Potential application of lignin from paddy husk for biovanilin production by phaenarochaeta crysosoporium in submerged fermentation

Abstract

The processing of paddy produces two main types of residues namely paddy husk and paddy straw. Paddy husk, the outer coat of paddy grain consists approximately 25-30% of lignin. It contains ferulic acid that acts as precursor for biovanillin production. In this study, lignin recovery from paddy husk was investigated for biovanillin production by Phanerochaete chrysosporium in batch culture, using submerged fermentation which was conducted at 30º C, 150 rpm. The biovanillin yield of lignin obtained from physical, chemical, physicochemical and biological pre-treatments were compared. Lignin recovered from microwave irradiation at 330W for 12 min was able to produce the biovanillin up to 0.0997 g/L. The recovery of lignin from microwave was optimized by Response Surface Methodology based on Central Composite Design to improve the production yield of vanillin. Three parameters were studied; namely time (5-30 min), solid to liquid ratio (5-25%) and microwave power (80-800 Watt). The lignin recovered from microwave was chosen for further study by considering the pre-treatment process without any chemical addition which is more environmental friendly for biovanillin production. Lignin recovered from paddy husk was successfully used for the production of biovanillin.