scholarly journals A Defined, Glucose-Limited Mineral Medium for the Cultivation of Listeria spp.

2013 ◽  
Vol 79 (8) ◽  
pp. 2503-2511 ◽  
Author(s):  
Rudolf Schneebeli ◽  
Thomas Egli
Keyword(s):  
Amino Acids ◽  
Growth Rates ◽  
Specific Growth ◽  
Synthetic Medium ◽  
Brain Heart Infusion ◽  
Mineral Medium ◽  
Content Type ◽  
Biomass Yields ◽  
Minimal Media ◽  
Specific Growth Rates

ABSTRACTMembers of the genusListeriaare fastidious bacteria with respect to their nutritional requirements, and several minimal media described in the literature fail to support growth of allListeriaspp. Furthermore, strict limitation by a single nutrient, e.g., the carbon source, has not been demonstrated for any of the published minimal media. This is an important prerequisite for defined studies of growth and physiology, including “omics.” Based on a theoretical analysis of previously published mineral media forListeria, an improved, well-balanced growth medium was designed. It supports the growth, not only of all testedListeria monocytogenesstrains, but of all otherListeriaspecies, with the exception ofL. ivanovii. The growth performance ofL. monocytogenesstrain Scott A was tested in the newly designed medium; glucose served as the only carbon and energy source for growth, whereas neither the supplied amino acids nor the buffering and complexing components (MOPS [morpholinepropanesulfonic acid] and EDTA) supported growth. Omission of amino acids, trace elements, or vitamins, alone or in combination, resulted in considerably reduced biomass yields. Furthermore, we monitored the specific growth rates of variousListeriastrains cultivated in the designed mineral medium and compared them to growth in complex medium (brain heart infusion broth [BHI]). The novel mineral medium was optimized for the commonly used strainL. monocytogenesScott A to achieve optimum cell yields and maximum specific growth rates. This mineral medium is the first published synthetic medium forListeriathat has been shown to be strictly carbon (glucose) limited.

scholarly journals Isolated Microbial Single Cells and Resulting Micropopulations Grow Faster in Controlled Environments

2012 ◽  
Vol 78 (19) ◽  
pp. 7132-7136 ◽  
Author(s):  
Christian Dusny ◽  
Frederik Sven Ole Fritzsch ◽  
Oliver Frick ◽  
Andreas Schmid
Keyword(s):  
Pichia Pastoris ◽  
Corynebacterium Glutamicum ◽  
Growth Rates ◽  
Specific Growth ◽  
Single Cells ◽  
Hansenula Polymorpha ◽  
Content Type ◽  
Controlled Environments ◽  
Specific Growth Rates ◽  
Extracellular Environment

ABSTRACTSingularized cells ofPichia pastoris,Hansenula polymorpha, andCorynebacterium glutamicumdisplayed specific growth rates under chemically and physically constant conditions that were consistently higher than those obtained in populations. This highlights the importance of single-cell analyses by uncoupling physiology and the extracellular environment, which is now possible using the Envirostat 2.0 concept.

scholarly journals PSV-32 Influence of chlorate and chlorate plus molybdate on the growth of multi-drug resistant staphylococci

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 295-295
Author(s):  
Oscar Ruiz ◽  
Yamicela Castillo-Castillo ◽  
Robin Anderson ◽  
Michael E Hume ◽  
Claudio Arzola ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Nitrate Reductase ◽  
Growth Rates ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Specific Growth ◽  
Brain Heart Infusion ◽  
Inhibitory Effect ◽  
Drug Resistant ◽  
Methicillin Resistant ◽  
Specific Growth Rates

Abstract This study was conducted to determine the effects of chlorate, a metabolic precursor of the bactericide chlorite, when administered without or with molybdate, an essential component of a co-enzyme contributing to nitrate reductase conversion of chlorate to chlorite, against methicillin-resistant staphylococci, important mastitic-pathogens of livestock. Two methicillin-resistant Staphylococcus aureus (strains CP and 49521) were individually cultured for 12 h at 39o C in nitrate-supplemented (5 mM) ½-strength Brain Heart Infusion broth (10 mL/tube) treated without (control) or with 5 mM chlorate (CL) or 5 mM chlorate plus 1 mM molybdate (CLMO). Control and treated cultures were incubated anaerobically in triplicate and growth was measured via absorbance at 600 nm. An analysis of variance revealed an inhibitory effect of treatments (P < 0.05) on maximum absorbances observed after the 12-h incubation, with maximum absorbances for CP (1.22, 0.10, and 0.46; SEM = 0.12) and 49521 (1.24, 0.22 and 0.06, SEM = 0.09) being higher in controls than in CL- and CLMO-treated cultures, respectively. Similarly, mean specific growth rates of S. aureus CP and 49521 were inhibited (P < 0.05) by both treatments during the first 6 h of growth, with rates being most rapid in control cultures, intermediate in CLMO-treated cultures and slowest in CL-treated cultures (0.68, 0.27 and 0.03 h-1, SEM= 0.15; and 0.92, 0.47 and 0.09 h-1, SEM = 0.08; for CP and 40521, respectively). Growth rates did not differ (P > 0.05) between controls or treatments during the last 6 h of incubation, averaging 0.74 and 0.75 h-1 for both CP and 49521 (SEM = 0.20 and 0.22, respectively). These results confirm that chlorate treatment inhibits methicillin-resistant Staphylococcus aureus strains CP and 49521 although moderate adaption by these strains began to occur after 6 h incubation which, contrary to expectation, was not overcome by co-treatment with molybdate.

scholarly journals Pichia pastoris Exhibits High Viability and a Low Maintenance Energy Requirement at Near-Zero Specific Growth Rates

2016 ◽  
Vol 82 (15) ◽  
pp. 4570-4583 ◽  
Author(s):  
Corinna Rebnegger ◽  
Tim Vos ◽  
Alexandra B. Graf ◽  
Minoska Valli ◽  
Jack T. Pronk ◽  
...  
Keyword(s):  
Pichia Pastoris ◽  
Growth Rates ◽  
Specific Growth ◽  
Energy Requirement ◽  
Maintenance Energy ◽  
Content Type ◽  
Chemostat Cultures ◽  
Zero Growth ◽  
Maintenance Energy Requirement ◽  
Specific Growth Rates

ABSTRACTThe yeastPichia pastorisis a widely used host for recombinant protein production. Understanding its physiology at extremely low growth rates is a first step in the direction of decoupling product formation from cellular growth and therefore of biotechnological relevance. Retentostat cultivation is an excellent tool for studying microbes at extremely low specific growth rates but has so far not been implemented forP. pastoris. Retentostat feeding regimes were based on the maintenance energy requirement (mS) and maximum biomass yield on glucose (YX/Smax) estimated from steady-state glucose-limited chemostat cultures. Aerobic retentostat cultivation enabled reproducible, smooth transitions from a specific growth rate (μ) of 0.025 h−1to near-zero specific growth rates (μ < 0.001 h−1). At these near-zero specific growth rates, viability remained at least 97%. The value ofmSat near-zero growth rates was 3.1 ± 0.1 mg glucose per g biomass and h, which was 3-fold lower than themSestimated from faster-growing chemostat cultures. This difference indicated thatP. pastorisreduces its maintenance energy requirement at extremely low μ, a phenomenon not previously observed in eukaryotes. Intracellular levels of glycogen and trehalose increased, while μ progressively declined during retentostat cultivation. Transcriptional reprogramming toward zero growth included the upregulation of many transcription factors as well as stress-related genes and the downregulation of cell cycle genes. This study underlines the relevance of comparative analysis of maintenance energy metabolism, which has an important impact on large-scale industrial processes.IMPORTANCEThe yeastPichia pastorisnaturally lives on trees and can utilize different carbon sources, among them glucose, glycerol, and methanol. In biotechnology, it is widely used for the production of recombinant proteins. For both the understanding of life in its natural habitat and optimized production processes, a better understanding of cell physiology at an extremely low growth rate would be of extraordinary value. Therefore, we have grownP. pastorisin a retentostat, which allows the cultivation of metabolically active cells even at zero growth. Here we reached doubling times as long as 38 days and found thatP. pastorisdecreases its maintenance energy demand 3-fold during very slow growth, which enables it to survive with a much lower substrate supply than baker's yeast.

Inhibitory Effect of Select Nitrocompounds on Growth and Survivability of Listeria monocytogenes In Vitro†‡

2006 ◽  
Vol 69 (5) ◽  
pp. 1061-1065 ◽  
Author(s):  
M. DIMITRIJEVIC ◽  
R. C. ANDERSON ◽  
T. R. CALLAWAY ◽  
Y. S. JUNG ◽  
R. B. HARVEY ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Growth Rates ◽  
Specific Growth ◽  
Brain Heart Infusion ◽  
Inhibitory Effect ◽  
Brain Heart Infusion Broth ◽  
Anaerobic Culture ◽  
Aerobic Culture ◽  
Specific Growth Rates

We report the effects of 2-nitro-1-propanol (2NPOH), 2-nitroethanol (2NEOH), and nitroethane (NE) on growth and survivability of Listeria monocytogenes. In all cases, inhibition was greatest with 2NPOH and least with NE. For example, specific growth rates of L. monocytogenes strain 18 declined (P &lt; 0.05) 76, 60, and 29% from controls during aerobic culture at 37°C in brain heart infusion broth containing 10 mM 2NPOH, 2NEOH, or NE, respectively. Mean specific growth rate for the controls incubated likewise without added nitrocompound was 0.62 ± 0.02 h−1. Specific growth rates of L. monocytogenes Scott A decreased (P &lt; 0.05) 67, 45, and 11%, respectively, from controls (0.67 ± 0.02 h−1) when cultured similarly. Specific growth rates for L. monocytogenes strain 18 incubated similarly except at 30°C were reduced (P &lt; 0.05) 76, 60, and 30%, respectively, and were reduced (P &lt; 0.05) 78, 23, and 23% during anaerobic culture at 30°C in brain heart infusion broth containing 15 mM 2NPOH, 2NEOH, or NE (control rates ranged from 0.37 ± 0.07 to 0.74 ± 0.05 h−1). Survivability of L. monocytogenes strain 18 was reduced (P &lt; 0.05) during aerobic storage (4 months at 4°C) in brain heart infusion broth containing 2NPOH or 2NEOH (by 7.8 and 1.9 log units, respectively) but not NE. The inhibitory effect of 2NPOH was approximately 20% greater during growth at pH 7.0 than at pH 5.6 or 8.0. These results demonstrate the differential inhibitory activity of 2NPOH, 2NEOH, and NE against L. monocytogenes in vitro.

scholarly journals Molecular Analysis of theIn SituGrowth Rates of Subsurface Geobacter Species

2012 ◽  
Vol 79 (5) ◽  
pp. 1646-1653 ◽  
Author(s):  
Dawn E. Holmes ◽  
Ludovic Giloteaux ◽  
Melissa Barlett ◽  
Milind A. Chavan ◽  
Jessica A. Smith ◽  
...  
Keyword(s):  
Growth Rates ◽  
Ribosomal Proteins ◽  
Specific Growth ◽  
Expression Patterns ◽  
Transcript Abundance ◽  
Metal Reduction ◽  
Content Type ◽  
Specific Growth Rates ◽  
Dissimilatory Metal Reduction

ABSTRACTMolecular tools that can provide an estimate of thein situgrowth rate ofGeobacterspecies could improve understanding of dissimilatory metal reduction in a diversity of environments. Whole-genome microarray analyses of a subsurface isolate ofGeobacter uraniireducens, grown under a variety of conditions, identified a number of genes that are differentially expressed at different specific growth rates. Expression of two genes encoding ribosomal proteins,rpsCandrplL, was further evaluated with quantitative reverse transcription-PCR (qRT-PCR) in cells with doubling times ranging from 6.56 h to 89.28 h. Transcript abundance ofrpsCcorrelated best (r2= 0.90) with specific growth rates. Therefore, expression patterns ofrpsCwere used to estimate specific growth rates ofGeobacterspecies during anin situuranium bioremediation field experiment in which acetate was added to the groundwater to promote dissimilatory metal reduction. Initially, increased availability of acetate in the groundwater resulted in higher expression ofGeobacter rpsC, and the increase in the number ofGeobactercells estimated with fluorescentin situhybridization compared well with specific growth rates estimated from levels ofin situ rpsCexpression. However, in later phases, cell number increases were substantially lower than predicted fromrpsCtranscript abundance. This change coincided with a bloom of protozoa and increased attachment ofGeobacterspecies to solid phases. These results suggest that monitoringrpsCexpression may better reflect the actual rate thatGeobacterspecies are metabolizing and growing duringin situuranium bioremediation than changes in cell abundance.

scholarly journals Contribution of Complex I NADH Dehydrogenase to Respiratory Energy Coupling in Glucose-Grown Cultures of Ogataea parapolymorpha

2020 ◽  
Vol 86 (15) ◽  
Author(s):  
Hannes Juergens ◽  
Xavier D. V. Hakkaart ◽  
Jildau E. Bras ◽  
André Vente ◽  
Liang Wu ◽  
...  
Keyword(s):  
Growth Rates ◽  
Complex I ◽  
Energy Coupling ◽  
Content Type ◽  
Batch Cultures ◽  
Cell Factories ◽  
Chemostat Cultures ◽  
Biomass Yields ◽  
Nadh Dehydrogenases ◽  
Specific Growth Rates

ABSTRACT The thermotolerant yeast Ogataea parapolymorpha (formerly Hansenula polymorpha) is an industrially relevant production host that exhibits a fully respiratory sugar metabolism in aerobic batch cultures. NADH-derived electrons can enter its mitochondrial respiratory chain either via a proton-translocating complex I NADH-dehydrogenase or via three putative alternative NADH dehydrogenases. This respiratory entry point affects the amount of ATP produced per NADH/O2 consumed and therefore impacts the maximum yield of biomass and/or cellular products from a given amount of substrate. To investigate the physiological importance of complex I, a wild-type O. parapolymorpha strain and a congenic complex I-deficient mutant were grown on glucose in aerobic batch, chemostat, and retentostat cultures in bioreactors. In batch cultures, the two strains exhibited a fully respiratory metabolism and showed the same growth rates and biomass yields, indicating that, under these conditions, the contribution of NADH oxidation via complex I was negligible. Both strains also exhibited a respiratory metabolism in glucose-limited chemostat cultures, but the complex I-deficient mutant showed considerably reduced biomass yields on substrate and oxygen, consistent with a lower efficiency of respiratory energy coupling. In glucose-limited retentostat cultures at specific growth rates down to ∼0.001 h−1, both O. parapolymorpha strains showed high viability. Maintenance energy requirements at these extremely low growth rates were approximately 3-fold lower than estimated from faster-growing chemostat cultures, indicating a stringent-response-like behavior. Quantitative transcriptome and proteome analyses indicated condition-dependent expression patterns of complex I subunits and of alternative NADH dehydrogenases that were consistent with physiological observations. IMPORTANCE Since popular microbial cell factories have typically not been selected for efficient respiratory energy coupling, their ATP yields from sugar catabolism are often suboptimal. In aerobic industrial processes, suboptimal energy coupling results in reduced product yields on sugar, increased process costs for oxygen transfer, and volumetric productivity limitations due to limitations in gas transfer and cooling. This study provides insights into the contribution of mechanisms of respiratory energy coupling in the yeast cell factory Ogataea parapolymorpha under different growth conditions and provides a basis for rational improvement of energy coupling in yeast cell factories. Analysis of energy metabolism of O. parapolymorpha at extremely low specific growth rates indicated that this yeast reduces its energy requirements for cellular maintenance under extreme energy limitation. Exploration of the mechanisms for this increased energetic efficiency may contribute to an optimization of the performance of industrial processes with slow-growing eukaryotic cell factories.

Effects of turbidity on prey consumption and growth in brook trout and implications for bioenergetics modeling

2001 ◽  
Vol 58 (2) ◽  
pp. 386-393 ◽  
Author(s):  
John A Sweka ◽  
Kyle J Hartman
Keyword(s):  
Growth Rates ◽  
Brook Trout ◽  
Specific Growth ◽  
Abiotic Factors ◽  
Foraging Strategies ◽  
Turbid Water ◽  
Daily Consumption ◽  
Consumption Rates ◽  
The Difference ◽  
Specific Growth Rates

Brook trout (Salvelinus fontinalis) were held in an artificial stream to observe the influence of turbidity on mean daily consumption and specific growth rates. Treatment turbidity levels ranged from clear (<3.0 nephelometric turbidity units (NTU)) to very turbid water (> 40 NTU). Observed mean daily specific consumption rates were standardized to the mean weight of all brook trout tested. Turbidity had no significant effect on mean daily consumption, but specific growth rates decreased significantly as turbidity increased. Brook trout in turbid water became more active and switched foraging strategies from drift feeding to active searching. This switch was energetically costly and resulted in lower specific growth rates in turbid water as compared with clear water. Bioenergetics simulations were run to compare observed growth with that predicted by the model. Observed growth values fell below those predicted by the model and the difference increased as turbidity increased. Abiotic factors, such as turbidity, which bring about changes in the activity rates of fish, can have implications for the accuracy of predicted growth by bioenergetics models.

Sex Ratio and Sex-Specific Growth Rates of Immature Green Turtles, Chelonia mydas, in the Southern Bahamas

Copeia ◽  
1992 ◽  
Vol 1992 (4) ◽  
pp. 1098 ◽  
Author(s):  
Alan B. Bolten ◽  
Karen A. Bjorndal ◽  
Janice S. Grumbles ◽  
David W. Owens
Keyword(s):  
Sex Ratio ◽  
Growth Rates ◽  
Specific Growth ◽  
Chelonia Mydas ◽  
Green Turtles ◽  
Specific Growth Rates

Physiological and cell morphology adaptation ofBacillus subtilisat near-zero specific growth rates: a transcriptome analysis

2014 ◽  
Vol 17 (2) ◽  
pp. 346-363 ◽  
Author(s):  
Wout Overkamp ◽  
Onur Ercan ◽  
Martijn Herber ◽  
Antonius J. A. van Maris ◽  
Michiel Kleerebezem ◽  
...  
Keyword(s):  
Cell Morphology ◽  
Transcriptome Analysis ◽  
Growth Rates ◽  
Specific Growth ◽  
Specific Growth Rates
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