BIOSYNTHESIS OF POLY-3-HYDROXYBUTYRIC ACID BY THE FACULTATIVELY METHANOL-ASSIMILATING BACTERIUM MYCOPLANA-RUBRA-B346 AND RECOMBINANT STRAINS

Mycoplana rubra B346 is a pink-pigmented facultatively methylotrophic bacterium which is capable of synthesizing and accumulating small amou nts of poly-3-hydroxybutyric acid (PHB) if a carbon source (e.g. metha nol) is provided in excess and if an essential nutrient (e.g. nitrogen or phoshorus, respectively) is limiting growth. Upon transfer of the PKA-biosynthesis genes of Alcaligenes eutrophus H16 or Chromatium vino sum D or of the isolated PHA-synthase structural gene of Methylobacter ium extorquens into M. rubra B346, the content of PHB increased from 9 .6 up to 25% of the cell dry matter. M. rubra and some recombinant str ains were characterized physiologically and morphologically, and the s ize of the cells and the PHB content were compared by flow cytometry.