里氏木霉与米根霉混合固态发酵产纤维素酶

以里氏木霉及米根霉单菌固态发酵为对象,考察不同混合发酵形式对里氏木霉与米根霉混合固态发酵产纤维素酶的影响。结果表明:同时接种里氏木霉与米根霉,试验考察的两菌种接种量比1∶1(以孢子个数计)及5∶1条件下,两菌未产生明显协同产酶作用。米根霉延时(24 h)接种且菌种量比5∶1以及米根霉延时(48 h)接种且菌种量比1∶1,2种发酵形式产酶情况类似,滤纸酶活(FPA)及羧甲基纤维素酶(CMCase)酶活相对米根霉单菌发酵有所提高,而β-葡萄糖苷酶(β-GA)酶活相对里氏木霉单菌固态发酵结束时分别增加4.66及4.40倍,可以发现两菌产生一定协同作用。在米根霉延时(48 h)接种且菌种量比5∶1的发酵形式下,FPA及CMCase在发酵第7天酶活分别达到44.04 IU/g、627.14 U/g(以1 g干曲计),分别是里氏木霉固态单菌发酵产酶达到稳定期时酶活的1.36和1.63倍,两菌产生了有效的协同作用。

Production of cellulase in mixed-culture of Trichoderma reesei and Rhizopus oryzae by solid-state fermentation

We studied the effect of mixed-culture of Trichoderma reesei and Rhizopus oryzae on cellulose production in solid-state fermentation. Parameters studied include delayed inoculation of R. oryzae and different inoculum ratios of the fungi （ spore counting） . Cellulase production by mono-culture of T. reesei or R. oryzae was used as the control. No obvious synergy of the two fungi was observed when inoculating the mixed fungi at ratios of 1∶1 （ spores） and 5∶1 at the same time. The result of delayed inoculation of R. oryzae for 24 h at inoculum ratio of 5∶1 was much similar with the result of delaying inoculation of Rhizopus oryzae for 48 h at inoculum ratio of 1∶1. The activities of filter paper activity （FPA） and CMCase were higher than those of mono-culture fermentation of R. oryzae. The activity of β-glucosidase （β-GA） raised about 4-66 and 4-40 times respectively compared with mono-culture fermentation of T. reesei. Therefore, the synergy was generated between the mixed fungi with a delayed inoculation of R. oryzae. When delayed inoculation of R. oryzae for 48 h at inoculum ratio of 5∶1, FPA and CMCase accounted for 44-04 IU/gram dry substrate, 627-14 U/g respectively, which were 1-36 and 1-63 times as those of mono-culture fementation of T. reesei, respectively, also higher than that of the mono-culture of R. oryzae.