Scanning Electron Microscopy of Microbial Attachment to Milk Contact Surfaces

Abstract

Milk contact surfaces were observed by scanning electron microscopy (5EM) techniques for possible microbial attach ment. Cultures of Pseudomonas fragi 4973, Staphylococcus aureus JAL, Streptococcus lactis C2. Streptococcus cremoris and Lactobacillus bulgaricus RR inoculated onto glass covtfrslips or stainless steel chips were examined. Stainless steel surfaces displayed many possible harborages for microbial colonization. SEM examination of P. fragi 4973 showed development of fibrous material, with numerous stick-like projectionsextending from the cell to the glass or stainless steel surface. These apparent attachment appendages became more pronounced as contact time increased. 5. aureus, S. lactis, S. cremoris and L. bulgaricus did not display such fibrous material.