Huang Guitao, Su Dongxiao, Lee Yuan-Kun, Zou Xiaoqin, Dong Lihong, Deng Mei, Zhang Ruifen, Huang Fei, Zhang Mingwei
Sericultural & Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Agricultural Products Processing, Guangzhou 510610, P. R. China.
College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China.
J Agric Food Chem. 2025 Feb 12;73(6):3669-3679. doi: 10.1021/acs.jafc.4c08859. Epub 2025 Jan 27.
In the current work, lychee pulp was subjected to ATCC 14917 fermentation, leading to a substantial increase (2.32-2.67-fold) in water-soluble polysaccharides (WSP). Concurrently, a significant degradation occurred in water-insoluble polysaccharides (WISP) composed of glucose (28.73%), arabinose (28.25%), galacturonic acid (25.07%), and galactose (11.00%). To clarify polysaccharide conversion and its relevant mechanism, carbohydrate-active enzyme encoding sequences in the ATCC 14917 genome and structural alterations of two polysaccharide fractions were dissected. By integrating the transcriptional assay, prokaryotic expression, and enzymic hydrolysis, three endoglucanases were demonstrated to catalyze WISP degradation, leading to WSP accumulation during lychee pulp fermentation with ATCC 14917. Reductions in proportions of galactose and galacturonic acid in WSPs were partly attributed to the actions of multiple galactosidases. These findings provide an enzyme-based explanation for WSP accumulation during fermentation and serve as a practical foundation for directional polysaccharide conversion.
在当前的研究中，荔枝果肉经过ATCC 14917发酵，导致水溶性多糖（WSP）大幅增加（2.32 - 2.67倍）。同时，由葡萄糖（28.73%）、阿拉伯糖（28.25%）、半乳糖醛酸（25.07%）和半乳糖（11.00%）组成的水不溶性多糖（WISP）发生了显著降解。为了阐明多糖转化及其相关机制，对ATCC 14917基因组中碳水化合物活性酶编码序列以及两种多糖组分的结构变化进行了剖析。通过整合转录分析、原核表达和酶解，证明了三种内切葡聚糖酶催化WISP降解，导致在荔枝果肉与ATCC 14917发酵过程中WSP积累。WSP中半乳糖和半乳糖醛酸比例的降低部分归因于多种半乳糖苷酶的作用。这些发现为发酵过程中WSP积累提供了基于酶的解释，并为多糖的定向转化奠定了实践基础。
