Enhancement of monacolin K production via intergeneric protoplast fusion between Aspergillus terreus

• 作 者: Chen Zhi Lin Wen Yu Ping Song
• 机 构: Department of Microbiology
• 出 处: 自然科学进展（英文版）
• 发表日期: 2004年期
• 关键词: monacolin K Monascus anka Aspergillus terreus protoplast fusion fermentation

Intergenric protoplast fusion between Aspergillus terreus CA99 and Monascus anka M-3, the high and low producers of monacolin K respectively, was performed for enhancement of monacolin K production. The 24-hour-old mycelia of A. terreus CA99 and M. anka M-3 were treated with 0.5 % lywallzyme, 0.3 % snailase and 0.3 % cellulase at 34 ℃ for 5 h and at 30 ℃ for 3.5 h, and their protoplasts formation reached 1.76 × 107/mL and 1.68 × 107/mL respectively. Parental protoplasts were irradiated with a 30 W UVlight away from 30 cm for 3 min and then mixed. The mixture was incubated with 30% PEG 6000 for 15 min. The reviving fusants were isolated on the regeneration plates. Of the 363 fusants isolated, over 100 showed enhanced monacolin K production compared with the parental strain M. anka M-3. Ten of them produced monacolin K about 1.6-fold of that M. anka M-3 does and the monacolin K titer of two fusants (F49 and F104) increased by about 1-fold. The monacolin K yields of F49 and F104 were 460 μg/mL and 457 μg/mL respectively. In optimized fermentation medium, the monacolin K titer of F49 reached 1216 μg/mL.