摘要

汞的一种重要的微生物抗性机制是将其还原成元素汞（由merA基因促进）。收集了来自埃及各种废水源的38种微生物分离物。这些分离物中大约有14种不仅表现出对汞的高度耐受性（高达160ppm），而且对其他测试的重金属具有高耐受性。从中选择10种最具抗性的分离株进行进一步研究，发现其中包括9种革兰氏阴性菌株和1种革兰氏阳性菌株。记录10个选择的分离株中的6个的多抗生素抗性谱。所有测试的革兰氏阴性菌株（n = 9）都含有质粒编码的merA基因。 10种选择的分离物的汞去除效率介于50-99.9％之间，其中嗜麦芽寡养单胞菌ADW10记录的最高比率（99.9％;初始汞浓度为20ppm）。据我们所知，这是第一项研究：（i）证明具有高Hg耐受能力的多金属抗性嗜麦芽窄食单胞菌的存在，使其成为未来重金属污染区域生物修复工作的合适候选者在埃及; （ii）报告Pseudomonas Ootitidis为MRB之一。

An important microbial resistance mechanism to mercury is its reduction into elemental mercury (facilitated by the merA gene). Thirty eight microbial isolates from a variety of wastewater sources in Egypt were collected. Approximately 14 of these isolates exhibited not only a high degree of tolerance to mercury (up to 160 ppm), but also a high resistance to other tested heavy metals. From them, the 10 most resistant isolates were selected for further study and were found to include 9 Gram-negative and 1 Gram-positive bacterial strains. Multi antibiotic resistance profiles were recorded for 6 out of the 10 selected isolates. All the tested Gram-negative isolates (n=9) harbored a plasmid-encoded merA gene. The mercury removal effectiveness for the 10 selected isolates ranged between 50-99.9%, among which Stenotrophomonas maltophilia ADW10 recorded the highest rate (99.9%; at an initial mercury concentration of 20 ppm). To the best of our knowledge, this is the first study to: (i) demonstrate the presence of multi metal resistant S. maltophilia bacterium with a high Hg tolerance capacity that would make it a suitable candidate for future bioremediation efforts in heavy metal polluted areas in Egypt; and (ii) report Pseudomonas otitidis as one of the MRB.

https://www.ncbi.nlm.nih.gov/pubmed/30633555