الفهرس 
MicroorgamismsOnly 14 pages are availabe for public view
 |  | from | 233 |  |  |
| | | from | 233 | | |
Abstract
This work began by quantitative determination of vitamin Ba2 microbiologically to determine the best and easier method. Three assays using Euglena gracilis CATCC 127163, LactobacilLus plantarum<ATCC 8014) and L.Leichmnnii CATCC 47971, in disk and tubes, were tried. The results indicated that the three microbiological methods gave a linear relationship specially in low concentrations of vitamin BIZ. Euglena gracilis assay is sensitive but time consuming L. Leichmnnii assay is not sensitive using disc compared to the sensitive and time saving, tube assay. Consequently the latter assay proved to be the best and therefore was used in the subsequent studies . The effeciency of Bacillus megaterium CNCIB 85081 to produce vitamin BIZ was studied using three different cultures; static, shake , and fermenter. The following paramenters were studied further, pH changes, dry weight and prodcution of vitamin Biz , which all varied under the different cultural conditions. The highest amounts of vitamin BiZ were obtained when the bacterium was grown on medium C121 for 3 days in static culture and 2 days in shake culture at 150 rpm. The volume of medium w a s 50 m1,