed the calculation of carbon fluxes toward fermentation products. Distributions between two- and three-carbon products were similar on all the carbohydrates (55 and 45%, respectively), but ethanol yields were different on glucose, GOS, lactose, and galactose, in decreasing order of production. Based on the stoichiometry of the fructose-6-phosphate shunt and on the carbon distribution among the products, the ATP yield was calculated. The highest yield was obtained on galactose, while the yields were 5, 8, and 25% lower on lactose, GOS, and glucose, respectively. Therefore, a correspondence among ethanol production, low ATP yields, and low biomass production was established, demonstrating that carbohydrate preferences may result from different distributions of carbon fluxes through the fermentative pathway. During the fermentation of a GOS mixture, substrate selectivity based on the degree of polymerization was exhibited, since lactose and the trisaccharide were the first to be consumed, while a delay was observed until longer oligosaccharides were utilized. Throughout the growth on both lactose and GOS, galactose accumulated in the cultural broth, suggesting that β(1-4) galactosides can be hydrolyzed before they are taken up.

scholarly journals Regulation of Major Cellulosomal Endoglucanases of Clostridium thermocellum Differs from That of a Prominent Cellulosomal Xylanase

2005 ◽  
Vol 187 (7) ◽  
pp. 2261-2266 ◽  
Author(s):  
Tali W. Dror ◽  
Adi Rolider ◽  
Edward A. Bayer ◽  
Raphael Lamed ◽  
Yuval Shoham
Keyword(s):  
Growth Rate ◽  
Clostridium Thermocellum ◽  
Transcript Level ◽  
Clear Correlation ◽  
Transcript Levels ◽  
Batch Cultures ◽  
Processive Endoglucanase ◽  
The Family ◽  
Genes Encoding ◽  
Family 10 Xylanase

ABSTRACT The expression of scaffoldin-anchoring genes and one of the major processive endoglucanases (CelS) from the cellulosome of Clostridium thermocellum has been shown to be dependent on the growth rate. For the present work, we studied the gene regulation of selected cellulosomal endoglucanases and a major xylanase in order to examine the previously observed substrate-linked alterations in cellulosome composition. For this purpose, the transcript levels of genes encoding endoglucanases CelB, CelG, and CelD and the family 10 xylanase XynC were determined in batch cultures, grown on either cellobiose or cellulose, and in carbon-limited continuous cultures at different dilution rates. Under all conditions tested, the transcript levels of celB and celG were at least 10-fold higher than that of celD. Like the major processive endoglucanase CelS, the transcript levels of these endoglucanase genes were also dependent on the growth rate. Thus, at a rate of 0.04 h−1, the levels of celB, celG, and celD were threefold higher than those obtained in cultures grown at maximal rates (0.35 h−1) on cellobiose. In contrast, no clear correlation was observed between the transcript level of xynC and the growth rate—the levels remained relatively high, fluctuating between 30 and 50 transcripts per cell. The results suggest that the regulation of C. thermocellum endoglucanases is similar to that of the processive endoglucanase celS but differs from that of a major cellulosomal xylanase in that expression of the latter enzyme is independent of the growth rate.

Influence of specific growth rate over the secretory expression of recombinant potato carboxypeptidase inhibitor in fed-batch cultures of Escherichia coli

2010 ◽  
Vol 45 (8) ◽  
pp. 1334-1341 ◽  
Author(s):  
Juan-Miguel Puertas ◽  
Jordi Ruiz ◽  
Mónica Rodríguez de la Vega ◽  
Julia Lorenzo ◽  
Glòria Caminal ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Specific Growth Rate ◽  
Specific Growth ◽  
Fed Batch ◽  
Secretory Expression ◽  
Batch Cultures ◽  
Carboxypeptidase Inhibitor

scholarly journals Homeostatic Adjustment and Metabolic Remodeling in Glucose-limited Yeast Cultures

2005 ◽  
Vol 16 (5) ◽  
pp. 2503-2517 ◽  
Author(s):  
Matthew J. Brauer ◽  
Alok J. Saldanha ◽  
Kara Dolinski ◽  
David Botstein
Keyword(s):  
Gene Expression ◽  
Growth Rate ◽  
Steady State ◽  
Stress Response ◽  
The State ◽  
Second Phase ◽  
Diauxic Shift ◽  
Batch Cultures ◽  
Chemostat Cultures ◽  
Metabolic Remodeling

We studied the physiological response to glucose limitation in batch and steady-state (chemostat) cultures of Saccharomyces cerevisiae by following global patterns of gene expression. Glucose-limited batch cultures of yeast go through two sequential exponential growth phases, beginning with a largely fermentative phase, followed by an essentially completely aerobic use of residual glucose and evolved ethanol. Judging from the patterns of gene expression, the state of the cells growing at steady state in glucose-limited chemostats corresponds most closely with the state of cells in batch cultures just before they undergo this “diauxic shift.” Essentially the same pattern was found between chemostats having a fivefold difference in steady-state growth rate (the lower rate approximating that of the second phase respiratory growth rate in batch cultures). Although in both cases the cells in the chemostat consumed most of the glucose, in neither case did they seem to be metabolizing it primarily through respiration. Although there was some indication of a modest oxidative stress response, the chemostat cultures did not exhibit the massive environmental stress response associated with starvation that also is observed, at least in part, during the diauxic shift in batch cultures. We conclude that despite the theoretical possibility of a switch to fully aerobic metabolism of glucose in the chemostat under conditions of glucose scarcity, homeostatic mechanisms are able to carry out metabolic adjustment as if fermentation of the glucose is the preferred option until the glucose is entirely depleted. These results suggest that some aspect of actual starvation, possibly a component of the stress response, may be required for triggering the metabolic remodeling associated with the diauxic shift.

Vitamin B12 and Marine Ecology. IV. The Kinetics of Uptake, Growth and Inhibition in Monochrysis Lutheri

1968 ◽  
Vol 48 (3) ◽  
pp. 689-733 ◽  
Author(s):  
M. R. Droop
Keyword(s):  
Growth Rate ◽  
Substrate Concentration ◽  
Specific Growth ◽  
Marine Ecology ◽  
Vitamin B ◽  
Batch Cultures ◽  
Washed Cell ◽  
Cell Quota ◽  
Kinetics Of Uptake ◽  
Kinetics Of

57Co-labelled vitamin B12 was used to study the kinetics of vitamin B12 limitation in Monochrysis lutheri in continuous and exponentially growing batch cultures and in washed cell suspensions.Specific growth rate in the chemostats was found not to depend directly on medium substrate concentration but on the concentration within the cells (cell quota), obeying a hyperbolic equation of the form

scholarly journals Fermentation of Dairy-Relevant Sugars by Saccharomyces, Kluyveromyces, and Brettanomyces: An Exploratory Study with Implications for the Utilization of Acid Whey, Part I

Fermentation ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 266
Author(s):  
Viviana K. Rivera Flores ◽  
Timothy A. DeMarsh ◽  
Patrick A. Gibney ◽  
Samuel D. Alcaine
Keyword(s):  
Value Added ◽  
Yeast Nitrogen Base ◽  
Sugar Consumption ◽  
Linear Modeling ◽  
Nitrogen Base ◽  
Fermentation Products ◽  
Significant Difference ◽  
Ethanol Yields ◽  
Acid Whey ◽  
Future Work

Acid whey from Greek-style yogurt (YAW) is an underutilized byproduct and a challenge for the dairy industry. One alternative is the fermentation of YAW by yeasts such as Saccharomyces, Brettanomyces, and Kluyveromyces spp., to produce new styles of fermented beverages. Previous research in our group suggested that the sugar profiles of the dairy coproducts impacted the fermentation profiles produced by B. claussenii. The present work aims to describe the fermentation of dairy sugars by S. cerevisiae, K. marxianus, and B. claussenii, under conditions comparable to those of YAW. For this purpose, four preparations of yeast nitrogen base, each containing 40 g/L of either lactose (LAC), glucose (GLU), galactose (GAL), or a 1:1 mixture of glucose and galactose (GLU:GAL), all at pH 4.20, were used as fermentation media. The fermentation was performed independently by each organism at 25 °C under anoxic conditions, while density, pH, cell count, ethanol, and organic acids were monitored. Non-linear modeling was used to characterize density curves, and Analysis of Variance and Tukey’s Honest Significant Difference tests were used to compare fermentation products. K. marxianus and S. cerevisiae displayed rapid sugar consumption with consistent ethanol yields in all media, as opposed to B. claussenii, which showed more variable results. The latter organism exhibited what appears to be a selective glucose fermentation in GLU:GAL, which will be explored in the future. These results provide a deeper understanding of dairy sugar utilization by relevant yeasts, allowing for future work to optimize fermentations to improve value-added beverage and ingredient production from YAW.

scholarly journals Characterization of a Novel β-Galactosidase fromBifidobacterium adolescentis DSM 20083 Active towards Transgalactooligosaccharides

2000 ◽  
Vol 66 (4) ◽  
pp. 1379-1384 ◽  
Author(s):  
Katrien M. J. Van Laere ◽  
Tjakko Abee ◽  
Henk A. Schols ◽  
Gerrit Beldman ◽  
Alphons G. J. Voragen
Keyword(s):  
Size Exclusion Chromatography ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Cell Extract ◽  
Degree Of Polymerization ◽  
Exchange Chromatography ◽  
Size Exclusion ◽  
Bifidobacterium Adolescentis ◽  
Exclusion Chromatography

ABSTRACT This paper reports on the effects of both reducing and nonreducing transgalactooligosaccharides (TOS) comprising 2 to 8 residues on the growth of Bifidobacterium adolescentis DSM 20083 and on the production of a novel β-galactosidase (β-Gal II). In cells grown on TOS, in addition to the lactose-degrading β-Gal (β-Gal I), another β-Gal (β-Gal II) was detected and it showed activity towards TOS but not towards lactose. β-Gal II activity was at least 20-fold higher when cells were grown on TOS than when cells were grown on galactose, glucose, and lactose. Subsequently, the enzyme was purified from the cell extract of TOS-grown B. adolescentis by anion-exchange chromatography, adsorption chromatography, and size-exclusion chromatography. β-Gal II has apparent molecular masses of 350 and 89 kDa as judged by size-exclusion chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, respectively, indicating that the enzyme is active in vivo as a tetramer. β-Gal II had an optimal activity at pH 6 and was not active below pH 5. Its optimum temperature was 35°C. The enzyme showed highestV max values towards galactooligosaccharides with a low degree of polymerization. This result is in agreement with the observation that during fermentation of TOS, the di- and trisaccharides were fermented first. β-Gal II was active towards β-galactosyl residues that were 1→4, 1→6, 1→3, and 1↔1 linked, signifying its role in the metabolism of galactooligosaccharides by B. adolescentis.

Effect of carbon dioxide on growth of Pseudomonas putida ATCC 11172 on asparagine, citrate, glucose, and lactate in batch and continuous culture

1985 ◽  
Vol 31 (9) ◽  
pp. 763-766 ◽  
Author(s):  
Göran Molin
Keyword(s):  
Carbon Dioxide ◽  
Growth Rate ◽  
Pseudomonas Putida ◽  
Continuous Culture ◽  
Specific Growth ◽  
Carbon Sources ◽  
Maximum Specific Growth Rate ◽  
The Other ◽  
Continuous Cultures ◽  
Batch Cultures

The growth of Pseudomonas putida ATCC 11172 on L-asparagine, citrate, D-glucose, and L-lactate was followed in air and in 40% CO2 + air, using batch and carbon-limited continuous cultures. Batch cultures in air utilized a mixture of the carbon sources simultaneously. However, a change to 40% CO2 favoured the utilization of glucose. The maximum specific growth rate (μmax) in air was about 0.3 h−1 on glucose and 0.6 h−1 on the other carbon sources. In CO2, the μmax for glucose was reduced by 16% compared with almost 60–70% for the others. An order of preference for the different carbon sources in continuous cultures was determined by comparing the dilution rates at which the different carbon sources started to appear in the effluent. Glucose was the first compound to appear as the dilution rate increased (lowest preference when grown in air). In 40% CO2, the μmax for glucose was slightly higher than the others and the recorded preference for glucose in continuous culture was equal to that for citrate but was somewhat lower than that of lactate and asparagine. D-Gluconate and glucono-δ-lactone were produced as a step in the utilization of glucose. The D-gluconate production was enhanced by CO2.

scholarly journals Mapping the Fundamental Niches of Two Freshwater Microalgae,Chlorella vulgaris(Trebouxiophyceae) andPeridinium cinctum(Dinophyceae), in 5-Dimensional Ion Space

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Terence J. Evens ◽  
Randall P. Niedz
Keyword(s):  
Growth Rate ◽  
Experimental Design ◽  
Chlorella Vulgaris ◽  
Growth Rates ◽  
Ion Concentration ◽  
Freshwater Microalgae ◽  
Batch Cultures ◽  
Fundamental Niche ◽  
Maximum Cell ◽  
Cell Densities

The fundamental niche defined by five ions,NO3 −,PO4 3−, K+, Na+, andCl−, was mapped forChlorella vulgaris(Trebouxiophyceae) andPeridinium cinctum(Dinophyceae) growth rates and maximum cell densities in batch cultures. A five dimensional ion-mixture experimental design was projected across a total ion concentration gradient of 1 to 30 mM to delineate the ion-based, “potential” niche space, defined as the entiren-dimensional hypervolume demarcated by the feasible ranges of the independent factors under consideration. The growth rate-based, fundamental niche volumes overlapped for ca. 94% of the ion mixtures, although the regions of maximal growth rates and cell densities were different for each alga. BothC. vulgarisandP. cinctumexhibited similar positive responses to cations and negative responses to anions. It was determined that total ion concentration for these five ions, from 1 to 30 mM, did not directly affect either growth rate or maximal cell density for either alga, although it did play an interactive role with several ions. This study is the first that we are aware of to attempt the mapping of a multivariate, ion-based, fundamental niche volume. The implications of the experimental design utilized and the potential utility of this type of approach are discussed.

scholarly journals The yield of experimental yeast populations declines during selection

2012 ◽  
Vol 279 (1746) ◽  
pp. 4382-4388 ◽  
Author(s):  
Jean-Nicolas Jasmin ◽  
Marcus M. Dillon ◽  
Clifford Zeyl
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Growth Rate ◽  
Life History ◽  
Population Density ◽  
Experimental Evolution ◽  
Growth Cycle ◽  
Antagonistic Pleiotropy ◽  
Trade Off ◽  
Batch Cultures ◽  
Diploid Populations

The trade-off between growth rate and yield can limit population productivity. Here we tested for this life-history trade-off in replicate haploid and diploid populations of Saccharomyces cerevisiae propagated in glucose-limited medium in batch cultures for 5000 generations. The yield of single clones isolated from the haploid lineages, measured as both optical and population density at the end of a growth cycle, declined during selection and was negatively correlated with growth rate. Initially, diploid populations did not pay this cost of adaptation but haploidized after about 1000–3000 generations of selection, and this ploidy transition was associated with a decline in yield caused by reduced cell size. These results demonstrate the experimental evolution of a trade-off between growth rate and yield, caused by antagonistic pleiotropy, during adaptation in haploids and after an adaptive transition from diploidy to haploidy.

Siderophore production by Fusarium venenatum A3/5

2002 ◽  
Vol 30 (4) ◽  
pp. 696-698 ◽  
Author(s):  
M. G. Wiebe
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Environmental Conditions ◽  
Continuous Flow ◽  
Specific Growth ◽  
Chemostat Culture ◽  
Siderophore Production ◽  
Batch Cultures ◽  
Chemostat Cultures ◽  
Fusarium Venenatum

Fusarium venenatum A3/5 was grown in iron-restricted batch cultures and iron-limited chemostat cultures to determine how environmental conditions affected siderophore production. The specific growth rate in iron-restricted batch cultures was 0.22 h−1, which was reduced to 0.12 h−1 when no iron was added to the culture. Derit in iron-limited chemostat culture was 0.1 h−1. Siderophore production was correlated with specific growth rate, with the highest siderophore production occurring at D = 0.08 h−1 and the lowest at D = 0.03 h−1. Siderophore production was greatest at pH 4.7 and was significantly reduced at pHs above 6.0. Siderophore production could be enhanced by providing insoluble iron instead of soluble iron in continuous flow cultures.

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