Pyruvic acid (pyruvate) the most important α-oxocarboxylic acid, plays a central role in energy metabolism in living organisms. It is used mainly as a starting material in the biosynthesis of pharmaceuticals as well as employed in the production of crop protection agents, polymers, cosmetics and food additives. Four Gramnegative, moderately halophilic, pyruvate and poly (3-hydroxybutyrate)- producing strains were isolated from soil samples collected from mangrove forest at Giao Thuy, Nam Dinh province. Preliminary screening results showed that among four strain, the ND7 strain was able to produce the highest bioplastic-poly (3- hydroxybutyrate) (PHB) and extracellular secretion of pyruvate, respectively, reaching 50.23% dry weight and 6.87 g/L after 60 hours of cultivation. When cultured in high alkaliphilic medium (pH 9.4), the pyruvate secretion increased significantly (21.02 g/L after 60 hours of cultivation). Based on the morphological, biochemical characteristics and nucleotide sequence analysis of partial 16S rRNA gene, the ND7 strain was identified as Halomonas maura. The results allow us to conclude that ND7 strain is a potential target for the exploitation of pyruvate in a larger scale.