Characterization of cotton stalk as a lignocellulosic feedstock for single-cell protein production

• Published in: Bioresource technology 2025-02, Vol.417, p.131797, Article 131797
• Main Authors: Zhong, Pingxiang, Chen, Pengyun, Huo, Pengju, Ma, Lei, Xu, Zhaoxian, Li, Fuguang, Cai, Chenggu
• Format: Article
• Language: English
• Subjects: byproducts; Candida - metabolism; Candida utilis; cotton; Cotton stalk valorization; Dietary Proteins; feedstocks; Gossypium - metabolism; Hydrolysis; lignin; Lignin - chemistry; Lignin - metabolism; Lignin characterization; lignocellulose; Lignocellulosic biorefinery; protein synthesis; protein value; Single-cell protein; sugars; technology
• ISSN: 0960-8524; 1873-2976; 1873-2976
• DOI: 10.1016/j.biortech.2024.131797

[Display omitted] •A compositional analysis is first conducted on six parts of the cotton stalk.•The fundamental lignin structural features of cotton stalk are unveiled.•The bark and root exhibit lower recalcitrance and release more fermentable sugars.•C. utilis is a suitable host for SCP production utilizing cotton stalk hydrolysate. Cotton stalk, an important by-product of cotton farming, is challenging in lignocellulosic feedstock application due to the limited understanding of their compositional and lignin structural characteristics. This study elucidates the composition of lignocellulose components and fundamental lignin structural features of cotton stalk. Lignocellulosic hydrolysates were prepared from various cotton stalk parts and used for single-cell protein production. As a proof of concept, cotton stalk hydrolysates were successfully converted into single-cell protein using the superior microbial host, Candida utilis ACCC20060, owing to its favorable sugar consumption efficiency and high protein quality. The highest SCP concentration of 5.74 g/L was obtained, yielding 0.23 g/g from the lignocellulose-derived sugars released from cotton stalk roots. This study provides valuable references for cotton stalk utilization toward lignocellulosic feedstock application and introduces a promising microbial host for single-cell protein production from such feedstocks.