Colonization and weathering of engineering materials by marine microorganisms: an SEM study
Colonization and weathering of engineering materials by marine microorganisms: an SEM study
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DOI：
10.1002/esp.2076
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发表时间：
2011-05-01
影响因子：
3.3
通讯作者：
Fairhurst, R. J.
中科院分区：
文献类型：
--
作者：
Coombes, M. A.;Naylor, L. A.;Fairhurst, R. J.
微生物是地球上大多数坚硬基质的普遍特征，它们在岩石和石头的地貌改变中的作用得到广泛认可。微生物在通过建造坚硬的海岸防御引入潮间带的工程材料改性中的作用还不太清楚。本文利用扫描电子显微镜（SEM）研究了英国康沃尔潮间带石灰岩、花岗岩和海工混凝土实验块体暴露8个月后的微生物定植和微尺度地貌特征，发现不同材料类型之间微生物生长特征、微尺度风化和侵蚀特征存在显著差异（ANOVA p < 0.000）。暴露的石灰岩块的特征是在地表上部34.0 +/- 12.3 μ m范围内的真石器钻孔侵蚀（发生率为99%）。在钻孔区下方，无机风化（化学溶解和盐作用）发生在125.0 +/- 39.0 μ m的深度。混凝土表面的钻孔不太常见（发生率为27%），而生物化学结壳则很丰富（发生率为94%，平均厚度为45.1 +/- 27.7 μ m）。结壳由生物细胞、盐和其他化学沉淀物组成。在上部风化带之下的石灰岩和混凝土中也观察到隐石增长的证据。在花岗岩上，生物活动仅限于薄的石膜（厚度< 10 mm），并有一些有限的机械breakdown.Results的证据在这里展示的影响，基层岩性，硬度和纹理的早期微型殖民化的性质，和不同的工程材料的敏感性有机风化和侵蚀过程中的潮间带。讨论了材料的初始变形响应差异对长期岩石风化、生态和工程耐久性的影响。版权所有（C）2010约翰威利父子有限公司
Microorganisms are a ubiquitous feature of most hard substrata on Earth and their role in the geomorphological alteration of rock and stone is widely recognized. The role of microorganisms in the modification of engineering materials introduced into the intertidal zone through the construction of hard coastal defences is less well understood. Here we use scanning electron microscopy (SEM) to examine microbial colonization and micro-scale geomorphological features on experimental blocks of limestone, granite and marine concrete after eight months' exposure in the intertidal zone in Cornwall, UK.Significant differences in the occurrence of microbial growth features, and micro-scale weathering and erosion features were observed between material types (ANOVA p < 0.000). Exposed limestone blocks were characterized by euendolithic borehole erosion (99% occurrence) within the upper 34.0 +/- 12.3 mu m of the surface. Beneath the zone of boring, inorganic weathering (chemical dissolution and salt action) had occurred to a depth of 125.0 +/- 39.0 mu m. Boring at the surface of concrete was less common (27% occurrence), while bio-chemical crusting was abundant (94% occurrence, mean thickness 45.1 +/- 27.7 mu m). Crusts consisted of biological cells, salts and other chemical precipitates. Evidence of cryptoendolithic growth was also observed in limestone and concrete, beneath the upper zone of weathering. On granite, biological activity was restricted to thin epilithic films (< 10 mm thickness) with some limited evidence of mechanical breakdown.Results presented here demonstrate the influence of substratum lithology, hardness and texture on the nature of early micro-scale colonization, and the susceptibility of different engineering materials to organic weathering and erosion processes in the intertidal zone. The implications of differences in initial biogeomorphic responses of materials for long-term rock weathering, ecology and engineering durability are discussed. Copyright (C) 2010 John Wiley & Sons, Ltd.