Flavobacterium croceum
| Flavobacterium croceum | ||||||||||||
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| Scientific name | ||||||||||||
| Flavobacterium croceum | ||||||||||||
| Park et al. 2006 |
Flavobacterium croceum is a type of bacteria . It was isolated from an activated sludge for the purification of waste water .
Appearance
The cells of Flavobacterium croceum are rod-shaped or slightly curved. They are between 0.3 and 0.5 μm wide and 1–3.2 μm long. There are no flagella . There is also no gliding motility . This type of movement is observed in many other species of the genus Flavobacterium and occurs in many other genera of the department of Bacteroidetes . The dye flexirubin is not produced by Flavobacterium croceum , in contrast to some other species of the genus. The gram test turns out negative.
Growth and metabolism
Flavobacterium croceum is facultatively anaerobic ; H. Growth takes place even in the complete absence of oxygen. However, some strains of the species have also been observed that are absolutely dependent on oxygen. Growth takes place at temperatures between 10 and 45 ° C. Optimal growth occurs between 25 to 35 ° C. With NaCl contents above 1%, there is only very limited growth, the best growth occurs at 0%. The bacterium grows at pH values in the range from 5.5 to 8.5, the optimum is at pH values from 7.5 to 8.0.
The catalase test is negative, the oxidase test is positive. The Congo red test is positive, the tests for the production of indole , hydrogen sulfide , acetoin and citrate are negative . Casein and gelatine are used for metabolism by the bacteria through hydrolysis . Aesculin , starch and tyrosine are not used . Nitrate is not reduced. The bacterium cannot break down urea , so the urease enzyme is not present. The tests for hydrolysis of carboxymethyl cellulose , hypoxanthine and xanthine , Tween 80 and 20 are also negative .
Chemotaxonomy
The predominant fatty acids within the cell membrane are the hydroxy fatty acid iso C 16: 0 3-OH, as well as the iso fatty acids iso -C 15: 1 G (this fatty acid could not be precisely determined), iso -C 15: 0 , iso -C 14: 0 , iso -C 16: 0 , as well as the saturated and unbranched fatty acid pentadecane (C 15: 0 ). These values correspond to the profile determined to be typical for the genus Flavobacterium .
The polar lipids present are phosphatidylethanolamines , diphosphatidylglycerol and phosphatidylcholines . The main quinone is the menaquinone MK-6. The GC content was determined in the first description to be 40.8%. In a further investigation, the GC content was determined to be 32.1%. The size of the genome was determined to be 2.95 megabase pairs (Mbp).
Systematics
Flavobacterium croceum one of the family of Flavobacteriaceae , which in turn to the class bacteroidetes is provided. It was described by Minjeong Park and co-workers in 2006.
etymology
The genus name Flavobacterium is based on the Latin word "Bacterium" (bacterium) and the Latin word "flavus", which means yellow. The latter refers to the colors of the colonies of the representatives of the genus, which range from relatively pale to pronounced yellow. The species name F. croceum is based on the Latin word "croceum" and means something like golden and also relates to the coloration of this species.
ecology
Representatives of the genus Flavobacterium are physiologically very diverse. There are species that are "cold-loving" ( psychrophilic ), such as B. F. psychrophilum . Others prefer environments with high salinity ( halophilic ). They also produce a variety of different enzymes . This suggests that the representatives of the genus play an important ecological role in the environment. This also makes them interesting for biotechnology .
The species Flavobacterium croceum was isolated and described during an examination and determination of members of the bacterial community of an activated sludge. An activated sludge is the accumulation of microorganisms in activated sludge process (also called activated sludge process, Eng .: activated sludge process ) can be used to clean wastewater. This was specifically an activated sludge process with cyclical changes from oxygen-free (anaerobic) and aerobic (presence of oxygen) states. This process is used to remove phosphate from wastewater. One speaks of phosphorus elimination . This method is also increasingly used to reduce the eutrophication process in lakes. Due to the possibility of anaerobic metabolism, Flavobacterium croceum is suitable for such processes and is therefore in the interest of improved, biological phosphorus elimination.
Individual evidence
- ↑ a b c d Minjeong Park, Shipeng Lu, Seung Hyun Ryu, Bok Sil Chung, Woojun Park, Chang-Jin Kim and Che Ok Jeon: Flavobacterium croceum sp. nov., isolated from activated sludge In: International Journal of Systematic and Evolutionary Microbiology (2006), Issue 56, pp. 2443-2447. doi : 10.1099 / ijs.0.64436-0
- ^ García-López et al .: Analysis of 1,000 Type-Strain Genomes Improves Taxonomic Classification of Bacteroidetes. In: Frontiers in Microbioly (2019). Edition 10, p. 2083. doi : 10.3389 / fmicb.2019.02083
- ^ Jean Euzéby, Aidan C. Parte: Species Flavobacterium croceum . In: List of Prokaryotic names with Standing in Nomenclature. Retrieved June 13, 2020 .
literature
- George M. Garrity : Bergey's Manual of Systematic Bacteriology . Volume 5: The Bacteroidetes, Spirochaetes, Tenericutes (Mollicutes), Acidobacteria, Fibrobacteres, Fusobacteria, Dictyoglomi, Gemmatimonadetes, Lentisphaerae, Verrucomicrobia, Chlamydiae, and Planctomycetes . Springer, New York 2011, ISBN 978-0-387-95042-6 .
- Minjeong Park, Shipeng Lu, Seung Hyun Ryu, Bok Sil Chung, Woojun Park, Chang-Jin Kim and Che Ok Jeon: Flavobacterium croceum sp. nov., isolated from activated sludge In: International Journal of Systematic and Evolutionary Microbiology (2006), Issue 56, pp. 2443-2447. doi : 10.1099 / ijs.0.64436-0