Microbial Ecology Department, Netherlands Institute of Ecology (NIOO), Droevendaalsesteeg 10, 6708 PB, Wageningen, the Netherlands.
Wageningen University and Research, Wageningen, the Netherlands.
Sci Total Environ. 2024 Nov 15;951:175577. doi: 10.1016/j.scitotenv.2024.175577. Epub 2024 Aug 16.
Asbestos poses a substantial environmental health risk, and biological treatment offers a promising approach to mitigate its impact by altering its chemical composition. However, the dynamics of microbial co-inoculation in asbestos bioremediation remain poorly understood. This study investigates the effect of microbial single cultures and co-cultures on modifying crocidolite and chrysotile fibers, focusing on the extraction of iron and magnesium. Seventy bacterial and eighty-three fungal strains were isolated from five diverse sites, characterized phylogenetically using the 16S rRNA gene and ITS region, respectively, and assessed for siderophore and organic acid production. Most bacterial strains were identified as Pseudomonas, while Penicillium predominated among fungal strains. Ten bacterial and 25 fungal strains were found to produce both organic compounds. Four microbial co-cultures (one bacterium-bacterium, two fungus-bacterium, and one fungus-fungus) exhibiting synergistic effects in plate assays, alongside their respective single cultures, were incubated with crocidolite and chrysotile. ICP-OES analysis revealed that in crocidolite, the co-culture HRF19-HRB12 removed more iron than their single cultures, while Penicillium TPF36 showed the highest iron removal. The co-culture of two Pseudomonas strains (HRB12-RB5) exhibited the highest magnesium concentration in the supernatant. In chrysotile, the co-culture HRB12-RB5 removed more iron than their individual cultures, with Penicillium TFSF27 exhibiting the highest iron concentration in the solution. Penicillium TFSF27 and the co-culture TFSF27-TPF36 demonstrated the highest magnesium removal. SEM-XRMA analysis showed a significant reduction in iron and magnesium content, confirming elemental extraction from the fibers' structure. This study significantly broadens the range of microbial strains capable of modifying asbestos fibers and underscores the potential of microbial co-cultures in asbestos remediation.
石棉对环境健康构成重大威胁，而生物处理通过改变其化学成分提供了一种有前途的减轻其影响的方法。然而，微生物共接种在石棉生物修复中的动态仍知之甚少。本研究调查了微生物单一培养物和共培养物对改性青石棉和温石棉纤维的影响，重点是铁和镁的提取。从五个不同的地点分离了 70 株细菌和 83 株真菌，分别使用 16S rRNA 基因和 ITS 区进行系统发育特征描述，并评估其产生铁载体和有机酸的能力。大多数细菌菌株被鉴定为假单胞菌，而真菌菌株中则以青霉为主。发现 10 株细菌和 25 株真菌同时产生有机化合物。在平板试验中，四种微生物共培养物（一种细菌-细菌、两种真菌-细菌和一种真菌-真菌）表现出协同作用，以及它们各自的单一培养物，与青石棉和温石棉一起孵育。ICP-OES 分析表明，在青石棉中，共培养物 HRF19-HRB12 比其单一培养物去除更多的铁，而 Penicillium TPF36 表现出最高的铁去除率。两种假单胞菌（HRB12-RB5）的共培养物在超滤液中表现出最高的镁浓度。在温石棉中，共培养物 HRB12-RB5 比其各自的培养物去除更多的铁，而 Penicillium TFSF27 则在溶液中表现出最高的铁浓度。Penicillium TFSF27 和共培养物 TFSF27-TPF36 表现出最高的镁去除率。SEM-XRMA 分析表明，铁和镁含量显著降低，证实了从纤维结构中提取元素。本研究显著扩大了能够修饰石棉纤维的微生物菌株的范围，并强调了微生物共培养物在石棉修复中的潜力。
