A Gram-stain negative, facultatively anaerobic, rod-shaped, non-motile and non-spore forming bacterium, designated ZS-11T, was isolated from an artificial freshwater lake in Guangzhou city, Guangdong province, China. Growth of strain ZS-11T was observed at the temperature 18-42 °C (optimum 32-37 °C), pH 6.0-8.0 (optimum 7.0) and 0.5-3.0% (w/v) NaCl (optimum 0.5%, w/v), and also found to be enhanced in the presence of CO2. Pairwise comparison of 16S rRNA gene sequences showed that the strain shared high similarities with Serratia entomophila DSM 12358T (96.1%), Serratia ficaria DSM 4569T (96.0%), Serratia plymuthica DSM 4540T (96.0%), Rahnella victoriana FRB 225T (95.9%) and Rouxiella badensis DSM 100043T (95.8%). The phylogenomic dendrograms showed that strain ZS-11T formed a distinct cluster within the clade of the genus Serratia. The major fatty acids (> 20%) present in the cells were C16:0, C16:1ω7c/C16:1ω6c and C18:1ω7c/C18:1ω6c, which were consistent with those of S. entomophila CCUG 55496T and Serratia liquefaciens CCUG 9285T. The DNA G + C content for the genome was 49.3%. Based on these phenotypic and genotypic data, strain ZS-11T is considered to represent a new species of the genus Serratia, for which the name Serratia microhaemolytica sp. nov. is proposed. The type strain is ZS-11T (= CCTCC AB 2018040T = KCTC 62413T).
Keywords: Artificial lake; Polyphasic taxonomy; Serratia microhaemolytica sp. nov..