Results
Mutagenesis and screening of mutants
Cells ofS. dimorphuswere gamma-irradiated to induce
mutagenesis, and the cells that survived were cultured in
BBM agar plates. Mutant screening was performed with
cells that survived after irradiation at doses from 100 to
800 Gy. At the absorbed doses of 200 and 500 Gy, the
survival rates ofS. dimosphuswere 58 and 27 %, respectively. At 800 Gy, the survival rate was less than 10 %. At
lower irradiation doses, the rate of survival cells was high,
but the mutant with higher lipid content was little obtained.
Therefore, the irradiation for the mutation was carried out
at the absorbed dose of 800 Gy.
After 5–7 days of culture, culture broths that showed
dark green were selected and neutral lipid levels were
measured by Nile red fluorescence. Several mutants ofS.
dimorphus showing increased intensity in fluorescence
were chosen for a more detailed characterization. For
accurate analysis, the cells were cultured in 100 mL of
liquid BBM medium to mid-log phase, and the relative
neutral lipid content was determined on a cell dry weight
basis. After this screening process, the mutant strain with
high lipid content named Sd-Pm210 was finally selected.
đang được dịch, vui lòng đợi..
