Effect of biological pretreatment of Agropyron elongatum ‘BAMAR’ on biogas production by anaerobic digestion

•Agropyron elongatum ‘BAMAR’ (Tall Wheat Grass) was treated with Flammulina velutipes.•Mesophilic anaerobic digestion of fungal pretreated Tall Wheat Grass for biogas production.•Fungal pretreatment caused as much as 35% of lignin degradation.•Both biogas and methane production were significantly improved. The aim of this work was to analyze the impact of three different moisture contents (MC), at 45% MC, 65% MC, 75% MC, on the degradation of cellulose, hemicellulose, and lignin during fungi treatment by Flammulina velutipes of Agropyron elongatum ‘BAMAR’ and on biogas production. The analysis of chemical composition shown that F. velutipes had greater selectivity for lignin biodegradation with the highest hemicellulose and lignin removal at 29.1% and 35.4%, respectively, and lowest cellulose removal (20.48%) at 65% MC. F. velutipes cultivated at 65% MC increased biogas production of 398.07Ndm3kg−1VS−1, which was 120% higher than the untreated sample. These treatment conditions resulted in 134% more methane yield compared with untreated sample. The results of this study suggested that A. elongatum is a potential biomass for biogas production in agriculture biogas plant and white-rot fungus F. velutipes provides an effective methods for improve biodegradation of A. elongatum.