Response surface methodology for the mixed fungal fermentation of Codonopsis pilosula straw using Trichoderma reesei and Coprinus comatus

Abstract

The objective of this study was to investigate the cellulose degradation rate (CDR) and lignin degradation rate (LDR) of Codonopsis pilosula straw (CPS) and the optimal fermentation parameters for mixed fungal fermentation. Single-factor tests were used to study the effects of the fungal ratio (Trichoderma reesei: Coprinus comatus), fungal inoculum, corn flour content, and fermentation time on the degradation rate of cellulose and lignin. Based on the results of this experiment, the optimal fermentation factors were identified, and the effects of various factors and their interactions on the degradation rates of cellulose and lignin were further evaluated using the response surface method. The quadratic polynomial mathematical model of degradation rates of the cellulose and lignin in CPS by mixed fungus fermentation was established using Design Expert software v8.0.6. Under the optimal parameters for fungal fermentation of CPS straw (fungal ratio 4:6, fungal inoculum 8%, corn flour content 10%, fermentation time of 15 d), the CDR and LDR reached 13.65% and 10.73%, respectively. Collectively, the mixed fungal fermentation of CPS resulted in decreased lignin and cellulose content, better retention of nutrients, and enhanced fermentation quality. The results of this study indicate that fermentation using Trichoderma reesei and Coprinus comatus is a productive method for straw degradation, providing a theoretical basis for the development of CPS as feed.

Efficient conversion of distillers grains as feed ingredient by synergy of probiotics and enzymes

“… Datsomor et al (2022) reported that the P. ostreatus treated straw had a lower lignin content (3.3%) compared to the P. chrysosporium (6.2%) with the raw straw recording the 8.2% lignin fraction. Wei et al (2023) reported that under the optimal parameters for fungal fermentation of Codonopsis pilosula straw, the cellulose degradation rate and lignin degradation rate reached 13.65 and 10.73%, respectively. These reports are consistent with our research results, proving that cellulose, hemicellulose and lignin in distillers grains can be degraded by microorganisms into simple sugars such as glucose and xylose.…”