The family Cohaesibacteraceae: The genera Cohaesibacter and Breoghania

Abstract

This chapter reviews the recently described family Cohaesibacteraceae, their two genera (Cohaesibacter and Breoghania) and three species (Cohaesibacter gelatinilyticus Hwang and Cho 2008, Cohaesibacter marisflavi Qu et al. 2011, and Breoghania corrubedonensis Gallego et al. 2010). The type species for each genus are Cohaesibacter gelatinilyticus and Breoghania corrubedonensis, respectively. Cohaesibacteraceae was created to accommodate strains that were not genetically similar enough to be classified into existing families of the order Rhizobiales. Besides the genetic dissimilarity, the sole major respiratory quinone (Q-10) and the polar lipid composition differentiate Cohaesibacteraceae from the other families of this order. The members of Cohaesibacteraceae are Gram-negative, facultative anaerobic (Cohaesibacter) or aerobic (Breoghania) rods and are motile by polar flagella. Cohaesibacter comprises strains isolated from coastal waters of the east coast of Korea and China, whereas Breoghania has its type strain isolated from coastal waters of northwest Spain. Nothing is known about their applications or ecological importance, so this chapter only provides phenotypic and genetic characterization. Additionally, the phylogenetic relationship with other families of the order Rhizobiales is presented. Finally, the formal taxonomical descriptions of both genera and their respective species are given.