This investigation was carried out at the experimental farm of Medicinal and Aromatic plants Research Department, Horticulture Research, Dokki, Giza during two successive seasons of 2009/2010 and 2010/2011.The research aimed to study the effect of compost rates (2,4and 8 ton/fed) and some biofertilizers (Azotobacter Chroococcum, Bacillus megaterium, Bacillus circulanse) alone or all strains in ...

Melanins, the ubiquitous hetero-polymer pigments found widely dispersed among various life forms, are usually dark brown/black in colour. Although melanins have variety of biological functions, including protection against ultraviolet radiation of sunlight and are used in medicine, cosmetics, extraction of melanin from the animal and plant kingdoms is not an easy task. Using complementary physi...

A transconjugant of Azotobacter chroococcum Mac 27 tagged with lac Z(A. chroococcum Mac27 L) was found to possess high levels of β-galactosidase activity constitutively. Further, the lac Z marker was found to be stably integrated into the chromosome of the A. chroococcum Mac 27 and did not have any adverse effect on growth, nitrogen fixation and excretion of ammonia. A quick method to determine...

Quantitative N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD) oxidase and superoxide dismutase (SOD) analyses were performed on representative organisms of the family Azotobacteraceae. Azotobacter vinelandii, Azotobacter chroococcum, Azotobacter paspali, and Derxia gummosa exhibited high quantitative TMPD oxidase activities, and their extracts possessed very active and electrophoretically homoge...

Bell pepper is an important vegetable crop containing lots of bioactive compounds. The present study was designed to improve the productivity and quality bell with application arbuscular mycorrhizal fungi (Rhizophagus irregularis) plant growth-promoting bacteria (Azotobacter chroococcum) in a combination chemical fertilizer. Five treatments consisted 75% fertilizer (T1), 100% (T2), + R. irregul...

Four types of utilization of nitrate nitrogen were observed with fourteen strains of the azotobacter. These were: (a) Those which utilize NO;-N with no or only a short lag; three strains of Azotobacter winelandii, a stock culture of A. chroococcum C-77, and seven strains of A. chrmoccum freshly isolated from soil were in this group; (b) A single strain, a stock culture of A. chroococcum C-44, w...

The presence of Azotobacter sp. in soils has beneficial effects on plants, but the abundance of these bacteria is related to many factors, especially soil pH and fertility. The presented study evaluated the abundance of Azotobacter sp. in various soils of southern Poland and confirmed the relationship between soil properties and the presence of these bacteria. Diagnostic tests indicate that all...

The chelating agents EDTA, o-phenanthroline, nitrilotriacetic acid (NTA), ethylenediamine-bis(o-hydroxyphenylacetic acid) (EDDA) or dimethylglyoxime prevented the expression of hydrogenase activity in batch cultures of nitrogen-fixing Azotobacter chroococcum, but did not inhibit preformed enzyme. The inhibition was reversed either by adding a mixture of trace elements (Cu2+, Mn2+, Zn2+, Co2+) o...

Microbial communities in rhizosphere interact with each other and form a basis of a cumulative impact on plant growth. Rhizospheric microorganisms like Piriformospora indica and Azotobacter chroococcum are well known for their beneficial interaction with plants. These features make P. indica/A. chroococcum co-inoculation of crops most promising with respect to sustainable agriculture and to und...