Thalassolituus haligoni sp. nov., BB40, a model species for non-cyanobacterial diazotrophs within Oceanospirillales isolated from a Fjord-like Inlet in Kjipuktuk

Le résumé fourni par la source

Abstract Marine non-cyanobacterial diazotrophs (NCDs) are recognized as globally distributed, however, few representatives have been isolated in pure cultures. As a result, understanding the physiology, growth rate, substrate preference and dinitrogen (N 2 ) fixation capabilities proves difficult. Thalassolituus haligoni . sp. nov., BB40 was isolated from a fjord-like inlet within Kjipuktuk (Halifax), Nova Scotia. The fully sequenced genome displayed all necessary genes required for N 2 fixation, and various carbon uptake pathways. The gram-negative flagellated rod shape bacterium displayed significantly higher growth rates in medium amended with nitrate (NO 3 - ) or ammonia (NH 3 ), compared to dissolved N 2 , as the sole nitrogen source. Biological N 2 fixation rates were detectable across all conditions, measuring a range from 9.34 × 10 -6 to 1.4 × 10 -1 fmol N cell -1 day -1 . Growth of the isolate was successful between 4 °C up to 35 °C, with a T opt of 20 °C for N 2 , and between 27 - 30 °C for fixed nitrogen (NO 3 - and NH 3 ). The closest relatives to T. haligoni , were found to be the uncultured Arc-gamma-03 (99% average nucleotide identity (ANI)) and Oceanobacter antarcticus (81% ANI). T. haligoni also displays versatile capabilities for growth on various carbon, and nitrogen sources, and antibiotics. Collectively this study provides an in-depth physiological assessment of an Oceanospirillales diazotrophic species which we presently have limited knowledge of.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.