An Na+-independent decarboxylation in a marine bacterium: Ion-controlled biotransformations with intact cells

Abstract The catabolism of o -phthalate by a marine Acinetobacter sp. required Na⁺ ions. In contrast, the decarboxylation of 4,5-dihydroxyphthalate, an intermediate in phthalate breakdown, occurred independently of Na⁺ ions and with a quantitative accumulation of the product, protocatechuate. In the presence of Na⁺ ions, protocatechuate did not accumulate and was further oxidized. Transport systems of marine bacteria require Na⁺ ions and extracellular enzymes probably account for Na⁺-independent conversions. Na⁺-independent reactions in marine bacteria present a biotechnological opportunity to use intact cells, rather than cell-free preparations, to effect specific biotransformations.