ABSTRACT
A single strain of a budding bacterium was isolated from freshwater. The strain had a life-cycle, with a multitrichous swarmer stage, and produced a phase-dark inclusion of packed ribosomes and nuclear material. The mol % G + C of the DNA was 64.4 +/- 1.0. A new genus, Gemmata with the type species Gemmata obscuriglobus is proposed. The type strain is UQM 2246.
Subject(s)
Bacteria/classification , Water Microbiology , Australia , Bacteria/isolation & purification , Bacteria/metabolism , Bacteria/ultrastructure , Fresh Water , Terminology as TopicABSTRACT
Budding and prosthecate bacteria were enumerated in spring and summer by viable counting procedures in several freshwater habitats in Australia including oligotrophic lakes, a mesotrophic lake, and eutrophic ponds.Caulobacter spp. were the most numerous type encountered. They were present in the highest concentrations (exceeding 1000/ml) in the mesotrophic lake during the summer. Their proportion to total viable heterotrophic bacteria was also highest (35.1 to 37.7) in this habitat. From 17 to 330/mlCaulobacter spp. were counted in the eutrophic habitats where their proportion to total viable numbers was less than 1.0%. In the oligotrophic lakes they varied from 5 to 23/ml and comprised greater than 5% of the total viable count.Hyphomicrobium- like bacteria were also numerous in the mesotrophic lake and in one oligotrophic lake during the summer sampling period.Ancalomicrobium spp. occurred in high concentrations (130/ml) in the mesotrophic lake. Budding bacteria of thePlanctomyces-Pasteuria group were most numerous in the eutrophic habitats where as many as 240/ml were counted; their proportion to total heterotrophs remained relatively constant regardless of trophic state, however. A similar pattern was observed withProsthecobacter spp.
