The growth of Acidiphilium species was inhibited by 0.4% yeast extract (Difco Laboratories). The growth inhibitory substances were purified from the yeast extract and identified as dl-lactic acid and succinic acid. The minimum inhibitory concentrations (MICs) of dl-lactic and succinic acids against Acidiphilium sp. 63 were 1 and 3 mM, respectively. The contents of dl-lactic and succinic acids in the yeast extracts were estimated at 43.9 and 1.2 mg/g using high-performance liquid chromatography. Acidiphilium species that we have been studying could be classified into two groups on the bases of the difference in susceptibility to these two organic acids.
ASJC Scopus subject areas
- Applied Microbiology and Biotechnology