• 미생물학회지
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• 제11권3호
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• pp.121-128
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• 1973

In order to clarify the best cultural conditions of Rhizopus niveus the effects of aeration, pH and various nutrients, such as different carbon and nitrogen sources, vitamins, and growth substances, on the mycelial growth were studied through liquid culture, and amylase activities of the fungus at different cultural periods were measured. Soluble starch, xylose and galactose are excellent sources of carbon for growth of the fungus. Sorbose and lactose are utilized slightly for growth. peptone, ammonium sulfate and alanine are excellent nitrogen sources for growth, tyrptophane nad potassium nitrate are utilized slightly for growth and sodium nitrite is not utilized. Thiamine nad gibberellin are excellent growth substances for the fungal growth, and biotin, nicotinamide and indole acetic acid (IAA) are also effective. Rhizopus niveus grows better at rotatory culture than at stationary culture and earlier growth of the fungus increases remarkably at rotatory culture. Optimum pH than at pH3. Growth increases linerly with an increase of soluble starch content up to 100g per liter medium, but 5 grams of ammonium sulfate per liter is the optimum nitrogen concentration for growth, if Pfeffer's medium is employed. Amylase activities of Rhizopus at different cultural periods showed that the maximum amylase production takes place after the cell population has reached its peak in the culture. Dextrinogenic amylase production has reached maximum at stationary phase, and maximum saccharogenic maylase production takes place in the pahse of negative gorwth acceleration.

• Journal of Microbiology
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• 제39권2호
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• pp.139-141
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• 2001

Medium-chain length polyhydrexyalkanoic acids (MCL-PHAs) degrading bacterium was isolated from the soil. The bacterium was identified as Janthinobacterium lividum by its biochemical properties, cell membrane fatty acids composition, and 16S rDNA sequence analysis. The bacterium showed a similarity of 0.911 with J. lividum according to the cell membrane fatty acids analysis and a similarity of 97% in the 16S rDNA requence analysis. Culture supernatant of the bacterium skewed the highest depolymerase activity toward polyhydroxynonanoic acid (PHN) that did not degrade the poly-$\beta$-hydroxybutyric acid (PHB). The esterase activity was also detected with p-nitrophenyl (PNP) esters of fatty acids such as PNP-dodecanoic PNP-dodecanoic acid, PNP-decanoic acid, and PNP-hexanoic acid.

• Journal of Microbiology
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• 제33권4호
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• pp.328-333
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• 1995

$\^$31/ P-NMR experiment was performed to detect phophonates (Pn) utilization and degradation in the several different C-P lyase mutants of E. coli and in E. aerogenes and the recombinants. The relative peak intensity (RPI) for the standard samples of 0.5 mM methylphosphonate (MPn) and 1.0 mM aminoethylphosphonate in glucose-MOPS medium showed 0.5 : 1.0 ratio. In the case of BW14329 (.DELTA.phnC-P, .delta.phoA), RPI did not change significantly after 24 hrs culturing, which means it nearly could not utilize Pn. In vivo $\^$31/ P-NMR spectrum of E. aerogens (BWKL 16627) during 3 hrs starvation showed two intense peaks at 0-2 ppm and at near-10 ppm which indicate intracellular orthophosphate (Pi) and pyrophosphate (PPi), respectively. Both of them might be released by degradation of inorganic polyphosphate pool. When MPn is supplied to the medium as an unique P source, Pi content in the cell has the constant, but PPi seems to be slightly decreased. Recombinants (BWKL 16954) grew slower than E. aerogenes in the glucose-MOPS media with various P sources. In vivo $\^$31/ P-NMR spectrum of recombinant did not show any intense signal in the cell. Surprisingly, under the cultivation adding with MPn, a few intense peaks in the region of Pi AND phospate monoester were detected.

• 미생물학회지
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• 제25권3호
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• pp.212-220
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• 1987

토양으로 부터 분리된 세포의 adenine deaminase를 생산하는 방선균인 J-275L 균주의 분류학적 특성 및 효소생산 조건이 검토도었다. J-275L 균주는 균사가 간상 또는 구상의 절편으로 단절되며, 세포벽의 아미노산 성부능로서 LL-diaminopimelic acid를 함유하고 mycolic acid를 함유하지 않아TEk. 분류학적 검색 결과 분리균 J-275L을 Nocardiovides sp. J-275L로 명명하였다. Nocardioides sp. J-275에 의한 세포외 adenine deaminasem이 생산조건을 검토한 결과, 효소생산을 위한 최적배지는 0.5% dextrin, 0.5% peptone, 1% yeast extract 및 0.2% $K_{2}HPO_{4}$로 설정되었으며, 배지의 최적 pH는 7.5이었다.

• 미생물학회지
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• 제27권4호
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• pp.415-421
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• 1989

Ten strains out of about 1,000 yeast strains isolated from byproducts of alcoholic industries, milk products, fruits, greens, food-related industries and soils of nature, revealed the killer activities. Two strains which have excellent killer activities among them were isolated and identified with Saccharomyces cerevisiae B 15-1 and Hansenula anomala Y 33 by investigation of the morphological, cultural and physiological properties. The optimal conditions on these strains for the production of killer toxin were investigated. The strain B 15-1 showed the highest killer toxin activities when it was cultured up to the log phase of 48 hr in YPD medium (pH 4.7) at $25^{\circ}C$. On the other hand, the strain Y33 revealed the highest activities when it was cultured up to the stationary phase of 60 hr in YPD medium (pH 4.0) at $20^{\circ}C$. The sensitive strain Kyokai 7 was found to be killed entirely by the killer toxin produced from the wild killer yeast B 15-1 when B 15-1 was cocultured with the same cell concentration ($10^{6}$ cells/ml) of Kyokai 7 after cultivation of 36 hr, and with large concentration ($9\times 10^{7}$ cells/ml) after 48 hr.

• Journal of Microbiology
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• 제45권4호
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• pp.311-317
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• 2007

In this study, the effects of phosphate concentration and carbon source on the patterns of alkaline phosphatase (APase) and phospholipase (PLase) expression in Vibrio vulnificus ATCC 29307 were assessed under various conditions. The activities of these enzymes were repressed by excess phosphate (4 mM) in the culture medium, but this repression was reversed upon the onset of phosphate starvation in low phosphate defined medium (LPDM) containing 0.2 mM of phosphate at approximately the end of the exponential growth phase. The expressions of the two enzymes were also influenced by different carbon sources, including glucose, fructose, maltose, glycerol, and sodium acetate at different levels. The APase activity was derepressed most profoundly in LPDM containing fructose as a sole carbon source. However, the repression/derepression of the enzyme by phosphate was not observed in media containing glycerol or sodium acetate. In LPDM-glycerol or sodium acetate, the growth rate was quite low. The highest levels of PLase activity were detected in LPDM-sodium acetate, followed by LPDM-fructose. PLase was not fully repressed by high phosphate concentrations when sodium acetate was utilized as the sole carbon source. These results showed that multiple regulatory systems, including the phosphate regulon, may perform a function in the expression of both or either APase and PLC, in the broader context of the survival of V. vulnificus.

• 미생물학회지
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• 제40권1호
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• pp.43-48
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• 2004

본 연구에서는 우모의 생물학적 처리를 위하여 keratinolytic pretense를 생성함으로써 우모를 분해할 수 있는 Bacillus megaterium을 붕괴된 우모로부터 분리하였다. 본 균주에 의한 keratinolytic pretense생산 최적배지 조성 및 배양조건은 0.2% glucose, 0.8% skim milk, 0.05% NaCl, 0,01% $(K_2HPO_4$, 0.02%, $(KH_2PO_4$, 0.01% $MgCl_2$, 초기 pH 6.5 및 $25^{\circ}C$이었다. 특히, skim milk의 첨가는 효소 생산에 가장 효과적이었다. 최적조건에서 배양 5일만에 269 U/ml의 효소가 생산되었으며, 배양 6일경 98%의 우모가 분해되었다.

• 미생물학회지
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• 제36권3호
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• pp.187-191
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• 2000

장티푸스는 Salmonella typhi 에 의해 유발되는 장감염성 질환으로 사람과 동물에 공통되는 질병이다. 본 연구에서는 기 보고된Salmonella typhi KNH100의 염색체 DNA로부 터 방향족 아미노산의 생합성에 관여하는 효소인 3-dehydroquinate hydratase(3- dehydroquinate)를 암호화하는 aroD 유전자를 포함하는 약 3.2 kb의 Sal I 절편을 pSAL62 이라 명명하였다. 클로닝된 재조합 plasmid인 pSAL61에는 ATG 개시코돈과 TGA 종결코돈 을 포함하는 759 염기로 구성된 aroD 유전자가 위치하고 있었다. 또한 S. typhi Ty2, Shigella dysenteriae, 그리고 Escherichia coli 등 다른 장내 세균의 aroD 유전자와 상동성을 비교하여 본 결과 각각 90%, 72.7% 그리고 73%의 상동성을 나타내었다.

• Journal of Microbiology
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• 제35권3호
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• pp.213-221
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• 1997

The secretion of the alkaliphilic Bacillus sp. S-1 extracellular pullulanase involves translocation across the cytoplasmic membrane of the Gram-positive bacterial cell envelope. Translocation of the intracellular pullulanase PUL-I, was traced to elucidate the mechanism and pathway of protein secretion from an alkaliphilic Bacillus sp. S-1. Pullulanase could be slowly bue quantitatively released into the medium during growth of the cells in medium contianing proteinase K. The released pullulanase lacked the N-terminal domain. The N-terminus is the sole membrane anchor in the pullulanase protein and was not affected by proteases, confirming that it is not exposed on the cell surface. Processing of a 180,000M$\_$r/ pullulanase to a 140,000M$\_$r/ polypeptide has been demonstrated in cell extracts using antibodies raised against 140,000M$\_$r/ extracellular form. Processing of the 180,000 M$\_$r/ protein occured during the preparation of extracts in an alkaline pH condition. A modified rapid extraction procedure suggested that the processing event also occured in vivo. Processing apparently increased the activity of pullulanase. The western blotting analysis with mouse anti-serum against 140-kDa extracellular pullulanase PUL-E showed that PUL-I is processed into PUL-X via intermediate form of PUL-E. Possible explanationa for the translocation are discussed.

• 미생물학회지
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• 제23권4호
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• pp.297-301
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• 1985

The dependence of activities of Aspergillus phoenicis on the culture conditions in the progesterone transformation reaction was investigated. In the beginning of the reaction, $6{\beta},\;11{\alpha}-dihydroxyprogesterone$ was not produced even at high concentration of $11{\alpha}-hydroxyprogesterone$. However, large amount of the product was obtained after the complete exhaustion of progesterone. When spores of A.phoenicis replaced mycelia as enzyme source, $11{\alpha}-hydroxyprogesterone$ was produced after a considerably long indyction period, and its maximum production rate followed the exponential growth phase. The $6{\beta}-hydroxylation\;of\;11{\alpha}-hydroxyprogesterone$ continued, even after the stationary growth phase. A. phoenicis showed high enzyme activity for these reactions when the phosphate buffer solutions were used in place of the ordinary culture medium. The buffer solutions of low pH gave more yield of $11{\alpha}-hydroxyprogesterone$ than those of high pH. However, the addition of flucose to the buffer solutions did not activate the transformation reaction. The presence of progesterone seems to be necessary for the induction of enzymes for the $6{\beta}-hydroxylation\;of\;11{\alpha}-hydroxyprogesterone\;since\;6{\beta},\;11{\alpha}-dihydroxyprogesterone$ is not produced in the reaction medium containing only $11{\alpha}-hydroxyprogesterone$ as a substrate.