Oil palm empty fruit bunches (OPEFB) are the most abundant, inexpensive, and environmentally friendly lignocellulosic biomass in Malaysia. Investigations on the microbial diversity of decaying OPEFB may reveal microbes with complex enzymes that have the potential to enhance the conversion of lignocellulose into second-generation biofuels as well as the production of other value-added products. In the present study, fungal and bacterial diversities in decaying OPEFB were identified using Illumina MiSeq sequencing of the V3 region of the 16S rRNA gene and V4 region of the 18S rRNA gene. Fungal diversity in decaying OPEFB was dominated by the phylum Ascomycota (14.43%), while most of the bacterial sequences retrieved belonged to Proteobacteria (76.71%). Three bacterial strains isolated from decaying OPEFB, designated as S18, S20, and S36, appeared to grow with extracted OPEFB-lignin and Kraft lignin (KL) as the sole carbon source. 16S rRNA gene sequencing identified the 3 isolates as Paenibacillus sp.. The molecular weight distribution of KL before and after degradation showed significant depolymerization when treated with bacterial strains S18, S20, and S36. The presence of low-molecular-weight lignin-related compounds, such as vanillin and 2-methoxyphenol derivatives, which were detected by a GC-MS analysis, confirmed the KL-degrading activities of isolated Paenibacillus strains.

中文翻译：

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腐烂的油棕空果串 (OPEFB) 中的微生物多样性和热带环境中木质素降解细菌的分离

油棕空果串 (OPEFB) 是马来西亚最丰富、最便宜、最环保的木质纤维素生物质。对腐烂的 OPEFB 微生物多样性的研究可能会揭示具有复杂酶的微生物，这些酶有可能增强木质纤维素向第二代生物燃料的转化以及其他增值产品的生产。在本研究中，使用 Illumina MiSeq 对 16S rRNA 基因的 V3 区和 18S rRNA 基因的 V4 区进行测序，鉴定了腐烂 OPEFB 中的真菌和细菌多样性。腐烂的 OPEFB 中的真菌多样性以子囊菌门（14.43%）为主，而检索到的大部分细菌序列属于变形菌门（76.71%）。从腐烂的 OPEFB 中分离出的三种细菌菌株，命名为 S18、S20 和 S36，似乎以提取的 OPEFB 木质素和硫酸盐木质素 (KL) 作为唯一碳源生长。16S rRNA基因测序鉴定这3株菌株为类芽孢杆菌。菌株S18、S20和S36处理后KL的分子量分布在降解前后均表现出明显的解聚作用。通过 GC-MS 分析检测到的低分子量木质素相关化合物（如香草醛和 2-甲氧基苯酚衍生物）的存在证实了分离的类芽孢杆菌菌株的 KL 降解活性。和 S36。通过 GC-MS 分析检测到的低分子量木质素相关化合物（如香草醛和 2-甲氧基苯酚衍生物）的存在证实了分离的类芽孢杆菌菌株的 KL 降解活性。和 S36。通过 GC-MS 分析检测到的低分子量木质素相关化合物（如香草醛和 2-甲氧基苯酚衍生物）的存在证实了分离的类芽孢杆菌菌株的 KL 降解活性。