Genome sequence of Halomonas hydrothermalis Y2, an efficient ectoine-producer isolated from pulp mill wastewater.

Halophilic microorganisms have great potentials towards biotechnological applications. Halomonas hydrothermalis Y2 is a halotolerant and alkaliphilic strain that isolated from the Na+-rich pulp mill wastewater. The strain is dominant in the bacterial community of pulp mill wastewater and exhibits metabolic diversity in utilizing various substrates. Here we present the genome sequence of this strain, which comprises a circular chromosome 3,933,432 bp in size and a GC content of 60.2%. Diverse genes that encoding proteins for compatible solutes synthesis and transport were identified from the genome. With a complete pathway for ectoine synthesis, the strain could produce ectoine from monosodium glutamate and further partially secreted into the medium. In addition, around 20% ectoine was increased by deleting the ectoine hydroxylase (EctD). The genome sequence we report here will provide genetic information regarding adaptive mechanisms of strain Y2 to its harsh habitat, as well as facilitate exploration of metabolic strategies for diverse compatible solutes, e.g., ectoine production.