Current status of water environment and their microbial biosensor techniques - Part I: Current data of water environment and recent studies on water quality investigations in Japan, and new possibility of microbial biosensor techniques.

In my 2010 review, I addressed conventional water analysis and biosensing of organic pollutants in Japan between 1960s and 2000s. It is now timely to reexamine current analytical and biomonitoring approaches in view of the new challenges in assessing pollution, particularly in closed water bodies, as pollutants tend to accumulate in these endorheic basins. In the present review series, I presented current water environment and its microbial biosensors. In this part, I presented current data of the water quality of these water bodies in Japan and established the need to further develop microbial biosensor technologies to address and monitor water quality here. Graphical Abstract Current water pollution indirectly occurring by anthropogenic eutrophication (Part I).