Derxia

Derxia

[′dərk·sē·ə]
(microbiology)
A genus of bacteria in the family Azotobacteraceae; rod-shaped, pleomorphic, motile cells; older cells contain large refractive bodies.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
The different N free media used were Waksman No 77 medium for Azotobacter, Becking' s medium (Becking, 1961) for Beijerinckia, Nitrogen-free glucose mineral medium for Derxia (Becking, 1961) and King's B medium (King et al., 1954) for Pseudomonas.
The isolates DeLTP2 and DeATM3 were found to be closely comparable to Methylocella silvestri and Derxia sp.
The beta proteobacteria was represented by Derxia (DeLT[P.sub.2] and DeAT[M.sub.3]).
These bacteria are of beneficial agricultural importance and belong to the genera Acetobacter, Acinetobacter, Alcaligenes, Arthrobacter, Azoarcus, Azospirillum, Azotobacter, Bacillus, Beijerinckia, Burkholderia, Derxia, Enterobacter, Gluconacetobacter, Klebsiella, Ochrobactrum, Pseudomonas, Rhodococcus, Serratia, Zoogloea, etc (Singh et al., 2011).
Representative species have been described from various nitrogen-fixing prokaryotic groups, such as: photosynthetic bacteria (Rhodospirillum rubrum), anaerobic bacteria (Clostridium spp.), micro-aerobic bacteria (Azospirillum spp., Herbaspirillum spp., Gluconacetobacter diazotrophicus, Azorhizobium caulinodans, Azoarcus spp., Burkholderia spp., Klebsiella spp., among others), aerobic bacteria (Azotobacter spp., Derxia spp.
Las bacterias diazotrofas puede ser simbioticas (obligadas, asociativas o endofitas) y de vida libre, representadas en Rhizobium y Frankia para las obligadas y por Cyanobacteria, Azospirillum, Azotobacter, Acetobacter diazotrophicus, Azoarcus entre las asociativas o endofitas; Achromobacter, Acetobacter, Alcaligenes, Arthrobacter, Azospirillum, Azotobacter, Azomonas, Bacillus, Beijerinckia, Clostridium, Corynebacterium, Derxia, Enterobacter, Herbaspirillum, Klebsiella, Pseudomonas, Rhodospirillum, Rhodopseudomonas y Xanthobacter, entre las no simbioticas.
Eight different nitrogen-free media (Jensen's medium; Burk's medium; nitrogen-free agar (NFA); medium for Klebsiella and Enterobacter (KE); medium for Derxia; medium for Beijerinckia; Dobereiner's medium; LGI) were used for maximum diversity.
The diazotrophic population was found to be different on the eight different media, with ranges 39-76 x 105cfu/g on Jensen's medium, 35-68 x [10.sup.5]cfu/g on Burk's medium, 30-42 x [10.sup.4]cfu/g on KE, 31-65 x [10.sup.4]cfu/g on NFA, 30-43 x [10.sup.4]cfu/g on LGI, 30-39 x [10.sup.4]cfu/g on Dobereiner's medium, 11 25 x [10.sup.3]cfu/g on the medium for Beijerinckia, and 17-35 x [10.sup.3]cfu/g on medium for Derxia. (Table 2).
O genero Derxia pertence a classe [beta]-proteobacteria e a familia Alcaligenaceae e possui apenas uma especie descrita a D.
Os trabalhos realizados com Derxia sao escassos, sendo que pouco se conhece sobre a ecologia desta bacteria.