OCCURRENCE OF POLYHYDROXYALKANOIC ACID GRANULE-ASSOCIATED PROTEINS RELATED TO THE ALCALIGENES-EUTROPHUS H16 GA24 PROTEIN IN OTHER BACTERIA

Fifty different polyhydroxyalkanoic acid (PHA)-accumulating bacterial strains were investigated for the occurrence of phasin proteins bound to PHA granules and related to the GA24 protein of Alcaligenes eutroph us H16, by isolating PHA granules and Western blot analysis of granule -associated proteins employing antibodies raised against the GA24 prot ein. It could be demonstrated that the PHA granules of many poly(3-hyd roxybutyrate)-accumulating bacteria exhibited a similar protein patter n, and a predominant protein of 24 +/- 2 kDa occurred in the granules of A. eutrophus strains A7, CH34, JMP222, N9A and TF93 exhibiting N-te rminal amino acid sequences identical to that of the GA24 protein. Pro teins bound to the granules of A. latus, Burkholderia caryophyli, B. c epacia B. solanacearum, Pseudomonas glathei, Rhodobacter sphaeroides a nd Telluria mixta also gave positive immunoreactions. Granule-associat ed proteins of small size also occurred in various strains of the Gram -positive bacteria Bacillus megaterium and R. ruber as well as in the Gram-negative bacteria Azotobacter sp., Chromatium vinosum, Comamonas acidovorans, Methylobacterium sp., Mycoplana rubra, Paracoccus denitri ficans, Pseudomonas sp., Rhodospirillum rubrum, Rubrivivax gelatinosus and Thiocystis violacea; however, they gave no immunoreaction. This s tudy clearly demonstrated that phasins are wide-spread if not essentia l in PHA-accumulating bacteria.