There is an increasing interest in developing innovative coatings and testing natural products with anti-fouling activity to substitute current highly toxic biocides that have a harmful impact on marine organisms. Bacillus licheniformis species have shown different anti-biofilm and anti-fouling activities in vitro, but so far, its efficacy in field trials has not been tested. For this purpose, the capacity of different extracts of Bacillus licheniformis NCTC 10341T to prevent micro and macro-fouling was first tested in vitro. The methanol cell extract (MCE) inhibited bacterial biofilm formation without significantly affecting planktonic growth and displayed a significant efficacy to prevent larval settlement of the macro-fouler Bugula neritina in vitro without inducing lethality. Additionally, the MCE presented low toxicity against the non-target species Artemia salina. The B. licheniformis MCE was then incorporated in a self-polishing paint at 2 and 5% w/w and tested in a static immersion experiment in the Gulf of Aqaba (northern Red Sea) for 180 days. Fouling coverage decreased by 30% in the 5% MCE-treated panels in comparison with the control panels. Differences in the anti-biofilm activity of the extracts depending on the culture medium highlight the importance of the strict control of culture conditions for the production of biomass with stable bioactive activity. The results indicate the potential of B. licheniformis NCTC 10341T crude extracts for environmentally friendly anti-fouling applications, although a deeper characterization of the bioactive compounds present in the B. licheniformis MCE and its mode of action is required to allow strict control of the activity of the extracts to achieve large-scale industrial production.

中文翻译：

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环境条件下地衣芽孢杆菌提取物的防污效果评价

人们越来越有兴趣开发创新涂料和测试具有防污活性的天然产品，以替代目前对海洋生物有有害影响的剧毒杀生物剂。地衣芽孢杆菌在体外表现出不同的抗生物膜和防污活性，但迄今为止，其在田间试验中的功效尚未得到测试。为此，首先在体外测试了地衣芽孢杆菌 NCTC 10341T 的不同提取物防止微观和宏观污染的能力。甲醇细胞提取物 (MCE) 抑制细菌生物膜的形成，而不会显着影响浮游生物的生长，并显示出显着的功效，可在体外防止大污虫 Bugula neritina 的幼虫沉降，而不会导致致死。此外，MCE 对非目标物种卤虫表现出低毒性。然后将地衣芽孢杆菌 MCE 以 2% 和 5% w/w 加入自抛光涂料中，并在亚喀巴湾（红海北部）进行 180 天的静态浸渍实验。与对照板相比，5% MCE 处理板的污垢覆盖率降低了 30%。提取物的抗生物膜活性的差异取决于培养基，突出了严格控制培养条件对于生产具有稳定生物活性的生物质的重要性。结果表明地衣芽孢杆菌 NCTC 10341T 粗提取物在环保防污应用方面的潜力，尽管对地衣芽孢杆菌中存在的生物活性化合物进行了更深入的表征。