ISSN:
1432-072X
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
Notizen:
Summary Water samples from various sources contained budding bacteria such as: Hyphomicrobium, Pedomicrobium, Ancalomicrobium, Rhodomicrobium, Planctomyces and Rhodopseudomonas. Most of these attach to surfaces, a fact which may have caused many to be overlooked. Introduction of glass slides into the stored water sample resulted in the attachment of cells and hence facilitated their observation. A study of the distribution of genera demonstrated their ubiquitous presence; most representatives tolerated in their habitats various degrees of salinity or concentrations of organic nutrients, different depths, and the climate of various geographical locations. They were observed during all seasons. A remarkable tolerance of nitrite possibly accounts for the growth of hyphomicrobia in cultures of nitrifying bacteria. Procedures for the enrichment of budding forms consisted of (a) storing water samples in the laboratory to increase their relative numbers, (b) omitting the addition of carbon sources, or adding these only in low concentrations (as vapor), and (c) offering glass slides for attachment. Budding purple bacteria requiring light and anaerobiosis needed acetate or ethanol as a suitable H-donor. Forty-four pure cultures were identified as: Hyphomicrobium (31), Pedomicrobium (12), or Rhodomicrobium (1); others may represent new genera. A detailed description and taxonomic study is in preparation. Reasons for and consequences of attachment to surfaces are discussed. Exploitation of a higher nutrient concentration in the attached state could be of ecological significance. Rosette, pellicle or curtain formation may offer similar advantages. The presence of budding bacteria in microbial slimes could be explained by a higher concentration of nutrients in or on the slimes. The question whether these cultures are “truly aquatic” is discussed and answered in the affirmative.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00425635
