玉米秸秆低温降解菌的分离与鉴定及复配菌降解效果研究
【目的】从本实验室经低温驯化获得的GF系列复合菌系中分离纤维素低温降解菌，构建玉米秸秆低温高效降解复配菌，并对复配菌的玉米秸秆降解效果进行分析。【方法】利用纤维素刚果红培养基，在15℃下，采用平板涂布法分离具有明显水解圈的单菌株，并根据单菌特性进行有效组配，在液态、固态和模拟环境3种培养模式下，通过测定滤纸酶活性及玉米秸秆降解率进行复配菌筛选及效果评价。【结果】分离纯化获得29株单菌，其中11株可在刚果红培养基中形成水解圈；组配获得10组复配菌，其中复配菌A、D、G在15℃条件下培养可分解滤纸，且复配菌的降解能力优于单菌。复配菌在3种培养模式条件下的玉米秸秆降解率总体趋势为模拟环境培养＞固体培养≥液体培养，其中复配菌G在模拟环境培养条件下降解效果最优，滤纸酶活性（Filter paper activity，FPA）为32.96 U/ml，降解率为47.56%，较对照增加20.98 U/ml，秸秆降解率较对照增加21.56%。经16SrDNA分子鉴定复配菌G由Pseudomonas sp.、Cellulosimicrobium cellulans、Achromobacter marplatensis、Pseudomonas fuscovaginae组成。【结论】复配菌的降解效果显著优于单菌，其中复配菌G效果最佳，为玉米秸秆菌剂的研究及利用提供一条新途径。
英文摘要:
【Objectives】The aims of the study were to isolate the low-temperature cellulose degradation microbes from GF series of microbial consortium which had obtained through low-temperature acclimation in low-temperature in our lab, establish the low-temperature and high-efficiency composite microbial system for corn stover degradation and analyze the its degradation effects.【Methods】Using Congo red medium, we isolated the single strain with obvious hydrolyzation circle through spread plate method at 15℃, then did effective pair based on its own characteristic. With 3 culture types (liquid state cultivation, solid state cultivation and simulation environment cultivation), we conducted microbial consortium selection and effect evaluation by determining filter paper enzymes (FPA) activity and corn stover degradation rate.【Results】Twenty-nine single strains were obtained after isolation and purification, and 11 strains showed obvious hydrolysis circle in cellulose Congo red medium. Also, we obtained 10 conjugate pairs strains, while conjugate pairs strain A, D and G degraded filter paper after 15 days culture at 15℃. The conjugate pairs strain had a better degradation ability than the single strain. The order of corn stover degradation rate of conjugate pairs strain at three different culture types is, simulation environment cultivation＞solid state cultivation≥liquid state cultivation, while conjugate pairs strain G showed the best degradation performance at simulation environment cultivation. The FPA was 32.96 U/ml with a 20.98 U/ml increase compared to CK, and the corn stover degradation rate of G was 47.56% with a 21.56% increase compared to CK. After 16SrDNA identification, the results showed that conjugate pairs strain G consisted of Pseudomonas sp., Cellulosimicrobium cellulans, Achromobacter marplatensis and Pseudomonas fuscovaginae.【Conclusions】The degradation performance of the conjugate pairs strain was significantly better than that of the single strain, while conjugate pairs strain G showed best. It provides us a new way for corn stover microbial inoculum research and utilization.
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