An attempt was made to characterise thermophilic microflora isolated in an industrial plant utilising food industry waste. Initial estimation of environmental requirements of a mixed microorganism population was performed using the method measuring changes in electrical im­pedance by means of the BacTrac 4100 Automatic Microorganisms Growth Analyzer. Control of the dynamics of microorganism growth on broth media supple­mented with sources of carbon, nitrogen and phosphorus and at various pH allowed initial assessment of their en­vi­ron­men­tal requirements. The course of alterations in electrical impedance during culturing of both single isolates and mixed mi­cro­or­ganism populations can be described by means of Gompertz’s curve characteristic for bacteria growth with a very high correlation coefficient. The mixed microorganism population and isolates obtained from it were also characterised from the point of view of their biodegradation potentials of wastewater obtained in the potato processing industry. Biodegradation processes carried out in conditions of shake flask cultures at a temperature of 55oC showed higher reducing potentials of chemical oxygen demand (COD) of a mixed bacteria culture. Single isolates were characterised by a distinctly inferior metabolic activity and lower biodegradation potentials of “ hot” potato wastewater.