Institute of Soil Biology and Biogeochemistry, Biology Centre CAS, České Budějovice, Czechia.
Faculty of Science, University of South Bohemia in České Budějovice, České Budějovice, Czechia.
Commun Biol. 2024 Sep 28;7(1):1204. doi: 10.1038/s42003-024-06821-2.
Millipedes are thought to depend on their gut microbiome for processing plant-litter-cellulose through fermentation, similar to many other arthropods. However, this hypothesis lacks sufficient evidence. To investigate this, we used inhibitors to disrupt the gut microbiota of juvenile Epibolus pulchripes (tropical, CH-emitting) and Glomeris connexa (temperate, non-CH-emitting) and isotopic labelling. Feeding the millipedes sterile or antibiotics-treated litter reduced faecal production and microbial load without major impacts on survival or weight. Bacterial diversity remained similar, with Bacteroidota dominant in E. pulchripes and Pseudomonadota in G. connexa. Sodium-2-bromoethanesulfonate treatment halted CH emissions in E. pulchripes, but it resumed after returning to normal feeding. Employing C-labeled leaf litter and RNA-SIP revealed a slow and gradual prokaryote labelling, indicating a significant density shift only by day 21. Surprisingly, labelling of the fungal biomass was somewhat quicker. Our findings suggest that fermentation by the gut microbiota is likely not essential for the millipede's nutrition.
千足虫被认为依赖肠道微生物群通过发酵来处理植物垃圾纤维素，这类似于许多其他节肢动物。然而，这一假设缺乏足够的证据。为了研究这一点，我们使用抑制剂来破坏幼年 Epibolus pulchripes（热带，CH 排放）和 Glomeris connexa（温带，非 CH 排放）的肠道微生物群，并进行同位素标记。给千足虫喂食无菌或抗生素处理过的垃圾会减少粪便的产生和微生物的负荷，而对其生存或体重没有重大影响。细菌多样性仍然相似，Bacteroidota 在 E. pulchripes 中占优势，Pseudomonadota 在 G. connexa 中占优势。使用 2-溴乙烷磺酸钠处理可阻止 E. pulchripes 中的 CH 排放，但在恢复正常喂养后又恢复了排放。使用 C 标记的叶垃圾和 RNA-SIP 揭示了一个缓慢而渐进的原核生物标记，表明只有在第 21 天，才会出现显著的密度转移。令人惊讶的是，真菌生物量的标记速度稍快一些。我们的研究结果表明，肠道微生物群的发酵可能不是千足虫营养的必要条件。
