A number of bacteria were isolated from sea water in Skagerrak, Denmark, at 30 m depth. Two of the isolates, strains D28 and D30 T , belonged to the Flavobacteriaceae within the Cytophaga-Flavobacterium-Bacteroides group. Sequencing of 16S rRNA genes of the two strains indicated strongly that they belonged to the genus Tenacibaculum and that they showed greatest similarity to the species Tenacibaculum amylolyticum and Tenacibaculum mesophilum. DNA-DNA hybridization values, DNA base composition and phenotypic characteristics separated the Skagerrak strains from the other species within Tenacibaculum. Thus, it is concluded that the strains belong to a novel species within the genus Tenacibaculum, for which the name Tenacibaculum skagerrakense sp. nov. is proposed, with strain D30 T (=ATCC BAA-458 T =DSM 14836 T ) as the type strain.Members of the Cytophaga-Flavobacterium-Bacteroides (CFB) group are assumed to be important in the degradation of polymeric organic matter because of their ability to produce hydrolytic enzymes (Cottrell & Kirchman, 2000;Giovannoni & Rappé, 2000). Members of the CFB group are widespread in the marine environment and are often associated with surfaces where they may benefit from their hydrolytic activity (Cottrell & Kirchman, 2000;Giovannoni & Rappé, 2000;Johansen et al., 1999;Suzuki et al., 2001). In addition to attached forms, the CFB group also includes pelagic (free-living) marine species (Giovannoni & Rappé, 2000;Gosink et al., 1998;Pinhassi et al., 1997).The taxonomy of the CFB group has had a turbulent history since the proposal of the genus Cytophaga (Winogradsky, 1929). In recent years, studies on phylogenetic characterization have led to several reclassifications and emended descriptions of species within this group. Bernardet et al. (1996) presented a new description of the family Flavobacteriaceae and rearranged the taxonomy of the genus Flavobacterium. However, the generic relationship of members of the presumed [Flexibacter] maritimus rRNA branch was left open, which inspired a reclassification of several existing genera and descriptions of new genera, including Psychroserpens and Gelidibacter (Bowman et al., 1997), Psychroflexus (Bowman et al., 1998), Polaribacter (Gosink et al., 1998), Cellulophaga (Johansen et al., 1999Bowman, 2000), Salegentibacter (McCammon & Bowman, 2000), Zobellia (Barbeyron et al., 2001) and Tenacibaculum. The latter genus contains the former [Flexibacter] maritimus, which has been reclassified to Tenacibaculum maritimum, the type species of the genus (Suzuki et al., 2001).In the present study, two strains, D28 and D30 T , related to the CFB group were isolated from a sea-water sample taken in the pelagic zone at 30 m depth in Skagerrak (57u 969 N 10u 789 E), Denmark. Skagerrak is a water body between Denmark and Norway that is strongly influenced by the North Atlantic Ocean. The strains were isolated on 10 %-strength ZoBell agar plates (ZoBell, 1946) were recorded with an Axiovert 100 TV microscope (Zeiss) fitted with an AT200 CCD camera. To te...
One hundred and sixty‐nine bacterial strains were isolated from activated sludge from a waste water treatment basin operating under alternating aerobic/anaerobic conditions. Sixteen strains from a subsample of 23 nitrogen oxide reducers were true respiratory denitrifiers, and all denitrified under both anaerobic and aerobic conditions. REP‐PCR band analysis showed different patterns for all strains. One strain (strain 1) produced large amounts of N2O and was studied in detail. Nitrous oxide was the major end product of denitrification by this strain, and NO−2 was reduced more efficiently than NO−3. The aerobic denitrification was most pronounced with NO−2 as electron acceptor, and the reduction of NO−2 was not coupled to NH+4 oxidation.
To test if the quality and concentration of dissolved nitrogen (N) species could be a selective force in shaping bacterioplankton community structure, competition for various N compounds among five heterotrophic marine bacteria (Pseudomonas strains B, B25, and AX; Bacillus strain A6; Erythrobacter strain F19) was examined. Two of the five strains (AX and B25) were capable of utilizing urea for growth. The five strains were inoculated into dilute (1/1,000 strength) ZoBell medium enriched with various N sources (free amino acids, casein, ammonium, nitrate, or urea). Regardless of the added N source, the communities were either dominated by strain B (at 50 microM N) or strain AX (at 250 microM N). Without any addition of N, strain F19 dominated. If F19 was not included in the community, strain B25 dominated. Despite these differences in community structure, consumption of the added N compounds was surprisingly similar and no advantages of urea for the urea-utilizing bacterium B25 were obvious. To examine if urea could be of selective advantage to the urea-degrading strains B25 and AX, communities with and without B25 were amended with urea N. As expected, strain B25 became dominant when present, but without this strain the non-urea-utilizing strain B outcompeted the urea-utilizing strain AX. Possibly, strain B benefited from N released during catabolism of urea by strain AX. Changes in community composition did not result in major changes in the nitrogen dynamics. The results indicate that dissolved N species can be a selective force in shaping microbial communities. Relative to nutrient generalists, nutrient specialists may either have competitive advantages or stimulate growth of other species by synergetic interactions. Results from the model communities suggest that there may be a large degree of unpredictability in the making of microbial communities, whereas major ecosystem functions such as N cycling appear relatively stable.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.