The use of newly isolated fungal cultures for the selective delignification of bamboo culms

Bo Zhao; Rui Liu; Qi Guo; Gang Xu; Li Zhang; Peng Sun; Ying Cao; Shanglian Hu

doi:10.3389/fbioe.2023.1265420

The use of newly isolated fungal cultures for the selective delignification of bamboo culms

Front Bioeng Biotechnol. 2023 Aug 31:11:1265420. doi: 10.3389/fbioe.2023.1265420. eCollection 2023.

Authors

Bo Zhao^#¹, Rui Liu^#¹, Qi Guo¹, Gang Xu¹, Li Zhang², Peng Sun², Ying Cao¹, Shanglian Hu¹

Affiliations

¹ School of Life Science and Engineering, Bamboo Research Institute, Southwest University of Science and Technology, Mianyang, China.
² Sichuan Academy of Forestry, Chengdu, China.

^# Contributed equally.

Abstract

The screening of ligninolytic enzyme-producing fungal species in samples led to the identification of Paracremonium sp. LCB1, Clonostachys compactiuscula LCD1 and C. compactiuscula LCN1. Both these strains produced high levels of hemicellulase and ligninolytic enzyme production over a relatively short fermentation period of 3-5 days while exhibiting very low levels of cellulase activity. The results of the tests indicated that co-culturing LCB1 and LCN1 enhanced the ability to degrade lignin, and the ideal degrading circumstances and internal degrading mechanism of combined fungi were examined. The results showed that under conditions of temperature (30°C), pH (5), culture time (40 d), solid-liquid ratio (1:2.5), the pretreatment of bamboo culms with a co-culture of LCB1 and LCN1 resulted in a pronounced 76.37% drop in lignin weight and a high lignin/cellulose loss ratio (>10). Fourier transform infrared spectroscopy, X-ray diffractometry, and scanning electron microscopy were used to characterize the physicochemical properties of these bio-pretreated bamboo culms, further confirming that LCB1 and LCN1 co-culture represents an effective approach to bamboo delignification.

Keywords: bamboo; combined fungi; ligninolytic enzyme production; orthogonal test; selective degradation.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was financially supported by the National Key R&D Program of China (2021YFD2200504_1 and 2021YFD2200505_2), the Science and Technology Project of Sichuan Province, China (2022NSFSC0093 and 2021YFYZ0006).