[show abstract][hide abstract] ABSTRACT: Lipid accumulation by Gordonia sp. DG using sodium gluconate as carbon source in comparison with Rhodococcus opacus PD630 was studied. Maximum lipid content 80% was observed at the beginning of the stationary phase for R. opacus and 72% at the end of stationary phase for Gordonia sp. Different agro-industrial wastes were used as carbon source. The cells of the two organism accumulated lipid more than
50% of the biomass with most tested agro-industrial wastes. The maximum value was in presence of sugar cane molasses (93 and
96%) for R. opacus and Gordonia sp. respectively. Maximum triacyglycerols (TAGs), 88.9 and 57.8mg/l, was obtained using carob and orange waste by R. opacus and Gordonia sp. respectively. The use of orange waste as carbon source by R. opacus, increased lipid unsaturation with C18:3 as the major unsaturated fatty acid. On the other hand, C22:0 and C6:0 were the
dominant fatty acids (54.5% of the total identified fatty acids) produced by Gordonia sp. in presence of orange waste as carbon source. Statistical optimization of the medium revealed that maximum lipid content
was achieved with 60% orange waste, 0.05g/l ammonium chloride and 0.2g/l magnesium sulphate.
World Journal of Microbiology and Biotechnology 01/2008; 24(9):1703-1711. · 1.26 Impact Factor
[show abstract][hide abstract] ABSTRACT: The ability of different local isolates in addition to some isolates from Germany to degrade kerosene in liquid medium was studied. The results showed that the percent of kerosene degradation varied among the different organisms and that 59-94% of kerosene was degraded after 21d. Two local isolates (Pseudomonas sp. AP and Pseudomonas sp. CK) and one German isolate (Gordonia sp. DM) were selected for this study. The addition of wheat bran, as co-substrate, stimulated the kerosene degradation by the two local strains, while glucose inhibited the degradation rate using the three organisms with different rates. Ammonium nitrate and urea was the best nitrogen sources. The use of superphosphate (as phosphorus source) in the presence of urea stimulates the degradation rate. It was also observed that the addition of 1% surfactants, like Triton X-100, Igepal, Tergitol, or Tween 20 and 80 enhanced the kerosene degradation. The degradation percent lied between 94% and 98%. The ability of the tested organisms to degrade kerosene concentration from 2% to 8% was evaluated. It was found that the three organisms degraded about 65-85% from 8% kerosene after 21d. The use of rice straw-immobilized cells reduced the time of degradation and enhanced the degradation ability of the organisms. The sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed the presence of a common protein band when the tested organisms were grown on kerosene.
[show abstract][hide abstract] ABSTRACT: Kerosene contaminated clay results in large amounts from the treatment of Jet kerosene produced from Merox process, in the
Middle East Operation and Maintenance for Oil Refineries (MIDOR), Alexandria and represent a great environmental pollution
problem. The treatment of the clay was performed with natural attenuation, biostimulation and bioaugmentation in lab and field-scale
microcosms. More than 90% of the kerosene was biodegraded in bioaugmentation and biostimulation processes, while only 50%
was obtained by natural attenuation after seven weeks. Urea 46% and superphosphate 15.5% were used as nitrogen and phosphorus
sources due to their low cost and local availability. The immobilized cells enhanced the biodegradation processes and reduced
the time. Dehydrogenase activity was affected by the time and type of the treatment. The degradation percent was found to
be 85–90% at temperature range 21–24°C, while only 57–68% was obtained at temperature 15–17°C. The lab-scale microcosm was
scaled up to field microcosm with a great success.
World Journal of Microbiology and Biotechnology 24(8):1451-1460. · 1.26 Impact Factor