The effect of culture media on antigenic expression in sulfate-reducing bacteria

The importance of sulfate-reducing bacteria (SRB) in nature has been widely recognized for many years. However, little is known about the ecology of S RB. The problem has been detecting, classifying, and quantifying these orga nisms. There are many shortcomings in the use of culture media for this pur pose. As an alternative, fluorescent antibody (FA) techniques were consider ed as a method for the detection and identification of SRB. Antisera were p repared against whole cells of different species of SRB and evaluated for d etection and identification of these organisms. Surface antigens of SRB wer e species specific. In addition, culture conditions influenced the expressi on of surface antigens, causing the antisera to be extremely specific. Thes e results were confirmed by the sodium dodecyl sulfate-polyacrylamide-gel e lectrophoresis (SDS-PAGE) profiles of membrane proteins. On the basis of th is specificity, the application of FA produced against culture collection s trains would have limited application for detecting, identifying, and enume rating these organisms in nature.