Profiling of Chemical and Structural Composition of Lignocellulosic Biomasses in Tetraploid Rice Straw.

Chen Chen,Zhixiong Chen,Jiajun Chen,Shaolong Sun,Bo Wang,Xiangdong Liu,Jiawei Huang,Huiling Li,Aimin Wu

doi:10.3390/polym12020340

Abstract

The improvement of the saccharification of rice straw is one of the strategies to reduce the sophisticated pretreatment that results in high cost and is unfriendly to the environment. We explored the cell wall features in tetraploid rice and highlighted the enhanced saccharification of tetraploid with large biomass. Results showed that lignin content and S/G ratio reduced to 17.09% and 0.37, respectively, in tetraploid straw by the determination of the pyGC-MS method. After the pretreatment, the cellulose crystallinity index decreased from 63.22% to 57.65% in tetraploid straw, which is lower than that of pretreated diploid straw. Surface topological analysis of SEM images indicated that tetraploid straw was more susceptible to the pretreatment. Tetraploid straw showed a strong advantage in the process of enzymatic hydrolysis. The enzyme efficiency reached the highest value of 77.60%, and the rate of enzyme reaction was improved to make the reaction saturated earlier than conventional rice. We concluded that the high saccharification has resulted from the alteration of lignin and cellulose in tetraploid rice. Our research provides an improved green feedstock for bioenergy, and the tetraploid rice straw shows the potential utilization value in bioethanol production.

Highlights

As one of the renewable energy sources, biomass energy has advantages in a sustainable and favorable environment
The results demonstrated that the changes in cell wall structure resulted in the enhanced saccharification degree in tetraploid rice, making it the promising green biomaterials
The samples were dewaxed by the soxhlet extraction method for 5 h with 2:1 (v/v) acetone-ethanol at 90 ◦ C, air-dried at room temperature to obtain the alcohol-insoluble residue (AIR)

Summary

Introduction

As one of the renewable energy sources, biomass energy has advantages in a sustainable and favorable environment. Research of biomass energy mainly focused on lignocellulose, which consists of cellulose, hemicellulose, and lignin [1]. Rice is one of the world’s main crops, with its vast acreage and yield, but is an excellent renewable energy resource. The biomass of straw cell wall is usually composed of 35%~50% cellulose, 20%~35% hemicellulose, and 10%~25% lignin in rice. The polyploid plant is significantly different from diploid plants, including morphology, yield, total biomass, cell wall composition, cell size, etc. The cell wall structure is often damaged by pretreatment to make it more susceptible to utilization, whereas, the polyploid plant has been characterized by changes in cell wall structure [4], revealing the potential roles in bioenergy fields

Methods

Results

Conclusion