Effect of the Combining Corn Steep Liquor and Urea Pre-treatment on Biodegradation and Hydrolysis of Rice Straw

Yulin Ma; Xu Chen; Muhammad Zahoor Khan; Jianxin Xiao; Gibson Maswayi Alugongo; Shuai Liu; Jingjun Wang; Zhijun Cao

doi:10.3389/fmicb.2022.916195

Effect of the Combining Corn Steep Liquor and Urea Pre-treatment on Biodegradation and Hydrolysis of Rice Straw

Front Microbiol. 2022 Jul 13:13:916195. doi: 10.3389/fmicb.2022.916195. eCollection 2022.

Authors

Yulin Ma¹, Xu Chen¹, Muhammad Zahoor Khan^{1

2}, Jianxin Xiao¹, Gibson Maswayi Alugongo¹, Shuai Liu¹, Jingjun Wang¹, Zhijun Cao¹

Affiliations

¹ State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China.
² Department of Animal Sciences, Faculty of Veterinary and Animal Sciences, University of Agriculture, Dera Ismail Khan, Pakistan.

Abstract

A novel pre-treatment using corn steep liquor (CSL) and urea was developed to enhance the enzymatic saccharification and degradability of rice straw (RS). We used RS (1) without (Con) or with additives of (2) 5% urea (U), (3) 9% CSL and 2.5% urea (CU), and (4) 9% CSL and 5% urea (C5U). The result showed that the water-soluble carbohydrate (WSC) conversion of RS reached 69.32% after C5U pre-treatment. Scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction analysis (XRD) confirmed that the surface of pre-treated RS exposed more cellulose and hemicellulose due to the disruption of the resistant structure of lignocellulose. Pre-treated RS significantly decreased neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents and increased crude protein (CP) content, microbial colonization, and induction of Carnobacterium and Staphylococcus attachment. Altogether, we concluded that pre-treatment of a combination of CSL and urea has the potential to improve the nutritive value of RS.

Keywords: corn steep liquor; enzymatic hydrolysis; microbial colonization; rice straw; urea-pre-treatment.