Novosphingobium nitrogenifigens sp. nov., a polyhydroxyalkanoate-accumulating diazotroph isolated from a New Zealand pulp and paper wastewater.

A diazotroph capable of accumulating significant amounts of polyhydroxyalkanoate was isolated in New Zealand from a bioreactor treating nitrogen-deficient pulp and paper-mill effluent. Strain Y88T is Gram-negative, rod-shaped and positive for catalase, nitrate reductase and urease activities. The complete 16S rRNA gene sequence was most similar to those of other members of the genus Novosphingobium, the highest level of similarity (94.7%) being found with respect to the type strain of Novosphingobium stygium. The combined phenotypic, chemotaxonomic and sequence data show that while strain Y88T belongs to the genus Novosphingobium, it is distinct from all currently recognized Novosphingobium species. Therefore, strain Y88T represents the first nitrogen-fixing species of the genus Novosphingobium, for which the name Novosphingobium nitrogenifigens sp. nov. is proposed. The type strain is Y88T (=ICMP 16470T=DSM 19370T).