• Mycobiology
• /
• 제39권3호
• /
• pp.174-181
• /
• 2011

The purpose of the present study was to investigate the influence of cultural and environmental parameters affecting the growth and bioactive metabolite production of the rare strain VUK-10 of actinomycete Pseudonocardia, which exhibits a broad spectrum of in vitro antimicrobial activity against bacteria and fungi. Production of bioactive metabolites by the strain was high the in modified yeast extract-malt extract-dextrose (ISP-2) broth, as compared to other tested media. Glucose (1%) and tryptone (0.25%) were found to be the most suitable carbon and nitrogen sources, respectively, for optimum production of growth and bioactive metabolites. Maximum production of bioactive metabolites was found in the culture medium with initial pH 7 incubated with the strain for four days at $30^{\circ}C$, under shaking conditions. This is the first report on the optimization of bioactive metabolites by Pseudonocardia sp. VUK-10.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제11권5호
• /
• pp.408-413
• /
• 2006

We assessed the ability of a Pseudonocardia sp. from soil samples to bioconvert vitamin $D_3$. The optimal culture conditions for the bioconversion of vitamin $D_3$ to active $1{\alpha}$,25-dihydroxyvitamin $D_3$ were investigated by varying the carbon and nitrogen sources, the metal salt concentrations, the initial pH, and the temperature. Microbial transformations were carried out with the addition of vitamin $D_3$ dissolved in ethanol. They were sampled by extraction with methanol-dichloromethane and the samples were examined by HPLC. Optimum culture conditions were found to be 0.4% yeast extract, 1% glucose, 3% starch, 1% fish meal, 0.2% NaCl, 0.01% $K_2HPO_4$, 0.2% $CaCO_3$, 0.01% NaF, and pH 7.0 at $28^{\circ}C$. The optimal timing of the addition of vitamin $D_3$ for the production of calcitriol by Pseudonocardia autotrophica ID9302 was concurrent with the inoculation of seed culture broth. Maximum calcitriol productivity and the yield of bioconversion reached a value of 10.4mg/L and 10.4% respectively on the 7th day in a 75L fementer jar under the above conditions.

• 한국초전도ㆍ저온공학회논문지
• /
• 제25권3호
• /
• pp.7-12
• /
• 2023

Isolation of pollutant-degrading bacteria is important in bioaugmentation, one of the methods for biological degradation of environmental contaminants. We focused on the magnetic activated sludge (MAS) process as a culture method that efficiently concentrates degrading bacteria, and cultured activated sludge with 1,4-dioxane as a model pollutant. After 860 days of operation, MLVSS, which indicates the amount of sludge, increased from 390 mg/L to 10,000 mg/L, and the removal rate of organic matter including 1,4-dioxane, tetrahydrofuran, and glucose in the artificial wastewater reached up to 97%. Based on these results, the MAS process was successfully used to acclimate activated sludge with 1,4-dioxane. Bacterial flora analysis in the MAS showed that bacteria of the genus Pseudonocardia, already reported as 1,4-dioxane degrading bacteria, play an important role in the degradation of this pollutant. The MAS process is a suitable culture method for acclimation of environmental pollutants, and the findings indicate that it can be used as an enrichment unit for pollutant-degrading bacteria.

• KSBB Journal
• /
• 제22권4호
• /
• pp.218-221
• /
• 2007

본 연구에서는 초음파 파쇄기를 이용하여 폴리엔 항진균 활성을 갖는 방선균 배양액으로부터 pellet을 회수하여 미생물농약으로 사용이 용이한 포자를 확보하기 위한 최적화 연구를 수행하였다. 그 결과, Streptomyces sp. MMBL001, MMBL003 그리고 Pseudonocardia autotrophica는 각각 12%, 18%, 12% 출력 (100%, 700 W)에서 최적의 포자 전환율을 보임을 확인하였다. 이렇게 확보한 포자를 10% skim milk 보호제를 사용하여 동결건조한 후 각각의 생균수를 측정한 결과, MMBL003이 MMBL001과 P. autotrophica에 비해 3배 이상의 생균수가 유지됨이 측정되었다. C. albicans를 대상으로 항진균 효과를 확인한 결과, 동결건조된 3종의 방선균주 모두 우수한 항진균 활성을 유지함으로써 신규 폴리엔 생산 방선균을 이용한 미생물농약으로서의 활용 가능성을 제시하였다.