King Abdullah University of Science and Technology (KAUST), Water Desalination and Reuse Center (WDRC), Division of Biological and Environmental Science and Engineering (BESE), Thuwal, 23955-6900, Saudi Arabia.
Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600, Dübendorf, Switzerland.
Water Res. 2018 Oct 1;142:227-235. doi: 10.1016/j.watres.2018.06.010. Epub 2018 Jun 6.
The bacterial growth potential is important to understand and manage bacterial regrowth-related water quality concerns. Bacterial growth potential depends on growth promoting/limiting compounds, therefore, nutrient availability is the key factor governing bacterial growth potential. Selecting proper tools for bacterial growth measurement is essential for routine implementation of the growth potential measurement. This study proposes a growth potential assay that is universal and can be used for different water types and soil extract without restrictions of pure culture or cultivability of the bacterial strain. The proposed assay measures the sample bacterial growth potential by using the indigenous community as inocula. Flow cytometry (FCM) and adenosine tri-phosphate (ATP) were used to evaluate the growth potential of six different microbial communities indigenous to the sample being analyzed, with increasing carbon concentrations. Bottled mineral water, non-chlorinated tap water, seawater, river water, wastewater effluent and a soil organic carbon extract were analyzed. Results showed that indigenous bacterial communities followed normal batch growth kinetics when grown on naturally present organic carbon. Indigenous bacterial growth could detect spiked organic carbon concentrations as low as 10 μg/L. The indigenous community in all samples responded proportionally to the increase in acetate-carbon and proportional growth could be measured with both FCM and ATP. Bacterial growth was proportional to the carbon concentration but not the same proportion factor for the different water samples tested. The effect of inoculating the same water with different indigenous microbial communities on the growth potential was also examined. The FCM results showed that the highest increase in total bacterial cell concentration was obtained with bacteria indigenous to the water sample. The growth potential assay using indigenous bacterial community revealed consistent results of bacterial growth in all the different samples tested and therefore providing a fast, more stable, and accurate approach for monitoring the biological stability of waters compared to the previously developed assays. The growth potential assay can be used to aid in detecting growth limitations by compounds other than organic carbon.
细菌生长潜力对于理解和管理与细菌再生相关的水质问题非常重要。细菌生长潜力取决于促进/限制生长的化合物，因此，营养物质的可用性是控制细菌生长潜力的关键因素。选择适当的细菌生长测量工具对于常规实施生长潜力测量至关重要。本研究提出了一种通用的生长潜力测定方法，可用于不同类型的水和土壤提取物，而不受细菌菌株的纯培养或可培养性的限制。该测定方法通过使用土著群落作为接种物来测量样品的细菌生长潜力。使用流式细胞术（FCM）和三磷酸腺苷（ATP）评估了六种不同微生物群落的生长潜力，这些微生物群落来源于被分析的样品，并且随着碳浓度的增加而增加。分析了瓶装矿泉水、未氯化自来水、海水、河水、废水和土壤有机碳提取物。结果表明，土著细菌群落在用天然存在的有机碳培养时遵循正常的分批生长动力学。土著细菌可以检测到低至 10μg/L 的添加有机碳浓度。所有样品中的土著细菌群落对乙酸盐-碳的增加呈比例响应，并且可以使用 FCM 和 ATP 测量比例生长。细菌生长与碳浓度成正比，但对于测试的不同水样，比例系数不同。还检查了用不同土著微生物群落接种相同水样对生长潜力的影响。FCM 结果表明，用水样中固有的细菌接种时，总细菌细胞浓度的增加最大。使用土著细菌群落的生长潜力测定法在所有测试的不同样品中均显示出一致的细菌生长结果，因此与先前开发的测定法相比，提供了一种快速、更稳定、更准确的监测水的生物稳定性的方法。生长潜力测定法可用于辅助检测除有机碳以外的化合物对生长的限制。
