Development of fungal consortium for the pretreatment of rice straw under optimized solid state and shake flask conditions

Abstract

Three consortia were developed out of the ligninolytic fungal isolates for pretreatment of rice straw. The fungal consortium of Pleurotus ostreatus and Phanerochaete chrysosporium, produced maximum laccase (Lac), lignin peroxidase (LiP), and manganese peroxidase (MnP) activities of 2.40 nkat/gds, 37.92 nkat/gds, and 62.50 nkat/gds, respectively. Response surface methodology (RSM) based on central composite design (CCD) was used to optimize pretreatment of rice straw under solid state conditions. With a desirability value of 0.862, the optimum conditions (moisture, 121.1%; temperature, 31.3°C; and log spore count, 8.0 spores/mL) resulted in 43.0%, 12.7% and 7.0% cellulose, hemicellulose, and lignin, respectively, from an initial respective values of 39.5%, 23.3%, and 11.5%. Optimization under shake flask conditions using 2.5 g rice straw, 8.0 mL concentrated ligninolytic enzyme extract, 10 mM Ca2+ ions, 45°C incubation temperature in an incubation period of 72 h resulted in 56.4%, 12.2%, and 2.2%, cellulose, hemicellulose, and lignin, respectively. © 2018 American Institute of Chemical Engineers Environ Prog, 38: 635–646, 2019

Effect of ligninolytic axenic and coculture white-rot fungi on rice straw chemical composition and in vitro fermentation characteristics

“…ostreatus S18 coculture also achieved a twofold lignin degradation rate 13 . Recently, Kaur et al 14 reported a maximum laccase (Lac), lignin peroxidase (LiP), and manganese peroxidase (MnP) activities of 2.40 nkat/gds, 37.92 nkat/gds, and 62.50 nkat/gds respectively using P . ostreatus and P .…”

Evaluation of fungal consortium lignozyme for biodelignification of agricultural residues

“…Remazole brilliant blue R is structurally similar to lignin backbone, which was efficiently decolorized by WRF‐secreting ligninozymes. In our laboratory, Kaur et al 11 . recorded LI readings of 2.4 and 2.2 for P. ostreatus and P. chrysosporium , respectively.…”

“…The synergistic effect of Lacc, LiP, and MnP as a fungal consortium for paddy straw pretreatment is in agreement with previous reports. Pretreatment of paddy straw with concentrated fungal ligninolytic enzymes resulted in 80.87% and 47.64% lignin and hemicellulose reduction, respectively, with a 29.96% rise in the proportion of cellulose 11 …”

“…Ligninolytic enzymes viz . LiP, MnP and Lacc were produced from consortium culture of P. chrysosporium and P. ostreatus , under the previously optimized fermentation conditions in our lab by Kaur et al 11 . whereby the consortium lignozyme was shown to have better enzyme activities compared to individual fungi, i.e.…”

Effect of Ligninolytic Axenic and Coculture White-Rot Fungi on Rice Straw Chemical and In Vitro Fermentation Characteristics.

“…Tobacco stalk substrate treated with T. hirsuta S13 and P. ostreatus S18 coculture also achieved a 2-fold lignin degradation rate (from 23.7 to 41.1%) 8 . Recently, Kaur, et al 9 reported a maximum laccase (Lac), lignin peroxidase (LiP), and manganese peroxidase (MnP) activities of 2.40 nkat/gds, 37.92 nkat/gds, and 62.50 nkat/gds respectively via a Pleurotus ostreatus and Phanerochaete chrysosporium fungal consortium on rice straw. These independent studies demonstrate the potential of white-rot fungal consortium to alter cell wall chemical constituents of various straw via their enzyme activities/secretions.…”