• Journal of Microbiology and Biotechnology
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• 제9권1호
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• pp.70-77
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• 1999

An extremely cadmium-tolerant budding yeast, Hansenula anomala B-7 underwent a morphological switch in response to either heat shock treatment or cadmium stress, respectively. It exhibited a morphological transition from a unicellular yeast form to a pseudohyphae-like coagulation when subjected to prolonged heat shock treatment. In contrast, the yeast cells showed an irregularity in surface morphology when given thermal stress for a short time. Patterns of proteins expressed in the pseudohyphae-like cells demonstrated that several proteins were overexpressed while others were underexpressed in comparison with those prepared from the cells in the yeast form. It was a striking feature, however, that nearly 40％ of the proteins extracted from the cells in the pseudohyphae form appeared to be composed of a single polypeptide. This polypeptide was apparently overexpressed during the pseudohyphae phase and its molecular weight was estimated to be 58 kDa according to SDS-PAGE analysis. However, a significant level of the protein was not observed in the cells before transition to pseudohyphae. The architecture of the cell shape was also damaged when incubated in a medium containing more than 1,000 ppm (8.9mM) of cadmium ions, although able to proliferate at a slow rate. However, the irregularity in the cell morphology exerted either by the brief heat shock treatment or by the cadmium stress with the high concentrations of the metal ions was not repaired, even though the damaged cells were allowed to grow for sufficient time in fresh, cadmium-free medium.

• 미생물학회지
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• 제34권3호
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• pp.75-81
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• 1998

자연계로부터 분리한 효모중에서 새우젓으로부터 분리한 효모균주 504D가 alkaline 조건에서 가장 우수한 proteinase 생산성을 보여 분류동정하였다. 분리효모의 형태학적 특성은 주로 영양세포로 출아증식을 하였으나, citric acid가 함유된 MM 배지에서만 위균사를 형성하였고, N-acetylglucosamin과 ${\beta}$-D-glucose가 첨가된 MM 배지에서만 진균사를 형성하였다. 유성적으로 자낭포자를 형성함으로써 반자낭균류이었고, 무성적으로 출아포자 및 분절 포자를 형성하였다. 생리생화학적인 특성으로 대부분의 탄소원과 nitrate 및 nitrate를 이용하지 못하였으나 일부 유기산과 알콜류를 이용하였다. 세포지방산을 분석한 결과, 불포화지방산 53.67%와 포화지방산 14.58%로 나타났으며, 대조균들에는 관찰되지 않는 C17:1이 관찰되었다. 전체적인 실험결과에서 분리균은 균사형성능과 세포지방산의 조성에서 약간의 차이를 제외하면 대조균 Saccharomycopsis lipolytica KCCM 12495 및 KCCM 35426의 모든 특성들과 거의 동일하여 분리효모 504D를 Yarrowia lipolytica로 동정하였다.