Dynamics of membrane fatty acid composition of succinic acid-producing Anaerobiospirillum succiniciproducens

• Fatty acid change of succinic acid-producing A. succiniciproducens was studied.
• The cells responded to acid stress by lowering saturated fatty acid content.
• The cells responded to acid stress by increasing unsaturated fatty acid content.
• The cells did not increase cyclic FA content in response to acid stress.

The dynamics of the membrane fatty acid composition of a succinic acid-producing bacterium, Anaerobiospirillum succiniciproducens, was studied using continuous and batch cultures. In both batch and chemostat continuous culture conditions, A. succiniciproducens grown on glucose or glycerol responded to acid stress by lowering the content of saturated fatty acids (SFAs) and increasing the content of unsaturated fatty acids (UFAs). Notably, A. succiniciproducens elongated C16:0 (SFA) and converted it to C18:1 (UFA) in the pH-uncontrolled culture, which is a common bacterial adaptation strategy to combat acid stress. Interestingly, A. succiniciproducens did not exhibit a significant increase in cyclic FA content, which is another common strategy to cope with acidic conditions.