Investigation of environmental pollution in Southeast Asia

东南亚热带河流受到近年来工业化和城市化的严重污染。人们日益认识到养护淡水资源的必要性和评价污染程度的重要性。这种分析不仅要用化学方法，而且要用生物方法。本研究采用活体染色、荧光原位杂交（FISH）和荧光噬菌体测定（FBA）等新方法，在单细胞水平上分析了热带河流微生物群落的结构和动态。研究了淡水微藻菌株对水生动物重金属污染的生物修复作用和生物标志物物质。在马来西亚的巴生河流域，停留菌的原位生理活性普遍较高，而在泰国的湄南河流域，停留菌的原位生理活性较低。在较宽较深的热带河流中，不到10%的细菌可培养，而在较窄较浅的河流和运河中，超过50%的细菌在R2A琼脂上形成菌落。据估计，这些河流和运河中的粪便细菌占细菌细胞总数的1 - 8%，其中大多数具有生理活性。这些粪便细菌无法通过传统的培养技术检测到。因此，它们应该在单个细胞水平上被检测到。应立即改善水质，特别是减少或防止生活废物被丢弃到狭窄的河流和运河中。对淡水微藻对化学物质的去除进行了研究，筛选出了7株具有较高去除能力的有益菌株。金属硫蛋白（MT）在淡水鱼（鲫鱼）中被评价为污染物污染的生物标志物，该MT由镉和地塞米松表达。MT应成为重金属污染的有用生物标志物。

Tropical rivers in Southeast Asia have been seriously polluted by recent industrialization and urbanization. There is an increasing awareness of the necessity for conserving fresh water resources and the importance of evaluating pollution levels. Such analyses must be performed not only using chemical methods but also biological ones. In this study, the structure and dynamics of microbial communities in tropical rivers were analyzed at a single cell level by new methods, such as vital staining, fluorescent in situ hybridization (FISH) and fluorescent bacteriophage assay (FBA). Freshwater microalgal strains for bioremediation and biomarker substances in aquatic animals for heavy metal contamination were also investigated.In situ physiological activity of resident bacteria was generally high in the Kelang River Basin (Malaysia) and low but present in the Chao Phraya River (Thailand). Less than 10% of bacteria in wide and deep tropical rivers were culturable, while more than 50% of bacteria in narrow and shallow rivers and canals formed their colonies on R2A agar. Estimates of fecal bacteria in these rivers and canals were accounted for 1 to 8% of total bacterial cells, and most of them had physiological activity. These fecal bacteria could not be detected by conventional culture techniques. Thus, they should be detected at a single cell level. Water quality should be immediately improved by reducing or preventing domestic waste being discarded into narrow rivers and canals in particular.The removal of chemicals by freshwater microalgae was also investigated, and 7 useful algal strains with high removal ability were screened.Metallothionein (MT) in the freshwater fish (Crucian Curp) was evaluated as a biomarker for the contamination of pollutants, and this MT is expressed by cadmium and dexamethazone. MT should be useful biomarker for the contamination of heavy metals.