The Isolated root-nodulating bacteria from Medicago sativa L. and its production of enzymes

Abstract

The soil, especially the agricultural one, contains millions of microorganisms as: fungi, algae, bacteria and protozoa. These microorganisms have an essential role in maintaining the fertility of the soil and provide the nutritional supplements to the plants, such as The root-nodulating bacteria or rhizobia and it's a Gram-negative bacteria has a symbiotic relationship with leguminous plants, and like any other living organisms they must be able to perform a set of chemical reactions, to continue to survive, grow and multiply. These interactions are carried out by enzymes in sequent reactions known as nutritional metabolism. Reference strain Ensifer meliloti and the rhizobial isolates (RBSU4, RBSU6, RBSU7, RBSU10, RBSU11, RBSU13 and RBSU28). This study aimed to know the ability of these isolates to produce a group of enzymes and using the production of its reactions in its nutritional metabolism. A series of enzymatic tests were included: Catalase, Oxidase, Tryptophanase, Amylase, Urease, Lactase, Gelatinase, Caseinase and Phosphatase. The result of this study showed the difference between isolations in using the target enzymes for this study. All the isolates including the reference strain were positive to catalase, Oxidase and Urease enzymes, and differentiate with the production of other enzymes, while the reference strains and the two RBSU11 and RBSU13 isolates were the most distinguish   isolates as it were able to produce many enzymes, while the RBSU6 and RBSU10 isolates were the lowest in the production of enzymes, So reference strains and the two RBSU11 and RBSU13 isolates can be used as a vaccine for leguminous plants, especially in dry and semi-dry areas with poor food resources.