ISSN:
1432-0614
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Summary A bacterium which is able to utilize the cyclic dimer of ∈-aminocaproic acid (ACA) as a sole source of carbon and nitrogen has been isolated, classified as a member of Alcaligenes and tentatively named D-2. The initial step of the ACA cyclic dimer metabolism in D-2 may be composed of the following three reactions, which are catalyzed by specific enzymes: opening of the ACA cyclic dimer, splitting of the ACA linear dimer and transamination of ACA. By treatment with mitomycin C or ethidium bromide, 2–3% of the D-2 cells lost both ACA cyclic dimer-opening and ACA linear dimer-splitting activities. Slow growth of colonies of this variant strain on ACA agar medium kept at 12±3° C for 4 weeks resulted in the production of a new variant which had lost the ACA transaminase activity as well as the hydrolysis activities. When the parent strain (D-2) was grown slowly on ACA cyclic dimer agar medium in the same way, the ACA transaminase activity alone was lost by about 30% of the colonies. All the variants have been stable during 6 months of culture by successive transfer on agar media. These facts suggest that both the ACA cyclic dimer-opening enzyme and the ACA linear dimer-splitting enzyme are encoded by the same plasmid whereas the ACA transaminase is encoded by a second plasmid.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00498013
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