الفهرس 
Marine streptomycetes as a source of bioactive compounds against pathogenic bacteria
ABSTRACTOnly 14 pages are availabe for public view
 |  | from | 241 |  |  |
| | | from | 241 | | |
Abstract
In response to the challenge and crisis of prevalence of multi-drug resistant pathogens, the major targets of the present study adopted two strategies and conducted in two parts. The major target of the first part was geared to explore a new bioactive metabolite from marine Streptomyces 10SAE while the other to steer and slow the evolutionary path of resistance using antibiotic adjuvant. The productivity and potency of the synthesized biomolecule(s) found to be medium and microorganism dependent. The optimum conditions for maximal productivity of bioactive metabolite using starch casein nitrate broth (SCNB) as reference medium simultaneously with shrimp shell (SS) as a monocomponent medium were as follow: 20% v/v loading volume, 2 or 3% v/v of 3-days old spores{u2019} suspension as inoculum size, agitation speed 180 rpm, initial pH 6.5-7.5 at 30 - 35{u00B0}C for 5 days.The highest productivity of bioactive compound(s) was achieved at gl-1: starch, 10; KNO₃, 2.0; casein, 0.3; K₂HPO₄, 2.5; MgSO₄.7H₂O, 0.5; FeSO₄.7H₂O, 0.01; NaCl, 5.0 and CaCO₃, 0.02.SS at 5.0 gl-1 proved its significance as a cheap suitable medium be better than or at least on par with SCNB. Antibacterial activity of the petroleum ether extract was more potent than crude filtrate. Minimum inhibition concentration (MIC) values of extract were generally lower than those obtained by reference antibiotics and minimum bactericidal concentration were 1- 4 folds of MIC values.The extract did not show any cytotoxic activity either against human tumor or normal cells up to 100 æg ml-1. All the separated purified fractions using the silica gel column chromatography gave single separated band with similar retention factor (Rf) value of 0.90 on TLC