Isolation and characterisation of the agarolytic bacterium Pseudoalteromonas ruthenica

Abstract

AbstractAgar is a polysaccharide that primarily constitutes the cell wall of red algae. It is a good source of carbon and energy for many microbes. In the present study, an agarolytic bacterium, UQAD-3, was obtained from the waters of Al-Uqair, the Arabian Gulf, Al-Ahsaa, Saudi Arabia. UQAD-3 exhibited agarolytic activity when grown on agar as the sole source of carbon and energy. The strain was identified asPseudoalteromonas ruthenicabased on comparative analysis of the 16S rRNA, with 99.6% similarity. This finding was further confirmed by phylogenetic analyses based on 16S rRNA gene sequences, which highlighted that UQAD-3 was assembled within the Pseudoalteromonas clade and constituted a monophyletic subcluster with P. ruthenica, KMM 300T. The strain was further characterised biochemically using the Biolog Gen III microtest system. UQAD-3 showed positive reactions to 16 (17%) of the 94 diverse traits assessed. Good growth was reported in 10% NaCl indicating its moderate halophilic nature. These observations indicate the agarolytic potential of the strain and opens new horizons for industrial applications in the future.