Zinc–Phosphorus Interactions and Variation in Zinc Accumulation during Growth of Chlamydomonas variabilis (Chlorophyceae) in Batch Culture

1985 ◽  
Vol 42 (1) ◽  
pp. 86-94 ◽  
Author(s):  
Stephen S. Bates ◽  
André Tessier ◽  
Peter G. C. Campbell ◽  
Martin Létourneau
Keyword(s):  
Stationary Phase ◽  
Batch Culture ◽  
Growth Cycle ◽  
Stationary Growth Phase ◽  
Cell Yield ◽  
Critical Threshold ◽  
Intracellular Zinc ◽  
Zinc Concentrations ◽  
Insoluble Phosphorus ◽  
High Concentrations

Concentrations of EDTA-extractable zinc ([Zn]a ~ surface-bound zinc) and non-EDTA-extractable zinc ([Zn]c ~ transported zinc) were measured over the growth cycle of Chlamydomonas variabilis Dangeard growing in pH-controlled batch culture in the presence of six concentrations of free ionic zinc. Values of [Zn]a generally decreased throughout the growth cycle in batch culture, the exact pattern of change depending on whether the cells used to inoculate the experiment were obtained from a stock culture in the exponential or stationary growth phase. Concentrations of cellular TCA-insoluble phosphorus (polyphosphate) also declined throughout the growth cycle. Values of [Zn]c increased linearly throughout the exponential phase for growth at all zinc concentrations studied, but during the stationary phase they either reached a plateau for growth at 1.4 and 8.4 μmol Zn2+∙L−1, continued to increase linearly for growth at 13.2, 15.8, and 20.6 μmol Zn2+∙L−1, or declined for growth at 25.4 μmol Zn2+∙L−1. The cell yield of C. variabilis during the stationary phase was significantly decreased (by up to 90%) for growth in the presence of high concentrations of free ionic zinc. These cells also contained significantly more phosphorus than those grown in the presence of low free ionic zinc concentrations, but did not remove all of the initially added phosphorus from the growth medium. We hypothesize that cellular polyphosphate binds the transported zinc. As the concentration of cellular polyphosphate declines with increasing culture age, a portion of the previously bound intracellular zinc is released into the cell and exceeds a critical threshold, disrupting phosphorus metabolism, interfering with cell division, and decreasing cell yield.

Effects of Ammonium and Nitrate on Growth and Domoic Acid Production by Nitzschia pungens in Batch Culture

1993 ◽  
Vol 50 (6) ◽  
pp. 1248-1254 ◽  
Author(s):  
Stephen S. Bates ◽  
Jean Worms ◽  
John C. Smith
Keyword(s):  
Stationary Phase ◽  
Batch Culture ◽  
Domoic Acid ◽  
Skeletonema Costatum ◽  
Cell Yield ◽  
Ammonia Toxicity ◽  
Lag Phase ◽  
Enhanced Production ◽  
Nitrogen Concentrations ◽  
Nitzschia Pungens

Four clones of Nitzschia pungens f. multiseries (toxin-producing form) and two of N. pungens f. pungens (nontoxic) were grown in batch culture at initial nitrogen concentrations of 55, 110, 220, 440, and 880 μM in the form of either nitrate or ammonium. As expected, only N. pungens f. multiseries clones produced the neurotoxin, domoic acid (DA). Ammonium at 880 μM prevented the growth of all N. pungens clones but not of Skeletonema costatum, although division rate was reduced. At 440 μM, ammonium lowered the cell yield obtained during the stationary phase, inhibited photosynthesis, and caused a lag phase during which DA was produced (by f. multiseries). At 220 and 440 μM ammonium, in contrast with the same concentrations of nitrate, stationary phase cellular DA production was enhanced by two- to fourfold. At 110 and 55 μM nitrogen, cell yield and DA production were equivalent for nitrate and ammonium but less DA was produced relative to the higher nitrogen concentrations, possibly due to nitrogen depletion. Enhanced production of DA at elevated ammonium concentrations may be a response to ammonia toxicity. This could be a useful tool for studying mechanisms of DA production and for maximizing the yield of this valuable toxin in large-scale cultures.

scholarly journals Conversion of Daidzein and Genistein by an Anaerobic Bacterium Newly Isolated from the Mouse Intestine

2008 ◽  
Vol 74 (15) ◽  
pp. 4847-4852 ◽  
Author(s):  
Anastasia Matthies ◽  
Thomas Clavel ◽  
Michael Gütschow ◽  
Wolfram Engst ◽  
Dirk Haller ◽  
...  
Keyword(s):  
Stationary Phase ◽  
Enzyme Induction ◽  
Growth Phase ◽  
Anaerobic Bacterium ◽  
Stationary Growth Phase ◽  
Gut Bacteria ◽  
Soy Isoflavones ◽  
Strictly Anaerobic ◽  
Stationary Growth ◽  
Mouse Intestine

ABSTRACT The metabolism of isoflavones by gut bacteria plays a key role in the availability and bioactivation of these compounds in the intestine. Daidzein and genistein are the most common dietary soy isoflavones. While daidzein conversion yielding equol has been known for some time, the corresponding formation of 5-hydroxy-equol from genistein has not been reported previously. We isolated a strictly anaerobic bacterium (Mt1B8) from the mouse intestine which converted daidzein via dihydrodaidzein to equol as well as genistein via dihydrogenistein to 5-hydroxy-equol. Strain Mt1B8 was a gram-positive, rod-shaped bacterium identified as a member of the Coriobacteriaceae. Strain Mt1B8 also transformed dihydrodaidzein and dihydrogenistein to equol and 5-hydroxy-equol, respectively. The conversion of daidzein, genistein, dihydrodaidzein, and dihydrogenistein in the stationary growth phase depended on preincubation with the corresponding isoflavonoid, indicating enzyme induction. Moreover, dihydrogenistein was transformed even more rapidly in the stationary phase when strain Mt1B8 was grown on either genistein or daidzein. Growing the cells on daidzein also enabled conversion of genistein. This suggests that the same enzymes are involved in the conversion of the two isoflavones.

scholarly journals Acinetobacter baylyi Starvation-Induced Genes Identified through Incubation in Long-Term Stationary Phase

2010 ◽  
Vol 76 (14) ◽  
pp. 4905-4908 ◽  
Author(s):  
C. Phoebe Lostroh ◽  
Bruce A. Voyles
Keyword(s):  
Gene Expression ◽  
Stationary Phase ◽  
Batch Culture ◽  
Exponential Growth ◽  
Hypothetical Proteins ◽  
Acinetobacter Baylyi ◽  
Metabolic Gene Expression ◽  
Induced Genes ◽  
Dna Maintenance

ABSTRACT Acinetobacter species encounter cycles of feast and famine in nature. We show that populations of A cinetobacter baylyi strain ADP1 remain dynamic for 6 weeks in batch culture. We created a library of lacZ reporters inserted into SalI sites in the genome and then isolated 30 genes with lacZ insertions whose expression was induced by starvation during long-term stationary phase compared with their expression during exponential growth. The genes encode metabolic, gene expression, DNA maintenance, envelope, and conserved hypothetical proteins.

scholarly journals Mycobacterial resistance to zinc poisoning requires assembly of P-ATPase-containing membrane metal efflux platforms

2021 ◽  
Author(s):  
Yves-Marie Boudehen ◽  
Marion Faucher ◽  
Xavier Marechal ◽  
Roger Miras ◽  
Jerome Rech ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Metal Binding ◽  
Bacterial Resistance ◽  
Binding Motif ◽  
Membrane Microdomain ◽  
High Zinc ◽  
Functional Membrane ◽  
Zinc Concentrations ◽  
Metal Efflux ◽  
High Concentrations

Transition metals are toxic at high concentrations. The P1B-ATPase metal exporter CtpC/Rv3270 is required for resistance to zinc poisoning in the human pathogen Mycobacterium tuberculosis. Here, we discovered that zinc resistance also depends on the chaperone-like protein PacL1/Rv3269. PacL1 bound Zn2+, but unlike PacL1 and CtpC, the PacL1 metal-binding motif (MBM) was required only at high zinc concentrations. PacL1 co-localized with CtpC in dynamic microdomains within the mycobacterial plasma membrane. Microdomain formation did not require flotillins nor the PacL1 MBM. Instead, loss of the PacL1 Glutamine/Alanine repeats led to loss of CtpC and sensitivity to zinc. PacL1 and CtpC are within the same operon, and homologous PacL1-P1B-ATPase pairs are widely distributed within and across prokaryotes. PacL1 colocalized and functioned redundantly with PacL orthologs in Mycobacterium tuberculosis. Overall, our study suggests that PacL proteins are scaffolds that assemble P-ATPase-containing metal efflux platforms, a novel type of functional membrane microdomain that underlies bacterial resistance to metal poisoning.

Associations Between Cellular Levels of ATP and Prodigiosin Pigment Throughout the Growth Cycle of Serratia marcescens

2021 ◽  
Author(s):  
Pryce L. Haddix
Keyword(s):  
Stationary Phase ◽  
Serratia Marcescens ◽  
Stationary Phases ◽  
Growth Cycle ◽  
High Density ◽  
High Rate ◽  
Lag Phase ◽  
Positive Role ◽  
Atp Production ◽  
Density Growth

ABSTRACT Serratia marcescens is a prolific producer of the red, membrane-associated pigment prodigiosin. Earlier work has established both a positive role for prodigiosin in ATP production during population lag phase and a negative role during high-rate, low cell density growth. This study uses the growth rate and growth phase modulation afforded by chemostat culture to extend prodigiosin functional analysis to the high density and stationary phases. Cellular levels of prodigiosin were positively associated with cellular levels of ATP during high-density growth, and artificial pigment induction during this phase increased cellular ATP. Following peak high density ATP per cell, early stationary phase enabled significant population growth while prodigiosin levels remained high and ATP declined. During late stationary phase, ATP per cell was positively associated with prodigiosin per cell while both declined during continued growth. These results provide correlational evidence for multiple effects of prodigiosin pigment on ATP production throughout the growth cycle. Earlier work and the data presented here enable formulation of a working model for the oscillating relationships between cellular levels of ATP and prodigiosin during batch culture.

Zinc concentrations in juvenile flatfish

1979 ◽  
Vol 59 (3) ◽  
pp. 761-775 ◽  
Author(s):  
N. J. Milner
Keyword(s):  
Sea Water ◽  
Chemical Properties ◽  
Estuarine Fish ◽  
Physico Chemical ◽  
Zinc Cadmium ◽  
Iron And Zinc ◽  
Lead Levels ◽  
Zinc Concentrations ◽  
High Concentrations ◽  
Cadmium And Lead

In most demersal and some pelagic marine fish O- and I-group stages are found on inshore nursery grounds which are often situated in coastal indentations and estuarieswhere flushing rates are low and the build up of persistent pollutants can be correspondingly high. Their movements are restricted, only leaving the nursery areas towards the end of their second year (Lockwood, 1974; Riley, 1973). This, coupled with the fact that juveniles may be more susceptible than adults to pollutants, makes them particularly vulnerable to the potential hazards of inshore pollution.The physico-chemical properties of most trace metals, however, generally preclude their occurrence at high concentrations in sea water itself. Instead, most of the metal is transferred to the particulate phase of the water mass and to sedimentary reservoirs (Renfro, 1973) so that concentrations of metals in sea water very rarely reach levels which are known to be acutely toxic to fish. The main risk from direct effects of metals lies in poisoning resulting from internal accumulation.Little information is available on metal concentrations occurring in young fish. Hardisty et al. (1974) and Hardisty, Kartar & Sainsbury (1974) have examined zinc, cadmium and lead levels in O-group and older flounders from the Bristol Channel. Andersen, Dommasnes & Hesthagen (1973) found high concentrations of zinc in O- and I-group herring and sprat from Oslo Fjord, Cross & Brooks (1973) reported on manganese, iron and zinc concentrations in juvenile estuarine fish. Pentreath (1973 b) has reported on zinc concentrations in the organs of I-group plaice.

GROWTH STUDIES ON ARTHROBACTER GLOBIFORMIS: II. CHANGES IN MACROMOLECULAR LEVELS DURING GROWTH

1962 ◽  
Vol 8 (5) ◽  
pp. 655-661 ◽  
Author(s):  
I. L. Stevenson
Keyword(s):  
Stationary Phase ◽  
Fold Increase ◽  
Growth Cycle ◽  
Phase Cell ◽  
Lag Phase ◽  
Differential Rate ◽  
Protein Ratio ◽  
Stationary Phase Culture ◽  
Protein Levels ◽  
Dna And Protein Synthesis

Changes in macromolecular levels (RNA, DNA, protein) have been followed during the growth cycle of A. globiformis. When a stationary phase culture is transferred to fresh medium a 12-fold increase in RNA level and 6-fold increases in DNA and protein levels are observed during the predivisional lag phase. Initially RNA synthesis precedes DNA and protein synthesis but all reach the same differential rate 2 to 3 hours prior to division. During the predivisional lag period the RNA/protein ratio per cell expands from 0.19 to 0.36. Once division occurs, cells of A. globiformis remain in the enlarged pleomorphic form until the medium becomes limiting; at this time synthesis of macromolecules ceases and the continued division (three to four generations) results in progressively smaller cells until the coccoid stationary phase cell-type is reached.

Correction of zinc and boron deficiencies and control of phytophthora root rot of avocardo by trunk injection

1991 ◽  
Vol 31 (4) ◽  
pp. 575 ◽  
Author(s):  
AW Whiley ◽  
KG Pegg ◽  
JB Saranah ◽  
PW Langdon
Keyword(s):  
Root Rot ◽  
Growing Season ◽  
Zinc Nitrate ◽  
Threshold Concentration ◽  
Persea Americana ◽  
Critical Threshold ◽  
Phytophthora Root Rot ◽  
Zinc Concentrations ◽  
Trunk Injection ◽  
And Control

Phosphonate at 3 concentrations (7.5, 10 and 20%) was injected into the trunks of avocado (Persea americana Mill.) trees showing advanced symptoms of canopy decline caused by phytophthora root rot. All formulations of phosphonate and potassium phosphonate, including the lower rates of 7.5 and 10%, successfully controlled root rot and resulted in improved tree health. The 7.5% phosphonate treatment permitted the formulation of chemically compatible mixtures containing zinc and boron which, when trunk-injected, increased the concentrations of these nutrients in mature summer-grown leaves. Phosphonate formulations containing 17% zinc chelate or 10% zinc nitrate and injected twice during a growing season, at 15 mL/m canopy diameter, increased leaf zinc concentrations above the critical level of 30 mg/kg DM. However, the inclusion of zinc chelate in formulations substantially increased the time of uptake of the injection compared with the formulation containing zinc nitrate. Phosphonate formulations with 0.9% boron, injected twice during a growing season at 15 mL/m canopy diameter, improved leaf boron concentrations, but they failed to reach the critical threshold concentration of 50 mg/kg DM.

scholarly journals Characterization of LrgAB as a stationary phase-specific pyruvate uptake system in Streptococcus mutans

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Sang-Joon Ahn ◽  
Kamal Deep ◽  
Matthew E. Turner ◽  
Ivan Ishkov ◽  
Anthony Waters ◽  
...  
Keyword(s):  
Carbon Source ◽  
Stationary Phase ◽  
Streptococcus Mutans ◽  
Feedback Regulation ◽  
Growth Conditions ◽  
Stationary Growth Phase ◽  
Uptake System ◽  
Independent Manner ◽  
Negative Feedback Regulation ◽  
Glucose Levels

Abstract Background Our recent ‘-omics’ comparisons of Streptococcus mutans wild-type and lrgAB-mutant revealed that this organism undergoes dynamic cellular changes in the face of multiple exogenous stresses, consequently affecting its comprehensive virulence traits. In this current study, we further demonstrate that LrgAB functions as a S. mutans pyruvate uptake system. Results S. mutans excretes pyruvate during growth as an overflow metabolite, and appears to uptake this excreted pyruvate via LrgAB once the primary carbon source is exhausted. This utilization of excreted pyruvate was tightly regulated by glucose levels and stationary growth phase lrgAB induction. The degree of lrgAB induction was reduced by high extracellular levels of pyruvate, suggesting that lrgAB induction is subject to negative feedback regulation, likely through the LytST TCS, which is required for expression of lrgAB. Stationary phase lrgAB induction was efficiently inhibited by low concentrations of 3FP, a toxic pyruvate analogue, without affecting cell growth, suggesting that accumulated pyruvate is sensed either directly or indirectly by LytS, subsequently triggering lrgAB expression. S. mutans growth was inhibited by high concentrations of 3FP, implying that pyruvate uptake is necessary for S. mutans exponential phase growth and occurs in a Lrg-independent manner. Finally, we found that stationary phase lrgAB induction is modulated by hydrogen peroxide (H2O2) and by co-cultivation with H2O2-producing S. gordonii. Conclusions Pyruvate may provide S. mutans with an alternative carbon source under limited growth conditions, as well as serving as a buffer against exogenous oxidative stress. Given the hypothesized role of LrgAB in cell death and lysis, these data also provide an important basis for how these processes are functionally and mechanically connected to key metabolic pathways such as pyruvate metabolism.

Evaluating In Vitro Antimicrobial Activity of Thymol toward Hygiene-Indicating and Pathogenic Bacteria

2007 ◽  
Vol 70 (2) ◽  
pp. 425-431 ◽  
Author(s):  
PASQUALE M. FALCONE ◽  
MARIANNA MASTROMATTEO ◽  
MATTEO A. DEL NOBILE ◽  
MARIA R. CORBO ◽  
MILENA SINIGAGLIA
Keyword(s):  
Antimicrobial Activity ◽  
Stationary Phase ◽  
Growth Kinetics ◽  
Active Compound ◽  
Quantitative Description ◽  
Lag Time ◽  
Growth Cycle ◽  
Microbial Response ◽  
Wide Range

Results of a study of the kinetics of bacterial inhibition by thymol in order to develop appropriate applications for the compound in food systems are presented. A modeling-based approach was used to provide a quantitative description of the antimicrobial activity of thymol toward some foodborne pathogens and hygiene-indicating bacteria, which could be postprocessing contaminants of ready-to-eat meat products. The effect of the active compound on the bacterial growth was assessed from growth kinetics curves and dose-response profiles in a wide range of thymol concentrations, i.e., from 50 to 1,000 ppm. Inhibitory data were produced using a macrodilution methodology based on a turbidimetric technique. Microbial response was discussed in terms of Gompertz's parameters as well as in terms of the active concentration of thymol affecting the growth status of microbial suspension (noninhibitory concentration and MIC). Results suggested that thymol can be successfully used as an alternative antimicrobial to increase the lag time as well as to decrease the maximum value of the growth index as reached in the stationary phase of the growth cycle for all investigated bacteria. Due to their high sensitivity to the antimicrobial stress as observed at sub-MIC, it is arguably a potential use of thymol for assurance of food safety and hygiene in combination with other preservative technologies. A quantitative evaluation of the antimicrobial properties of the active compound was performed using a macrodilution methodology based on a turbidimetric technique to produce inhibitory data. Both the growth kinetics and inhibition profile in a wide range of thymol concentrations were obtained for each test bacterium, mathematically modeled, and analyzed. Noninhibitory concentration and MIC were determined to investigate both the microbial sensibility and resistance toward thymol, and Gompertz's parameters were evaluated to assess the microbial response at each phase of growth cycle. The in vitro–obtained results suggested that thymol may be successfully used as a alternative preservative to increase the lag time as well as to decrease the maximum cell load reached in the stationary phase of growth cycle for all investigated bacteria.

Sign in / Sign up

Export Citation Format

Share Document