title: Improvement of selective lignin degradation in fungal pretreatment of sweet sorghum bagasse using synergistic CuSO4-syringic acid supplements.
abstract: Sweet sorghum bagasse (SSB) generated in large quantities could be hydrolyzed to sugar and then fermented to green fuels. The hydrolysis of SSB polysaccharides interlocked in recalcitrant lignin network is the major problem. Pretreatment of SSB in SSF by using Coriolus versicolor with CuSO4-syringic acid supplements for effects on production of ligninocellulolytic enzymes, lignin degradation and selectivity values (SV) were studied. C. versicolor was selected based on high ligninolytic and low cellulolytic abilily. Individually, CuSO4increased the activities of laccase (4.9 folds) and PPO (1.9 folds); syringic acid increased LiP (13 folds), AAO (2.8 folds) and laccase (5.6 folds) resulting in increased lignin degradation and SVs. Combined syringic acid (4.4 μmol g-1SSB) and CuSO4(4.4 μmol g-1SSB) increased the activities of laccase, LiP, MnP, PPO and AAO by 11.2, 17.6, 2.8, 2.4 and 2.3 folds respectively due to synergistic effect, resulting in maximum lignin degradation 35.9 ± 1.3% (w w-1) (1.86 fold) and highest SV 3.07 (4.7 fold). Enzymatic hydrolysis of pretreated SSB yielded higher (∼2.2 times) fermentable sugar. Pretreated SSB was characterized by XRD, SEM, FTIR and TGA/DTG analysis to confirm results. It is possible to improve fungal pretreatment of agricultural waste by combination of supplements.
authors.affiliation: Department of Biotechnology, Dr B R A National Institute of Technology, Jalandhar, 144011, Punjab, India.
authors.forename: Vartika
authors.initials: V
authors.lastname: Mishra
authors.affiliation: Department of Biotechnology, Dr B R A National Institute of Technology, Jalandhar, 144011, Punjab, India. Electronic address: janaak@nitj.ac.in.
authors.forename: Asim K
authors.initials: AK
authors.lastname: Jana
authors.affiliation: Department of Chemistry, Dr B R A National Institute of Technology, Jalandhar, 144011, Punjab, India.
authors.forename: Mithu Maiti
authors.initials: MM
authors.lastname: Jana
authors.affiliation: Department of Biotechnology, Dr B R A National Institute of Technology, Jalandhar, 144011, Punjab, India.
authors.forename: Antriksh
authors.initials: A
authors.lastname: Gupta
mesh_terms: D002482:Cellulose / Q000378:metabolism; D005658:Fungi / Q000378:metabolism; D006868:Hydrolysis; D042845:Laccase / Q000378:metabolism; D008031:Lignin / Q000378:metabolism*; D045868:Sorghum / Q000378:metabolism*
chemical_list: D002482:Cellulose; D008031:Lignin; D042845:Laccase
keywords: Delignification; Enzymatic hydrolysis; Fungal pretreatment; Ligninocellulosic waste; Ligninolytic enzymes; Supplements