1. 8 prototrophic Acetobacter-strains were examined for spontaneous auxotrophic mutants.

2. A vaccine against a microbial pathogen comprised of a live, immunogenic but prototrophic and Avirulent mutant strain of the selected microbial pathogen in an amount effective to confer immunity

3. A lipoic acid Auxotroph of Escherichia coli K-12, strain W1485lip2 (ATCC25645), produced pyruvic acid aerobically from glucose under the lipoic acid-deficient conditions, while the prototrophic parent strain, W1485 (ATCC12435), produced 2-oxoglutaric acid aas the main product