Production of polyhydroxyalkanoates by Halomonas sp. HG01, a halophilic bacterium from northern Peru, using various...

Halomonas sp. HG01, a moderate halophilic bacterium isolated from a northern Peru salt mine, is promising as a polyhydroxyalkanoate (PHA) producer. Experimental data and genome analysis were used to evaluate its capabilities. Shaken flask experiments revealed that HG01 can accumulate 70-86 wt% poly(3-hydroxybutyrate) [P(3HB)] from various carbon sources, including glucose, sucrose, and fructose. In a fed-batch bioreactor, it achieved a cell dry weight (CDW) of 12.2 g/L with 63 % P(3HB) content after 72 hours. The PHA synthase enzyme exhibited substrate specificity for C4 to C5 compounds. HG01 strain also produced poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] from propionic and valeric acids, with a maximum 3HV content of 25.53 mol% monomers into the polymer (69.40 %wt) when valeric acid was used. The complete bacterial 3.66 Mbp genome sequence revealed metabolic pathways for carbohydrate and fatty acid catabolism, PHA biosynthesis, and stress tolerance factor. This genetic information enhances our understanding of PHA synthesis and supports the development of metabolic engineering strategies, positioning Halomonas sp. HG01 as a promising candidate for biotechnological applications.