• 미생물학회지
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• 제54권3호
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• pp.266-271
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• 2018

플라스미드가 제거된 Acinetobacter sp. B-W 균주의 돌연변이체를 글루탐산을 유일한 탄소 원과 질소원으로 함유한 배지에 $28^{\circ}C$에서 배양한 결과 글루탐산으로부터의 시드로포어 생산이 억제되었다. B-W 원 균주의 20 kb 플라스미드를 가진 형질 전환체 대장균 $DH5{\alpha}$는 같은 조건의 배지에서 시드로포어를 생산하는 것으로 조사되었다. 그러나 $36^{\circ}C$에서는 형질 전환체 대장균 $DH5{\alpha}$의 시드로포어 생산이 강하게 억제되었으며, 돌연변이체 B-W 균주는 $28^{\circ}C$에서와 마찬가지로 $36^{\circ}C$에서도 시드로포어를 생산하지 못하였다. 형질 전환체로부터 생산된 시드로포어의 종류는 원 균주 B-W와 마찬가지로 Arnow 시험 결과 카테콜 형으로 조사되었으며, $10{\mu}M\;FeCl_3$를 첨가한 배지에서는 시드로포어 생산이 완전히 억제되었다. 형질전환체로부터 생산된 시드로포어의 TLC상에서의 Rf값은 butanol-acetic acid-water (12:3:5) 용매상에서 0.32로 원 균주 B-W에서 생산된 시드로포어와 같았다. 위와 같은 실험 결과로 글루탐산으로부터 생산된 시드로포어의 생합성에 관여하는 유전자들이 20 kb 플라스미드 상에 있는 것으로 추정되었다.

• 미생물학회지
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• 제53권2호
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• pp.97-102
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• 2017

포도당과 글루탐산을 함유한 배지에서 시드로포어인 2, 3-dihydroxybenzoic acid (DHB)를 생산하는 Acinetobacter sp. B-W 균주를 글루탐산을 유일한 탄소원과 질소원으로 함유한 배지에 배양한 결과, 상등액에서 2, 3-DHB가 아닌 카테콜 형의 시드로포어를 생산하는 것으로 조사되었다. 글루탐산의 농도는 3%에서 시드로포어 생산이 최고로 나타났으며, 3% 보다 높은 농도에서는 감소하는 것으로 조사되었다. 글루탐산을 유일한 탄소원과 질소원으로 함유한 배지에서 자란 균주 B-W는 배양 온도 $28^{\circ}C$에서는 시드로포어를 생산하지만 $36^{\circ}C$에서는 생산하지 않았다. 또한 $10{\mu}M\;FeCl_3$를첨가한 배지에서는 시드로포어 생산이 완전히 억제되었다. 글루탐산 배지에서 생산된 균주 B-W의 시드로포어는 TLC 전개 용매 butanol: acetic acid: water =12:3:5에서 Rf치가 0.32로 나타나 Rf치가 0.82인 2, 3-DHB와는 다른 것으로 조사되었으며, 또한 항산화 활성도 없는 것으로 나타나 항산화 활성을 가진 2, 3-DHB와는 다른 시드로포어인 것으로 추정되었다.

• Journal of Microbiology and Biotechnology
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• 제14권4호
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• pp.822-828
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• 2004

Nopaline-type Agrobacterium tumefaciens strain C58 cannot utilize octopine (Oct) as the sole carbon and nitrogen sources. This strain harbors two plasmids; a virulent plasmid, pTiC58, and a megaplasmid, pAtC58. From strain NT1, which is a derivative of C58 harboring only pAtC58, we isolated spontaneous mutants that utilize Oct as the sole nitrogen source. These Oct-catabolizing mutants, however, could not utilize the opine as the sole carbon source. In contrast, strain UIA5, a plasmid-free derivative of C58, could not give rise to such mutants. The mutations isolated from NT1 were mapped to socR in pAtC58, which is a negative regulator of the soc operon responsible for the uptake and catabolism of an Amadori opine, deoxyfructosyl glutamine (Dfg). A derivative of UIA5 carrying a clone of the soc operon with a transposon inserted in socR also utilizes Oct as the sole nitrogen source. However, UIA5 harboring the operon with mutations in each of the structural genes in the soc operon, socA, B, C, and D, lost the ability to generate spontaneous Oct-utilizing mutants, suggesting that soc genes in pAtC58 are required for the utilization of Oct as a nitrogen source, and that derepressed expression of these genes allows cells to utilize Oct. In contrast, Oct-catabolizing mutants derived from C58, which grew using Oct as the sole nitrogen source, could also utilize the opine as the sole carbon source. These mutants did not carry any detectable mutations in socR or the region upstream to the gene in pAtC58, suggesting that mutations occurring elsewhere in the genome, most likely in pTiC58, allow the uptake and catabolism of the opine.

• Journal of Microbiology and Biotechnology
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• 제14권3호
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• pp.532-539
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• 2004

For efficient lincomycin production from Streptomyces lincolnensis L1245, various vegetable oils, natural nitrogen sources, and surfactants were investigated at the pilot-scale level in the flask. Olive oil as the sole carbon source was the most suitable one for producing lincomycin. When 20 g/lof olive oil was used, the lincomycin concentration and lipase activity reached 1.01 g/land 182 U/ml, respectively, after 5 days of culture. Among the various unsaturated fatty acids, when linolenic acid was used, the cell growth and lincomycin production were markedly decreased. On the other hand, when 0.2 g/l of oleic acid was added to the culture broth, the maximum lincomycin concentration was 1.0 g/l, which was about 1.7-fold higher than that obtained without the addition of oleic acid. Among the various natural nitrogen sources, pharmamedia or soybean meal was the most suitable nitrogen source. In particular, in the case of a mixture of 10 g/l of pharmamedia and soybean meal, 1.5 g/l of lincomycin concentration and 220 U/ml of lipase activity were obtained. When Span 180 was used as the surfactant, lincomycin production, lipase activity, and oil consumption increased. The correlation between the consumption rates of oil and lincomycin production in a culture using olive oil as the sole carbon source was also investigated. The lincomycin production depended on the consumption rate of olive oil. Using these results, fed-batch cultures for comparing the use of olive oil and starch as a conventional carbon source were carried out in a 5-1 fermentor. When olive oil was used as the sole carbon source, 34 g/l of olive oil was consumed after 7 days of culture. The maximum lincomycin concentration was 3.0 g/l, which was about 2.0-fold higher than that of starch medium after 7 days of culture. The product yield was 0.09 gig of consumed carbon source, which was about 3.0-fold higher than that of starch medium after 7 days of culture.

• Journal of Microbiology and Biotechnology
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• 제12권6호
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• pp.979-985
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• 2002

The possibility of microalgal nitrogen treatment was tested in wastewaters with a low carbon/nitrogen (C/N) ratio. Chlorella kessleri was cultured in the two different artificial wastewaters with nitrate as a nitrogen source: one contained glucose for an organic carbon source and the other without organic carbon sources. The growth rates of the two cultures were almost identical when the aeration rate was over 1 vvm. These results suggest that microalgae could successfully remove nitrogen from wastewater, as far as the mass transfer of $CO_2$, was not limited. Nitrate was successfully reduced to below 2 mg $NO_3^-$-N/ml from the initial nitrate concentration of 140 mg $NO_3^-$-N/ml in 10 days, even in the wastewater with no organic carbon source. Similar results were obtained when ammonium was used as the sole nitrogen source instead of nitrate. Higher concentrations of nitrogen of 140, 280, 560 and 1,400 mg/ml were also tested and similar amounts of nitrogen were removed by algal cultures without showing any substrate inhibition.

• 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.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.347-350
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• 2001

The dextran prodution by Leuconostoc mensenteroids NRRL-B512F was studied in a synthetic medium from sucrose as a sole carbon source. Especially, effect of nitrogen source was treated and compared in this study. In oder to maximize the cell growth and dextran produtivity through fermentation two nitrogen sources, yeast extract and tryptone, were used with various concentrations. At the end of fermentation, when the concentration of yeast extract was 9g/L we can obtain the maximum dry cell weight(14.1g/L), dextran dry weight(25.4g/L) and productivity(1.4g/L ${\cdot}$ hr).

• Environmental Engineering Research
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• 제12권4호
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• pp.136-147
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• 2007

In an effort to identify possible microbes for seeking bioagents for remediation of herbicide-contaminated soils, seven species of phototrophic nonsulfur bacteria (Rhodobacter capsulatus and sphaeroides, Rhodospirillum rubrum, Rhodopseudomonas acidophila, blastica and viridis, Rhodomicrobium vannielii) were grown in the presence of the herbicide, butachlor, and bacterial growth rates and nitrogen fixation were measured with different carbon sources. Under general conditions, all species showed 17-53% reductions in growth rate following butachlor treatment. Under nitrogen-fixing conditions, Rb. capsulatus and Rs. rubrum showed 1-4% increases in the growth rates and 2-10% increases in nitrogen-fixing abilities, while the other 5 species showed decreases of 17-47% and 17-85%, respectively. The finding that Rp. acidophila, Rp. blastica, Rp. viridis and Rm. vannielii showed stronger inhibitions of nitrogenase activity seems to indicate that species in genera Rhodobacter and Rhodospirillum are less influenced by butachlor than those in Rhodopseudomonas and Rhodomicrobium in terms of nitrogen-fixing ability. Overall, nitrogenase activity was closely correlated with both growth rate and glutamine synthetase activity (representing nitrogen metabolism). When the carbon sources were compared, pyruvate (three carbons) was best for all species in terms of growth rate and nitrogen fixation, with malate (four carbons) showing intermediate values and ribose(five carbons) showing the lowest; these trends did not change in response to butachlor treatment. We verified that each of the 7 species had a plasmid ($12.2{\sim}23.5\;Kb$). We found that all 7 species could use butachlor as a sole carbon source and 3 species were controlled by plasmid-born genes, but it is doubtful whether plasmid-born genes were responsible to nitrogen fixation.

• Journal of Microbiology
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• 제44권6호
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• pp.583-590
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• 2006

In this study, an organic solvent tolerant bacterial strain was isolated. This strain was identified as Pseudomonas sp. strain S5, and was shown to degrade BTEX (Benzene, Toluene, Ethyl-Benzene, and Xylene). Strain S5 generates an organic solvent-tolerant lipase in the late logarithmic phase of growth. Maximum lipase production was exhibited when peptone was utilized as the sole nitrogen source. Addition of any of the selected carbon sources to the medium resulted in a significant reduction of enzyme production. Lower lipase generation was noted when an inorganic nitrogen source was used as the sole nitrogen source. This bacterium hydrolyzed all tested triglycerides and the highest levels of pro-duction were observed when olive oil was used as a natural triglyceride. Basal medium containing Tween 60 enhanced lipase production to the most significant degree. The absence of magnesium ions ($Mg^{2+}$) in the basal medium was also shown to stimulate lipase production. Meanwhile, an alkaline earth metal ion, $Na^+$, was found to stimulate the production of S5 lipase.

• Journal of Microbiology
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• 제44권6호
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• pp.689-693
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• 2006

Pbh1, from the fission yeast Schizosaccharomyces pombe, is a baculoviral inhibitor of apoptosis (IAP) repeat (BIR) domain-containing protein. Its unique encoding gene was previously found to be regulated by nitric oxide and nitrogen starvation. In the current work, the Pbh1-lacZ fusion gene was used to elucidate the transcriptional regulation of the pbh1 gene under various carbon sources. When fermentable carbon sources, such as glucose (at a low concentration of 0.2 %), sucrose (2.0 %) and lactose (2.0 %), were the sole carbon source, the synthesis of $\beta$-galactosidase from the Pbh1-lacZ fusion gene was reasonably enhanced. However, the induction by these fermentable carbon sources was abolished in the Pap1-negative S. pombe cells, implying that this type of induction of the pbh1 gene is mediated by Pap1. Ethanol (2.0%), a nonfermentable carbon source, was also able to enhance the synthesis of $\beta$-galactosidase from the fusion gene in wild-type cells but not in Pap1-negative cells. The results indicate that the S. pombe pbh1 gene is up-regulated under metabolic oxidative stress in a Pap1-dependent manner.