PHYSICOCHEMICAL FACTORS INFLUENCING GROWTH AND PIGMENT SYNTHESIS BY MICROCOCCUS ROSEUS

1966 ◽  
Vol 12 (4) ◽  
pp. 691-698 ◽  
Author(s):  
O. C. Thierry ◽  
J. J. Cooney
Keyword(s):  
Stationary Phase ◽  
Visible Light ◽  
Action Spectrum ◽  
Maximum Growth ◽  
Defined Medium ◽  
Pigment Content ◽  
Pigment Synthesis ◽  
Inhibition Of Growth ◽  
Environmental Variations ◽  
Micrococcus Roseus

Growth of and carotenoid synthesis by Micrococcus roseus are optimum at pH 6.8 and pH 7.5 in a defined medium. Maximum growth and pigment content were obtained in aerobic cultures at 25 C. Supplementing the medium with more than 0.2% NaCl resulted in less growth and decreased pigment content per unit mass of cells. At pH 7.5 the absence of visible light had no effect on growth or pigment content, but at pH 6.8 both were decreased in dark-grown cultures. Biotin did not reverse inhibition of growth in the dark. Dark inhibition was reversed by exposure of lag or early log phase cultures to visible light for 30 min, but late log or stationary phase cultures grown in the dark did not respond. Stationary phase dark-grown cultures resumed growth and pigment synthesis during a 24-h period in light. Serial culture in the dark did not result in a further decrease in growth or pigment synthesis; and when cells from serial cultures grown in darkness were used as inoculum for cultures grown in the light, maximum growth and pigment synthesis occurred. These data suggest that light is required for induction of maximum growth and pigment synthesis. A crude action spectrum was determined and suggests that light in the range from 625 to 700 mμ may be responsible for photoinduction.None of the environmental variations altered the absorption spectrum of pigment extracts. Conditions which were optimum for growth were also optimum for pigment synthesis.

A DEFINED MEDIUM FOR GROWTH AND PIGMENT SYNTHESIS OF MICROCOCCUS ROSEUS

1966 ◽  
Vol 12 (1) ◽  
pp. 83-89 ◽  
Author(s):  
J. J. Cooney ◽  
O. C. Thierry
Keyword(s):  
Carbon Source ◽  
Minimal Medium ◽  
Mevalonic Acid ◽  
Defined Medium ◽  
Pigment Content ◽  
Inorganic Salts ◽  
Good Growth ◽  
Pigment Synthesis ◽  
Culture Development ◽  
Micrococcus Roseus

A defined medium has been developed which supports good growth and pigment synthesis of Micrococcus roseus ATCC 516. The medium contains fructose, adenine, alanine, arginine, glutamic acid, glycine, isoleucine, methionine, proline, serine, and inorganic salts. The medium is not a minimal medium, but omission of any component decreases growth or pigment content, or both. Pigment synthesis parallels culture development. Addition of leucine or mevalonic acid decreases pigment content. Diphenylamine (10−7 M) decreases pigment content 27%, suggesting that the carotenoids are principally xanthophylls. Absorption spectra of extracted pigments differ when glucose or fructose is the carbon source, and when fructose-containing medium is supplemented with mevalonic acid.

The cell cycle and its relationship to development in Acanthamoeba castellanii

1987 ◽  
Vol 88 (5) ◽  
pp. 579-590
Author(s):  
MICHAEL STÖHR ◽  
KURT BOMMERT ◽  
INGRID SCHULZE ◽  
HELGA JANTZEN
Keyword(s):  
Cell Cycle ◽  
Stationary Phase ◽  
Nuclear Dna ◽  
Acanthamoeba Castellanii ◽  
Nuclear Dna Content ◽  
Defined Medium ◽  
G2 Phase ◽  
D Cells ◽  
High Degree ◽  
The Relationship

The cell cycle and the relationship between particular cell cycle phases and the differentiation of trophozoites into cysts were reinvestigated in Acanthamoeba castellanii using flow fluorometric measurements of nuclear DNA content and synthesis and synchronization of cells by release from the stationary phase. The investigation was performed with cultures growing in non-defined medium (ND cells) showing a high degree of encystation in response to starvation and with subcultures growing in chemically defined nutrient medium (D cells) exhibiting a very low encystation competence. In both cultures the cell cycle starts with a short S phase taking place simultaneously with cytokinesis followed by a long G2 phase. A G1 phase seems to be either absent or very short. Synchronization experiments reveal that in ND cells encystation is initiated from a particular position of late G2. The high encystation competence of stationary phase ND cells seems to be due to arrest of cells at this particular cell cycle position. The lack of encystation competence of stationary phase D cells correlates with the loss of accumulation of cells at this particular stage of the cell cycle. This change of the property of cells is related to the growth condition and not to an irreversible loss of encystation competence of D cells.

QUALITATIVE STUDIES OF SOIL MICROORGANISMS: IX. AMINO ACID REQUIREMENTS OF RHIZOSPHERE BACTERIA

1950 ◽  
Vol 28c (1) ◽  
pp. 1-6 ◽  
Author(s):  
R. H. Wallace ◽  
A. G. Lochhead
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Soil Microorganisms ◽  
Maximum Growth ◽  
Defined Medium ◽  
Chemically Defined Medium ◽  
Special Significance ◽  
Specific Amino Acid ◽  
Pronounced Decrease ◽  
Amino Acid Requirements

A study was made of the more specific amino acid requirements of bacteria from the rhizospheres of clover, flax, and wheat plants for which a chemically defined medium containing 23 amino acids provided essentials for maximum growth. Of seven groups of amino acids, the sulphur-containing group (cysteine, methionine, and taurine) was found to be of special significance, the omission of this group resulting in a pronounced decrease in the percentage of organisms able to develop. Further study of organisms dependent upon this group of amino acids for growth showed methionine to be by far the most essential compound. While evident for bacteria from the rhizosphere of all three crops, the effect was more pronounced in the case of clover than with flax or wheat.

scholarly journals Flux Analysis of the Metabolism ofClostridium cellulolyticum Grown in Cellulose-Fed Continuous Culture on a Chemically Defined Medium under Ammonium-Limited Conditions

2001 ◽  
Vol 67 (9) ◽  
pp. 3846-3851 ◽  
Author(s):  
Mickaël Desvaux ◽  
Henri Petitdemange
Keyword(s):  
Cellulose Degradation ◽  
Lactate Production ◽  
Nitrogen Sources ◽  
Maximum Growth ◽  
Defined Medium ◽  
Flux Analysis ◽  
Specific Rate ◽  
Cellulolytic Bacteria ◽  
Limiting Nutrient ◽  
Mesophilic Bacterium

ABSTRACT An investigation of cellulose degradation by the nonruminal, cellulolytic, mesophilic bacterium Clostridium cellulolyticum was performed in cellulose-fed chemostat cultures with ammonium as the growth-limiting nutrient. At any dilution rate (D), acetate was always the main product of the catabolism, with a yield of product from substrate ranging between 37.7 and 51.5 g per mol of hexose equivalent fermented and an acetate/ethanol ratio always higher than 1. AsD rose, the acetyl coenzyme A was rerouted in favor of ethanol pathways, and ethanol production could represent up to 17.7% of the carbon consumed. Lactate was significantly produced, but with increasing D, the specific lactate production rate declined, as did the specific rate of production of extracellular pyruvate. The proportion of the original carbon directed towards phosphoglucomutase remained constant, and the carbon surplus was balanced mainly by exopolysaccharide and glycogen biosyntheses at highD values, while cellodextrin excretion occurred mainly at lower ones. With increasing D, the specific rate of carbon flowing down catabolites increased as well, but when expressed as a percentage of carbon it declined, while the percentage of carbon directed through biosynthesis pathways was enhanced. The maximum growth and energetic yields were lower than those obtained in cellulose-limited chemostats and were related to an uncoupling between catabolism and anabolism leading to an excess of energy. Compared to growth on cellobiose in ammonium-limited chemostats (E. Guedon, M. Desvaux, and H. Petitdemange, J. Bacteriol. 182:2010–2017, 2000), (i) a specific consumption rate of carbon of as high as 26.72 mmol of hexose equivalent g of cells−1h−1 could not be reached and (ii) the proportions of carbon directed towards cellodextrin, glycogen, and exopolysaccharide pathways were not as high as first determined on cellobiose. While the use of cellobiose allows highlighting of metabolic limitation and regulation of C. cellulolyticumunder ammonium-limited conditions, some of these events should then rather be interpreted as distortions of the metabolism. Growth of cellulolytic bacteria on easily available carbon and nitrogen sources represents conditions far different from those of the natural lignocellulosic compounds.

EFFECTS OF SOME AMINO ACID ANALOGUES ON BACILLUS CEREUS SPORULATION USING STATIC AND SHAKEN CULTURES

1963 ◽  
Vol 9 (6) ◽  
pp. 791-797 ◽  
Author(s):  
John P. Perkins ◽  
Daniel D. Louie ◽  
John N. Aronson
Keyword(s):  
Amino Acid ◽  
Bacillus Cereus ◽  
Developmental Stages ◽  
Defined Medium ◽  
Culture Conditions ◽  
General Validity ◽  
Static Culture ◽  
Inhibition Of Growth ◽  
Amino Acid Antagonists ◽  
Static Systems

The possible utility of static culture conditions for sporulation studies was evaluated. The effects of a series of potential amino acid antagonists on the growth and sporulation of a strain of Bacillus cereus in a defined medium were compared under both static and shaken culture conditions. A randomly picked series of 24 analogues was observed to produce all of the possible effects (no inhibition of growth or sporulation, inhibition of growth, inhibition of sporulation, delay of growth and sporulation) with no important qualitative differences between the shaken and static systems. The commonly accepted premise that shaken cultures must be used for sporulation studies has no general validity; the simpler technique of static culture may have great value for observation of the developmental stages of sporulation.

scholarly journals Persistence of Streptococcus mutans in Stationary-Phase Batch Cultures and Biofilms

2004 ◽  
Vol 70 (10) ◽  
pp. 6181-6187 ◽  
Author(s):  
John A. Renye ◽  
Patrick J. Piggot ◽  
Lolita Daneo-Moore ◽  
Bettina A. Buttaro
Keyword(s):  
Lactic Acid ◽  
Dental Caries ◽  
Stationary Phase ◽  
Streptococcus Mutans ◽  
Defined Medium ◽  
Etiological Agent ◽  
Chemically Defined Medium ◽  
Batch Cultures ◽  
Sucrose Starvation ◽  
Light Staining

ABSTRACT Streptococcus mutans is a member of oral plaque biofilms and is considered the major etiological agent of dental caries. We have characterized the survival of S. mutans strain UA159 in both batch cultures and biofilms. Bacteria grown in batch cultures in a chemically defined medium, FMC, containing an excess of glucose or sucrose caused the pH to decrease to 4.0 at the entry into stationary phase, and they survived for about 3 days. Survival was extended up to 11 days when the medium contained a limiting concentration of glucose or sucrose that was depleted by the time the bacteria reached stationary phase. Sugar-limited cultures maintained a pH of 7.0 throughout stationary phase. Their survival was shortened to 3 days by the addition of exogenous lactic acid at the entry into stationary phase. Sugar starvation did not lead to comparable survival in biofilms. Although the pH remained at 7.0, bacteria could no longer be cultured from biofilms 4 days after the imposition of glucose or sucrose starvation; BacLight staining results did not agree with survival results based on culturability. In both batch cultures and biofilms, survival could be extended by the addition of 0.5% mucin to the medium. Batch survival increased to an average of 26 (±8) days, and an average of 2.7 × 105 CFU per chamber were still present in biofilms that were starved of sucrose for 12 days.

scholarly journals Changes in Cell Size and DNA Content inSulfolobus Cultures during Dilution and Temperature Shift Experiments

1999 ◽  
Vol 181 (18) ◽  
pp. 5669-5675 ◽  
Author(s):  
Karin Hjort ◽  
Rolf Bernander
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Stationary Phase ◽  
Growth Medium ◽  
Temperature Shift ◽  
Chromosome Replication ◽  
Cellular Growth ◽  
Inhibition Of Growth ◽  
Ice Water ◽  
Fresh Growth Medium

ABSTRACT Stationary-phase cultures of different hyperthermophilic species of the archaeal genus Sulfolobus were diluted into fresh growth medium and analyzed by flow cytometry and phase-fluorescence microscopy. After dilution, cellular growth started rapidly but no nucleoid partition, cell division, or chromosome replication took place until the cells had been increasing in size for several hours. Initiation of chromosome replication required that the cells first go through partition and cell division, revealing a strong interdependence between these key cell cycle events. The time points at which nucleoid partition, division, and replication occurred after the dilution were used to estimate the relative lengths of the cell cycle periods. When exponentially growing cultures were diluted into fresh growth medium, there was an unexpected transient inhibition of growth and cell division, showing that the cultures did not maintain balanced growth. Furthermore, when cultures growing at 79°C were shifted to room temperature or to ice-water baths, the cells were found to “freeze” in mid-growth. After a shift back to 79°C, growth, replication, and division rapidly resumed and the mode and kinetics of the resumption differed depending upon the nature and length of the shifts. Dilution of stationary-phase cultures provides a simple protocol for the generation of partially synchronized populations that may be used to study cell cycle-specific events.

Accumulation and Release of Geosmin during the Growth Phases of Anabaena circinalis (Kutz.) Rabenhorst

1992 ◽  
Vol 25 (2) ◽  
pp. 185-190 ◽  
Author(s):  
B. H. Rosen ◽  
B. W. MacLeod ◽  
M. R. Simpson
Keyword(s):  
Stationary Phase ◽  
Closed Loop ◽  
Defined Medium ◽  
Exponential Growth Phase ◽  
Growth Media ◽  
Growth Phases ◽  
Flame Ionization ◽  
The Media ◽  
High Concentrations ◽  
Anabaena Circinalis

Anabaena circinalis (Kutz.) Rabenhorst was isolated during a taste and odor episode characterized by high concentrations of geosmin, with raw water containing up to 45 ng geosmin/L. This species has been successfully cultured with sustained geosmin synthesis on both sterile river water and defined medium. Gas chromatography of cellular extracts and closed-loop stripping of growth media indicated that this organism produces geosmin and not 2-methylisoborneol (MIB). With cultures we examined the changes in cell-associated geosmin, chlorophyll and released geosmin during exponential and stationary growth phases of Anabaena. Cell-associated geosmin samples were collected daily from cultures and filtered onto a polycarbonate filter, extracted in acetone, and quantified by capillary gas Chromatograph using flame ionization detection. Media-associated geosmin was quantified from algae-free filtrates from each culture concentrated by closed-loop stripping and analyzed as above. Cell-associated geosmin averaged at 8 × 10−6 ng geosmin/cell in the exponential phase and dropped to 2.5 × 10−6 ng geosmin/cell in the stationary phase of growth. The loss in cell-associated geosmin was accompanied by an increase in geosmin released into the media. Media-associated geosmin reached 12 ng/mL in the stationary phase. Apparently cell lysis in the stationary phase caused the release of cell-associated geosmin into the media. Cell-associated geosmin was closely correlated with filament number (average r2 from 4 experiments =0.96) during the exponential growth phase and was correlated with chlorophyll a (average r2 from 3 experiments =0.95).

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