Effect of Fungal Treatments of Rape Straw on Chemical Composition and in vitro Rumen Fermentation Characteristics

Abstract

The use of rape straw in ruminant production is limited by its high lignin content and low ruminal degradability. White rot fungi are the most efficient known degraders of lignin. Four white rot fungi were investigated for their potential to degrade lignin and improve rumen fermentation of rape straw. Solid state fermentation of the straw was carried out for 0 to 30 days to determine changes in chemical composition and in vitro rumen fermentation. Results showed that Phanerochaete chrysosporium and Lentinula edodes degraded about 45% of lignin and enhanced the in vitro organic matter digestibility (IVOMD) and volatile fatty acid production; however, about 55% of the cellulose was lost after 30 days of incubation. Ceriporiopsis subvermispora and Phlebia acerina degraded a fraction (< 30%) of lignin and cellulose, but inhibited ruminal fermentation. Fungal incubation increased the chitin content of rape straw. Regression analysis showed that the IVOMD increase depended on the combined action of neutral detergent fiber loss and chitin content increase in rape straw. This study indicates that considerations of the conversion of rape straw into ruminant feed with white-rot fungi should take into account the degradation of lignin, fiber loss, and the chitin produced along with the growth of fungi.

Expression of a Recombinant Lentinula edodes Xylanase by Pichia pastoris and Its Effects on Ruminal Fermentation and Microbial Community in in vitro Incubation of Agricultural Straws

“…L. edodes can use its enzymatic machineries to efficiently degrade cellulose and hemicellulose of agricultural straws, but the products are used for the growth of its spawn or sporophore, which results in the great losses of nutritional value of straws ( Mata and Savoie, 1998 ; Tuyen et al, 2013 ; Zhao et al, 2015 ). To improve the utilization of agricultural straws, a recombinant xylanase from L. edodes was produced using P. pastoris and its effects on ruminal fermentation and microbial community was investigated in current study.…”

“…White-rot fungi are the most efficient known lignocellulose degrader in nature ( Zhao et al, 2015 ). As one of white-rot fungi, Lentinula edodes can use its enzymatic machineries to break down lignocellulose and improve nutritive value of low quality feeds, such as rape straw, wheat straw, rice straw, corn stover, and sugarcane bagasse, but also resulted in the great losses of cellulose and hemicellulose during the degradation, which limits its practical use ( Tuyen et al, 2012 , 2013 ; Zhao et al, 2015 ). However, at least it means that L. edodes is a good source for fibrolytic enzymes gene pool.…”

Response of rumen bacterial diversity and fermentation parameters in beef cattle to diets containing supplemental daidzein

“…To determine total and individual VFA, acidified samples were centrifuged at 11,000Âg for 10 min, with the supernatant fraction filtered through a 0.45-mm filter. The VFA concentrations in the filtered samples were determined by a gas chromatograph (Agilent Technologies 7820A, USA) equipped with a free fatty acid phase capillary column (30 m  0.25 mm  0.33 mm, Lanzhou Atech, Lanzhou, China) (Zhao et al 2015). Crotonic acid was used as an internal standard.…”

Heterologous Expression of Laccase From Lentinula edodes in Pichia pastoris and Its Application in Degrading Rape Straw

“…Though massive rape is grown in China every year, little of the rape straw produced is used efficiently and majority of it is burnt or naturally decayed as waste. Rape straw can theoretically be used as ruminants feed due to its high cellulose and hemicellulose contents, but severe lignification and complex cross-linked structure between fiber and lignin limit the penetration of ruminal microorganisms and their enzymes into plant cell wall (Ramirez-Bribiesca et al, 2011;Zhao et al, 2015). To improve the ruminal degradation of rape straw, it is necessary to disrupt the cross-linked structure and increase the surface area of available fiber.…”