Evaluation of a novel fungal strain Cerrena unicolor GV01 for the biological pretreatment of crop straw

Abstract

Lignin is main residue of agro-industrial biomass which can be decomposed through enzymatic hydrolysis by fungi. In this study, we screened a kind of fungus from birch forest with degradation properties for lignin from nature to make full use of the agricultural straws being discarded as waste. The strain was identified as Cerrena unicolor GV01 by 18S rDNA gene-sequencing technology. The production performances of related enzyme secreted by GV01 were determined. The maximum activity of Lac produced by GV01 was 8396 U•L-1 with corn stalk on the 7th day. Three different crop straws (corn stalk, rice straw and wheat straw) were selected as the research material. The degradation rates of lignin of corn stalk, rice straw and wheat straw were 26.2%, 34.3% and 24.3% by GV01, respectively. The analyses of scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR) and thermal gravimetric analyzer (TGA) further showed that the pretreatment process by GV01 had significant effects on the structures of corn stalk, rice straw and wheat straw. Thus, GV01 could effectively degrade lignocellulose wastes, which not only saves the cost but also protects the environment.