Activated carbon as a better habitat for water and wastewater treatment microorganisms

2000 ◽  
Vol 42 (12) ◽  
pp. 149-154 ◽  
Author(s):  
M. Okada ◽  
H. Morinaga ◽  
W. Nishijima
Keyword(s):  
Batch Culture ◽  
Bacterial Growth ◽  
Membrane Filter ◽  
Synthetic Medium ◽  
Dialysis Tubing ◽  
Water And Wastewater Treatment ◽  
Batch Cultures ◽  
K 12 ◽  
Bacterial Yield ◽  
Adsorption Desorption

Effects of PAC on bacterial activity were evaluated by sequencing batch cultures (20 hours each) of E.coli K-12 on synthetic medium containing glucose as a sole carbon source. Four suspended sequencing batch culture systems were operated; CP: cultures supplemented with PAC, CR: cultures with removal of metabolites by PAC at the end of each batch culture, CD: cultures supplemented with PAC in dialysis tubing to separate from E.coli, and CC: cultures without PAC (control). The supernatant of each batch culture was filtered through a membrane filter (0.2 μm) and was mixed with the same volume of fresh medium to be used as the medium for the next batch culture. The sequencing batch cultures were repeated three times for all the systems. The bacterial growth in CC was inhibited with the increase in the number of batch cultures. Although a significant amount of metabolites was accumulated in the 3rd batch culture of CC, little accumulation was noted in the 3rd batch culture of CP. No growth inhibition was noted in CP for all the batch cultures. The little differences in the bacterial yield and metabolite accumulation between CR and CD suggested that adsorption/desorption of metabolites with PAC did not play a major role in bacterial growth. PAC addition may partly stimulate the growth by the removal of growth inhibiting metabolites. However, the fact that CP showed higher yield than CR and CD indicated that the contact between bacteria and PAC plays a significant role in the growth of bacteria.

scholarly journals A buffered media system for yeast batch culture growth

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Rianne C. Prins ◽  
Sonja Billerbeck
Keyword(s):  
Nitrogen Source ◽  
Ammonium Sulfate ◽  
Batch Culture ◽  
Biomass Production ◽  
Buffering Capacity ◽  
Drop Out ◽  
Batch Cultures ◽  
Media System ◽  
The Media ◽  
Media Types

Abstract Background Fungi are premier hosts for the high-yield secretion of proteins for biomedical and industrial applications. The stability and activity of these secreted proteins is often dependent on the culture pH. As yeast acidifies the commonly used synthetic complete drop-out (SD) media that contains ammonium sulfate, the pH of the media needs to be buffered in order to maintain a desired extracellular pH during biomass production. At the same time, many buffering agents affect growth at the concentrations needed to support a stable pH. Although the standard for biotechnological research and development is shaken batch cultures or microtiter plate cultures that cannot be easily automatically pH-adjusted during growth, there is no comparative study that evaluates the buffering capacity and growth effects of different media types across pH-values in order to develop a pH-stable batch culture system. Results We systematically test the buffering capacity and growth effects of a citrate-phosphate buffer (CPB) from acidic to neutral pH across different media types. These media types differ in their nitrogen source (ammonium sulfate, urea or both). We find that the widely used synthetic drop-out media that uses ammonium sulfate as nitrogen source can only be effectively buffered at buffer concentrations that also affect growth. At lower concentrations, yeast biomass production still acidifies the media. When replacing the ammonium sulfate with urea, the media alkalizes. We then develop a medium combining ammonium sulfate and urea which can be buffered at low CPB concentrations that do not affect growth. In addition, we show that a buffer based on Tris/HCl is not effective in maintaining any of our media types at neutral pH even at relatively high concentrations. Conclusion Here we show that the buffering of yeast batch cultures is not straight-forward and addition of a buffering agent to set a desired starting pH does not guarantee pH-maintenance during growth. In response, we present a buffered media system based on an ammonium sulfate/urea medium that enables relatively stable pH-maintenance across a wide pH-range without affecting growth. This buffering system is useful for protein-secretion-screenings, antifungal activity assays, as well as for other pH-dependent basic biology or biotechnology projects.

The effect of energy and nitrogen supply pattern on rumen bacterial growthin vitro

1991 ◽  
Vol 53 (2) ◽  
pp. 165-175 ◽  
Author(s):  
P. H. Henning ◽  
D. G. Steyn ◽  
H. H. Meissner
Keyword(s):  
Bacterial Growth ◽  
Specific Growth ◽  
Growth Efficiency ◽  
Bacterial Growth Efficiency ◽  
Batch Cultures ◽  
Time Zero ◽  
N Supply ◽  
Pulse Dose ◽  
Supply Pattern ◽  
Glucose Supply

AbstractThe effect of energy and nitrogen (N) supply pattern on rumen bacterial growth was investigated in vitro. In experiment 1, glucose was was fed to batch cultures of mixed rumen bacteria according to three patterns namely a pulse dose at time zero (P); even increments at 0·5-h intervals (G) or an intermediate pattern (I), whilst N was supplied in excess. In experiment 2, glucose and N (not in excess) were fed to batch cultures according to four patterns namely glucose and N as pulse doses at time zero, (EPNP); glucose as a pulse dose at time zero and N in 24 even increments at 0·5-h intervals (EPNG); glucose in 24 even increments at 0·5-h intervals and N as a pulse dose at time zero (EGNP) or both glucose and N in 24 even increments at 0·5-h intervals (EGNG). Fermentaton was studied over a 12-h period for both experiments.In experiment 1, bacterial growth efficiency and specific growth rate (39·8,35·5 and 29·9 (g bacterial dry matter (DM) per mol glucose utilized) and 0·33, 0·27 and 0·20 (fraction per h) for treatments P, I, and G respectively) differed significantly between glucose supply patterns. In experiment 2, bacterial growth efficiency and specific growth rate (33·8, 34·7, 25·9 and 22·5 (g baterial DM per mol glucose) and 0·21, 0·18, 0·14 and 0·13 (fraction per h) for treatments EPNP, EPNG, EGNP and EGNG respectively) differed significantly only between glucose supply patterns.It is concluded that the pattern according to which a given amount of energy becomes available affects bacterial growth efficiency, with the fastest supply rate giving the highest efficiency and that, within accepted levels of N supply, synchronization between energy and N availability may be of less importance to bacterial growth efficiency than the energy supply pattern.

scholarly journals STUDIES ON THE ANTIBACTERIAL ACTION OF THE SULFONAMIDE DRUGS

1942 ◽  
Vol 75 (4) ◽  
pp. 383-394 ◽  
Author(s):  
W. Barry Wood ◽  
Robert Austrian
Keyword(s):  
Bacterial Growth ◽  
Culture Medium ◽  
Organic Dyes ◽  
Synthetic Medium ◽  
Antibacterial Properties ◽  
Antagonistic Action ◽  
Bacteriostatic Action ◽  
Great Excess ◽  
Related Drug

1. In cultures of Staphylococus aureus in a synthetic medium nicotinamide and cozymase were shown to block the bacteriostatic action of chemically unrelated sulfonamide drugs as well as the chemically related compound sulfapyridine. The antibacterial properties of organic dyes totally unrelated to the sulfonamide compounds (methylene blue and thionine) were also nullified by the addition of cozymase to the culture medium. 2. The antagonistic action of the pyridine-containing coenzyme, cozymase, was found, by quantitative study, to be no greater against sulfapyridine than against other structurally dissimilar sulfonamide compounds. 3. The antidrug effects of nicotinamide and cozymase in staphylococcus cultures were observed to be directly proportional to their ability to stimulate the growth of the organism in the synthetic medium. When tested in cultures of B. coli in which they failed to accelerate bacterial growth, these same substances failed to influence the bacteriostatic action of the sulfonamide drugs. 4. The in vitro action of the coenzyme, cocarboxylase, as measured in the Warburg respirometer, was shown to be unaffected by the chemically related drug, sulfathiazole, even when the latter was present in great excess. The above observations fail to support the theory that sulfapyridine, sulfathiazole, and sulfadiazine prevent bacterial growth by interfering with the functioning of the chemically related coenzymes, cozymase, and cocarboxylase. The mode of action of sulfanilamide and its more common derivatives is discussed in the light of these observations, and a tentative theory is offered to explain the differences in bacteriostatic potency exhibited by the various sulfonamide compounds.

Heterotrophic Fed-Batch Cultures of Nostoc flagelliforme and Production of Extracellular Polysaccharides

2012 ◽  
Vol 518-523 ◽  
pp. 5468-5471
Author(s):  
Shi Ru Jia ◽  
Zhen Ding ◽  
Ning Tan ◽  
Nan Wang ◽  
Pei Pei Han ◽  
...  
Keyword(s):  
Batch Culture ◽  
Economic Value ◽  
Culture Conditions ◽  
Extracellular Polysaccharides ◽  
Nostoc Flagelliforme ◽  
Fed Batch ◽  
Batch Cultures ◽  
Dissociated Cells ◽  
Fed Batch Culture ◽  
Different Cultures

Nostoc flagelliforme is a kind of terrestrial cyanobacterium with high economic value. Dissociated cells, which separated from a natural colony of N. flagelliforme, could be cultivated heterotrophically in the darkness on xylose and glucose under fed-batch culture conditions. Growth and extracellular polysaccharides (EPS) production in different cultures are investigated. At harvest time, the cultures contain 1.215 g•L-1 of biomass and 122.5 mg•L-1 of EPS respectively. The gravimetric EPS production rate is 17.5 mg•g-1•day-1, which is 1.65 times higher than previously reported results for heterotrophic Nostoc flagelliforme grown on xylose batch culture.

Removal of Toxic Volatile Compounds in Batch Culture Prolongs Stationary Phase and Delays Death of Escherichia coli

2021 ◽  
Author(s):  
Melisa G. Osborne ◽  
Christopher J. Geiger ◽  
Christopher H. Corzett ◽  
Karin E. Kram ◽  
Steven E. Finkel
Keyword(s):  
Escherichia Coli ◽  
Life Cycle ◽  
Stationary Phase ◽  
Volatile Compounds ◽  
Batch Culture ◽  
Future Research ◽  
Bacterial Strains ◽  
Batch Cultures ◽  
Death Phase

The mechanisms controlling entry into and exit from death phase in the bacterial life cycle remain unclear. While bacterial growth studies in batch cultures traditionally focus on the first three phases during incubation, two additional phases, death phase and long-term stationary phase, are less understood. Although there are a number of stressors that arise during long-term batch culture, including nutrient depletion and the accumulation of metabolic toxins such as reactive oxidative species, their roles in cell death are not well-defined. By manipulating environmental conditions of Escherichia coli incubated in long-term batch culture through chemical and mechanical means, we investigated the role of volatile metabolic toxins in modulating the onset of death phase. Here, we demonstrate that with the introduction of substrates with high binding affinities for volatile compounds, toxic byproducts of normal cell metabolism, into the headspace of batch cultures, cells display prolonged stationary phase and delayed entry into death phase. Addition of these substrates allows cultures to maintain a high cell density for hours to days longer than cultures incubated under standard growth conditions. A similar effect is observed when the gaseous headspace in culture flasks is continuously replaced with sterile air, mechanically preventing the accumulation of metabolic byproducts in batch cultures. We establish that toxic compound(s) are produced during exponential phase, demonstrate that buildup of toxic byproducts influence entry into death phase, and present a novel tool for improving high density growth in batch culture that may be used in future research, industrial, or biotechnology applications. IMPORTANCE Bacteria, such as Escherichia coli , are routinely used in the production of biomaterials because of their efficient and sustainable capacity for synthesis of bioproducts. Industrial applications of microbial synthesis typically utilize cells in stationary phase, when cultures have the greatest density of viable cells. By manipulating culture conditions to delay the transition from stationary phase to death phase, we can prolong stationary phase on a scale of hours to days, thereby maintaining the maximum density of cells that would otherwise quickly decline. Characterization of the mechanisms that control entry into death phase for the model organism Escherichia coli not only deepens our understanding of the bacterial life cycle, but also presents an opportunity to enhance current protocols for batch culture growth and explore similar effects in a variety of widely used bacterial strains.

scholarly journals Inhibition of bacterial growth by pure ozone in the presence of nutrients

1949 ◽  
Vol 47 (2) ◽  
pp. 146-158 ◽  
Author(s):  
M. Ingram ◽  
R. B. Haines
Keyword(s):  
Bacterial Growth ◽  
Synthetic Medium ◽  
Industrial Research ◽  
Nutrient Broth ◽  
Bacterial Metabolism ◽  
Cellular Respiration ◽  
Secondary Effects ◽  
Inhibition Of Growth ◽  
Complex Process ◽  
Micro Organisms

Data are given showing the concentration of pure ozone required to inhibit the growth of, and to destroy, various micro-organisms when growing on agar, in nutrient broth, a synthetic medium, or simply suspended in water. The following is shown:1. Different organisms vary in their susceptibility towards this gas. Achromobacter and Pseudomonas strains, such as occur on chilled meat, are the most resistant. On the whole, mould fungi are about as susceptible as bacteria.2. Very much higher concentrations are required to arrest established growth than can be used if inoculation and admission of inhibitor are coincident.3. Lower concentrations are inhibitory at lower temperatures. These results are ascribed to dissipation of the ozone by combination with products of bacterial metabolism. It seems that any factor which diminishes growth will augment the effectiveness of ozone.4. Comparatively small concentrations (less than 10 p.p.m.) suffice to destroy bacteria suspended in water. Somewhat larger concentrations inhibit growth in a synthetic medium.5. Still larger quantities (several hundred p.p.m.) are required in nutrient broth.6. Nutrient broth treated with ozone will support little or no bacterial growth, due to change of pH, growth taking place slowly if the pH is restored to its original value. Inhibition of growth in such a medium is therefore a complex process depending in part upon the secondary effects of decomposition of the medium.7. To kill them, bacteria require still more ozone (in some cases several thousand p.p.m.) if growing on agar. These results are ascribed to combination of ozone with the supporting medium.8. When applied to organisms growing on food, combination with ozone not only spoils the food, but it makes it difficult to interpret the effect on the microbes in terms of the ozone applied.9. The inhibitory concentrations are higher than humans can tolerate.10. Ozone destroys the dehydrogenating enzymes of the cell, and it is suggested that its germicidal action may be partly due to interference with cellular respiration.The work described in this paper was carried out as part of the programme of the Food Investigation Organization of the Department of Scientific and Industrial Research.

scholarly journals Sulfur and Nitrogen Limitation in Escherichia coli K-12: Specific Homeostatic Responses

2005 ◽  
Vol 187 (3) ◽  
pp. 1074-1090 ◽  
Author(s):  
Prasad Gyaneshwar ◽  
Oleg Paliy ◽  
Jon McAuliffe ◽  
David L. Popham ◽  
Michael I. Jordan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Open Reading Frames ◽  
Mrna Levels ◽  
Growth Responses ◽  
Transcriptional Responses ◽  
Batch Cultures ◽  
Cross Links ◽  
K 12 ◽  
And Oxidative Stress ◽  
Reading Frames

ABSTRACT We determined global transcriptional responses of Escherichia coli K-12 to sulfur (S)- or nitrogen (N)-limited growth in adapted batch cultures and cultures subjected to nutrient shifts. Using two limitations helped to distinguish between nutrient-specific changes in mRNA levels and common changes related to the growth rate. Both homeostatic and slow growth responses were amplified upon shifts. This made detection of these responses more reliable and increased the number of genes that were differentially expressed. We analyzed microarray data in several ways: by determining expression changes after use of a statistical normalization algorithm, by hierarchical and k-means clustering, and by visual inspection of aligned genome images. Using these tools, we confirmed known homeostatic responses to global S limitation, which are controlled by the activators CysB and Cbl, and found that S limitation propagated into methionine metabolism, synthesis of FeS clusters, and oxidative stress. In addition, we identified several open reading frames likely to respond specifically to S availability. As predicted from the fact that the ddp operon is activated by NtrC, synthesis of cross-links between diaminopimelate residues in the murein layer was increased under N-limiting conditions, as was the proportion of tripeptides. Both of these effects may allow increased scavenging of N from the dipeptide d-alanine-d-alanine, the substrate of the Ddp system.

Vitamin B12and Marine Ecology III. An experiment with a chemostat

1966 ◽  
Vol 46 (3) ◽  
pp. 659-671 ◽  
Author(s):  
M. R. Droop
Keyword(s):  
Batch Culture ◽  
Marine Ecology ◽  
Vitamin B ◽  
Batch Cultures

A 250 ml. chemostat has been used to measure the parameters of vitamin B requirement in the chrysomonadMonochrysis lutheri.The yield constant wasca.0·25 × 10 cells/μμg., i.e. one-third of the figure previously measured in batch cultures.The saturation constant lay between 2 and 6 μμ/ml., i.e. at least twenty times the figure indicated by previous batch culture measurements.Internal inconsistencies in the chemostat's operation indicate the presence of factors not accounted for by theory.It is argued that only factors analogous to the release of protein-bound vitamin into the medium could in principle account for all the discrepancies.

Evidence of self-inhibition by filamentous fungi accounts for unidirectional hyphal growth in colonies

1998 ◽  
Vol 44 (4) ◽  
pp. 390-393 ◽  
Author(s):  
Edward J Bottone ◽  
Nimesh Nagarsheth ◽  
Kenneth Chiu
Keyword(s):  
Filamentous Fungi ◽  
Membrane Filter ◽  
Hyphal Growth ◽  
Cross Reactivity ◽  
Clear Zone ◽  
Dialysis Tubing ◽  
Directional Growth ◽  
Radial Pattern ◽  
Molecular Weight Cutoff ◽  
Agar Surface

Hyphal growth in filamentous fungi proceeds in an unidirectional radial pattern from a point inoculation. An inhibitor produced, secreted, and absorbed by the advancing hyphae has been speculated to account for directional growth. Working with Mucor and Aspergillus, laboratory evidence is provided for the production of an inhibitor by the advancing hyphae of these filmentous fungi that precludes back growth. Strains of Mucor and Aspergillus inoculated in agar on a 0.45-mm membrane filter placed on agar surfaces grow radially beyond the filter perimeter and onto the agar surface. Removal of the filter pad does not result in hyphal extension back into the clear zone underlying the membrane filter. Inoculation of the clear zone with a fresh Mucor or Aspergillus spore suspension does not result in hyphal growth. Instead, germinating spores show aberrant and aborted hyphae. The fungal inhibitor shows cross-reactivity between Mucor and Aspergillus, is resistant to pronase (10 mg/mL) but not chloroform inactivation, and passes through dialysis tubing with a molecular weight cutoff of 3500.Key words: fungal inhibitor, unidirectional hyphal growth, radial hyphal growth, Mucor, Aspergillus.

Sign in / Sign up

Export Citation Format

Share Document