Nisaea sediminum sp. nov., a heavy metal resistant bacterium isolated from marine sediment in the East China Sea.

Suting Zhu,Weiyan Zhang,Chaobo Guo,Shan He,Feilu Xie,Yuping Cheng,Dawoon Jung

doi:10.1007/s10482-021-01665-w

Abstract

A Gram-negative, rod-shaped, motile and strictly aerobic bacterium, designated NBU1469T, was isolated from marine sediment sampled on Meishan Island located in the East China Sea. Strain NBU1469T grew optimally at temperature of 40°C, NaCl concentration of 2.0% (w/v) and pH 7.5. Catalase and oxidase activities, H2S production, nitrate reduction and hydrolysis of Tween 20 were positive. Indole, methyl red reaction, urease, hydrolysis of gelatin, starch, casein, Tweens 40, 60 and 80 were negative. The major cellular fatty acids were C16:0, C19:0 cyclo ω8c and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c). The only respiratory quinone was ubiquinone-10 (Q-10). The major polar lipids were phosphatidylglycerol, two unidentified amino-phospholipids and two unidentified phospholipids. Comparative analysis of the 16S rRNA gene sequence showed highest similarities to the species with validated name Nisaea nitritireducens DR41_18T (98.1%) and Nisaea denitrificans DR41_21T (97.6%). Phylogenetic analyses indicated that strain NBU1469T formed a distinct lineage with strains Nisaea nitritireducens DR41_18T and Nisaea denitrificans DR41_21T within the genus Nisaea. The average nucleotide identity and digital DNA-DNA hybridization values between strain NBU1469T and related species of genus Nisaea were well below the threshold limit for prokaryotic species delineation. The DNA G + C content was 63.6%. Based on its phenotypic, chemotaxonomic and genotypic data, strain NBU1469T is considered to be a representative of a novel species in the genus Nisaea, for which the name Nisaea sediminum sp. nov. is proposed. The type strain is NBU1469T (=KCTC 82224T =MCCC 1K04763T).

Highlights

The genus Nisaea, belonging to the family Rhodospirillacea in the class Alphaproteobacteria, was originally proposed by Urios et al (2008) with the description of Nisaea nitritireducens DR41_18T and Nisaea denitrificans DR41_21T
The major cellular fatty acids (C16:0, C19:0 cyclo ω8c and summed feature 8), predominant respiratory quinone, major polar lipids (PG, PN1, PN2, PL1 and PL2), phylogenetic trees and phylogenomic tree supported that strain NBU1469T should be classified into the genus Nisaea
There are some additional differences between strain NBU1469T and the related type strains of genus Nisaea

Summary

Introduction

The genus Nisaea, belonging to the family Rhodospirillacea in the class Alphaproteobacteria, was originally proposed by Urios et al (2008) with the description of Nisaea nitritireducens DR41_18T and Nisaea denitrificans DR41_21T. At the time of writing, the genus Nisaea only contained the above two validly published species (https://www.bacterio.net/genus/Nisaea), which were reported from coastal, surface waters (Urios et al, 2008). Cells of N. nitritireducens DR41_18T and N. denitrificans DR41_21T were reported as Gram-negative, motile, rod-shaped, catalase- and oxidase- positive, containing ubiquinone-10 (Q-10) as the predominant quinone, with very high amounts of C18:1 ω7c and the DNA G+C content was 60 mol%. We describe a novel strain, designated NBU1469T, isolated from a marine sediment sample collected from Meishan Island in the East China Sea. Following the polyphasic taxonomic approach, we propose that strain NBU1469T represents a novel species of the genus Nisaea

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Conclusion