Metabolic changes in a conidia-induced Claviceps paspali strain during submerged fermentation

1987 ◽  
Vol 33 (7) ◽  
pp. 602-606 ◽  
Author(s):  
V. Gaberc-Porekar ◽  
H. Sočič ◽  
E. Pertot ◽  
S. Miličić
Keyword(s):  
Nutrient Uptake ◽  
Mutant Strain ◽  
Submerged Fermentation ◽  
Parent Strain ◽  
Lysergic Acid ◽  
Mutagenic Treatment ◽  
Γ Irradiation ◽  
Metabolic Pattern ◽  
Metabolic Activities ◽  
Claviceps Paspali

Chemical changes in the mycelium of the conidial Claviceps paspali mutant strain, isolated after γ irradiation, were followed during the course of submerged fermentation and compared with the mycelial parent strain; both strains are capable of producing simple lysergic acid derivatives. The syntheses of lipids, carbohydrates, phosphates, nucleic acids, proteins, and alkaloids, as well as nutrient uptake, were determined. It was found that conidiation induced by mutagenic treatment was accompanied by a set of changes in the metabolic pattern. In the conidial mutant, the primary and secondary metabolic activities were repressed and the protein to nonprotein compound ratio of the cells was changed in favour of protein compounds.

Temperature-sensitive forms of large and small invertase in a mutant derived from a SUC1 strain of Saccharomyces cerevisiae

1981 ◽  
Vol 1 (5) ◽  
pp. 460-468
Author(s):  
T Mizunaga ◽  
J S Tkacz ◽  
L Rodriguez ◽  
R A Hackel ◽  
J O Lampen
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Parent Strain ◽  
Specific Activity ◽  
Single Gene ◽  
Companion Paper ◽  
Cellular Level ◽  
Temperature Sensitive ◽  
Mutagenic Treatment ◽  
Intracellular Degradation ◽  
Subunit Molecular Weight

Mutagenesis of the sucrose-fermenting (SUC1) Saccharomyces cerevisiae strain 4059-358D yielded an invertase-negative mutant (D10). Subsequent mutagenic treatment of D10 gave a sucrose-fermenting revertant (D10-ER1) that contained the same amount of large (mannoprotein) invertase as strain 4059-358D but only trace amounts of the smaller intracellular nonglycosylated enzyme. Limited genetic evidence indicated that the mutations in D10 and D10-ER1 are allelic to the SUC1 gene. The large invertases from D10-ER1 and 4059-358D were purified and compared. The two enzymes have similar specific activity and Km for sucrose, cross-react immunologically, and show the same subunit molecular weight after removal of the carbohydrate with endo-beta-N-acetylglucosaminidae H. They differ in that the large enzyme from the revertant is rapidly inactivated at 55 degrees C, whereas that from the parent is relatively stable at 65 degrees C. The small invertase in extracts of D10-ER1 is also heat sensitive as compared to the small enzyme from the original parent strain. The low level of small invertase in mutant D10-ER1 may reflect increased intracellular degradation of this heat-labile form. In several crosses of D10-ER1 with strains carrying the SUC1 or SUC3 genes, the temperature sensitivity of the large and small invertases and the low cellular level of small invertase appeared to cosegregate. These findings are evidence that SUC1 is a structural gene for invertase and that both large and small forms are encoded by a single gene. A detailed genetic analysis is presented in a companion paper.

scholarly journals Characterization of a Second Rhodococcus erythropolis SQ1 3-Ketosteroid 9α-Hydroxylase Activity Comprising a Terminal Oxygenase Homologue, KshA2, Active with Oxygenase-Reductase Component KshB

2008 ◽  
Vol 74 (23) ◽  
pp. 7197-7203 ◽  
Author(s):  
R. van der Geize ◽  
G. I. Hessels ◽  
M. Nienhuis-Kuiper ◽  
L. Dijkhuizen
Keyword(s):  
Mutant Strain ◽  
Parent Strain ◽  
Gene Deletion ◽  
Amino Acid Level ◽  
Rhodococcus Erythropolis ◽  
Pcr Primers ◽  
Transcriptional Analysis ◽  
Reporter Protein ◽  
Steroid Substrate ◽  
Key Enzyme

ABSTRACT Previously we have characterized 3-ketosteroid 9α-hydroxylase (KSH), a key enzyme in microbial steroid degradation in Rhodococcus erythropolis strain SQ1, as a two-component iron-sulfur monooxygenase, comprised of the terminal oxygenase component KshA1 and the oxygenase-reductase component KshB. Deletion of the kshA1 gene resulted in the loss of the ability of mutant strain RG2 to grow on the steroid substrate 4-androstene-3,17-dione (AD). Here we report characteristics of a close KshA1 homologue, KshA2 of strain SQ1, sharing 60% identity at the amino acid level. Expression of the kshA2 gene in mutant strain RG2 restored growth on AD and ADD, indicating that kshA2 also encodes KSH activity. The functional complementation was shown to be dependent on the presence of kshB. Transcriptional analysis showed that expression of kshA2 is induced in parent strain R. erythropolis SQ1 in the presence of AD. However, promoter activity studies, using β-lactamase of Escherichia coli as a convenient transcription reporter protein for Rhodococcus, revealed that the kshA2 promoter in fact is highly induced in the presence of 9α-hydroxy-4-androstene-3,17-dione (9OHAD) or a metabolite thereof. Inactivation of kshA2 in parent strain SQ1 by unmarked gene deletion did not affect growth on 9OHAD, cholesterol, or cholic acid. We speculate that KshA2 plays a role in preventing accumulation of toxic intracellular concentrations of ADD during steroid catabolism. A third kshA homologue was additionally identified in a kshA1 kshA2 double gene deletion mutant strain of R. erythropolis SQ1. The developed degenerate PCR primers for kshA may be useful for isolation of kshA homologues from other (actino) bacteria.

scholarly journals Metabolism of pyrithiamine by the pyrithiamine-requiring mutant of Staphylococcus aureus

1968 ◽  
Vol 107 (2) ◽  
pp. 165-169 ◽  
Author(s):  
Asru K. Sinha ◽  
G. C. Chatterjee
Keyword(s):  
Staphylococcus Aureus ◽  
Mutant Strain ◽  
Parent Strain ◽  
Culture Broth ◽  
Exponential Phase ◽  
Optimum Growth ◽  
Solvent Fractionation ◽  
Prolonged Incubation ◽  
Inhibition Index

1. A mutant strain of Staphylococcus aureus that requires pyrithiamine for its optimum growth was found to utilize pyrithiamine during the exponential phase of growth. 2. Pyrithiamine was deaminated by the organism to form oxypyrithiamine, the reaction being enzymic with no cofactor requirement. 3. On prolonged incubation of S. aureus A cultures, the concentration of deaminating enzyme increased in the culture broth, from which pyrithiamine-deaminating enzyme could be isolated by solvent fractionation. 4. Oxypyrithiamine is not a competitive analogue of thiamine although it inhibited the growth of the parent strain of S. aureus; the inhibition index of this compound, however, was lower than that of pyrithiamine.

scholarly journals Loss of Catabolite Repression Function of HPr, the Phosphocarrier Protein of the Bacterial Phosphotransferase System, Affects Expression of the cry4A Toxin Gene in Bacillus thuringiensis subsp. israelensis

2002 ◽  
Vol 184 (19) ◽  
pp. 5410-5417 ◽  
Author(s):  
Sharik R. Khan ◽  
Nirupama Banerjee-Bhatnagar
Keyword(s):  
Bacillus Thuringiensis ◽  
Mutant Strain ◽  
Catabolite Repression ◽  
Parent Strain ◽  
Inhibitory Effect ◽  
Toxin Gene ◽  
Wild Type ◽  
Phosphotransferase System ◽  
Gene Transcripts ◽  
Bacterial Phosphotransferase System

ABSTRACT HPr, the phosphocarrier protein of the bacterial phosphotransferase system, mediates catabolite repression of a number of operons in gram-positive bacteria. In order to participate in the regulatory process, HPr is activated by phosphorylation of a conserved serine-46 residue. To study the potential role of HPr in the regulation of Cry4A protoxin synthesis in Bacillus thuringiensis subsp. israelensis, we produced a catabolite repression-negative mutant by replacing the wild-type copy of the ptsH gene with a mutated copy in which the conserved serine residue of HPr was replaced with an alanine. HPr isolated from the mutant strain was not phosphorylated at Ser-45 by HPr kinase, but phosphorylation at His-14 was found to occur normally. The enzyme I and HPr kinase activities of the mutant were not affected. Analysis of the B. thuringiensis subsp. israelensis mutant harboring ptsH-S45A in the chromosome showed that cry4A expression was derepressed from the inhibitory effect of glucose. The mutant strain produced both cry4A and σ35 gene transcripts 4 h ahead of the parent strain, but there was no effect on σ28 synthesis. In wild-type B. thuringiensis subsp. israelensis cells, cry4A mRNA was observed from 12 h onwards, while in the mutant it appeared at 8 h and was produced for a longer period. The total amount of cry4A transcripts produced by the mutant was higher than by the parent strain. There was a 60 to 70% reduction in the sporulation efficiency of the mutant B. thuringiensis subsp. israelensis strain compared to the wild-type strain.

scholarly journals Efficacy of trimethoprim in murine experimental infection with a thymidine kinase-deficient mutant of Escherichia coli.

1997 ◽  
Vol 41 (5) ◽  
pp. 1042-1045 ◽  
Author(s):  
T Tokunaga ◽  
K Oka ◽  
A Takemoto ◽  
Y Ohtsubo ◽  
N Gotoh ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Thymidine Kinase ◽  
Mutant Strain ◽  
Experimental Infection ◽  
Therapeutic Efficacy ◽  
Parent Strain ◽  
E Coli

The antimicrobial activity of trimethoprim is antagonized by thymidine in in vitro susceptibility tests. The purpose of this investigation was to determine whether this antagonism also occurred during experimental infection in mice, which have high serum thymidine concentrations. We derived a mutant strain of Escherichia coli, TT-48, incapable of utilizing exogenous thymidine from parent strain E. coli KC-14 and then investigated the in vitro and in vivo antimicrobial activities of trimethoprim, sulfamethoxazole, cefdinir, and ofloxacin against these strains. E. coli TT-48 lacked the activity of thymidine kinase, which catalyzes the conversion of thymidine to thymidylate, but its growth curve remained close to that of the parent strain. The MICs of all of the antimicrobial agents tested, except cefdinir, for the mutant strain were slightly inferior to those for the parent strain. The bactericidal effect of trimethoprim against the parent strain was antagonized by thymidine at concentrations of more than 1 microg/ml, while that against the mutant strain was not affected by thymidine even at the highest concentration (10 microg/ml). The therapeutic efficacy of trimethoprim in experimental murine infections was significantly higher when the mutant rather than the parent strain was used, whereas the therapeutic efficacy of cefdinir or ofloxacin, whose antimicrobial action is independent of folic acid synthesis, was the same with both strains. Unexpectedly, sulfamethoxazole also had similar efficacy against both strains. Thus, high thymidine concentrations antagonized the antimicrobial activity of trimethoprim in vitro and in vivo.

New aspects of submerged fermentation of Claviceps paspali

1991 ◽  
Vol 34 (6) ◽  
Author(s):  
Ren�ta Bumbov�-Linhartov� ◽  
Miroslav Flieger ◽  
Petr Sedmera ◽  
Ji?� Zima
Keyword(s):  
Submerged Fermentation ◽  
Claviceps Paspali

scholarly journals Pathogenicity and Immunogenicity of a Mutant Strain ofListeria monocytogenesin the Chicken Infection Model

2011 ◽  
Vol 18 (3) ◽  
pp. 500-505 ◽  
Author(s):  
Yuelan Yin ◽  
Debin Tian ◽  
Hongmei Jiao ◽  
Chenju Zhang ◽  
Zhiming Pan ◽  
...  
Keyword(s):  
Immune Response ◽  
Mutant Strain ◽  
Parent Strain ◽  
Lethal Dose ◽  
Oral Route ◽  
Infection Model ◽  
Listeriolysin O ◽  
Wild Type ◽  
Strong Immune Response ◽  
Booster Immunization

ABSTRACTListeria monocytogeneshas been exploited as a vaccine carrier based upon its ability to induce a strong cell-mediated immune response. At present, the safety of live, attenuatedL. monocytogenesvaccines in patients is being studied in clinical trials.L. monocytogenesis also an attractive vaccine vector for use in poultry; however, the pathogenicity and immunogenicity of this organism in poultry remain to be fully elucidated. In this study, we investigated the pathogenicity and immunogenicity of anactA- andplcB-deficientL. monocytogenesstrain, yzuLM4ΔactA/plcB, and its wild-type parent strain, yzuLM4, in an avian infection model. The results showed that the wild-type strain could infect ISA brown chickens, causing serious tissue disruptions, including various degrees of degeneration, necrotic lesions, and inflammatory cell infiltration in the liver, spleen, heart, and kidney. However, the mutant strain showed reduced virulence in embryonated eggs compared with that of the parent strain (the 50% lethal dose [LD50] was 3 logs higher). The mutant strain also showed low virulence in chickens and was rapidly eliminated by the host. There were no obvious pathological changes in tissue sections, but the mutant strain still retained the ability to stimulate high levels of antibody against the protein listeriolysin O (LLO). Booster immunization with the mutant strain led to rapid bacterial clearance from the livers and spleens of chickens challenged by the intramuscular route or the oral route. Collectively, our data suggest that the wild-type serotype 1/2aL. monocytogenesstrain can cause serious disease in chickens but the mutant strain with a deletion of theactAandplcBgenes is less virulent but induces a strong immune response. This mutant strain ofL. monocytogenesis therefore a promising candidate as a safe and effective vector for the delivery of heterologous antigens to prevent zoonosis and infectious disease in poultry.

scholarly journals Biological Role of Xanthomonadin Pigments inXanthomonas campestris pv. Campestris

2000 ◽  
Vol 66 (12) ◽  
pp. 5123-5127 ◽  
Author(s):  
A. R. Poplawsky ◽  
S. C. Urban ◽  
W. Chun
Keyword(s):  
Mutant Strain ◽  
Parent Strain ◽  
Xanthomonas Campestris ◽  
Uv Light ◽  
High Light Intensity ◽  
Biological Role ◽  
Insertion Mutant ◽  
Mutant Strains ◽  
Epiphytic Survival

ABSTRACT Previous studies have indicated that the yellow pigments (xanthomonadins) produced by phytopathogenic Xanthomonasbacteria are unimportant during pathogenesis but may be important for protection against photobiological damage. We used a Xanthomonas campestris pv. campestris parent strain, single-site transposon insertion mutant strains, and chromosomally restored mutant strains to define the biological role of xanthomonadins. Although xanthomonadin mutant strains were comparable to the parent strain for survival when exposed to UV light; after their exposure to the photosensitizer toluidine blue and visible light, survival was greatly reduced. Chromosomally restored mutant strains were completely restored for survival in these conditions. Likewise, epiphytic survival of a xanthomonadin mutant strain was greatly reduced in conditions of high light intensity, whereas a chromosomally restored mutant strain was comparable to the parent strain for epiphytic survival. These results are discussed with respect to previous results, and a model for epiphytic survival of X. campestris pv. campestris is presented.

Production of lysergic acid derivatives with immobilized Claviceps paspali mycelium

1989 ◽  
Vol 32 (1) ◽  
pp. 5-10 ◽  
Author(s):  
Damjana Rozman ◽  
Elizabeta Pertot ◽  
Radovan Komel ◽  
Miro Prošek
Keyword(s):  
Lysergic Acid ◽  
Claviceps Paspali
Sign in / Sign up

Export Citation Format

Share Document