Variation in Particle Size, Moisture Content and Supplements for Improvement of Cotton Stalks’ Lignin Degradation by Phlebia radiata and Saccharification

Abstract

Particle size, moisture content and media supplements were studied for delignification of cotton stalks by Phlebia radiata MTCC 2791 in solid-state fermentation. Highest lignin degradation of 31.02 ± 1.27% (w/w) with cellulose loss of 14.39 ± 0.53% (w/w) observed in cotton stalks having particle size 5 mm and 75% moisture content, after 40 days. Supplements Cu²⁺, Mn²⁺ and veratryl alcohol (VA) enhanced the lignolytic enzymes production and the lignin degradation. Supplements Mn²⁺ at 1 mM with lignin degradation 36.58 ± 0.28% (w/w), high selectivity value (SV) 2.81; Cu²⁺ at 0.5 mM with lignin degradation 31.75 ± 1.74% (w/w), SV 2.56; VA 0.5 mM with lignin degradation 33.96 ± 0.54% (w/w), SV 2.30 were optimal for pretreatment. The glucose yield increased to 113.22 ± 3.79 mg/g from 40 days pretreated cotton stalks with Mn²⁺ (1 mM) supplements, more than twofolds higher from untreated cotton stalks. Strong linear correlation of R² = 0.956 between lignin degradation and glucose yield was observed.

Keywords:

• Particle size
• Moisture content
• Supplements
• Delignification
• Enzymatic hydrolysis

Acknowledgements

Mr. Harmanpreet Meehnian gratefully acknowledges Ministry of Human Resource Development (MHRD), Govt of India for providing the fellowship during the study.

Disclosure Statement

No potential conflict of interest was reported by the authors.

Supplemental data

Supplemental data for this article can be accessed https://doi.org/10.1080/00194506.2017.1350826.