Growth of Azotobacter vinelandii on Soil Nutrients

Abstract

Azotobacter vinelandii cells grew well in a medium made from soil and distilled water which contained little or no carbohydrate. They utilized p-hydroxybenzoic acid and other phenolic acids, soil nitrogen, and water-soluble mineral substances. Seventeen soils which supported excellent growth of A. vinelandii contained 11 to 18 different phenolic acids each, including p-hydroxybenzoic, m-hydroxybenzoic, vanillic, p-coumeric, syringic, cisand trans-ferrulic, and other unidentified aromatic acids. Three white, chalky "caliche" soils which were taken from areas where no plants grew failed to support the growth of A. vinelandii, and these contained no, two, and three phenolic acids, respectively. A. vinelandii did not fix nitrogen when growing in dialysates of soils which contained numerous phenolic acids. Growth was ample and rapid in most of the soils tested, but cell morphology was different from that usually seen in chemically defined, nitrogen-free media which contain glucose.

Effect of Wastewater From Olive Oil Mills on Nitrogenase Activity and Growth of Azotobacter Chroococcum

“…Our results show that alpechin at concentrations ranging from 5 to 15% (v/v) positively affected mi- reported as similar to the natural environment [14]. Although the alpechin had some initial negative effects on growth and nitrogenase activity of Azotobacter, the negative effects disappeared after 24 h. Apparently A. chroococcum in dialyzed-soil media can tolerate high amounts of alpechin.…”

“…Phenolic acids are energy-rich substances metabolized by some members of soil microorganisms, Azotobacter being prominent among them. In a previous work, Wu et al [14] and Moreno et al [16] reported that A . vinelandii can utilize phenolic acids as carbon and energy sources, suggesting that the growth of Azotobacter in soil and its ability to fix dinitrogen in natural environments depend on the amounts of available phenolic acids or polymers of these substances.…”

Adaptation and population dynamics of Azotobacter vinelandii during aerobic biological treatment of olive-mill wastewater

“…Certain simple phenolic compounds that have been shown to reduce A. vinelandii growth [42] have been identi¢ed in the phenolic fraction isolated from OMW extracts and it is therefore reasonable to anticipate the slow growth of A. vinelandii observed during the ¢rst bioremedation stages when the concentration of polyphenols in the medium is high. On the other hand, A. vinelandii may use phenolic compounds as carbon and energy sources in di¡erent soil extracts [20] and in pure growth media where particular ring cleavage enzymes for aromatic intermediates have been identi¢ed [19]. Phenolics such as phydroxybenzoic acid, which is a major simple phenolic compound in OMW, may be readily utilised [20,43] and support A. vinelandii growth [42].…”

“…On the other hand, A. vinelandii may use phenolic compounds as carbon and energy sources in di¡erent soil extracts [20] and in pure growth media where particular ring cleavage enzymes for aromatic intermediates have been identi¢ed [19]. Phenolics such as phydroxybenzoic acid, which is a major simple phenolic compound in OMW, may be readily utilised [20,43] and support A. vinelandii growth [42].…”

“…Azotobacter vinelandii is a free-living N 2 -¢xing bacterium that has been shown to degrade phenolic compounds and use them as a carbon and energy source [19,20]. A. vinelandii strain A was isolated from soil repeatedly treated with OMW [21] and was shown to be a particularly active dinitrogen ¢xer when grown in sterile OMW [22,23].…”