Pathways of assimilation of (/sup 13/N)N/sub 2/ and /sup 13/NH/sub 4//sup +/ by cyanobacteria with and without heterocysts. [Gloeothece sp. , Anacystis nidulans]

Journal Article · Thu Sep 01 00:00:00 EDT 1977 · J. Bacteriol.; (United States)

OSTI ID:5112880

Meeks, J C; Wolk, C P; Lockau, W; Schilling, N; Shaffer, P W; Chien, W S

The principal initial product of metabolism of (/sup 13/N)N/sub 2/ and /sup 13/NH/sub 4//sup +/ by five diverse cyanobacteria is glutamine. Methionine sulfoximine inhibits formation of (/sup 13/N)glutamine except in the case of Gloeotnece sp., an organism with a thick sheath through which the inhibitor may not penetrate. Thus, glutamine synthetase appears to catalyze the initial step in the assimilation of N/sub 2/-derived or exogenous NH/sub 4//sup +/ by these organisms. (/sup 13/N)Glutamate is, in all cases, the second major product of assimilation of /sup 13/N-labeled N/sub 2/ and NH/sub 4//sup +/. In all of the N/sub 2/-fixing cyanobacteria studied, the fraction of /sup 13/N in glutamine declines and that in glutamate increases with increasing times of assimilation of (/sup 13/N)N/sub 2/ and /sup 13/NH/sub 4//sup +/, and (Gloeothece again excepted) methionine sulfoximine reduces incorporation of /sup 13/N into glutamate as well as into glutamine. Glutamate synthase therefore appears to catalyze the formation of glutamate in a wide range of N/sub 2/-fixing cyanobacteria. However, the major fraction of (/sup 13/N)glutamate formed by Anacystis nidulans incubated with /sup 13/NH/sub 4//sup +/ may be formed by glutamic acid dehydrogenase. The formation of (/sup 13/N)alanine from /sup 13/NH/sub 4//sup +/ appears to be catalyzed principally either by alanine dehydrogenase (as in Cylindrospermum licheniforme) or by a transaminase (as in Anabaena variabilis).

• Research Organization: Michigan State Univ., East Lansing
• OSTI ID: 5112880
• Journal Information: J. Bacteriol.; (United States), Vol. 134:1
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
AMMONIA
METABOLISM
AMMONIUM COMPOUNDS
BACTERIA
BIOCHEMISTRY
BIOSYNTHESIS
DEHYDROGENASES
GLUTAMINE
LIGASES
NITROGEN 13
NITROGEN COMPOUNDS
AMIDES
AMINO ACIDS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
CARBOXYLIC ACIDS
CHEMISTRY
ELECTRON CAPTURE RADIOISOTOPES
ENZYMES
HYDRIDES
HYDROGEN COMPOUNDS
ISOTOPES
LIGHT NUCLEI
MICROORGANISMS
MINUTES LIVING RADIOISOTOPES
NITROGEN HYDRIDES
NITROGEN ISOTOPES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDOREDUCTASES
RADIOISOTOPES
SYNTHESIS
550700* - Microbiology
550500 - Metabolism