种间双亲灭活原生质体融合选育高产Monacolin K红曲菌

Breeding of Monascus spp.with high monacolin K production by interspecific protoplast fusion of inactivated parental strains

为获得高产Monacolin K的红曲菌菌株,将经农杆菌介导转化获得的携带潮霉素抗性基因且以甘油为原料液态发酵高产Monacolin K的发白红曲菌H2和以大米为原料固态发酵产MonacolinK的烟色红曲菌9908作为亲本,对其原生质体分别进行热灭活及紫外灭活,然后对灭活双亲用PEG作融合剂进行原生质体融合。从融合子中选出有潮霉素抗性的突变株,通过发酵与亲本对比,筛选得到一株以大米为原料固态发酵高产Monacolin K的融合株F12-11,其Monacolin K产量达到8.73 mg/g;较发白红曲菌H2与烟色红曲菌9908分别提高了100.23%和48.98%;一株以甘油为原料液态发酵高产Monacolin K的融合株F13-2,其Monacolin K的产量达到1752.46 mg/L,较发白红曲菌H2与烟色红曲菌9908分别提高了32.98%和1979.33%。

In order to obtain high monacolin K producing strains, Monascus albidus H2 and Monascus fumeus 9908 were used as parents. M. albidus H2 with hygromycin resistance gene was acquired by Agrobacterium-mediated transformation and had high monacolin K production by liquid state fermentation using glycerol as main carbon source, and M. fumeus 9908 could convert rice into monacolin K in solid state fermentation. The protoplasts of parents were inactivated by heat and ultraviolet respectively, and fused with PEG as fusion agent. Fusants with hygromycin resistance gene were selected for further fermentation and compared with parental strains. Two fusants, F12-11 and F13-2 were obtained. It was revealed the fusant F12-11 produced more monacolin K by solid state fermentation with rice, the monacolin K yield was 8.73 mg/g, increased by 100.23% and 48.98% respectively compared with M. albidus H2 and M. fumeus 9908; the monacolin K yield of the fusant F13-2 was 1752.46 mg/L in liquid state fermentation with glycerol, increased by 32.98% and 1979.33% respectively compared with M. albidus H2 and M. fumeus 9908.