Department of Marine Chemistry, Zhejiang Ocean University, Zhoushan, China.
School of Computer and Control Engineering, Yantai University, Yantai, China.
Antonie Van Leeuwenhoek. 2021 Aug;114(8):1195-1203. doi: 10.1007/s10482-021-01588-6. Epub 2021 May 4.
An aerobic, Gram-stain-negative, straight or curved rods and dimorphic prosthecate bacterium designated as strain LZ-16-1 was isolated from phycosphere microbiota of routinely laboratory-cultured and highly-toxic marine dinoflagellate Alexandrium catenella LZT09. Strain LZ-16-1 produces active bioflocculanting exopolysaccharides (EPS). Cells were dimorphic with non-motile prostheca, or non-stalked and motile by a single polar flagellum. Growth occurred at 10-40 °C, pH 5-9 and 1-8% (w/v) NaCl, with optimum growth at 25 °C, pH 7-8 in the presence of 2-4% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain LZ-16-1 was affiliated to the genus Maricaulis, and closely related to M. parjimensis MCS 25 (99.5%) and M. virginensis VC-5 (99.0%). However, based on genome sequencing and phylogenomic calculations, the average nucleotide identity (ANI) and digtal DNA-DNA genome hybridization (dDDH) values between strains LZ-16-1 and its closest relative, M. parjimensis MCS 25 were only 85.0 and 20.9%, respectively. The dominant fatty acids of strain LZ-16-1 were summed feature 8, C, C, C, C ω9c and summed feature 9. Major polar lipids were sulfoquinovosyl diacylglycerol, six glycolipids, one unidentified phospholipid and one unidentified polar lipid. The predominant isoprenoid quinone was Q-10. The DNA G + C content calculated from the genome was 63.6 mol%. Physiological and chemotaxonomic characterizations further confirmed the distinctiveness of strain LZ-16-1 from other Maricaulis members. Thus, strain LZ-16-1 represents a novel species of the genus Maricaulis, for which the name Maricaulis alexandrii sp. nov. (type strain LZ-16-1 = KCTC 72194 = CCTCC AB 2019006) is proposed.
一株好氧、革兰氏阴性、直或弯的杆状和二态菌毛状的细菌，被命名为 LZ-16-1 菌株，从常规实验室培养的、高毒性海洋甲藻亚历山大藻的藻球微生物群中分离得到。LZ-16-1 菌株可产生活性生物絮凝胞外多糖 (EPS)。细胞呈二态性，无运动菌毛，或无柄，通过单一极鞭毛运动。在 10-40°C、pH5-9 和 1-8%（w/v）NaCl 条件下生长，在 2-4%（w/v）NaCl 存在下，最适生长温度为 25°C、pH7-8。基于 16S rRNA 基因序列的系统发育分析表明，LZ-16-1 菌株属于 Maricaulis 属，与近缘种 M. parjimensis MCS 25（99.5%）和 M. virginensis VC-5（99.0%）密切相关。然而，基于基因组测序和系统基因组计算，LZ-16-1 菌株与其最接近的亲缘种 M. parjimensis MCS 25 的平均核苷酸同一性 (ANI) 和数字 DNA-DNA 杂交 (dDDH) 值分别仅为 85.0%和 20.9%。LZ-16-1 菌株的优势脂肪酸为 sumFeature8、C、C、C、C ω9c 和 sumFeature9。主要极性脂类为 sulfoquinovosyl diacylglycerol、六种糖脂、一种未鉴定的磷脂和一种未鉴定的极性脂类。主要的类异戊二烯醌为 Q-10。从基因组计算得出的 DNA G+C 含量为 63.6mol%。生理和化学分类特征进一步证实了 LZ-16-1 菌株与其他 Maricaulis 成员的独特性。因此，LZ-16-1 菌株代表了 Maricaulis 属的一个新种，现命名为亚历山大藻 Maricaulis alexandrii sp. nov.（模式菌株 LZ-16-1=KCTC 72194=CCTCC AB 2019006）。
