Synergistic mechanisms of selected microbial fermentation and black soldier fly larvae on sugarcane bagasse conversion: Insights into microbial shifts

Sugarcane bagasse, a major by-product of sugarcane produced in large quantities after industrial processing of sugarcane, is causing a serious threat to human health, biodiversity, and ecosystem stability. Black soldier fly larvae (BSFL) offer a promising solution for organic waste management by converting it into insect protein. This study aimed to elucidate the mechanism of selected microbial fermentation and BSFL on sugarcane conversion, as well as the influence of fermented sugarcane bagasse on the BSFL gut microbial shifts and lignocellulose degradation enzymes using metagenomic analysis. The results revealed a notable increase in Firmicutes phylum, along with its beneficial strains such as Bacillus licheniformis, Bacillus safensis, Bacillus pumilus, Cytobacillus kochii, and Lysinibacillus fusiformis, in the gut of BSFL reared on fermented sugarcane bagasse, leading to improved gut homeostasis and reduced pathogenic loads. This study further explored the co-conversion mechanisms of microbial fermentation and BSFL on lignocellulose degradation and identified high abundances of carbohydrate-active enzymes (CAZymes) involved in hemicellulase and cellulase degradation at both class and family levels. These findings underscore the potential of integrating microbial fermentation and BSFL in sustainable waste management, offering a promising approach to mitigate the challenges posed by organic waste.

甘蔗渣（sugarcane bagasse）是甘蔗经工业化加工后产生的大宗副产物，其对人类健康、生物多样性及生态系统稳定性均构成严重威胁。黑水虻幼虫（black soldier fly larvae, BSFL）可将有机废物转化为昆虫蛋白，为有机废物治理提供了极具潜力的解决方案。本研究旨在阐明筛选得到的微生物发酵与黑水虻幼虫对甘蔗原料的转化机制，并通过宏基因组分析探究发酵甘蔗渣对黑水虻幼虫肠道菌群结构变化及木质纤维素降解酶的影响。研究结果显示，取食发酵甘蔗渣的黑水虻幼虫肠道内厚壁菌门（Firmicutes）及其有益菌株（包括地衣芽孢杆菌Bacillus licheniformis、沙福芽孢杆菌Bacillus safensis、短小芽孢杆菌Bacillus pumilus、科奇杆菌Cytobacillus kochii及梭形赖氨酸芽孢杆菌Lysinibacillus fusiformis）的丰度显著提升，进而改善了肠道稳态并降低了致病菌载量。本研究进一步探究了微生物发酵与黑水虻幼虫协同降解木质纤维素的机制，并在纲与科水平上鉴定出大量高丰度的、参与半纤维素酶与纤维素酶降解的碳水化合物活性酶（carbohydrate-active enzymes, CAZymes）。上述研究结果凸显了将微生物发酵与黑水虻幼虫技术相结合在可持续废物治理中的应用潜力，为应对有机废物带来的挑战提供了极具前景的解决方案。