复合菌系17N对玉米秸秆的降解作用

egradation Effects of Compound Strain 17N on Maize Stalks

秸秆是一类重要的生物质能源,但由于秸秆直接还田后降解速率慢,影响下一茬作物的生长;因此,筛选秸秆降解菌对于农业生产中秸秆还田的高效利用尤为重要。为筛选能够快速高效降解玉米秸秆的菌系资源,将玉米秸秆壳分别浸泡于土浸液、土浸液(10%培养基)、土浸液(20%培养基)和纯净水中。结果表明,14和35 d时的土浸液对玉米秸秆壳的降解率均高于纯净水的降解率,且土浸液与土浸液(10%培养基)、土浸液(20%培养基)的降解率无明显差异。土浸液中进一步分离获得了复合降解菌系17N,用该复合菌系的发酵液浸泡三角瓶中的玉米秸秆壳,14和35 d时土浸液与复合菌系17N发酵液的降解率均高于纯净水。复合降解菌系17N发酵液对埋土玉米秸秆块具有良好的降解效果,优于三角瓶中对玉米秸秆块的降解效果。灭菌花盆土+灭菌网袋秸秆块+600 mL发酵液的降解率为37.0%,未灭菌花盆土+灭菌网袋秸秆块+600 mL发酵液的降解率为24.7%,三角瓶+发酵液+秸秆块的降解率为34.7%,不加发酵液的处理,即灭菌花盆土+灭菌网袋秸秆块处理的降解率仅为18.1%,明显低于3个加发酵液的处理。说明复合菌系17N对埋土玉米秸秆具有良好的降解作用。

Straw is a kind of important biomass energy.However,due to the slow degradation rate after the straw is directly returned to the field,it also affects the growth of the next crop.Therefore,screening degrading bacteria to straw is particularly important for the efficient utilization of straw in agricultural field.In order to screen bacterial resources that can degrade maize straw quickly and efficiently.In this study,maize straw husks were soaked in soil solution,soil solution(10%medium),soil solution(20%medium)and purified water,respectively.The degradation rate analysis at 14 days and 35 days showed that the degradation rate of maize stalks husks by soil leaching solution was higher than that of pure water.There was no obvious difference in the degradation rate between soil solution and soil solution(10%medium)and soil solution(20%medium).The composite degrading strain 17N was isolated from soil solutions.When the fermentation broth of the composite bacterial strain was soaked in the maize stalks husks in the triangular flask,the degradation rate of the soil solution and the fermentation broth of the composite bacterial strain 17N was higher than that of pure water at 14 days and 35 days.The results showed that the composite degrading strain 17N fermentation broth had a good degradation effect on buried maize stalks blocks,superior to the degradation effect on maize stalks blocks in a triangular flask.The degradation rate of the treatment without fermentation broth,namely sterilized flower pot soil+sterilized mesh bag straw block,was obviously lower than that of the three treatments with fermentation broth.The degradation rate of sterilized flower pot soil+sterilized mesh bag straw block was 18.1%,the degradation rate of sterilized flower pot soil+sterilized mesh bag straw block+fermentation broth was 37.0%,the degradation rate of not sterilized flower pot soil+sterilized mesh bag straw block+fermentation broth was 24.7%,and the degradation rate of triangular flask+fermentation broth+straw block was 34.7%.The results indicated that the composite strain 17N had a good degradation effect on buried maize stalks.