Pseudomonas extremaustralis sp. nov., a Poly(3-hydroxybutyrate) Producer Isolated from an Antarctic Environment

Abstract

A Gram-negative, mobile, rod-shaped, non-spore-forming bacterium (strain 14-3(T)) was isolated from a temporary pond in Antarctica. On the basis of 16S rRNA gene sequence similarity, strain 14-3(T) was shown to belong to the genus Pseudomonas sensu stricto. Physiological and biochemical tests supported the phylogenetic affiliation. Strain 14-3(T) is closely related to Pseudomonas veronii DSM 11331(T), sharing 99.7% sequence similarity. DNA-DNA hybridization experiments between the two strains showed only moderate reassociation similarity (35.1%). Tests for arginine dihydrolase and nitrate reduction were positive, while those for denitrification, indol production, glucose acidification, urease, ss-galactosidase, esculin, caseine and gelatin hydrolysis were negative. Growth of this bacterium occurred in a range from 4 to 37 degrees C but not at 42 degrees C. It accumulated poly(3-hydroxybutyrate) when grown on sodium octanoate medium. Strain 14-3(T) therefore represents the type strain of a new species, for which the name Pseudomonas extremaustralis sp. nov. is proposed. The type strain 14-3(T) has been deposited as DSM 17835(T) and as CIP 109839(T).

High Polyhydroxybutyrate Production in Pseudomonas extremaustralis Is Associated with Differential Expression of Horizontally Acquired and Core Genome Polyhydroxyalkanoate Synthase Genes

“…Pseudomonas extremaustralis is a highly stress resistant bacterium isolated from Antarctica, able to accumulate large quantities of PHB [6]. Previous studies in this strain have allowed the identification of a PHB gene cluster ( phaRBAC ) located within a genomic island [7], [8].…”

Production of Polyhydroxyalkanoate (PHA) Biopolyesters by Extremophiles?

“…14-3, was characterized by López et al [90] by 16S rRNA gene sequence analysis as well as by physiological and biochemical tests. It was revealed that the strain belongs to the genus Pseudomonas sensu stricto, and displays 99.7 % sequence similarity to Pseudomonas veronii DSM 11331T, although DNA-DNA hybridization experiments between the two strains reveled only modest re-association similarity.…”

Biosynthesis of Polyhydroxyalkanaotes by a Novel Facultatively Anaerobic Vibrio sp. under Marine Conditions

“…Following the discovery of P(3HB), many types of bacteria, such as Bacillus spp., Pseudomonas spp., Cupriavidus spp., and Aeromonas spp., have been studied for their potential use in producing PHA more efficiently for industrial use (Shimamura et al 1994;Abe et al 1994;Saito and Doi 1994;Fuchtenbusch et al 2000). Although a few kinds of marine bacteria have also been investigated for the production of PHA under marine conditions, the resultant PHAs have not been characterized in detail (GonzalezGarcia et al 2008;Wang et al 2010;Lopez et al 2009). The advantages of biosynthesizing PHA under marine conditions include avoiding contamination with bacteria that lack salt-water resistance, and the ability to use filtered seawater as a culture medium, which would enable the large-scale industrial production of PHA.…”