Research progress on using cellulose degrading bacteria to improve straw returning efficiency*

The prosperous development of Chinese agriculture has generated diverse and abundant straw resources. As one of the abundant renewable biological resources, straw has the characteristics of large quantity, diverse types, and wide distribution. However, how to efficiently utilize straw resources has become an urgent problem to be solved, and returning straw to the field is currently an effective solution strategy. Under natural environmental conditions, the decomposition rate of straw is very slow, but long-term accumulation may lead to a decrease in soil fertility, which can seriously affect crop yield. Numerous studies have shown that using microorganisms to treat straw is an effective method to accelerate straw decomposition. Cellulose-degrading bacteria play a critical role in this process; their efficient degradation capabilities significantly enhance straw return efficiency while reducing the incidence of soil-borne diseases. This paper focuses on the core role of cellulose-degrading bacteria in improving the efficiency of straw return to the field, outlining the main types of cellulose-degrading bacteria and exploring their key roles in different methods of straw return, particularly in the current research status and progress regarding direct return to the field and composting. Additionally, it summarizes the effects of adding microbial agents during the straw return and degradation process on soil physical and chemical properties, microbial community dynamics, and soil-borne diseases. Research indicates that various bacteria and fungi can efficiently degrade cellulose; however, most studies are concentrated on the screening and optimization of single strains. Currently, the focus is on constructing composite microbial consortia using efficient cellulose-degrading strains, exploring cellulose degradation mechanisms to identify high-efficiency strains, and enhancing strain degradation capacity through molecular biology techniques. This includes identifying enzyme-producing genes and using metagenomics and meta transcriptomics to elucidate the functional patterns of cellulose-degrading bacteria within ecosystems, aiming for efficient straw decomposition and resource conversion. However, the construction of composite microbial consortia, the dynamic changes in soil microbial communities, and the mechanisms of cellulose-degrading bacteria in controlling soil-borne diseases still require further exploration. Future research could integrate bioinformatics and genetic engineering approaches to optimize cellulose-degrading bacteria, providing theoretical and technical support for the effective implementation of straw return. This would offer ideas and strategies for constructing composite microbial consortia, deeply analyzing dynamic changes in soil microbial communities, and understanding mechanisms of soil-borne disease control, ultimately aiming to enhance the efficiency of straw return and promote the sustainable development of agriculture.