Longang Adégilns, Buck Chris, Kirkwood Kathlyn M
a Department of Chemical and Biological Engineering , University of Ottawa, Ottawa , ON , Canada.
Environ Technol. 2016;37(9):1133-40. doi: 10.1080/09593330.2015.1102333. Epub 2015 Nov 2.
Hydrocarbon-contaminated environments often also experience co-contamination with elevated levels of salt. This paper investigates the occurrence of halotolerance among several hydrocarbon-degrading bacteria, as an initial assessment of the importance of salt contamination to bioremediation strategies. Halotolerance was common, but not ubiquitous, among the 12 hydrocarbon-degrading bacteria tested, with many strains growing at up to 75 or 100 g NaCl L(-1) in rich medium. Greater sensitivity to elevated salt concentrations was observed among aromatics degraders compared to saturates degraders, and in defined medium compared to rich medium. Observed effects of high salt concentrations included increased lag times and decreased maximum growth. Many strains exhibited flocculation at elevated salt concentrations, but this did not correlate to any patterns in cell surface hydrophobicity, measured using the Bacterial Adhesion to Hydrocarbon assay. The occurrence of halotolerance in hydrocarbon-degrading bacteria suggests the potential for native microorganisms to contribute to the bioremediation of oil and salt co-contaminated sites, and indicates the need for a better understanding of the relationship between halotolerance and hydrocarbon biodegradation capabilities.
受碳氢化合物污染的环境通常还会受到高浓度盐分的共同污染。本文研究了几种碳氢化合物降解菌的耐盐性，作为对盐分污染对生物修复策略重要性的初步评估。在所测试的12种碳氢化合物降解菌中，耐盐性普遍存在但并非全都具备，许多菌株在富含营养的培养基中能在高达75或100 g NaCl L⁻¹的环境下生长。与饱和烃降解菌相比，芳烃降解菌对盐分浓度升高更为敏感，并且在限定培养基中比在富含营养的培养基中更敏感。高盐浓度的影响包括延长延迟期和降低最大生长量。许多菌株在盐分浓度升高时会出现絮凝现象，但这与使用细菌对碳氢化合物的粘附试验测得的细胞表面疏水性的任何模式均无关联。碳氢化合物降解菌中耐盐性的存在表明本地微生物有可能促进石油和盐分共同污染场地的生物修复，并表明有必要更好地了解耐盐性与碳氢化合物生物降解能力之间的关系。
