Generally, symbiotic marine bacteria are renowned for the synthesis of compounds with bioactive properties, and this has been documented in many previous studies. Therefore, the present study was aimed to isolate novel bacterial symbionts of gastropods that have the ability to synthesize bioactive compounds. These bioactive compounds could be used effectively as antibiofilm agents in order to overcome the problems associated with biofilm. The bacteria associated with the surface of marine gastropods were isolated and characterized. Following this, the bacterial metabolites were extracted and their antibiofilm effect was evaluated on biofilm-forming bacteria on artificial substrates. Moreover, the biofilm-forming bacterium Alteromonas sp. was treated with the extracts of symbiotic bacteria in order to evaluate the influence of extracts over the synthesis of extracellular polymeric substance (EPS). Besides, the biologically active chemical constituents of the extracts were separated using thin-layer chromatography and subjected to gas chromatography and mass spectrometry (GC-MS) analysis for characterization. Three bacterial strains belonging to the species Bacillus firmus, Bacillus cereus and Bacillus subtilis were identified from the bacterial community associated with the gastropods. The antibiofilm assays revealed that the extract of three symbiotic bacteria significantly (p < 0.05) reduced the biofilm formation by the marine bacterium Alteromonas sp. on artificial materials. Also, the EPS synthesis by Alteromonas sp. was significantly inhibited due to symbiotic bacterial extract treatment. The chemical composition of the bioactive fraction isolated from the symbiotic bacteria extract revealed that most of the detected compounds were belonging to aromatic acid, fatty acid and carboxylic acid. The results of this study clearly revealed that the bacteria belonging to the above listed Bacillus species can be considered as a promising source of natural antibiofilm agents.

中文翻译：

---

与海洋腹足动物有关的共生芽孢杆菌物种的抗生物膜活性

通常，共生海洋细菌以具有生物活性的化合物的合成而著称，这在许多先前的研究中已有记载。因此，本研究的目的是分离具有合成生物活性化合物能力的腹足动物的新型细菌共生体。这些生物活性化合物可以有效地用作抗生物膜剂，以克服与生物膜相关的问题。分离并鉴定了与海洋腹足动物表面有关的细菌。此后，提取细菌代谢产物，并评估它们在人造基质上对形成生物膜的细菌的抗生物膜作用。此外，形成生物膜的细菌Alteromonas sp.。为了评估提取物对细胞外聚合物质（EPS）合成的影响，用共生细菌提取物处理了Hydrogen。此外，使用薄层色谱法分离提取物的生物活性化学成分，并进行气相色谱和质谱分析（GC-MS）进行表征。从与腹足动物有关的细菌群落中鉴定出了三种细菌菌株，它们分别是牢固的芽孢杆菌，蜡状芽孢杆菌和枯草芽孢杆菌。抗生物膜测定表明，三种共生细菌的提取物显着（p <0.05）减少了海洋细菌Alteromonas sp。的生物膜形成。在人造材料上。另外，Alteromonas sp。的EPS合成。由于共生细菌提取物的治疗而被显着抑制。从共生细菌提取物中分离出的生物活性级分的化学成分表明，大多数检测到的化合物都属于芳香酸，脂肪酸和羧酸。这项研究的结果清楚地表明，属于上述芽孢杆菌属的细菌可被视为天然抗生物膜药物的有前途的来源。