The aim was to isolate, characterize, and explore potentials of gut bacteria from the earthworm (Metaphire posthuma) and imply these bacteria for remediation of Cu(II) and Zn(II). An extracellular polymeric substance (EPS) producing gut bacteria (Bacillus licheniformis strain KX657843) was isolated and identified based on 16S rRNA sequencing and phylogenetic analysis. The strain showed maximum tolerance of 8 and 6 mM for Cu(II) and Zn(II) respectively. It removed 34.5% of Cu(II) and 54.4% of Zn(II) at 25 mg L⁻¹ after 72 and 96 h incubation respectively. The bacteria possessed a great potential to produce indole acetic acid (38.49 μg mL⁻¹) at 5 mg mL⁻¹ l-tryptophan following 12 days incubation. The sterilized seeds of mung beans (Vigna radiata) displayed greater germination and growth under bacterium enriched condition. We observed that the bacterial strain phosphate solubilization ability with a maximum of 204.2 mg L⁻¹ in absence of Cu(II) and Zn(II). Endowed with biosurfactant property the bacterium exhibited 24% emulsification index. The bacterium offered significant potential of plant growth promotion, Cu(II) and Zn(II) removal, and as such this study is the first report on EPS producing B. licheniformis KX657843 from earthworm which can be applied as powerful tool in remediation programs of Cu(II) and Zn(II) contaminated sites.

中文翻译：

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探索一种从g（Metaphire posthuma）肠内容物中分离的新型细胞外聚合物合成细菌（地衣芽孢杆菌）在环境修复中的潜在应用。

目的是隔离，表征以及从蚯蚓（探索的肠道细菌的电位Metaphire posthuma）和暗示这些细菌对Cu（II）和Zn（II）的修复。基于16S rRNA测序和系统发育分析，分离并鉴定了产生细胞外聚合物质（EPS）的肠道细菌（地衣芽孢杆菌菌株KX657843）。该菌株对Cu（II）和Zn（II）的最大耐受性分别为8和6 mM。温育72小时和96小时后，分别以25 mg L ^-1去除了34.5％的Cu（II）和54.4％的Zn（II）。细菌具有以5 mg mL ^-1 l产生吲哚乙酸（38.49μgmL ^-1）的巨大潜力。 -色氨酸孵育12天后。绿豆（Vigna radiata）的灭菌种子在细菌富集的条件下表现出更大的发芽和生长。我们观察到在没有Cu（II）和Zn（II）的情况下，细菌菌株的磷酸盐溶解能力最大为204.2 mg L ^-1。具有生物表面活性剂特性的细菌表现出24％的乳化指数。该细菌具有促进植物生长，去除Cu（II）和Zn（II）的巨大潜力，因此，本研究是有关EPS产生EPS的地衣芽孢杆菌KX657843的首份报道，可将其用作强效的修复程序。 Cu（II）和Zn（II）污染的位置。