Response of soil microbial glycoside hydrolase family 6 cellulolytic population to lignocellulosic biochar reveals biochar stability toward microbial degradation
Document Type
Article
Publication Date
7-1-2024
Abstract
Biochar produced from lignocellulosic biomass offers an opportunity to recycle waste into a valuable soil amendment. The application of biochar has been proposed to mitigate climate change by sequestering carbon in the soil. However, the field impact of biochar treatment on the cellulolytic microbial populations involved in the earlier steps of cellulose degradation is poorly understood. A field trial spanning three consecutive crop cycles of Zea mays was conducted in a degraded tropical Ultisol of Peninsular Malaysia. The soil was amended with two contrasting biochar made from oil palm kernel shells (pyrolyzed at 400 degrees C) and rice husks (gasified at 800 degrees C) with or without fertilizer supplementation. Soil samples were taken at each harvesting stage and analyzed for total organic carbon, labile active organic carbon, total cellulase, and beta-glucosidase. Microbial glycoside hydrolase family 6 (GH6) cellulase genes and transcripts, involved in the early steps of cellulose degradation, were quantified from the extracted soil deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), respectively. Total organic carbon, labile active organic carbon, and beta-glucosidase activity were significantly increased, while no effect on total cellulase activity was found. Both biochars stimulated the total population (DNA-derived) abundance of soil microorganisms harboring the GH6 cellulase genes. The biochar amendment did not affect the active population (RNA-derived) of the GH6 cellulolytic community, showing no significant changes in transcript expression. This indirectly corroborates the role of biochar as a potential carbon sequester in the soil. Total organic carbon has significantly increased, with no effect on total cellulase activity. Lignocellulosic biochar stimulates microbial glycoside hydrolase family 6 (GH6) cellulase genes but not transcripts. Biochar did not stimulate the metabolically active population due to the availability of more labile carbon (C) sources. The overall result validates the biochar stability toward soil microbial degradation.
Divisions
InstituteofBiologicalSciences
Funders
Institut Pengurusan dan Pemantauan Penyelidikan, Universiti Malaya, UM International Collaboration (ST065-2022),Universiti Malaya, UM International Collaboration
Publication Title
Journal of Environmental Quality
Volume
53
Issue
4
Publisher
Wiley
Publisher Location
111 RIVER ST, HOBOKEN 07030-5774, NJ USA