Lenka Jessica, González-Tortuero Enrique, Kuba Shweta, Ferry Natalie
School of Science, Engineering and Environment, University of Salford, Salford, United Kingdom.
School of Life Sciences, Faculty of Natural Sciences, Keele University, Staffordshire, United Kingdom.
Front Microbiol. 2025 Jan 3;15:1401965. doi: 10.3389/fmicb.2024.1401965. eCollection 2024.
The microbiota within the guts of insects plays beneficial roles for their hosts, such as facilitating digestion and extracting energy from their diet. The African palm weevil (APW) lives within and feeds on the high lignin-containing trunk of palm trees; therefore, their guts could harbour a large community of lignin-degrading microbes. In this study, we aimed to explore the bacterial community within the gut of the APW larvae, specifically with respect to the potential for lignin degradation in various gut segments as a first step to determining the viability of mining bacterial lignin-degrading enzymes for the bioconversion of lignocellulosic biomass to biofuels and biomaterials. Bacterial metagenomic DNA was extracted from the foregut, midgut, and hindgut of larvae of the APW, and the V3-V4 hypervariable region of the 16S rRNA gene was sequenced using the Illumina MiSeq platform. The generated data were analysed and taxonomically classified to identify the different bacterial phylotypes within the gut community cumulatively and per gut segment. We then determined the presence, diversity, and abundance of bacteria associated with lignin degradation within each larval gut compartment as a basis for suggesting the gut segment(s) where lignin degradation occurs the most. All sequences were classified and belonged to the bacterial kingdom. (54.3%) and (42.5%) were the most dominant phyla within the gut, followed distantly by (1.7%) and (1.4%). , , , , , , , , , and constituted the most abundant genera found across all gut segments. The foregut and midgut had many similar genera, whilst the hindgut appeared unique. Overall, 29.5% of total gut bacteria comprising 21 genera were lignin degraders found predominantly in the and Proteobacteria phyla (56.8 and 39.5%, respectively), then moderately in (2.5%) and (1.1%). The most abundant ligninolytic genera were (46.4%), (22.9%), (10.7%), (5.9%), (2.2%), (1.8%), (1.8%), (1.5%), (1.1%), and (1.0%) found in different amounts in different gut compartments. The foregut had the most diverse and highest abundance of lignin-degrading phylotypes, and we present reasons that point to the foregut as the main location for the depolymerization of lignin in the APW larval gut.
昆虫肠道内的微生物群对其宿主发挥着有益作用，例如促进消化以及从食物中提取能量。非洲棕榈象甲（APW）生活在棕榈树富含高木质素的树干内并以其为食；因此，它们的肠道可能含有大量降解木质素的微生物群落。在本研究中，我们旨在探索APW幼虫肠道内的细菌群落，特别是不同肠道段中木质素降解的潜力，以此作为确定挖掘细菌木质素降解酶用于将木质纤维素生物质生物转化为生物燃料和生物材料可行性的第一步。从APW幼虫的前肠、中肠和后肠中提取细菌宏基因组DNA，并使用Illumina MiSeq平台对16S rRNA基因的V3 - V4高变区进行测序。对生成的数据进行分析并进行分类学分类，以累计和按肠道段识别肠道群落内不同的细菌系统型。然后，我们确定每个幼虫肠道隔室内与木质素降解相关的细菌的存在、多样性和丰度，以此为推断木质素降解最活跃的肠道段提供依据。所有序列均被分类并属于细菌界。厚壁菌门（54.3%）和变形菌门（42.5%）是肠道内最主要的菌门，其次是放线菌门（1.7%）和拟杆菌门（1.4%）。芽孢杆菌属、肠杆菌属、乳杆菌属、梭菌属、葡萄球菌属、假单胞菌属、不动杆菌属、伯克霍尔德菌属、嗜甲基菌属和柠檬酸杆菌属是在所有肠道段中发现的最丰富的属。前肠和中肠有许多相似的属，而后肠则显得独特。总体而言，占肠道细菌总数29.5%的21个属为木质素降解菌，主要存在于厚壁菌门和变形菌门（分别为56.8%和39.5%），其次是放线菌门（2.5%）和拟杆菌门（1.1%）。最丰富的木质素分解属为芽孢杆菌属（46.4%）、肠杆菌属（22.9%）、梭菌属（10.7%）、葡萄球菌属（5.9%）、假单胞菌属（2.2%）、不动杆菌属（1.8%）、伯克霍尔德菌属（1.8%）、嗜甲基菌属（1.5%）、柠檬酸杆菌属（1.1%）和乳杆菌属（1.0%），在不同肠道隔室中的含量各不相同。前肠具有最多样化且丰度最高的木质素降解系统型，我们给出了一些理由，表明前肠是APW幼虫肠道中木质素解聚的主要部位。
