PROTEINASE BIOSYNTHESIS BY STREPTOCOCCUS LIQUEFACIENS: II. PURINE, PYRIMIDINE, AND VITAMIN REQUIREMENTS

1957 ◽  
Vol 3 (4) ◽  
pp. 553-558 ◽  
Author(s):  
R. E. Hartman ◽  
L. N. Zimmerman ◽  
R. Rabin
Keyword(s):  
Synthetic Medium ◽  
Inhibitory Effect ◽  
Enzyme Synthesis ◽  
Nitrogen Bases ◽  
Best Response ◽  
Straight Line ◽  
Amino Acid Requirements ◽  
Enzyme Formation ◽  
Vitamin Requirements ◽  
Initial Medium

Proteinase biosynthesis by Streptococcus liquefaciens, strain 31, may be obtained from an entirely synthetic medium. Adenine and uracil seem to satisfy best the purine and pyrimidine requirement while pyridoxal and riboflavin is the combination of vitamins that leads to maximal enzyme biosynthesis. Biotin and folic acid together, or thiamine, have an inhibitory effect on enzyme synthesis. The amino acid requirements for optimum activity are unaffected by the reduced number of vitamins and nitrogen bases present in the final medium as compared to the initial medium. A reduction in the number of vitamins (to pyridoxal and riboflavin), however, showed that only adenine and uracil gave the best response to the purine and pyrimidine demands for biosynthesis; prior to this, in the presence of a complete vitamin pool, several combinations of nitrogen bases yielded equal enzymatic activity. When proteinase synthesis is plotted against time, enzyme formation ceases at about 3 hours. The shape of the curve indicates a straight-line relationship after an initial lag period of 90 minutes.

scholarly journals PHAGE FORMATION IN STAPHYLOCOCCUS MUSCAE CULTURES

1949 ◽  
Vol 32 (3) ◽  
pp. 301-311 ◽  
Author(s):  
Winston H. Price
Keyword(s):  
Active Substance ◽  
Synthetic Medium ◽  
Calf Thymus ◽  
Enzyme Formation ◽  
In Cells

1. A non-dialyzable fraction from fresh bakers' yeast stimulates the formation of S. muscae virus in cells in synthetic medium in the log phase of multiplication. 2. A similar fraction was not found in calf thymus, pancreas, or liver. 3. The active substance in this fraction has been partially purified. 4. This substance is taken up by the cells. In the absence of virus the added substance is metabolized to a form no longer available for virus formation. 5. A purified yeast fraction, which stimulates adaptive enzyme formation in yeast, has been found to stimulate virus formation in the S. muscae system. 6. The similarities between the yeast fraction that stimulates adaptive enzyme formation and the yeast fraction that stimulates virus formation are discussed.

scholarly journals ON THE NATURE OF SPOROGENESIS IN SOME AEROBIC BACTERIA

1952 ◽  
Vol 35 (6) ◽  
pp. 907-927 ◽  
Author(s):  
W. A. Hardwick ◽  
J. W. Foster
Keyword(s):  
De Novo ◽  
Enzyme Synthesis ◽  
Aerobic Bacteria ◽  
Low Molecular Weight ◽  
Inhibitory Effects ◽  
Nitrogenous Substances ◽  
Enzyme Formation ◽  
Spore Forming Bacteria ◽  
Endogenous Process ◽  
Exogenous Source

Washed vegetative cells of various species of aerobic spore-forming bacteria sporulate abundantly when shaken in distilled water in air. The spores thus formed possess the same heat resistance as spores formed in a complete growth medium. Various factors influencing sporogenesis in water are described. Glucose in low concentration completely suppresses sporogenesis under these conditions and the suppression is relieved by the presence of ammonia as an exogenous source of nitrogen. Various amino acid and purine antimetabolite analogues inhibit sporogenesis and their inhibitory effects are completely reversed by much smaller amounts of the corresponding metabolites. Sporogenesis is thus regarded as a de novo synthesis of spore proteins from preexisting endogenous (enzyme) proteins. Cells low in protein fail to sporulate and the capacity of the cell to adaptively attack maltose and trehalose is strongly interfered with after the cell is irreversibly committed to sporulation, but not before that. Evidence is advanced supporting the hypothesis that sporogenesis is an endogenous process which commences when the supply of exogenous energy and carbon is depleted. It utilizes low molecular weight nitrogenous substances liberated by the degradation of preexisting enzyme proteins of the vegetative cell. Sporogenesis and adaptive enzyme formation are regarded as competitive synthetic processes, both utilizing endogenous enzyme proteins. The events of sporogenesis suggest that this process may be an adaptive protein synthesis, analogous to adaptive enzyme synthesis.

Growth and Aflatoxin Production by Aspergillus parasiticus in a Medium Containing Plant Hormones, Herbicides or Insecticides

1987 ◽  
Vol 50 (12) ◽  
pp. 1044-1047 ◽  
Author(s):  
R. S. FARAG ◽  
M. A. EL-LEITHY ◽  
A. E. BASYONY ◽  
Z. Y. DAW
Keyword(s):  
Acetic Acid ◽  
Gibberellic Acid ◽  
Plant Hormones ◽  
Aspergillus Parasiticus ◽  
Synthetic Medium ◽  
Fungal Growth ◽  
Aflatoxin Production ◽  
Inhibitory Effect ◽  
Indol Acetic Acid ◽  
Acid Herbicides

The effect of some widely used plant hormones (indol-3-acetic acid and gibberellic acid), herbicides (gramoxone, stomp and treflan) and insecticides (malathion, actellic and guthion) on Aspergillus parasiticus growth and aflatoxin production in a synthetic medium was studied. Addition of indol acetic acid to the medium increased aflatoxin production more than gibberellic acid. Treflan at 5, 10 and 20 ppm levels caused a highly significant stimulatory effect on A. parasiticus growth and aflatoxin production. In contrast, stomp at 10 and 20 ppm produced the reverse effect. Guthion, an insecticide, caused a marked decrease in fungal growth and aflatoxin production. The inhibitory effect of insecticides under study on both fungal growth and aflatoxin production in effectiveness followed the sequence: guthion>actellic>malathion. At the recommended application rate (10 ppm), with the exception of indol acetic acid and treflan, all compounds suppressed mold growth and aflatoxin production.

THE ROLE OF A PROTEASE IN SPORULATION OF PENICILLIUM JANTHINELLUM

1966 ◽  
Vol 44 (5) ◽  
pp. 579-584 ◽  
Author(s):  
A. Thangamani ◽  
T. Hofmann
Keyword(s):  
Acridine Orange ◽  
Synthetic Medium ◽  
Acid Protease ◽  
Logarithmic Phase ◽  
Penicillium Janthinellum ◽  
Indirect Connection ◽  
High Enzyme ◽  
Complete Synthetic Medium ◽  
Enzyme Formation

Although peptidase A, the trypsinogen-activating acid protease of Penicillium janthinellum, is formed during the post-logarithmic phase of growth and while the organism is actively sporulating, there is no direct correlation between the production of the enzyme and sporulation. The evidence for this is threefold: (a) in surface cultures acridine orange almost completely suppresses enzyme formation but reduces sporulation to a much smaller extent; (b) 6-ethyl-thiopurine decreases spore formation but stimulates the production of peptidase A; (c) transfer of mycelium in the log phase from a complete, synthetic medium to a medium lacking nitrate induces the formation of high enzyme levels without affecting the spore count.The possibility of an indirect connection between sporulation and peptidase production is not ruled out.

scholarly journals The Role of Microbial Biofilm in Removing Ammonia in Floating Treatment Wetlands

2021 ◽  
Vol 40 (2) ◽  
pp. 101-114
Author(s):  
Muwafaq Hussein Al Lami ◽  
Michael John Whelan ◽  
Arnoud Boom ◽  
David Malcolm Harper
Keyword(s):  
Surface Area ◽  
Removal Rate ◽  
Synthetic Medium ◽  
Microbial Transformation ◽  
Inhibitory Effect ◽  
Major Effect ◽  
Ammonia Removal ◽  
Design Parameters ◽  
High Concentration ◽  
Treatment Wetland

Abstract Laboratory experiments were conducted under controlled conditions to quantify the potential of microbial transformation associated with floating matrix of floating treatment wetland (FTW) in ammonia removal and nitrification kinetics. The effect of different design parameters on ammonia removal from synthetic medium was investigated to optimize system performance. Effects of surface area of mat material, range of ammonia concentrations, and aeration on ammonia removal kinetics were studied using microcosm systems. A simple dynamics model of mineral nitrogen transformation was used as a framework for interpreting the experimental results. The results revealed that ammonia removal was enhanced in FTWs, and the magnitude of removal was controlled by the design factors examined. Removal by nitrification was directly proportional to mat surface area. The higher ammonia removal efficiency was caused by a larger surface area, which could support the growth of more microbes. Removal rate constants for treatments were 0.011, 0.015, 0.026, 0.035, and 0.033 day–1 for T1, T2, T3, T4, and T5, respectively. There was also a clear inhibitory effect of NH3 on second-stage nitrification manifested as low production of NO3–. Quantitative index of optimized knit/calibrated knit indicated high inhibition effects of NH3 at high concentration of total ammonia (60 mg N L–1). There was no major effect of oxygen saturation on NHx removal using aerated and nonaerated conditions. Better mechanistic understanding of the fundamental processes operating in FTWs should provide the basis for improving FTW design and efficacy.

scholarly journals Characterization of an Exo-β-1,3-Glucanase Produced by Pichia anomala Strain K, Antagonist of Botrytis cinerea on Apples

1998 ◽  
Vol 88 (4) ◽  
pp. 335-343 ◽  
Author(s):  
M. Haïssam Jijakli ◽  
Philippe Lepoivre
Keyword(s):  
Botrytis Cinerea ◽  
Culture Media ◽  
Morphological Changes ◽  
Synthetic Medium ◽  
Inhibitory Effect ◽  
Pichia Anomala ◽  
Cell Swelling ◽  
Glucanase Activity ◽  
Cell Wall Preparation

The exo-β-1,3-glucanase (EC 3.2.1.58) activity of Pichia anomala strain K, an antagonistic yeast of Botrytis cinerea on postharvest apples, was studied in a synthetic medium supplemented with laminarin, a cell wall preparation (CWP) of B. cinerea, or glucose. The highest enzyme activity was detected in culture media containing a CWP of B. cinerea as the sole carbon source, whereas the lowest activity was observed in culture media supplemented with glucose. Exoglc1, an exo-β-1,3-glucanase, was purified to homogeneity from culture filtrates of strain K containing a CWP. The molecular mass of exoglc1 was estimated to be under 15 kDa. Optimum activity of exoglc1 was recorded at 50°C and pH 5.5. The exoglc1 Km value was estimated at 22.4 mg/ml. Exoglc1 showed in vitro a stronger inhibitory effect on germ tube growth of B. cinerea than on conidia germination and caused morphological changes such as leakage of cytoplasm and cell swelling. Exo-β-1,3-glucanase activity was detected on apples treated with strain K and was similar to exoglc1 on the basis of activity on native gel. Moreover, the addition of a CWP to a suspension of P. anomala stimulated both in situ exo-β-1,3-glucanase activity and protective activity against the pathogen, strengthening the hypothesis that exo-β-1,3-glucanase activity is one of the mechanisms of action involved in the suppression of B. cinerea by P. anomala strain K.

Aflatoxin B1 effect on enzyme biosynthesis in Bacillus cereus and Bacillus licheniformis

1970 ◽  
Vol 16 (11) ◽  
pp. 1059-1065 ◽  
Author(s):  
Eivind B. Lillehoj ◽  
Alex Ciegler
Keyword(s):  
Bacillus Cereus ◽  
Bacillus Licheniformis ◽  
Enzyme Production ◽  
Actinomycin D ◽  
Inhibitory Effect ◽  
Enzyme Synthesis ◽  
Low Levels ◽  
Aflatoxin B ◽  
Mediated Reduction ◽  
Enzyme Biosynthesis

The effect of aflatoxin B1 on induced and constitutive enzyme synthesis was examined in strains of Bacillus cereus (NRRL B-569, NRRL B-3537) and Bacillus licheniformis (NRRL B-3560, NRRL B-3540). Although B1 partially blocked penicillinase elaboration in B. cereus after incubation with the toxin, the level of B1-mediated reduction in total protein synthesis was similar to the diminished production of penicillinase. Comparative studies on the effects of aflatoxin B1 and actinomycin D on enzyme synthesis and growth in B. licheniformis demonstrated that actinomycin D exerted a differential inhibitory effect on induction of penicillinase and α-glucosidase, whereas levels of reduction of enzyme production initiated by aflatoxin resembled toxin-mediated growth inhibition. Thus, the mode of action of aflatoxin B1 is not exclusively analogous to that of actinomycin D in B. licheniformis. However, induced-penicillinase production in B. licheniformis was enhanced by relatively low levels of both actinomycin D and aflatoxin B1.

Inhibitory Effect of Glucose on Enzyme Formation

Nature ◽  
1956 ◽  
Vol 178 (4537) ◽  
pp. 801-802 ◽  
Author(s):  
FREDERICK C. NEIDHARDT ◽  
BORIS MAGASANIK
Keyword(s):  
Inhibitory Effect ◽  
Enzyme Formation ◽  
Effect Of Glucose
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