Fungi's selectivity in the biodegradation of Dendrocalamus sinicus decayed by white and brown rot fungi

Dendrocalamus sinicus is the largest bamboo in the world. It can offer enormous potential for bio-pulping or bio-oil through biological processes, due to its abundant cell walls as a renewable and abundant bioresource. Worth mentioned in bio-conversion process, white-rot fungi are advantageous and have potential for lignocellulose pretreatment due to less energy consumption and waste materials, meanwhile brown-rot fungi can maximize the proportion of valuable aromatic hydrocarbons. In this study, the lignocellulolytic enzymes secreted by white-rot fungi T. versicolor, brown-rot fungi G. trabeum and R. placenta were investigated to evaluate and compare their biodegradation abilities in Dendrocalamus sinicus during various periods. In addition, changes of bamboo in chemical characterization were also researched, which arose from the various lignocellulolytic enzymes accordingly. The results showed that fungi secreted and employed various lignocellulosic enzymes to biodegrade Dendrocalamus sinicus, while different fungi biodegraded bamboo in their own selective path. White-rot fungi T. versicolor caused selective rot, and it initially degraded starch and pectin, followed by hemicellulose and lignin, thereby cellulose relatively retained selectively. In both brown-rot fungi, the highest lignocellulolytic enzyme activities mainly occurred at 40-50th days, indicating brown-rot fungi mainly attacked bamboo in the middle stage. They preferentially degrade carbohydrates, but G. trabeum can degrade hemicellulose selectively, while R. placenta had selectivity for degradation of cellulose.