The isolation and purification activities of bacterial strains from the Black Sea ecosystem resulted in a number of 82 isolates, out of which 12 were selected as PHA-producing strains. Following molecular analysis of 16S gene sequencing, these strains
have been taxonomically identified as belonging to various bacterial species, some of them poorly studied as PHA-producers. For a suitable metabolic and taxonomic characterization, the selected strains were analyzed by Biolog system for their ability to metabolize
multiple carbon and nitrogen sources, and in terms of osmotic and ion effects (e.g. tolerance to different salts concentrations). The enzymatic profile, determined by API assays, showed high similarities between the isolates, but BIOLOG tests showed a metabolic
diversity of the carbon and nitrogen sources. As expected, high salts tolerance confirmed their provenance from saline and hypersaline marine environments such as those from Norwegian partners. The optimization of growth conditions and PHA production
parameters primarily consisted of cultivation on carbon sources of low economic value: molasses, glycerol, starch, fructose, in combination with various nitrogen sources. The results obtained were extremely diverse, each strain analyzed behaved differently
in terms of multiplication and PHA production capacity. Of all the strains analyzed, C2/2 Photobacterium seems to have nutritional needs that have led to values of 20-25 DO cultures, which is biotechnologically important. Moreover, the extremely intense
fluorescent signal we have obtained confirms PHA production potential of this strain, which belongs to a less studied species with no emphasis on PHA production capacity. Bioreactor tests have shown that C2/2 strain can store up to 70% PHA in the cell and
can produce up to 4g PHA / L, results comparable to other studies. Although PHA production for strains N16b Halomonas and C2/10 Leisingera, was slightly lower, they still accumulate up to 40-58% of the dry weight, which are interesting results
that can be exploited biotechnologically.
European Conference of Biotechnology, Athena, Greece Aprile 26-28, 2018, Polyhydroxyalkanoate production potential of Black Sea new bacterial isolates, Mereuta I,
Chiciudean I, Lascu I, Avramescu SM, Stoica I, Tanase AM, abstract published in Journal of Biotechnology: DOI: 0.1016/j.jbiotec.2018.06.148.
Ioana Mereuta, Iulia Chiciudean, Irina Lascu, Sorin Avramescu, Ana-Maria Tanase, Ileana Stoica,
Microbial community screening for bacterial PHA producers Roumanian Biotechnological Letters, 2019 (under review)
Mereuta Ioana, Chiciudean Iulia, Vassu Tatiana, Tanase Ana-Maria, Stoica Ileana Metabolic and molecular
profiling of microbial communities following controlled kerosene pollution in Bucharest Botanical Garden pristine soil, Polish Journal of Environmental Sciences, 2019 (accepted)