Advances in the microbial degradation of corn straw cellulose: A review

Corn straw, as a massively produced agricultural waste, holds significant importance for promoting sustainable agricultural development and achieving carbon emission reduction. However, its complex lignocellulosic structure, particularly the encasement of cellulose by lignin, results in slow and inefficient natural degradation. Conventional microbial inoculants are subjected to a threefold stress, namely “low temperature, high salinity and drought”, which results in a loss of activity exceeding 90%. Microbial degradation technology, especially utilizing efficient degrading strains and their synthetic microbial consortium, can significantly accelerate straw degradation. This review is notable for its systematic integration of a four-dimensional research framework, encompassing the disciplines of “strain-enzyme-community-engineering”. The dimensions of the strain and enzyme elucidates the functional complementary strategies of bacteria, fungi and actinomycetes, and analyses the taxonomy and catalytic mechanisms of cellulase systems belonging to the GH and AA families. Community dimension discloses the metabolic interaction networks of synthetic microbial consortium, with a particular emphasis on the molecular adaptation mechanisms of cold-tolerant strains and strategies for constructing low-temperature synthetic microbial consortium. This section thus addresses a significant gap in the application of these communities within extreme environments. The engineering dimension provides an analysis of multi-level regulatory mechanisms. Furthermore, research on the microbial degradation of corn straw will be deeply integrated with interdisciplinary technologies such as synthetic biology, omics technologies and bioinformatics. The current status of full-chain applications will be assessed from an industrialisation perspective, analysing the threefold gap between efficiency, cost and stability.