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The liquid‐liquid extraction of an extracellular alkaline protease from its fermentation broth was carried out, using a reversed micellar organic solvent. Optimum process parameters were determined for extraction using a 250 mM AOT in isooctane micellar solution. With unequal phase volume ratios, purification factors as high as 6 have been obtained from completely untreated broth. Yields up to 56% were achieved from the same broth using a three‐stage cascade.

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Aims:  Burkholderia sp. USM (JCM15050) isolated from oil‐polluted wastewater is capable of utilizing palm oil products and glycerol to synthesize poly(3‐hydroxybutyrate) [P(3HB)]. To confer the ability to produce polymer containing 3‐hydroxyhexanoate (3HHx), plasmid (pBBREE32d13) harbouring the polyhydroxyalkanoate (PHA) synthase gene of Aeromonas caviae (phaCAc) was transformed into this strain. Methods and Results:  The resulting transformant incorporated approximately 1 ± 0·3 mol% of 3HHx in the polymer when crude palm kernel oil (CPKO) or palm kernel acid oil was used as the sole carbon source. In addition, when the transformed strain was cultivated in the mixtures of CPKO and sodium valerate, PHA containing 69  mol% 3HB, 30 mol% 3‐hydroxyvalerate and 1  mol% 3HHx monomers was produced. Batch feeding of carbon sources with 0·5% (v/v) CPKO at 0 h and 0·25% (w/v) sodium valerate at 36 h yielded 6 mol% of 3HHx monomer by controlled‐feeding strategies. Conclusions:  Burkholderia sp. USM (JCM15050) has the metabolic pathways to supply both the short‐chain length (SCL) and medium‐chain length (MCL) PHA monomers. By transforming the strain with the Aer. caviae PHA synthase with broader substrate specificity, SCL‐MCL PHA was produced. Significance and Impact of the Study:  This is the first study demonstrating the ability of transformant Burkholderia to produce P(3HB‐co‐3HHx) from a single carbon source.

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