Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, Jiangsu Province, PR China.
Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, Jiangsu Province, PR China; Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou University of Science and Technology, Suzhou, 215011, Jiangsu Province, PR China.
Chemosphere. 2023 Dec;344:140384. doi: 10.1016/j.chemosphere.2023.140384. Epub 2023 Oct 6.
Quorum sensing (QS) have been explored extensively. However, most studies focused on N-acyl homoserine lactones (AHLs) participating in intraspecies QS. In this study, autoinducer-2 (AI-2, participating in interspecies QS) with different concentration was investigated for chain elongation in microbial electrosynthesis (MES). The results demonstrated that the R3 treatment, which involved adding 10 μM of 4,5-dihydroxy-2,3-pentanedione (DPD) in the reactor, exhibited the best performance. The concentration of caproate was increased by 66.88% and the redox activity of cathodic electroactive biofilms (EABs) was enhanced. Meanwhile, microbial community data indicated that Negativicutes relative abundance was increased obviously in R3 treatment. In this study, the transcriptome Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) databases were used to analyze the metabolic pathway of chain elongation involving fatty acid biosynthesis (FAB) pathway and reverse β-oxidization (RBO) pathway. KEGG analysis revealed that fatty acid elongation metabolism (p < 0.001), tryptophan metabolism (p < 0.01), arginine and proline metabolism (p < 0.05) were significantly improved in R3 treatment. GO analysis suggested that R3 treatment mainly upregulated significantly transmembrane signaling receptor activity (p < 0.01), oxidoreductase activity (p < 0.05), and phosphorelay signal transduction (p < 0.05). Moreover, metatranscriptomic analyses also showed that R3 treatment could upregulate the LuxP extracellular receptor, LuxO transcriptional activator, LsrB periplasmic protein, and were beneficial to both FAB and RBO pathways. These findings provided a new insight into chain elongation in MES system.
群体感应（QS）已被广泛研究。然而，大多数研究都集中在参与种内 QS 的 N-酰基高丝氨酸内酯（AHLs）上。在这项研究中，研究了不同浓度的自动诱导物-2（AI-2，参与种间 QS）在微生物电合成（MES）中的链延伸。结果表明，涉及在反应器中添加 10 μM 4,5-二羟基-2,3-戊二酮（DPD）的 R3 处理表现出最佳性能。己酸的浓度增加了 66.88%，并且阴极电活性生物膜（EAB）的氧化还原活性增强。同时，微生物群落数据表明，R3 处理中 Negativicutes 的相对丰度明显增加。在这项研究中，京都基因与基因组百科全书（KEGG）和基因本体论（GO）数据库用于分析涉及脂肪酸生物合成（FAB）途径和反向β-氧化（RBO）途径的链延伸代谢途径。KEGG 分析表明，脂肪酸延伸代谢（p<0.001）、色氨酸代谢（p<0.01）、精氨酸和脯氨酸代谢（p<0.05）在 R3 处理中显著改善。GO 分析表明，R3 处理主要上调显著的跨膜信号受体活性（p<0.01）、氧化还原酶活性（p<0.05）和磷酸接力信号转导（p<0.05）。此外，宏转录组分析还表明，R3 处理可以上调 LuxP 细胞外受体、LuxO 转录激活剂、LsrB 周质蛋白，有利于 FAB 和 RBO 途径。这些发现为 MES 系统中的链延伸提供了新的见解。
