Adherence of Microbes to Conventional Containers

Abstract

In India, Aluminium and Galvanized iron sheets are used for making cans and other milk containers. Glass bottles are still in use for distribution of milk. Attachment of spoilage organisms to these conventional containers is a major problem. The present work was conducted to study the mode of adherence of spoilage organisms to the surfaces and their total viable count was determined. Bacillus stearothermophilus was found to be the dominant organism in conventional containers used in NDRI Experimental Dairy. Standard Bacillus stearothermophilus QUM 29B obtained from Microbiology Dept., University of Queensland, Australia, was used for in vitro studies. The culture was grown in Tryptone Yeast Broth and stored in saline at 4°C. Clean Glass and Galvanized sheet pieces were dipped in sterilized skim milk containing known number of B. stearothermophilus cells and stored at ambient temperature (30°C). Viable counts were observed by Standard Plate Technique at different periods of incubation and different sanitizer levels. It was found that the viable counts increased with the increase in period of incubation and roughness of surface and decreased with increasing concentration of sanitizer. The exact mode of attachment of B. stearothermophilus (QUM) 29B to these surface conditions were studied using SEM.