ISSN:
1432-072X
Keywords:
Pleiotropic mutants
;
Alcaligenes eutrophus
;
Hydrogenase
;
Ribulosebisphosphate carboxylase
;
Transport
;
Urease
;
Formamidase
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Chromosomal mutants of Alcaligenes eutrophus unable to grow with molecular hydrogen as the energy source also failed to grow with nitrate as the terminal electron acceptor or as a nitrogen source. The mutants (Hno−) (i) formed neither soluble nor particulate hydrogenase antigens, (ii) expressed only about 50% the wild type level of ribulosebisphosphate carboxylase activity, and (iii) transported nickel, an essential constituent of active hydrogenase, at a significantly lower rate than wild type cells. Moreover, the mutants grew very slowly with urea as nitrogen source and did not express urease. Growth on formamide was also affected and formamidase activity was induced to only a very low level. Growth of the Hno− mutants on succinate, glutamate, fumarate, and malate was significantly slower than wild type, and a reduced rate of succinate incorporation into the mutant cells was demonstrated. The highly pleiotropic phenotype of Hno− mutants is indicative of a chromosomal gene with a considerable physiological importance. It affected the expression of both chromosomal and megaplasmid encoded systems of energy, carbon, and nitrogen metabolism. Thus, the hno mutation restricts the metabolic versatility but does not affect the basic metabolic functions of the organism.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00425590
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