Screening,identification and optimization of conditions for a multifunctional straw lignin-degrading strain
In order to realize the utilization of straw resources and increase crop yield,this study screened lig-nin degrading strains from straw and investigated their various functions to explore microbial resources,evaluate the straw degradation,plant growth promotion and disease resistance potential of the strain by combining aniline blue plate screening,lignin enzyme activity,IAA capacity measurement,and plate confrontation test.Strains identi-fication was achieved through morphological,physiological,biochemical,and 16S rRNA sequence analysis;the straw shake bottle test and the rice growth effects of the strain were assessed;a single factor experiment was con-ducted to determine the optimal conditions for bacterial growth.The straw degrading bacteria isolated and screened were identified as Raoultella planticola.The results showed that the lignin peroxidase activity of strain M15H2 reached 129.49 U·mL-1,manganese peroxidase activity reached 23.91 U·mL-1 and laccase activity reached 8.91 U·mL-1.Compared to the control,the straw decomposition rate was increased by 32.59% after 55 days of applica-tion with the M15H2 bacterial liquid.The production of IAA in M15H2 was 3.90 mg·L-1,and the germination rate,bud length,and root length values of rice plants increased by 5.67%,31%,and 40% compared to the control,re-spectively;the bacterial suspension M15H2 had a certain disease resistance effect,and the ratio of the diameter of the antibacterial zone to the diameter of the bacterial colony was 1.20.The optimal fermentation conditions for strain M15H2 were:pH 5.0;fermentation temperature,28-32 ℃;carbon and nitrogen sources,sucrose and yeast powder,respectively,and the liquid volume,50 mL/250 mL.The selected strain M15H2 is a straw-promoting and resistant resistance,which can accelerate the degradation of straw and promote the healthy growth of plants,and has a wide prospect of development and utilization.
万方数据
维普
