马尾藻极地杆菌新种和噬褐藻酸杆菌新种的分离与鉴定：两种具有降解藻类多糖能力的新物种。

Isolation and characterization of Polaribacter sargassicola sp. nov. and Algibacter ulvanivorans sp. nov.: two novel species with ability to degrade algal polysaccharides.

作者信息

Li Jin, Mao Aihua, Peng Chao, Li Linhui, Li Binghan, Zhou Lijuan, Xu Yan, Zhong Mingqi, Hu Zhong

机构信息

Key Laboratory of Southwest China Wildlife Resource Conservation (China West Normal University), Ministry of Education, Nanchong, 637002, China.

College of Life Sciences, China West Normal University, Nanchong, 637002, China.

出版信息

Antonie Van Leeuwenhoek. 2025 Jul 1;118(8):99. doi: 10.1007/s10482-025-02117-5.

DOI:10.1007/s10482-025-02117-5

PMID:40591017

Abstract

The genera Polaribacter and Algibacter, which are members of the Bacteroidota family Flavobacteriaceae, are well known for their arsenal of carbohydrate-active enzymes (CAZymes) and specialized polysaccharide utilization loci (PULs). In this study, two aerobic, gram-negative, and rod-shaped bacterial strains, designated strains DS7-9 and PT7-4, were isolated from the surface of seaweed collected from the coastal zone of Fujian Province, China. The two strains exhibited broad tolerance ranges to salinity (0-4%), temperature (10-40 °C) and pH (5.0-10.0). The predominant fatty acids in strain DS7-9 were iso-C (53.7%) and iso-C 3-OH (10.9%), whereas those in strain PT7-4 were iso-G-C (33.2%) and iso-C (27.1%). Additionally, the predominant menaquinone was MK-6. The 16S rRNA gene of strain DS7-9 shares 97.5% similarity with that of Polaribacter haliotis KCTC 52418, whereas that of strain PT7-4 is 97.0% sequence similarity with that of Algibacter mikhailovii KCTC 12710. Phylogenomic analysis revealed that the highest average nucleotide identity (ANI) value between strain DS7-9 and its closest relative reached 84.7%, whereas the corresponding value for strain PT7-4 was 84.2%. Genomic characterization revealed DNA G + C contents of 29.5% and 31.9% for strains DS7-9 and PT7-4, respectively. Both strains possessed complete circular chromosomes, with genome sizes of 3.7 Mb (DS7-9) and 3.5 Mb (PT7-4). Bioinformatic analysis revealed that strain DS7-9 harbors 5 PULs putatively associated with laminarin, ulvan, fucoidan, and alginate catabolism, whereas strain PT7-4 possesses 7 PULs predicted to target ulvan, alginate, and starch metabolism. On the basis of their distinct physiological characteristics, two strains are suggested for classification into novel species: Polaribacter sargassicola sp. nov. (type strain DS7-9 = MCCC 1K08670 = KCTC 102076) and Algibacter ulvanivorans sp. nov. (type strain PT7-4 = MCCC 1K08669 = KCTC 102077).

摘要

极地杆菌属（Polaribacter）和藻杆菌属（Algibacter）是拟杆菌门黄杆菌科（Bacteroidota family Flavobacteriaceae）的成员，以其丰富的碳水化合物活性酶（CAZymes）和专门的多糖利用位点（PULs）而闻名。在本研究中，从中国福建省沿海地区采集的海藻表面分离出两株需氧、革兰氏阴性、杆状细菌菌株，分别命名为DS7-9和PT7-4菌株。这两株菌株对盐度（0-4%）、温度（10-40°C）和pH值（5.0-10.0）表现出广泛的耐受性。DS7-9菌株中的主要脂肪酸为异-C（53.7%）和异-C 3-OH（10.9%），而PT7-4菌株中的主要脂肪酸为异-G-C（33.2%）和异-C（27.1%）。此外，主要的甲基萘醌为MK-6。DS7-9菌株的16S rRNA基因与鲍氏极地杆菌（Polaribacter haliotis）KCTC 52418的16S rRNA基因相似度为97.5%，而PT7-4菌株的16S rRNA基因与米氏藻杆菌（Algibacter mikhailovii）KCTC 12710的序列相似度为97.0%。系统基因组分析表明，DS7-9菌株与其最接近的亲缘种之间的最高平均核苷酸同一性（ANI）值达到84.7%，而PT7-4菌株的相应值为84.2%。基因组特征分析表明，DS7-9和PT7-4菌株的DNA G+C含量分别为29.5%和31.9%。两株菌株均具有完整的环状染色体，基因组大小分别为3.7 Mb（DS7-9）和3.5 Mb（PT7-4）。生物信息学分析表明，DS7-9菌株含有5个可能与海带多糖、石莼多糖、岩藻依聚糖和藻酸盐分解代谢相关的PULs，而PT7-4菌株拥有7个预测靶向石莼多糖、藻酸盐和淀粉代谢的PULs。基于它们独特的生理特征，建议将这两株菌株分类为新物种：马尾藻极地杆菌（Polaribacter sargassicola）新种（模式菌株DS7-9 = MCCC 1K08670 = KCTC 102076）和食石莼藻杆菌（Algibacter ulvanivorans）新种（模式菌株PT7-4 = MCCC 1K08669 = KCTC 102077）。