الفهرس 
Effect of carbon source on (PHB) productionOnly 14 pages are availabe for public view
 |  | from | 170 |  |  |
| | | from | 170 | | |
Abstract
A key constraint to successfully commercializing beneficial microorganisms is overcoming difficulties in formulating a viable, cost effective, and user friendly final product. The live nature of the active ingredient (i.e., the microbial agent) underscores the importance of formulation in maintaining the microbial cells in a metabolically and physiology competent state in order to obtain the desired benefit when applied.
In the present study rhizobial strains used are Rhizobium leguminosarum bv. viceae, Rhizobium leguminosarum bv. phaseoli, Rhizobium leguminosarum bv. trifolii, Bradyrhizobium japonicum and Bradyrhizobium Sp.
Mannitol, the most expensive ingredient in yeast extract mannitol broth (selective media for rhizobia) was replaced with a cheap ingredient (molasses) at rate of 12g /L to reduce the cost of rhizobial inoculant production. The inoculants used were evaluated under laboratory and green house conditions.
Molasses was superior or similar compared with mannitol on cell growth, exopolysaccharides (EPS) production, poly-B-hydroxybutyrate (PHB) accumulation, enzymes activities, indole acetic acid (IAA) and hydrogen cyanide (HCN) production, salt tolerance, as well as protein profile by the five rhizobial strains used.
The inoculants produced with molasses can maintain rhizobial numbers as well as that produced by the standard mannitol media during storage at room temperature (shelf life time).
The inoculation of faba bean (Vicia faba) and peanut plants (Arachis hypogaea) with molasses based inoculants showed slight increases in nitrogenase activity, straw & seed yield and crude protein than mannitol based inoculant.
The current study showed that none of the parameters examined was negatively affected by molasses application. This modification permitted a 95% reduction in the cost of growth media.
Key words: Inoculant production, Rhizobium, Bradyrhizobium, Molasses, carbon source, YEM, cell growth, EPS production, PHB accumulation, enzymes activities, IAA and HCN production, Salt tolerance, Protein profile , Faba bean and Peanut.