Consumption of food and water contaminated with heavy metals poses a huge threat to the life. Both of Lead (Pb) and Cadmium (Cd) are heavy metals and important environmental pollutants. Away from traditional treatments, the current study aims to adopt probiotic bacteria Pediococcus pentosaceu to treat heavy metal pollution. Present results indicated a good probiotic property of P. pentosaceus, where they were able to survive pH range from 3-9, during incubation periods 3 and 24 hours, and bile salt range 0.15-0.5% for the same period. The number of bacteria in gastric (pH 3) and intestinal juices (pH 8) after 24 hours of incubation was 390 and 205, respectively. Bacteria showed an inhibitory effect against pathogenic bacteria Salmonella sp. The antibiotic susceptibility test revealed them resistant to clindamycin, intermediate resistant against benzylpenicillin, ampicillin, and their sensitivity to the rest tested antibiotics. Isolated bacteria identified based on their morphology, biochemical characteristic in addition to the use of automated instrument for bacterial identification (Vitek II), and depending on the results bacteria were identified as P. pentosaceus. In bioremediation study, the lowest inhibitory concentration of lead and cadmium and (MIC) was done, followed by assay the removal capacity by P. pentosaceus, using atomic absorption spectrometry (AAS) analysis. Bacteria show high MIC (1800 and 150 ppm) for Pb and Cd respectively. With removal efficiency for Pb 62.10-68.39% in the concentrations 25 and 50 ppm, respectively, and for Cd 52.71-11.25% in the same concentrations. Depending on the present finding probiotic bacteria (P. pentosaceus) can apply in the bioremediation of heavy metals in the fish ponds when contamination occurs, in addition to their tradition used as safety additive to prevent fish disease and an enhancement agent .Finally the isolation of these bacteria from fish ponds can be considered as a good indicator for a healthy state of fish ponds in the studied area.

Aiming to find the solution to the problem of soil polluted by hydrocarbons and the associated heavy metals, the present study focused on the biodegradation and bioremediation capability of Sphingomonas paucimobilis. Morphological and biochemical tests have been used to identify bacterial isolates and to confirm that an automated instrument for bacterial identification (Vitek II) has been used. Based on the results, the bacteria were identified as Sphingomonas paucimobilis. The bioremediation capacity was monitored: the lowest inhibitory concentration (MIC) of lead (Pb) and cadmium (Cd) followed by an assay of the removal capacity of S. paucimobilis using the atomic absorption spectrometry (AAS) analyzer. The bacteria showed higher MIC value for Pb (2000 ppm) the Cd (500 ppm). The percentage of removal for Pb and Cd were 27.95% and 58.78%, and 22.37% and 48.21% for the concentration 25 ppm and 50 ppm, respectively. These findings showed the high aliphatic hydrocarbon biodegradation capacity of S. paucimobilis, with the percentage of degradation being 48.15% and 63.40% of the concentration of crude oil by 2% and 5%, respectively. S. paucimobilis can potentially be a safe biological treatment strategy to remediate soil polluted with hydrocarbons in crude oil extraction sites.

In the present study heavy metals resistant bacteria were isolated from soil collected from Al-Zubair district in Basra governorate south of Iraq. On the basis of morphological, biochemical, 16S rRNA gene sequencing and phylogeny analysis, the isolates were authentically identified as Shewanella oneidensis in addition to Bacillus thuringiensis and Deinococcus radiodurans. The minimal inhibitory concentration (MIC) of isolates against cadmium (Cd) and lead (Pb) was determined on solid medium. S. oneidensis showed significant resistance to high concentrations of Cd (1000 mgl-1) and Pb (700 mgl-1). The bioaccumilation capabilities of S. oneidensis for Cd and Pb were monitored at different ion concentrations and contact times. The transmission electron microscope (TEM) study confirmed the accumulation of Cd and Pb by S. oneindensis causing morphological changes.

The bacterium Deinococcus radiodurans has been isolated from soil. On the basis of morphological, biochemical, 16S rRNA gene sequencing and phylogeny analysis revealed that, the isolates were authentically identified as D. radiodurans.D. radiodurans showed significant resistance to high concentrations of Pb and Cd, but it was more tolerant to Cd than Pb. Minimum inhibitory concentration was 400 mgl -1 for Pb, while it was 600 mgl -1 for Cd. The potent bacterium has the optimal bioaccumulation capacity differ according to metal type, concentration, and contact time. In bioaccumulation experiment, the results showed the highest increase in accumulation of Pb in the concentration 50 mgl -1 at 6 h of incubation (0.33 mgg -1 ), while the lowest accumulation was in concentration 5 mgl -1 (0.029 mgg -1 ) at 2h of incubation. For Cd the results showed maximum accumulation at 24h for concentration 100 mgl -1 then decreased at 48 h.The results of biosorption experiment showed that D. radiodurans has a good ability to absorption both Pb and Cd in considering to the metals concentrations and times. This which can be clarified from the elevated percentage of Pb absorption (63.46%) in concentration 50 mgl -1 and during 2h. For biosorption of Cd the was decreased with the increasing time and the high biosorption noticed during 2h at concentration 50 mgl -1 (31.23%).

The present study was performed to spotlight the potential role of soil bacteria in the Al-Rumaila oil field as a bioindicator of heavy metals pollution. For this purpose, nine soil samples were collected from different sites, with 20cm depth, to assess the pollution status depending on the total and available concentrations of heavy metals. The result indicates pollution of the studied soils with the following metals: Cd, Cu, Fe, Zn, and Pb. The mean of total concentration for all studied metals was higher than the allowed maximum limit based on the international limit:(3. 394, 3.994, 39.993, 8844.979,150.372, and 103.347 µg/g), respectively. While measuring the total Metal concentration is important in determining the degree of pollution in the environment; it cannot be depended to determine their impact on the living organisms. In the present study the means of available concentration of studied metals were as follows: 0.015, 0.787, 0.021, 0.515, and4.304 µg/g. respectively, which were lower than their total concentration. Different types of bacterial genera (Serratia marcescens, Sphingomonas paucimobilis, Bacillus subtilis, Pseudomonas aeruginosa, and Staphylococcus lentus) were isolated from the same soil. And broadcasts through the results their presence in all studied soils. Therefore, the isolated bacteria play a significant role as an indicator of metal pollution in the soil, which was proved through the result of the Minimum inhibitor concentration (MIC), which indicated a high tolerance ability towered these metals.