The paper presents results of research concerning possibilities of applications of reporter-genes based microorganisms, including the selective presentation of defects and advantages of different new scientific achievements of methodical solutions in genetic system constructions of biosensing elements for environmental research. The most robust and popular genetic fusion and new trends in reporter genes technology – such as LacZ (β-galactosidase), xylE (catechol 2,3-dioxygenase), gfp (green fluorescent proteins) and its mutated forms, lux (prokaryotic luciferase), luc (eukaryotic luciferase), phoA (alkaline phosphatase), gusA and gurA (β-glucuronidase), antibiotics and heavy metals resistance are described. Reporter-genes based biosensors with use of genetically modified bacteria and yeast successfully work for genotoxicity, bioavailability and oxidative stress assessment for detection and monitoring of toxic compounds in drinking water and different environmental samples, surface water, soil, sediments.