Screening the Carbon Source Type in Solid-State Fermentation with Phanerochaete chrysosporium to Improve the Forage Value of Corn Straw and Rice Straw

SIMPLE SUMMARY: The addition of carbon sources to white rot fermentation straw can promote the decomposition of organic matter by white rot fungi, shorten the fermentation cycle, and help retain more nutrients in the straw feed. Carbon sources (glucose, sucrose, molasses, or soluble starch) were added in 21 days of fermentation of corn and rice straw by white rot fungus (Phanerocacee pusosporium). The results showed that the molasses and glucose as carbon sources showed the greatest enhancement in the nutritional value of maize and rice straw after 14 days of solid-state fermentation (SSF) treatment. ABSTRACT: Poor quality straw can be made more digestible and palatable through delignification using white rot fungi as a biological treatment in SSF. The decomposition of organic matter by white rot fungi is improved when a carbon source is added. Reducing the fermentation cycle can also help retain more nutrients in straw feed. To increase rumen digestibility and nutrient utilization, corn straw and rice straw were subjected to SSF with white rot fungi (Phanerochaete chrysosporium) for 21 days. The type of carbon source (glucose, sucrose, molasses, or soluble starch) was optimized, and the nutrient composition and in vitro fermentation parameters of the fermented straw were assessed. In the fermented corn straw and rice straw supplemented with different carbon sources, the results showed a decrease in lignin content, dry matter, cellulose, and hemicellulose loss, and an increase in crude protein content after 21 days. Total volatile fatty acid and ammonium nitrogen concentrations increased significantly (p < 0.01) during in vitro fermentation. Overall, the most enhanced nutritional values for corn straw and rice straw were observed after 14 days of SSF in the groups using molasses or glucose as a carbon source.