CHARACTERIZATION OF THREE BENZOATE DEGRADING ANOXYGENIC PHOTOSYNTHETIC BACTERIA ISOLATED FROM THE ENVIRONMENT

Abstrak

Three  anoxygenic photosynthetic bacteria, DS-1, DS-4 and Cas-13, have been examinated  for  themorphological and physiological  properties. All strains were rod-shape cells with  a swollen terminal  endGram  negative, motile, non-halophilic, non-alkalophilic  and non-acidophilic,  and capable of utilizinbenzoate aerobically and photo-anaerobically. Sequence analysis of part of 16S rRNA genes showed that DS1 and Cas-13 were closely related to Rhodopseudomonas palustris Strain 7 with a similarity of 97%, whereaDS-4 may not be closely related to the former two strains with a similarity of 78% based on the constructephylogenic  tree. Spectral analysis indicated that the three  bacteria  had  bacteriochlorophyl  a  and normaspirilloxanthin series. Growth in medium enriched with vitamin and supplemented with benzoate as their sole C-sources wabetter than in medium without vitamin. Benzoate degradation in medium with vitamin was accelerated. Thability  to grow on benzoate without added vitamins indicated  that  the bacteria were able to synthesize  theown vitamins. Key words: anoxygenic photosynthetic bacteria/ benzoate degradation/ 16S rRNA gene.