Oligotrophic bacteria from the Antarctic Ocean

• Main Authors: Tan, Tjhing Lok, Rüger, Hans-Jürgen
• Format: Dataset
• Language: English
• Published: PANGAEA 1999
• Subjects: ANT-VIII/6; Cosmonaut Sea; Indian Ocean; Lazarev Sea; Polarstern; PS16; PS16/507; PS16/509; PS16/518; PS16/526; PS16/530; PS16/534; PS16/535; PS16/547; PS16/549; PS16/554; PS16/557; Riiser-Larsen Sea; South Atlantic Ocean; Water sample; WS; Antarctic; Antarctic Ocean; Indian; Lazarev; Riiser-Larsen; The Antarctic; Antarc*; Cosmonaut sea
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.745115; https://doi.org/10.1594/PANGAEA.745115

From enrichment cultures in dialysis chambers held in natural seawater tanks, 104 strains were isolated and kept in culture. All strains proved to be Gram-negative and psychrotrophic, having optimum growth temperatures of between 20 and 24 °C. Maximal growth temperatures were 30 to 37 °C, or even higher. With 55 isolates, substrate utilizations in Biolog MicroPlates were determined, and the obtained metabolic fingerprints used for clustering. Five groups could be distinguished at the 80% similarity level. Fifteen strains belonged to cluster 1, seven strains to cluster 2, and each of the clusters 3 and 4 contained nine strains. Cluster 5 can be divided into subcluster 5a and 5b, with 6 strains showing a few substrates metabolized, and 9 strains without any reactions, or weak reactions for one or two substrates, respectively. Each cluster could be characterized by specific metabolic fingerprints. Strains from cluster 1 metabolized N-acetyl-D-glucosamine, alpha-hydroxybutyric acid and gamma-hydroxybutyric acid, strains from cluster 2 citric acid, formic acid, thymidine and putrescine, strains from cluster 3 glycyl-L-aspartic acid, glycyl-L-glutamic acid, L-threonine and inosine, whereas strains from cluster 4 metabolized alpha-cyclodextrin and N-acetyl-D-galactosamine, typically. Methylamine was not utilized by the isolates, but strains from cluster 1, 2 and 3 could grow on basal seawater agar. Morphological characteristics and photomicrographs of the oligotrophic strains are presented. Due to their typical morphologies and ampicillin resistence, the nine strains from cluster 3 can be regarded as new species of the genus Planctomyces. These bacteria have not been cultivated before.