• 한국미생물·생명공학회지
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• 제18권5호
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• pp.530-534
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• 1990

방선균의 한 종인 Thermoactinomuces sp. CH-53이 퇴비에서 분리되었다. 분리된 이 균은 pH 6.5-9.5, 수분 55-65의 무살균계분에서 왕성히 성장하며, 밀기울 배지에 포자를 충분히 착생시켜 시판의 배합사료에 1 비율로 첨가하여 닭에 급여해서 방선균의 생균수가$10^7-10^8$. cell/g에 도달하는 계분을 얻었으며, 처리 동안 악취성분이 소실되었다. 처리된 계분의 비료효과실험은 pot에서 Brassica rapa var. perviridis의 생육조사에서 다량시용에도 생육저해가 없었으며 질소함량으로 pot당 0.4g에 해당하는 시용구에서 최대생산을 보였다.

• 한국미생물·생명공학회지
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• 제28권3호
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• pp.167-171
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• 2000

두엄에서 분리한 Thermoactinomycese sp. E79는 탈지 대두박(defatted soycean meal)을 특이적이로 분해하는 내열성 alkaline 단백질 분해효소를 생산한다. 이 효소를 생산하기 위한 환경인자를 조사하였는데 배지의 초기 pH가 6에서 8까지는 유사한 균체농도를 얻을 수 있었고 pH10에서는 단백질분해효소의 발현이 되지 않았다. 탄소원은 수용성 전분을 이용할 경우 최적의 값을 보여 9.2U/mL의 효소역가를 얻었고 포도당을 탄소원으로 사용한 경우 단백질분해효소의 발현이 억제되었다 최적의 효소발현을 위해 tryptone을 세포성장에 soytone을 단백질 분해효소 생산에 가장 적합한 질소원으로 선택하였다. 호기성 세균인 Thermoactinomycese sp. E79의 산소요구성으 알아보기 위해 산소전달속도를 달리하여 발효인자를 결정하였고 volumetric oxygen transfer coefficient 가 1.93$\times$102 hr-1 일 때 균체농도 6.58 g/L 효소역자 43.0 U/mL 의최대값을 보였다 또한 효소역가를 증강시키기 위해 200mg/L의 humic acid를 첨가한 경우 비첨가 대조구에 비해 단백질 분해효소 역가는 1.64배 세포성장은 1.77배 증가하였다.

• Journal of Microbiology and Biotechnology
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• 제27권12호
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• pp.2190-2198
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• 2017

Thermoactinomyces sp. strain YT06 was isolated from poultry compost and observed to degrade integral chicken feathers completely at $60^{\circ}C$, resulting in the formation of 3.24 mg/ml of free amino acids from 50 ml of culture containing 10 g/l chicken feathers. Strain YT06 could grow and secrete keratinase using feather as the only carbon and nitrogen sources without other supplement, but complementation of 10 g/l sucrose and 4 g/l $NaNO_3$ increased the production of the keratinolytic enzyme. The maximum protease activity obtained was 110 U/ml and for keratinase was 42 U/ml. The keratinase maintained active status over a broad pH (pH 8-11) and temperature ($60-75^{\circ}C$). It was inhibited by serine protease inhibitors and most metal ions; however, it could be stimulated by $Mn^{2+}$ and the surfactant Tween-20. A reductive agent (${\beta}$-mercaptoethanol) was observed to cleave the disulfide bond of keratin and improve the access of the enzyme to the keratinaceous substrate. Zymogram analysis showed that strain YT06 primarily secreted keratinase with a molecular mass of approximately 35 kDa. The active band was assessed by MALDI-TOF mass spectrometry and was observed to be completely identical to an alkaline serine protease from Thermoactinomyces sp. Gus2-1. Thermoactinomyces sp. strain YT06 shows great potential as a novel candidate in enzymatic processing of hard-to-degrade proteins into high-value products, such as keratinous wastes.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 1998년도 제38회 춘계학술발표대회
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• pp.54.2-54.2
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• 1998

• Journal of Microbiology and Biotechnology
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• 제9권4호
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• pp.469-474
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• 1999

Thermoactinomyces sp. E79 produced two types of thermostable alkaline proteases extracellularly. A minor protease was separated from a major protease by using DEAE-column chromatography. This enzyme was purified to homogeneity by ammonium sulfate and DEAE-Sepharose ion-exchange chromatography. The purified minor protease showed different biochemical properties compared to the major protease. The molecular mass of the purified enzyme was estimated by SDS-PAGE to be 36 kDa. Its optimum temperature and pH for proteolytic activity against Hammarsten casein were $70^{\circ}C$ and 9.0, respectively. The enzyme was stable up to$75^{\circ}C$ and in an alkaline pH range of 9.0-11.0. The enzyme was inhibited by phenylmethylsulfonyl fluoride (PMSF) and $Hg^{2+}, indicating that the enzyme may be a cysteine-dependent serine protease. In addition, the enzyme cleaved the endoproteinase substrate, succinyl-Ala-Ala-Pro-Phe-p- nitroanilide, and the $K_m$ value for the substrate was 1.2 mM.

• Journal of Microbiology and Biotechnology
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• 제11권1호
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• pp.85-91
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• 2001

To construct an efficient Bacillus subtilis expression vector, strong promoters were isolated from the chromosomal DNA libraries of Clostridium acetobutylicum ATCC 4259, Thermoactinomyces sp. E79, and Bacillus thermoglucosidasius KCTC 3400. The $P_{C27}$ promoter cloned from the clostridial chromosmal DNA showed a 5-fold higher promoter strength than the $P_{SP02}$ promoter in the expression of the cat gene, and its sequence was estimated as an upstream region of the predicted hypothetical gene (tet-R family bacterial transcription regulator gene) in C. acetobutylicum. As a promoter element, $P_{C27}$ exhibited putative nucleotide sequences that can bind with bacterial RNAP and the 3'end of the 16S rRNA just upstream of the start codon. In addition, the promoter activity of $P_{C27}$ was distinctively repressed in the presence of glucose. Using $P_{C27}$ as the promoter element, a glucose controllable B. subtilis expression vector was constructed and the lipase gene from Staphylococcus haemolyticus KCTC 8957P was expressed in B. subtilis. When compared with the lipase expression by the T7 promoter induced by IPTG in E. coli, the $P_{C27}$ promoter showed about a 1.5-fold higher expression level in B. subtilis than that without induction.