One of the major challenges that face oil & gas industry in Kuwait is microbiologically influenced corrosion (MIC). In spite of biocide treatment in KOC facilities the bacteria culturing result continue to confirm a high proliferation of sessile and planktonic bacteria in water handling systems. Planktonic samples from different gathering centers have been analyzed for their molecular identities based on 16s ribosomal RNA characterization. The results demonstrate the presence of eight distinct groups of bacteria in effluent and brackish water systems. These bacteria groups can be broadly classified as sulfate reducing bacteria (SRB) sulfur oxidizing bacteria (SOB) aerobic bacteria and anaerobic bacteria. This paper focuses on the linkage between the findings of 16s ribosomal RNA characterization of planktonic bacteria with the field analyzes of sessile bacteria based on culture media techniques. The key issues relate to the identification of acid producing bacteria (APB) in general aerobic (GAB) and APB in general anaerobic bacteria (GAnB).