Porphyrobacter cryptus sp. nov., a novel slightly thermophilic, aerobic, bacteriochlorophyll a-containing species

Abstract

Two strains of a novel aerobic, bacteriochlorophyll a-containing species of the a-4 subclass of the Proteobacteria were isolated from the hot spring at Alcafache in central Portugal. 16S rRNA gene sequence-based phylogenetic analyses showed the two novel isolates to be phylogenetically related to members of the genera Erythrobacter, Erythromicrobium and Porphyrobacter. The strains produce reddish-orange-pigmented colonies, have an optimum growth temperature of about 50˚C and could be distinguished from the species Porphyrobacter tepidarius, which also has a high growth temperature, primarily on the basis of the fatty acid composition. The novel species does not grow anaerobically in the presence or absence of a light source. The strains of the novel species utilize several single carbon sources for growth, most of which are also used by P. tepidarius. The species status of strains ALC-2 T and ALC-3 was confirmed by low reassociation values of the DNA with species of the genera Erythrobacter, Erythromicrobium and Porphyrobacter. Phenotypic characteristics and 16S rRNA gene sequence analyses also show that strains ALC-2 T (=DSM 12079 T =ATCC BAA-386 T ) and ALC-3 (=DSM 12080) represent a novel species, for which the name Porphyrobacter cryptus sp. nov. is proposed. INTRODUCTIONMany species within the a-subclass of the Proteobacteria synthesize bacteriochlorophyll a (Bchl a) under aerobic conditions. Photoautotrophic growth under anaerobic or aerobic conditions has not been shown in these organisms, although some organisms may be photoheterotrophic under a limited range of cultivation conditions (Takamiya et al., 1987). Many of these organisms are exclusively chemoorganotrophic, leading to the view that the organisms are photoheterotrophic under unknown growth conditions. The a-4 subclass of the Proteobacteria comprises the Bchl a-containing species of the genera Erythrobacter , 1997). The species Erythrobacter longus and Erythrobacter litoralis originate from marine samples, are slightly halophilic and multiply by binary fission. The species Erythromicrobium ramosum also grows by binary fission, but, as the name implies, this organism can form slightly branching cells. The species Porphyrobacter neustonensis, unlike the other Bchl a-synthesizing bacteria of the a-4 subclass of the Proteobacteria, produces unusual pleomorphic cells, some of which have stalk-like structures and reproduce by budding. The other species of this genus, Porphyrobacter tepidarius, produces short, ovoid, rod-shaped cells, divides by binary fission and has an optimum growth temperature of about 45-50˚C. Another species, invalidly described as 'Citromicrobium bathyomarinum', was isolated from an abyssal hot-spring plume, is mesophilic, yellow-pigmented, contains Bchl a under aerobic growth and forms pleomorphic cells that resemble those of Erythromicrobium ramosum (Yurkov et al., 1999). Other strains closely related to the genera Erythrobacter, Erythromicrobium and Porphyrobacter Abbreviation: Bchl a, bacteriochlorophyll a.The GenBank/EMBL/...

Erythrobacter aquimaris sp. nov., isolated from sea water of a tidal flat of the Yellow Sea in Korea

“…1). The results obtained in the morphological and chemotaxonomic analyses are consistent with the result of the monothetic classification by 16S rRNA gene sequence analysis, although clear chemotaxonomic differentiation is not necessarily possible between the genus Erythrobacter and the two phylogenetically related genera Porphyrobacter and Erythromicrobium (Fuerst et al, 1993;Rainey et al, 2003;Yurkov et al, 1994). Strains SW-110 T , SW-116 and SW-140 show nearly identical phenotypic characteristics (Table 1).…”

Croceicoccus marinus gen. nov., sp. nov., a yellow-pigmented bacterium from deep-sea sediment, and emended description of the family Erythrobacteraceae

“…Table 1. Phenotypic characteristics that differentiate strain E4A9 T from other related members of the family Erythrobacteraceae Strains/taxa: 1, strain E4A9 T ; 2, Altererythrobacter (Yoon et al, 2005b;Kwon et al, 2007); 3, Erythrobacter (Shiba & Simidu, 1982;Yurkov et al, 1994;Denner et al, 2002;Yoon et al, 2003Yoon et al, , 2004aYoon et al, , 2005aIvanova et al, 2005); 4, Erythromicrobium (Yurkov et al, 1994;Rainey et al, 2003); 5, Porphyrobacter (Fuerst et al, 1993;Hanada et al, 1997;Hiraishi et al, 2002;Rainey et al, 2003;Yoon et al, 2004bYoon et al, , 2006. Data refer to all species within the genera.…”

“…Ubiquinone-10 is the major respiratory quinone. Most species in the family have been isolated from various aquatic environments such as freshwater, seawater, marine mats or sediment, a hot spring, seaweed, a starfish and coral (Shiba & Simidu, 1982; Fuerst et al, 1993;Yurkov et al, 1994; Hanada et al, 1997; Denner et al, 2002; Hiraishi et al, 2002;Rainey et al, 2003;Yoon et al, 2003Yoon et al, , 2004a Yoon et al, , b, 2005a Yoon et al, , b, 2006Ivanova et al, 2005;Kwon et al, 2007). This study focuses on the description of strain E4A9 T , isolated from a deep-sea sediment sample.…”

“…Cell morphology and motility were examined by optical microscopy (BX40; Olympus) and electron microscopy (S260, Cambridge; JEM-1230, JEOL). Pigment absorption spectrum analysis was performed by the method described by Rainey et al (2003) using a Beckman Coulter DU 800 spectrophotometer.…”

Porphyrobacter colymbi sp. nov. isolated from swimming pool water in Tokyo, Japan

“…The major cellular fatty acids of strain TPW-24 T were C 18:1 ω7c (67.0%), C 14:0 2OH (8.2%) and C 17:1 ω6c (5.9%). This fatty acid profile was similar to that of P. neustonensis (Fuerst et al, 1993), P. sanguineus (Hiraishi et al, 2002), P. cryptus (Rainey et al, 2003) and P. donghaensis (Yoon et al, 2004); however, it differed from that of P. dokdonensis (Yoon et al, 2006). As with other members of the genus Porphyrobacter (Yoon et al, 2004(Yoon et al, , 2006, the predominant quinone of strain TPW-24 T was ubiquinone-10 (Q-10).…”