Meng Shanshan, Qian Youfen, Liu Xiaobo, Wang Yali, Wu Fasi, Wang Wanfu, Gu Ji-Dong
Environmental Engineering Program, Guangdong Technion-Israel Institute of Technology (GTIIT), 142 Daxue Road, Shantou, Guangdong 515063, China.
School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China.
Sci Total Environ. 2023 Jun 10;876:162665. doi: 10.1016/j.scitotenv.2023.162665. Epub 2023 Mar 8.
Epilithic biofilms colonising outdoor stone monuments can intensify the deterioration processes of the stone materials and pose great challenges to their protection. In this study, biodiversity and community structures of the epilithic biofilms colonising the surfaces of five outdoor stone dog sculptures were characterised by high-throughput sequencing. Although they are exposed to the same envrionment in a small yard, the analysis of their biofilm populations revealed high biodiversity and species richness as well as great differences in community compostions. Interestingly, populations responsible for pigment production (e.g., Pseudomonas, Deinococcus, Sphingomonas and Leptolyngbya) and for nitrogen (e.g., Pseudomonas, Bacillus, and Beijerinckia) and sulfur cycling (e.g., Acidiphilium) were the core common taxa in the epilithic biofilms, suggesting the potential biodeterioration processes. Furthermore, significant positive corrolections of metal elements rich in stone with biofilm communities showed that epilithic biofilms could take in minerals of stone. Importantly, geochemical properties of soluble ions (higher concentration of SO than NO) and slightly acidic micro-environments on the surfaces suggest corrosion of biogenic sulfuric acids as a main mechanism of biodeterioration of the sculptures. Interestingly, relative abundacne of Acidiphilium showed a positive correlation with acidic micro-environments and SO concentrations, implying they could be an indicator of sulfuric acid corrosion. Together, our findings support that micro-environments are inportant to community assembly of epilithic biofilms and the biodeterioration processes involved.
附着在户外石雕上的表生生物膜会加剧石材的劣化过程，并对其保护构成巨大挑战。在本研究中，通过高通量测序对附着在五座户外石质犬类雕塑表面的表生生物膜的生物多样性和群落结构进行了表征。尽管它们在一个小院子里暴露于相同的环境中，但对其生物膜种群的分析显示出高生物多样性和物种丰富度，以及群落组成上的巨大差异。有趣的是，负责色素产生的种群（如假单胞菌属、嗜放射菌属、鞘氨醇单胞菌属和细鞘丝藻属）以及负责氮（如假单胞菌属、芽孢杆菌属和拜耶林克氏菌属）和硫循环（如嗜酸菌属）的种群是表生生物膜中的核心常见分类群，这表明存在潜在的生物劣化过程。此外，石材中富含的金属元素与生物膜群落之间存在显著的正相关，表明表生生物膜可以吸收石材中的矿物质。重要的是，表面可溶性离子的地球化学性质（硫酸根浓度高于硝酸根）和微酸性微环境表明，生物源硫酸的腐蚀是雕塑生物劣化的主要机制。有趣的是，嗜酸菌属的相对丰度与酸性微环境和硫酸根浓度呈正相关，这意味着它们可能是硫酸腐蚀的一个指标。总之，我们的研究结果支持微环境对表生生物膜的群落组装和所涉及的生物劣化过程很重要。
