Biochemical Methods for Bacteriology

Summary: A series of biochemical methods using heavy suspensions of organisms and chemically-defined solutions are described; they include fermentations, reduction of nitrate and of methylene blue, production of indole, hydrogen sulphide and acetoin, and hydrolysis of gelatin, starch and urea. The tests use the preformed enzymes of the bacterial cells and the results are not complicated by side effects or the multiple reactions that occur in cultures growing in a nutrient medium containing the test substrate.