Poly-3-hydroxyalkanoic acids (PHAs) are bacterial storage polymers commonly used in bioplastic production. Halophilic bacteria are industrially interesting organisms as their salinity tolerance and psychrophilic nature lowers sterility requirements and subsequent production costs. We investigated the PHA synthesis in two bacterial strains, Halomonas sp. 363 and Paracoccus sp. 392, isolated from Southern Ocean sea ice and elucidated the related PHA biopolymer accumulation and composition with various approaches, such as transcriptomics, microscopy and chromatography. We show that both bacterial strains produce PHAs at 4 °C when the availability of nitrogen and/or oxygen limited growth. The genome of Halomonas sp. 363 encoded three phaC synthase genes and transcribed genes along three PHA pathways (I–III), whereas Paracoccus sp. 392 carry only one phaC gene and transcribed genes along one pathway (I). Thus Halomonas sp. 363 has versatile repertoire of phaC genes and pathways enabling production of both short- and medium chain length PHA products.
- 11832 Mikrobiologi och virologi