Research progress on anaerobic digestion and degradation of lignocellulosic waste by rumen microorganisms

Lignocellulosic biomass waste is an important raw material for anaerobic digestion to produce bioenergy. However, its complex three-dimensional structure leads to a low substrate conversion rate and poor technical economic efficiency during anaerobic digestion. Rumen fluid from ruminant slaughterhouse waste can selectively enhance the degradation and transformation of lignocellulosic biomass. When combined with anaerobic digestion, it is expected to improve the overall efficiency. In recent years, domestic and foreign scholars have conducted extensive research on the anaerobic digestion of rumen microorganisms for degrading lignocellulosic biomass. Furthermore, artificial rumen fermentation systems based on bionic principles have gradually emerged. This paper reviews the composition, diversity and related genes of rumen microorganisms and lignocellulosic component degrading enzymes in ruminants. It also summarizes the research progress of rumen microorganisms in biomass waste degradation and the production of methane, volatile fatty acid (VFAs), hydrogen and other value-added products. Additionally, this review provides an overview of the construction principles and application effects of anaerobic digestion methane production systems in simulated rumen. It further presents prospects and suggestions for the research of rumen microorganisms in the energy and resource utilization of anaerobic digestion. The intention is to provide ideas and methods for the degradation, transformation, and high-value utilization of lignocellulosic biomass by rumen microorganisms.