Monaibacterium sp. ALG8 (=MCCC 1 K04733) was isolated from seawater around brown algae. The genome of Monaibacterium sp. ALG8 was sequenced, one circular 3,036,380 bp chromosome and six circular plasmids ranging from 12,229 to 151,263 bp were found after assembly. The results of genomic annotation showed that Monaibacterium sp. ALG8 lacks the ability to degrade alginate, indicating its ecological role may not be directly related to the degradation of brown algae. The comparison of genomic features in the plasmids showed that almost all of these plasmids, except pALG4, were horizontally recruited from donors, not ancestors. Based on predicted functions, the existence of plasmids may provide strain ALG8 with advantages including nitrate reduction, tolerance of osmotic stress via glycine betaine, resistance to heavy metal stress such as mercury and cobalt, degradation of benzoate metabolites such as p-cumate, transformation of the swim-or-stick lifestyle and improvement of the immune system with two CRISPR–Cas systems. This study provides evidence for the carbon metabolic patterns of Monaibacterium sp. ALG8 and predicts the functions and donors of six plasmids in this strain, broadening our understanding of the ecological roles of bacteria in the environment around brown algae and the functions and evolutionary patterns of plasmids in marine Roseobacter lineage members.

单杆菌属 ALG8 (=MCCC 1 K04733) 从褐藻周围的海水中分离出来。单杆菌属的基因组。对ALG8进行测序，组装后发现1条环状3,036,380 bp染色体和6条12,229至151,263 bp的环状质粒。基因组注释结果表明单杆菌sp. ALG8 缺乏降解藻酸盐的能力，表明其生态作用可能与褐藻的降解没有直接关系。质粒中基因组特征的比较表明，除了 pALG4 外，几乎所有这些质粒都是从供体而非祖先中水平招募的。基于预测的功能，质粒的存在可以为菌株 ALG8 提供优势，包括硝酸盐还原、甘氨酸甜菜碱对渗透胁迫的耐受性、对汞和钴等重金属胁迫的抗性、苯甲酸盐代谢物如p- cumate 的降解、转化游泳或坚持的生活方式和通过两个 CRISPR-Cas 系统改善免疫系统。这项研究为单杆菌的碳代谢模式提供了证据sp. ALG8 并预测了该菌株中六个质粒的功能和供体，拓宽了我们对细菌在褐藻周围环境中的生态作用以及海洋玫瑰杆菌谱系成员中质粒的功能和进化模式的理解。