Oceanobacillus chironomi sp. nov., a halotolerant and facultatively alkaliphilic species isolated from a chironomid egg mass

Chinomids (Diptera; Chironomidae) are the most abundant insect in freshwater aquatic habitats. Females of the genes Chironomus lay egg masses containing hundreds of eggs embedded in a gelatinous matrix. A bacterial strain, designated T3944D^T, was isolated from a chironomid egg mass sampled from a waste-stabilization pond in northern Israel and was found to be Gram-positive, motile by peritrichous flagella, endospore-forming, halotolerant and facultatively alkaliphilic. Comparative 16S rRNA gene sequence analysis showed that strain T3944D^T belonged to the genus Oceanobacillus, exhibiting the highest levels of similarity with the sequences of Oceanobacillus oncorhynchi subsp. incaldanensis DSM 16557^T (94.9%), Oceanobacillus oncorhynchi subsp. oncorhynchi JCM 12661^T (94.8%), Oceanobacillus iheyensis JCM 11309^T (94.7%) and Oceanobacillus picturae LMG 19416 (94.5%). Strain T3944D^T grew optimally at 1-3% NaCl, pH 8.5 and 37 °C. The major cellular fatty acids were anteiso-C_15:0 (60.0%) and anteiso-C_17:0 (12.9%)and the DNA G+C content was 38.1 mol%. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain T3944D^T represents a novel species in the genus Oceanobacillus, for which the name Oceanobacillus chironomi sp. nov. is proposed. The type strain is T3944D^T (=LMG 23627^T =DSM 18262^T).