根癌农杆菌介导的VHb异源表达及其对里氏木霉的影响

里氏木霉是生产纤维素酶的重要菌株,在其浸没式发酵过程中,氧传递是重要影响因素。为了减轻溶氧的限制,本研究借助根癌农杆菌将透明颤菌血红蛋白基因vgb引入里氏木霉。qPCR结果表明,pki及gpd启动子均可以有效启动vgb在里氏木霉中的表达。进一步实验结果表明,在摇瓶培养中,供氧充足情况下野生菌和转化株的生长无明显差异,但是在静止培养条件下,氧气供应受限,转化菌株的干重是野生菌的17.8~25.5倍。

Heterologous expression of Vitreoscilla hemoglobin by Agrobacterium tumefaciens-mediated transformation and its effects on Trichoderma reesei

Trichoderrna reesei is an industrial important fungus for the production of cellulase. It is reported that oxygen transfer is a key process parameter for economical production of cellulase in submerged fermentation. In order to alleviate the oxygen limitation, Vitreoscilla hemoglobin （vgb） gene was integrated into the genome of T. reesei by Agrobacterium tumefaciens-mediated transformation. The results of qPCR showed that both promoter pki and gpd were appropriate to drive the expression of vgb in T. reesei. In the shake-flask fermentation, it indicated that the mycelia growth showed negligible difference between VHb-expressing transformants and the wild-type strain under high aeration condition. However, the significant difference was observed when cultured under oxygen-limited condition, the dry weight of the transformants were 16.8 - 24.5 times higher than that of the wild-type.