This is the abstract of one of my latest scientific papers Bacterial resistance to heavy metals pollutants in some Egyptian soil types By Wesam A. Abd, Reda R. Shahin*, Mohamed Abdel-Aleim and Hassan A. Khater Faculty of Agriculture, Cairo University, Giza, Egypt. *Corresponding Author: dredashahin@gmail Abstract Normal alluvial, calcareous as well as sewage farm soil samples amended with peptone nutrient solution were subjected to increasing concentrations of Pb, Cd, Zn and Ni and incubated for 7 days at 25 C. Total counts (MPN) for the colony forming unites (CFU) of bacteria recorded the highest values in Abu-Rawash soils (sewage farm) even in the presence of the increasing levels of Cd, Zn and Pb followed by the normal alluvial ( Faculty’s Farm) and calcareous (Wadi-Natrun) soils. Under Ni stress, calcareous soil showed the highest MPN due to lime effect. In alluvial soil MPN largely reduced to nearly 1% of the normal growth by applying only 3 mg Cd/kg soil while it was @ 10% in Abu-Rawash soil. This indicated that bacterial population present in Abu-Rawash was relatively more tolerant to Cd toxicity than that for alluvial one. Regarding Pb and Zn-toxicity in soils, it was Alluviall= Abu-Rawash>calcareous, and Ni-toxcity order was Alluvial.>Abu-Rawash> calcareous. Dehyrogenase activity decreased by 32% (in FFS), 35% (in ARS) and 17% (in WNS) as the applied Cd increased from 3 to 8 mg/kg soil. The increase of applied Zn and Ni also inhibited dehydrogenase activity by higher percentages (36-44%) in FFS and ARS as compared to that of WNS (17-22%). Significant positive correlation coefficient (P
Posted on: Fri, 20 Sep 2013 11:09:38 +0000
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