Identification of bacterial types in various atmospheric corrosion sites using standard test kits

It is well-known that bacterial activity can contribute significantly to corrosion in marine and buried conditions. Herein, the possibility of bacterial influence on corrosion under atmospheric conditions is investigated, using the commercially available LAB-BART ® system to identify and to some degree quantify the major groups of bacteria present in corrosion products, including the sulphate reducing bacteria (SRB), iron reducing bacteria (IRB), heterotrophic aerobic bacteria (HAB), denitrifying bacteria (DN), acid producing bacteria (APB) and slime producing bacteria (SLYM). This is sufficient for most engineering purposes to assess the likelihood of corrosion being influenced by atmospherically borne bacteria. Bacterial testing was conducted at nine widely different atmospheric test locations. Significant SRB were not identified at any of the locations, IRB were identified in significant populations at all locations including, surprisingly, at the desert location. HAB were identified in small amounts at some locations but in greater concentrations at a turf farm and at an inland dam site. DN were not present at any location except at the desert site. APB was present in significant amounts at all sites and SLYM varied from almost nil at the ocean beach to quite high populations at the turf farm and at the dairy. These results are compared with nutrient deposition at these sites.