Section for Microbial Ecology and Biotechnology, Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg, Denmark.
DHI, Agern Alle 5, 2970 Hørsholm, Denmark.
Sci Total Environ. 2019 Jan 15;648:408-421. doi: 10.1016/j.scitotenv.2018.08.080. Epub 2018 Aug 6.
Effects of ballast water (BW) treatment by ultra-violet (UV) light and electrochlorination (EC) on survival, activity and diversity of marine bacterioplankton and release of organic matter from cell damage were examined at discharge in a large-scale BW test facility (250 m tanks) at Hundested harbour, Denmark. The tests were performed in accordance with the requirements for type approval testing by International Maritime Organization (IMO) and US Coast Guard. After treatment, the water was held in the tanks for one day (EC) before discharge, or 6 days (UV, including also a final UV re-treatment) before discharge. In the discharged and treated water, numbers of viable bacteria and bacterial growth rate had decreased significantly relative to the untreated water, but the total number of bacteria only was reduced in the EC-treated water. After additional storage for up to 10 days in small-scale laboratory incubations, significant regrowth of bacteria was observed after either treatment. Sequencing of 16S rRNA gene amplicons demonstrated that α-Proteobacteria initially were dominant, but γ-Proteobacteria dominated after regrowth. Bacteria used to document BW treatment efficiency (E. coli, Vibrio spp., enterococci) survived both treatments; neither treatment reduced the risk of pathogen dispersal. Concentrations of amino acids in the water were used as indicators of treatment-induced cell damage and demonstrated higher concentrations at discharge, but only after the EC treatments. Our results indicate that activity of bacteria, rather than their abundances, should be used when examining effects by ballast water treatment on microorganisms and that none of the examined treatment technologies could eliminate pathogenic bacteria.
紫外线（UV）光和电氯化（EC）处理压载水对海洋细菌浮游生物的存活、活性和多样性以及细胞损伤释放的有机物的影响，在丹麦 Hundested 港的大型压载水测试设施（250 m 罐）中进行了排放测试。测试是按照国际海事组织（IMO）和美国海岸警卫队的型式认可测试要求进行的。处理后，水在罐中停留一天（EC）后排放，或在排放前六天（UV，包括最后一次 UV 再处理）。在排放和处理的水中，与未处理的水相比，活细菌数量和细菌生长速率显著下降，但仅在 EC 处理的水中减少了总细菌数量。在小型实验室孵育中进一步储存长达 10 天后，无论是哪种处理方式，都观察到细菌的明显再生长。16S rRNA 基因扩增子的测序表明，α-变形菌最初占主导地位，但在再生长后γ-变形菌占主导地位。用于记录 BW 处理效率的细菌（大肠杆菌、弧菌属、肠球菌）在两种处理中均存活下来，两种处理均未降低病原体传播的风险。水中氨基酸的浓度被用作处理诱导的细胞损伤的指示物，在排放时显示出更高的浓度，但仅在 EC 处理后。我们的结果表明，在研究压载水处理对微生物的影响时，应使用细菌的活性而不是其丰度，并且所检查的处理技术都不能消除致病性细菌。
