Isolating, evaluating and optimizing lignocellulosic decomposition of various microbial strains

Abstract

This research was conducted in order to find out active strains those can well decompose and remove lignin from agricultural waste sources for the production of biofuels by biological pathways. Fiffty fungal strains were isolated and assessed degree of lignin and cellulose degradation based on speed and diameter of round-resolution on lignin and CMC medium. The experiment was expected to select highly active strains in biomass degradation ability. The selected strains were determined enzymatic activities including Lignin peroxidase, Manganese peroxidase and Cellulase. We also tested factors those could affect the biosynthesis of lignin and cellulose enzymes, it was indicated that the 4 strains: strains 5, 10, 14 and P201 were superior as compared with other strains. Based on enzyme assay, the strain 10 shown up to 163.391 UI/L 0.838 UI/L and 1098.914 UI/L for LiP, MnP and cellulase activities, respectively, this strain was considered to be the most active on both ligninase and cellulase systems. The obtained results also showed that avicel medium was suitable for the biosynthesis of cellulase enzyme; While, PGB medium was suitable for biosynthesis enzyme ligninase system. LiP activity was highest on the fifth day in PGB medium; with a value of 223.587 UI/L. MnP activity reached maximal value ​​on the third day in PGB medium with a value of 0.935 UI/L. For cellulase enzyme systems, enzymatic activity on avicel medium was higher on PGB medium and achieved the highest value on the third day with a value of 2340.148 IU/L.