一组高效木质素降解复合菌的筛选

Screening of an Efficient Lignin-degrading Composite Microorganisms

木质素的有效降解是秸秆等农业废物减量化及资源化利用的难点.采用连续驯化培养的方法,从农业废物堆肥过程升温、降温和腐熟3个阶段的微生物菌群中分别筛选驯化出3组具有木质素降解能力的复合菌MC1、MC2和MC3.通过初筛和复筛实验,筛选出一组性能稳定并具有高效木质素降解能力的复合菌,并对其继代培养的稳定性进行了验证.结果表明,从堆肥升温阶段筛选出的复合菌MC1的木质素降解能力最强.在37℃静置条件下液态发酵培养14d,d6时复合菌MC1各酶活值均达到最大,其中木质素过氧化物酶酶活为258.37UL-1,锰过氧化物酶酶活486.39UL-1,漆酶酶活为49.25UL-1;d14时木质素降解率达到36.25%.继代培养实验结果表明复合菌MC1具有较好的稳定性.

The lignin of agricultural wastes is difficult to be effectively degraded and reduced,and also conserved as resources,for the structure of lignin is extremely complex.This experiment was done aiming to improve effective degradation of lignin.Three composite microorganisms （MC1,MC2 and MC3） able to degrade lignin were screened from three stages of agricultural waste composting by a series of domesticated cultivation,and the three stages were warming stage,cooling stage and falling stage,respectively.The composite microorganisms with the most efficient lignin-degrading ability was selected through initial and further screenings,and their stability was studied then.The results showed that composite microorganism MC1 screened from the warming stage had the strongest ability to degrade lignin.The activities of lignin peroxidase,manganese peroxidase and laccase reached the maximum values after 6 days at 37 ℃ under the static culture of submerged fermentation,which were 258.37 U L^-1,486.39 U L^-1 and 49.25 U L^-1,respectively,and the lignin degradation rate was 36.25% after 14 days.The subculture of composite microorganism MC1 showed that it was very stable.Fig 2,Tab 1,Ref 19