盐碱地纤维素分解菌筛选及其菌剂对秸秆腐解效果的研究OA

To address the issues of slow natural straw decomposition and limited soil fertility improvement in saline-alkali land,this study used saline-alkali soil as a microbial source to screen salt-tolerant cellulolytic bacteria,construct a composite microbial consor-tium,and evaluate its application effect on in-situ straw decomposition and return.The Congo red staining method was used to screen salt-tolerant cellulolytic bacteria,and their enzyme activities as well as salt-alkali tolerance were determined.Antagonism tests and combinatorial performance assays were conducted to construct the composite consortium.In-situ decomposition and return experiments of maize and cucumber straw were carried out to analyze the effects of the composite microbial agent on straw decomposition rate,soil organic matter,alkali-hydrolyzable nitrogen,available phosphorus,available potassium,viable bacterial count,and cucumber yield.Four bacterial strains with strong salt-tolerant cellulolytic ability were successfully screened.Among them,strain JGX10 exhibited sig-nificantly higher ratio of clear zone diameter to colony diameter(D/d)and enzyme activity than the other strains,and showed the strongest single-strain tolerance to salt and alkali,withstanding 14%NaCl and pH 11.0.Two composite microbial agents were formu-lated with different ratios of JGX10 and JGX14,among which JGXF01(1∶1)achieved the highest enzyme activity of 39.57 U·mL-1.Both composite agents effectively increased the decomposition rate of maize straw,enhanced cucumber yield,raised soil organic matter and available nitrogen,phosphorus,and potassium contents,and improved soil viable bacterial counts.JGXF01(1∶1)performed best in multiple indicators.Therefore,JGXF01(1∶1)can effectively promote straw decomposition and soil fertility improvement in saline-alkali land,providing efficient microbial resources and technical support for straw resource utilization and soil fertility enhancement in saline-alkali regions.