Ratheesh Anjana, Sreelekshmy Bhuvanendran Revamma, T R Anil Kumar, Sasidharan Sarika, Basheer Rubina, Nair Kanakangi Sukumaran, Nair Ananthakrishnan Jayakumaran, Shibli Sheik Muhammadhu Aboobakar
Department of Biotechnology, University of Kerala, Kariavattom Campus, Thiruvananthapuram, Kerala 695 581, India.
Rajagiri College of Social Sciences, Kalamassery, Cochin, Kerala 683 104, India.
ACS Appl Bio Mater. 2025 Jun 16;8(6):4924-4936. doi: 10.1021/acsabm.5c00310. Epub 2025 May 20.
Lignocellulose recalcitrance remains a significant economic challenge in modern biomass conversion processes. Microbial strategies offer considerable promise for ecofriendly bioenergy generation. This study presents an advanced integrated approach that combines bacterial treatment with a bioelectrochemical system (BES) to enhance the conversion efficiency of lignocellulosic biomass. Unlike integrated or sequential approaches, a comparative evaluation of two distinct pretreatment strategies, alkaline delignification and biological treatment, was conducted independently to assess their individual effectiveness in sugar cane bagasse (SCB) degradation and their performance in a microbial fuel cell (MFC). Biological treatment with alone yielded superior outcomes in terms of saccharification efficiency, microbial growth, and bioelectricity generation, as evidenced by higher open-circuit potentials in MFC half-cell studies in comparison with alkali delignified SCB. Notably, treatment increased cellulose content by 72% and reduced hemicellulose and lignin by approximately 0.84-fold, indicating effective enzymatic action. Metabolomic profiling identified 2846 metabolites that significantly diverged between the experimental groups. Notably, lignin-derived compounds such as ferulic acid, syringic acid, and p-coumaric acid were detected at elevated levels, confirming enhanced ligninase activity in pretreated SCB. Additionally, the presence of organic acids (e.g., acetic acid), amino acids, and their derivatives, resulting from the breakdown of cellulose, hemicellulose, and lignin, provided essential bioenergy substrates for exoelectrogenic organisms in BESs. This integration led to a maximum power density of 353 ± 5 mW/m and a current density of 200 ± 3 mA/m, demonstrating significant enhancement in performance of MFC. Furthermore, the biotransformation of SCB facilitated the channeling of metabolites into value-added products, increasing the overall efficiency of the biomass valorization. Thus, the rational utilization of SCB underscores its potential for scalable biorefinery applications and its broader implications for sustainable bioenergy production.
木质纤维素的顽固性仍然是现代生物质转化过程中的一个重大经济挑战。微生物策略为生态友好型生物能源生产提供了巨大的前景。本研究提出了一种先进的综合方法，将细菌处理与生物电化学系统（BES）相结合，以提高木质纤维素生物质的转化效率。与综合或顺序方法不同，对两种不同的预处理策略——碱性脱木质素和生物处理——进行了独立的比较评估，以评估它们在甘蔗渣（SCB）降解中的各自有效性及其在微生物燃料电池（MFC）中的性能。单独进行生物处理在糖化效率、微生物生长和生物电产生方面产生了更好的结果，MFC半电池研究中的开路电位高于碱脱木质素的SCB，证明了这一点。值得注意的是，生物处理使纤维素含量增加了72%，半纤维素和木质素减少了约0.84倍，表明酶促作用有效。代谢组学分析确定了实验组之间有显著差异的2846种代谢物。值得注意的是，在预处理的SCB中检测到阿魏酸、丁香酸和对香豆酸等木质素衍生化合物的含量升高，证实了预处理SCB中木质素酶活性增强。此外，纤维素、半纤维素和木质素分解产生的有机酸（如乙酸）、氨基酸及其衍生物的存在，为BES中的产电生物提供了必需的生物能源底物。这种整合导致最大功率密度为353±5 mW/m，电流密度为200±3 mA/m，表明MFC的性能有显著提高。此外，SCB的生物转化促进了代谢物向增值产品的转化，提高了生物质增值的整体效率。因此，SCB的合理利用突出了其在可扩展生物精炼应用中的潜力及其对可持续生物能源生产的更广泛意义。
