• 한국식품영양학회지
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• 제7권1호
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• pp.58-63
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• 1994

Sporulation of Streptomyces griseus NRRL B-2682 occurs at 26~28 hours during incubation while shaking at 3$0^{\circ}C$ in a defined medium. The time of sporulation is the same when the levels of each nutrient is increased ten times. The levels of the carbon, nitrogen and phosphate source are at a high level when sporulation begins. Sporulation of S. griseus B-2682 is clearly not caused by nutrient deprivation. It appears that a clock mechanism is involved instead. Once spores are germinated, the time of sporulation is programmed. Sporulation of S. griseus is repressed by high levels of casein hydrolysate. A study of the effect of individual amino acids revealed that L-valise when added to the normal growth medium causes an inhibition or repression of sporulation without affecting growth.

• Mycobiology
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• 제31권1호
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• pp.36-41
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• 2003

Influence of physiological and environmental factors on an antagonistic strain of Trichoderma viride RSR7 were studied optimize its biocontrol potential. The growth and sporulation of T. viride was greatly influenced by various carbon and nitrogen sources, and the environmental factors such as pH and temperature. The best growth and sporulation of T. viride was observed when sucrose, peptone and trehalose were supplemented in the medium as sole carbon sources. Rhamnose, pyruvic acid and sorbitol also supported a good growth. However, with these carbon sources the sporulation was poor. Growth and sporulation was also affected by various nitrogen sources. Growth and sporulation both were favoured by ammonium forms of nitrogen compared to nitrite or nitrate forms. Urea did not support either growth or sporulation. Among amino acids, glutamic acid, asparagine, leucine, aspartic acid, glutamic acid and alanine supported good growth as well as sporulation. T. viride was able to utilize large number of amino acids as sole nitrogen source. Proline was good for growth, but not for sporulation. Maximum growth and sporulation of T. viride was between pH 4.5 to 5.5. Temperatures between $20^{\circ}C\;and\;37^{\circ}C$ were good for both growth and sporulation of T. viride. At lower temperatures(i.e. below $20^{\circ}C$) growth and sporulation were inhibited. Based on the present study it may be concluded that T. viride RSR7 is capable of growing and sporulating with varied nutritional and environmental conditions and, therefore, this strain of T. viride may be useful as a biocontrol agent under diverse physiological and environmental conditions.

• 미생물학회지
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• 제17권2호
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• pp.81-93
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• 1979

The mycelium of Rhizopus nigricans was harvested at intervals during the sporulation periods, fractioned into various cell components and analyzed the con!eiits of various cell materials in order to clarify the optimum conditions of sporulation and some characteristics of the metabolism during tke sporulation periods. The changes in enzyme activities, such as amylase and protease, were also measured during the sporulation period,. 1. Mycelium in distilled water culture, as control, did not sporulate but mycelial mat cultured in Petridish without mutrient spourulated. Optimum temperature range for sporulation was $20{\sim}25^{\circ}C$. 2. During the sporulation and maturation periods, proteins, especially alkali-labile protein were decreased remarkably but free amino acid and ninhydrin reactive substances in acid soluble fraction were increased, compared with control. 3. Acid solable polyphosphate was decreased but acid insoluble polyphosphate was increased, during the sporulation. 4. Carbohydrate and hexosamine in acid soluble fraction were increased, while carbohydrate in alkali insoluble residual fraction was decreased during the sporulation periods. 5. Amounts of UV-absorbing material in deoxyribonucleic acid fraction was increased a little but those in ribonucleic acid fraction was decreased, compared with control. 6. Intracellular amylases and proteases activities insporulating mycelial mat were increased continuously during the sporulation and maturation periods.

• 한국균학회지
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• 제15권4호
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• pp.238-246
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• 1987

1. 검정곰팡이(Aspergillus niger)를 실험균주로 하여 동조적으로 액침배양한 결과 포자의 발아로 부터 균사의 생장, 생식기관의 성숙 및 무성포자의 형성까지를 재현시켰다. 2. 포자형성용 배지(D배지)에 cAMP를 첨가한 실험구에 있어서는 포자형성이 촉진되었고, 그 최적 농도는 $10^{-4}M$이었다. 3. 포자형성용 배지(D배지)에 첨가한 테오필린은 포자형성을 촉진하였고, 그 최적농도는 10mg/ml이었다. 4. 포자형성용 배지(D배지)에 첨가한 카페인은 포자형성을 촉진하였고, 그 최적농도는 300mg/ml이었다. 5. 포자형성용 배지(D배지)에 cAMP와 테오필린을 함께 첨가한 실험구에서는 cAMP 단독 첨가 실험구보다 포자형성 촉진효과가 더욱 강화되었다. 6. 포자형성용 배지(D배지)에 cAMP와 카페인을 함께 첨가한 실험구에서는 cAMP 단독 첨가 실험구보다 포자형성 촉진효과가 더욱 강화되었다. 7. 포자형성용 배지(D배지)에 AMP나 ATP를 첨가한 실험구에서는 포자형성 촉진효과가 거의 없었다. 8. 아세트산염 배지에 cAMP, 테오필린, 카페인을 각각 첨가한 실험구에서는 포자형성에 대해 촉진효과를 나타내었다.

• Journal of Microbiology and Biotechnology
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• 제11권6호
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• pp.1106-1110
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• 2001

The parasporal biogenesis of crystal inclusion during the sporulation of Bacillus sphaericus strain 1593 was observed using transmission electron microscopy. The crystal biogenesis and sporulation process involved a sequence of events talking about 10 h. The sporulation Precesses were found to be similar to previous findings. The crystal biogenesis of B. sphaericus was initiated at the start of engulfment and nearly completed by the time of exosporium formation. The crystal formation was clearly associated with the outer forespore membrane from stages III through VI, and the crystals grew from polypeptide-like chains originated from the outer forespore membrane. These observations are different from previous findings, which report no association with the forespore membrane. The crystals were located adjacent to the outer membrane of the spore until the release stage. The axes size of the bipyramidal crystal was approximately $0.25{\mu}m{\times}42{\mu}m$. During crystal biogenesis, the crystal development could be classified into four stages; initiation stage Cl (sporulation stage . III), growth stage C2 (sporulation III to V), envelopment and maturation C3 (sporulation V to V), and finally release stage C4 (sporulation Vll).

• Journal of Microbiology
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• 제43권3호
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• pp.244-250
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• 2005

The effect of cytochrome $c_{550}$ encoded by cccA in Bacillus subtilis during the event of sporulation was investigated. The sporulation of cccA-overexpressing mutant was significantly accelerated, while disruptant strain showed delayed sporulation in spite of the same growth rate. Activity of sporulation stage-0-specific enzyme, extracellular $\alpha-amylase$ of mutant strains was similar to that of the control strain, but cccA-overexpressing mutant exhibited higher activity of stage-II-specific alkaline phosphatase and stage-III-specific glucose dehydrogenase when compared to deletion mutant and control strain. Northern blot analysis also revealed that cccA-overexpressing mutant showed high level of spo0A transcripts, while the disruptant rarely expressed spo0A. These results suggested that although cytochrome $c_{550}$ is dispensable for growth and sporulation, expression of cccA may play an important role for initiation of sporulation through regulation of spo0A expression.

• The Plant Pathology Journal
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• 제15권6호
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• pp.330-334
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• 1999

Applying the method of quantitative analysis of pycnidiospore from the detached warts produced by the infection of Botryosphaeria dothidea on apple stems, repeated productivity of spores within the detached warts, variations in the amount of spores within the detached warts, variations in the amount of spores by the length of induction time for sporulation, and the effects of temperature and moisture on the sporulation were investigated. In addition to these experiment, the changes in the state of spores within the pycnidia contained in the warts accompanied by the induction of sporulation and dispersal of spores were also investigated. When detached warts were kept in moist conditions, the sporulation and discharge of spores were also investigated. When detached warts were kept in moist conditions, the sporulation and discharge of spores could be repeated several times, and the amount of spores were almost constant after each repeat of sporulation induction and dispersal of spores in a given period. The fact that the pycnidia filled with spores were observed at considerable rates within the warts which were subjected to the shaking in the water to release spores indicated that the spores might never be released until the pycnidia were fully matured. From the high rate of empty pycnidia even in the warts which were kept in moist conditions for induction of sporulation, the pycnidiospores might be produced through the development of new pycnidia. A considerable amount of pycnidiospores were produced at $5^{\circ}$, and the sporulation was accelerated with the rise of temperature until $35^{\circ}$. When the warts were supplied with sufficient moisture, sporulation was further accelerated. The results obtained in these experiment will be applied in developing the method for assessing the inhibitory efficacies of fungicides on the sporulation of this fungus, with which a new control measure would be developed.

• 미생물학회지
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• 제16권4호
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• pp.148-154
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• 1978

Saccharomyces cerevisiae J170, a mutant, was used for $DL-^{14}C-leucine$ uptake during the sporulation and vegetative stage. $^{14}C-Leucine$ uptake into yeast cells appeared the highest at pH 6.0, indicating the same result of glucose transport, $^{14}C-Leucine$ uptake in sporulation period was higher than in growth phase, showing the evidence that leucine is more required for protein synthesis. This tendency has the evidence tht leucine is more required for protein synthesis. This tendency has the evidence that leucine is more required for protein synthesis. This tendency has been also supported from the result of Km values of leucine uptake in two stages of yeast. Leucine uptake was inhibited by 2,4-dinitrophenol in two stages of yeast. This means that leucine transport system is associated with energy dependent in both stages. The contents of all amino acid in growth phase cells were higher than those of sporulation stge cells, and those of methionine and tyrosine were showed in trace during the sporulation stage. In contrast, the content of glutamic acid in sporulation stage was compared with those of other amino acids.

• The Plant Pathology Journal
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• 제16권3호
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• pp.147-150
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• 2000

Sporulation patterns of rice blast fungus were studied at relatively later stages of leaf blast and neck blast seasons in Icheon, Korea. This experiment was done by detaching lesion-bearing leaves and panicle bases. The number of conidia remaining on the leaf blast lesions of different cultivars from Jul 20 to Jul 23 ranged from 3,640 to 82,740 spores. More conidia were observed on the adaxial surface because they were released from abaxial surface. After heading, sporulation was observed from the lesions on the flag leaves but the number of spores was less than in the late July. Detached panicle bases or uppermost internodes infected by Pyricularia grisea produced abundant amount of conidia. Among these panicle bases, 30.1 mm size lesion recorded the highest count of 244,560 spores. When we compared the sporulation amount using the KY-type spore trap, more conidia were recorded from intact lesions than from the lesions which removed conidia and conidiophore The ratio of conidia release against total sporulation ranged from 20.5%-25.0% for leaf blast and 8.2%-25.3% in the neck blast. Effective inoculum potential was also discussed.

• Journal of Microbiology
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• 제35권1호
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• pp.61-65
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• 1997

A novel strategy was developed for isolating suppressors from sporulation-deficient mutants. The mutation in the BCY1 gene, which codes for the regulatory subunit of cAMP-dependent protein kinase, when homozygous, results in diploids being meiosis and sporulation deficient. Two plasmids, YCp-MAT.alpha. and YEp-SPOT7-lacZ, were introduced into MAT.alpha. BCY1$\^$+/ or MAT.alpha. bcy1 haploid cells. The transformant of the BCY1$\^$+/ haploid cell produced .betha.-galactosidase under nutrient starvation, but the bcy1 transformant did not. Using this system, the mutagenesis experiment performed on the bcy1 transformant strain resulted in a number of sporulation mutants that produced .betha.-galactosidase under nutrient starvation. One complementation group, sob1, was identified from the isoalted suppressor mutants and characterized as a single recessive mutation by tetrad analysis. Genetic analysis revealed that the sob1 mutation suppressed the sporulation deficiency, the failure to arrest at the G1 phase of the cell cecle, and the sensitivity to heat or nitrogen starvation caused by the bcy1 mutation. However, the sob1 mutation did not suppress the sporulation deficiency of ime1 and of ime2 diploids. These results suggest that the sob1 mutation affects a gene which functions as a downstream regulator in both meiosis and cell cycle regulation.