Agarivorans aestuarii sp. nov., an agar-degrading bacterium isolated from a tidal flat

Abstract

A Gram-reaction-negative, aerobic, non-spore forming, rod-shaped bacterium motile with a single polar flagellum, designated strain hydD622 T , was isolated from the sediment of a tidal flat at Asan Bay, Korea. Strain hydD622 T exhibited an agarolytic activity. Comparison of 16S rRNA gene sequences revealed that strain hydD622 T was closely related to Agarivorans litoreus KCTC 42116 T , Agarivorans albus KCTC 22256 T and Agarivorans gilvus KCTC 32555 T with similarities of 98.4, 98.0 and 96.5 %, respectively. Strain hydD622 T was clustered distantly from the other genera in the family Alteromonadaceae but formed a unique clade within the genus Agarivorans based on the 16S rRNA gene sequence. The DNA-DNA relatedness with Agarivorans litoreus KCTC 42116 T and Agarivorans. albus KCTC 22256 T was 39.0 and 37.8 %, respectively. The major fatty acids (>10 %) were C 16 : 0 ,C 16 : 1 !6c/C 16 : 1 !7c and C 18 : 1 !6c/C 18 : 1 !7c. The respiratory quinone was ubiquinone-8, and the polar lipid profile consisted of phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and an unidentified lipid. The DNA G+C content was 44 mol%. On the basis of physiological, chemotaxonomic and phylogenetic analyses, strain hydD622 T represents a novel species within the genus Agarivorans, for which the name Agarivorans aestuarii sp. nov. is proposed. The type strain of Agarivorans aestuarii sp. nov. is hydD622 T (=KCTC 32543 T =CGMCC 1.12692 T ).The genus Agarivorans was first proposed by Kurahasi & Yokota (2004), who isolated bacterial strains from the marine mollusk Omphalius pfeifferi in the Kanto area, Japan. The major characteristic of the genus Agarivorans is its agarolytic activity, and members have isolated from marine environments including marine animals, seawater, and seaweeds (Kurahasi & Yokota, 2004;Du et al., 2011;Park et al., 2014). Agar is a complex polysaccharide and can be obtained from red algae. Agar has been used as a food additive in many Asian countries. It is also one of the gelling materials commonly used in preparation of solid medium for cultivation of microorganisms. On the other hand, degradation products of agar formed by the hydrolysing enzyme agarase are simple sugars that can be used as substrates for biofuel production (Chi et al., 2012). During a sample collection and bacterial biodiversity study to isolate novel bacteria in Asan Bay, Korea, one novel strain, designated strain hydD622 T ,with agardegrading activity was recovered. Phylogenetic analysis of the 16S rRNA gene sequence showed that the isolate is affiliated within the genus Agarivorans by having similarity with Agarivorans litoreus GJSW-6 T (98.4 %), Agarivorans albus MKT 106 T (98.0 %) and Agarivorans gilvus WH0801 T (96.5 %), respectively. Through phenotypic and phylogenetic analyses, we report that strain hydD622 T represents a novel species in the genus Agarivorans for which the name Agarivorans aestuarii sp. nov is proposed.To isolate strain hydD622 T , a serially diluted seawater suspension of tidal flat sediment from Asan...

A Novel Enzyme Portfolio for Red Algal Polysaccharide Degradation in the Marine Bacterium Paraglaciecola hydrolytica S66T Encoded in a Sizeable Polysaccharide Utilization Locus

“…Likewise, Glaciecola agarilytica dominated an agar-degrading community ( Wietz et al, 2015 ) in accordance with the agarolytic phenotype reported for this bacterium ( Yong et al, 2007 ). Several other genera within the Alteromonadaceae family have been connected with agarolytic activities such as Agarivorans ( Kim et al, 2016 ), Gayadomonas ( Chi et al, 2013 ), and Catenovulum ( Yan et al, 2011 ), however, little is known about the responsible enzymatic systems within these taxa. Paraglaciecola hydrolytica S66 T represents a newly isolated Gammaproteobacterium of the Alteromonadaceae family, which has the ability to degrade both agar and carrageenan ( Bech et al, 2017 ).…”

Draft genome sequence of Agarivorans aestuarii strain ZMCS4, a putative CAZyme-producing bacteria isolated from the marine brown algae Cladostephus spongiosus

“…The genus Agarivorans was initially proposed by Kurahashi and Yokota in 2004 ( 1 ).Currently, this genus comprises four species, all of which have been isolated from various marine environments, including marine animals, seawater, marine sediments, and seaweeds ( 1 – 4 ). The major characteristics among Agarivorans spp.…”

Complete genome sequence of a species of the genus Agarivorans from the Sea of Japan

“…To date, four species under the genus Agarivorans have been identified: Agarivorans albus , Agarivorans gilvus , Agarivorans aestuarii , and Agarivorans litoreus ( 1 – 4 ). These are Gram-negative, aerobic bacteria known for their agar-degrading capacity, a feature that potentially influences the carbon cycle in marine ecosystems ( 1 – 4 ). We isolated Agarivorans sp.…”