Process for making polycarboxylic acids

A process for making azelaic acid comprising the steps of:

• (1) fermenting a beta-oxidation blocked C. tropicalis cell wherein both copies of the chromosomal POX5 gene and the chromosomal POX4A and POX4B genes are disrupted in a culture medium comprised of a nitrogen source, oleic acid and a cosubstrate to produce 9-octadecenedioic acid;
• (2) reacting 9-octadecenedioic acid with an oxidizing agent to produce azelaic acid.

A process for making a saturated dicarboxylic acid comprising the steps of:

• (1) fermenting a beta-oxidation blocked C. tropicalis call wherein both copies of the chromosomal POX5 gene and the chromosomal POX4A and POX4B genes are disrupted in a culture medium comprised of a nitrogen source, an organic substrate and a cosubstrate wherein said substrate is an unsaturated aliphatic compound having at least one internal carbon--carbon double bond and at least one terminal methyl group, a terminal carboxyl group and/or a terminal functional group which is oxidizable to a carboxyl group by biooxidation to form an unsaturated dicarboxylic acid having one or more carbon--carbon double bonds in a carbon chain terminated by at least one of the carboxyl groups of said unsaturated dicarboxylic acid;
• (2) reacting said unsaturated dicarboxylic acid with an oxidizing agent to produce one or more saturated dicarboxylic acids.

A process for making azelaic acid comprising the steps of:

• (1) fermenting C. tropicalis H 5343 in a culture medium comprised of a nitrogen source, oleic acid and a cosubstrate to produce 9-octadecenedioic acid;
• (2) reacting 9-octadecenedioic acid with an oxidizing agent to produce azelaic acid.

A process for making an aliphatic polycarboxylic acid comprising the steps of:

• (1) fermenting a beta-oxidation blocked C. tropicalis cell wherein both copies of the chromosomal POX5 gene and the chromosomal POX4A and POX4B genes are disrupted in a culture medium comprised of a nitrogen source, an internal olefin and a cosubstrate;
• (2) reacting the product of step (1) with an oxidizing agent to produce one or more polycarboxylic acids.