Abstract

A Gram-stain-negative, aerobic, rod-shaped (0.3–0.5 × 1.0– 1.9 μm), non-motile marine bacterium designated as ALE3EIT was isolated from a saline volcanic rock aquifer (lava seawater) on Jeju Island, Republic of Korea. The 16S rRNA gene sequence analysis revealed that strain ALE3EIT showed high similarity to ‘Altibacter lentus’ JLT2010T (97.2%), followed by Marixanthomonas ophiurae KMM 3046T (94.5%). Growth was observed at 10–41°C (optimum, 30°C), at pH 6.0–8.5 (optimum, pH 7.5) and at 0.5–8% (optimum, 4.0%) NaCl. The predominant cellular fatty acids were iso-C15:0 (23.5%), iso-C16:0 (10.2%), iso-C16:0 3OH (10.5%), and iso-C17:0 3OH (16.8%). The DNA G + C contents was 40.4 mol%. The major respiratory quinone was MK-6. The major polar lipids were determined to be phosphatidylethanolamine, two unidentified glycolipids, and two unidentified aminolipids. Several phenotypic characteristics such as production of acetoin, activities of arginine dihydrolase and acid phosphatase, and utilization pattern of carbon sources differentiate strain ALE3EIT from ‘A. lentus’ JLT2010T. Activities of the lipase, trypsin, α- chymotrypsin and gelatinase and utilization pattern of carbon sources differentiate strain ALE3EIT from M. ophiurae KMM 3046T. The genome of strain ALE3EIT is 3.0 Mbp long and its ANI and AAI values against ‘A. lentus’ JLT2010T were 76.58 and 72.76, respectively, however, AAI values against members in other genera were lower than 72%. The phylogenomic tree inferred by PhyloPhlAn clearly differentiated the strain ALE3EIT together with strain JLT2010T from other genera in the Falvobacteriaceae. This polyphasic taxonomic data indicates that strain ALE3EIT should be identified as a novel species in the genus ‘Altibacter’, however, the name has not been validated. Therefore, the strain is classified as a novel genus and is proposed as Constantimarinum furrinae gen. nov., sp. nov. The type strain is ALE3EIT (= KCCM 43303T = JCM 33022T).

• Keywords: DNA double strand breakage;DNA repair;SbcD;Staphylococcus aureus;crystal structure;nuclease