Khaled A. Tarawneh

Reproductive toxicity and infertility effect of Ferula hormonis extracts in mice

The anti-fertility, anti-implantation, and ovarian histological alterations of the ethanolic extract of Ferula hormonis have been investigated in female mice. The intragastric application of 3 mg/kg per day of such extract for 6 weeks resulted in a significant reduction in female mice fertility. Furthermore, it caused a decrease in the number of mated females, the total number of implantations, and the number of viable fetuses. These changes were also associated with ovarian atrophy and a concomitant increase in the connective tissue. The ova showed degeneration while most of the ovarian follicles suffered follicular atresia.

Rate of Biodegradation of Phenol by Klebsiella oxytoca in Minimal Medium and Nutrient Broth Conditions

ABSTRACT The rate of biodegradation of phenol by Klebsiella oxytoca strain was studied in the nutrient broth and M9 minimal medium. It was found that K. oxytoca degrade phenol at elevated phenol concentration where 75% of initial phenol concentration of 100 ppm will degrade within 72 h. This rate was increased with increasing the initial cell densities, increasing the aeration rate and increasing the time required for complete degradation. At phenol concentration above 400 ppm, the cells were unable to degrade the substrate efficiently due to the increasing concentration of phenol in the medium. The culture conditions were also showed a significant impact on the ability of these cells to remove phenol. The optimum solution pH and temperature were 6.8 and 37°C, respectively. The growth of these cells in the presence and absence of phenol was modeled and it was found that the Recatti equation best fit the growth in the absence of phenol whereas the Voltera equation accounted for the history of the cell population in the presence of phenol.

Antimicrobial Activity of Secondary Metabolites from a Soil Bacillus Sp. 7B1 Isolated from South Al-Karak , Jordan

Soil is considered as a promising environment for discovering and isolating bacterial strains that are able to produce novel natural products. Therefore, a Gram positive Bacillus sp. 7B1 was isolated from a soil sample collected from south AlKarak, Jordan. The bacterial isolate was cultivated, identified and its culture medium was extracted. The crude extract was purified using silica gel column chromatography. The antibacterial activity of the crude extract and the purified fractions was evaluated by agar diffusion test as well as by measuring the minimum inhibitory concentration in microbroth dilution assay. The produced crude extract was active only against the tested Gram positive bacteria, namely Bacillus subtilis, Micrococcus luteus and Staphylococcus aureus. Bioactivity-guided fractionations of the resulted crude extract led to the purification of compound (C2). In the present work, Micrococcus luteus was the most susceptible bacterial test strain to compound (C2) with a minimum inhibitory concentration of 25 μg/ml. Our findings highlighted the importance of soil bacterial isolates for production of compounds with interesting bioactivities that may contribute to the drug research field. .Keyword: Bacillus, Antimicrobial, Partial purification, Al-Karak, Jordan. * Corresponding author. e-mail: wzereini@mutah.edu.jo.

Cadmium-Resistance Plasmid Affected Cd+2 Uptake More Than Cd+2 Adsorption in Klebsiella oxytoca

ABSTRACT A bacterial strain was isolated from Petra City Wastewater Treatment Plant. This isolate was identified as Klebsiella oxytoca based on 16S rDNA analysis. A single plasmid (> 23 kb) was detected in this strain and transformed into Esherichia coli JM83. The transformed E. coli cells exhibited elevated resistance to cadmium as compared to parental plasmid-free cells. The sodium dodecyl sulfate (SDS)-treated cells showed higher efficiency in plasmid curing than the ethidium bromide–treated cells. The ethidium bromide–cured cells grew only in a 10 μ g/ml Cd+ 2 minimal tolerable concentration, whereas the SDS-treated cells had no growth in any of the Cd concentrations tested (2, 5, 10, 20, 30, 40, and 50 ppm). Contrary to the Freundlich model, the Langmuir model gave a good fit to the Cd biosorption data by K. oxytoca cells. Plasmid curing caused 80%, 82%, and 70% inhibition in the Cd biosorption, adsorption, and uptake, respectively. Furthermore, the absence of lysine decarboxylase (LDC) activity in the cured strain strongly implies that the structural gene-encoding LDC in this bacterium is plasmid encoded. After curing of the plasmid, 100% of the antibiotic-resistant loci were observed as chromosomal encoded. All of the results shown above indicated that the Cd resistance is plasmid mediated.