A series of experiments was conducted to identify the molecular species responsible for surface active emulsification (surfactant) bioactivity in Bacillus subtilis subsp. subtilis strain ATCC PTA‐125135, and to describe culture conditions to support the enriched production of said bioactivity in cultured plaque of the strain. The assay for methylene blue active substances (MBAS) was found to be suitable for describing surfactant activity, where a solvent‐extracted molecular fraction from the biofilm was found to retain surfactant activity and positively quantified as MBAS. Furthermore, an HPLC‐refined protein fraction was found to quantify as MBAS with approximately 1·36‐fold or greater surfactant activity per mol than sodium dodecyl sulphate, and a proteomic analysis of solvent extracted residues confirmed that biofilm surface layer protein BslA was a primary constituent of extracted residues. Surfactant bioactivity, quantified as MBAS, was enriched in cultured plaque by the supplementation of culture media with calcium chloride or calcium nitrate.

中文翻译：

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枯草芽孢杆菌菌斑中的亚甲蓝活性物质。枯草芽孢杆菌和培养基中补充钙的富集

进行了一系列实验以鉴定在枯草芽孢杆菌亚种中负责表面活性乳化（表面活性剂）生物活性的分子种类。枯草杆菌菌株 ATCC PTA-125135，并描述培养条件，以支持该菌株培养菌斑中所述生物活性的富集生产。发现亚甲蓝活性物质 (MBAS) 的测定适合描述表面活性剂活性，其中从生物膜中溶剂提取的分子部分被发现保留了表面活性剂活性，并被正量化为 MBAS。此外，发现 HPLC 精制的蛋白质级分被量化为 MBAS，每摩尔表面活性剂活性比十二烷基硫酸钠高约 1·36 倍或更高，溶剂提取残留物的蛋白质组学分析证实生物膜表层蛋白 BslA 是提取残留物的主要成分。表面活性剂的生物活性，量化为MBAS，通过在培养基中补充氯化钙或硝酸钙而在培养菌斑中得到富集。