**5. Conclusion**

*Pseudomonas aeruginosa - An Armory Within*

sorbents [49].

the future [2].

compounds from other groups [53].

quinolones, aminoglycosides and β-lactam [54].

In another study, *Pseudomonas aeruginosa* isolated from the waste water of electroplating industry, is able to absorb chromium, nickel and zinc, by 20% concentration. The highest percentage of the reduction was observed in nickel after 10 days and lowest for 10 days chromium, so the bacteria can be used as bio

In addition, another study was investigated for biosorption of ionic cadmium by *P. aeruginosa* under varying conditions which the values have the first pH of the cadmium solution ranges from 1 to 7, the maximum removal of cadmium is obtained at pH 6. From the perspective of the application of the procedure, the time for bio sorbents was 70 minutes and biosorption concentrated (1 g/l) is a suitable

*Pseudomonas aeruginosa* launches resistance to heavy metals such as cadmium, chromium, nickel and lead. DNA plasmid was isolated from *P. aeruginosa* and has been defined as pBC15 and the plasmid size is about 23 kb [52]. Also, results of heavy metal tolerance and accumulation experiments concluded that *Pseudomonas aeruginosa* bacterial strain has the tendency for tolerate heavy metals due to it has plasmid that carry genes and play important role in tolerance of heavy metals, so it will be promising for new trends in heavy metals bioremediation and bioaccumulation in

In addition, genes are set for the degradation of environmental pollution, such as heavy metals, toluene, acids, and pesticides, Halogen and this toxic waste. So, plasmids are required for each compound. It is not that one plasmid reduces all toxic

In bioremediation of chromium, bacterial strains show chromosome plasmid resistance and reduced enzyme coordination. In molecular engineering, it can now extract stress by improving even under stress conditions [4]. Also, it has been reported that the plasmid resistance gene is determined in pathogenic bacteria of the genus *Escherichia*, *Salmonella*, *Shigella*, *Klebsiella*, *Aeromonas* and *Pseudomonas* which determining factors for resistance to heavy metals such as cadmium, cobalt, nickel, zinc, and mercury, also different groups of drugs, such as tetracycline,

Additionally, *Pseudomonas aeruginosa* use different types of mechanisms in response to heavy metals stress. These mechanisms can be encoded with chromosomal genes, but more often resistance is located on plasmid [55]. Plasmid curing in *Pseudomonas aeruginosa* is a testament to the relationship between genetic presentation and the transmission of a specific feature in heavy metals tolerance and removal. Various approaches have been developed to cure of plasmid, including

Firstly, metals-microbial interactions might have several environmental implica-

, Zn+

and Ni2+)

chemical and physical agents for the elimination of plasmid [56].

tions. Main resistance mechanisms for some heavy metals as (Cu+

**4.5 Evaluation of resistant genes in** *Pseudomonas aeruginosa*

bio sorbent for treatment of cadmium ion (up to 100 ppm) [50].

**4.4 Plasmid mediated heavy metals in** *Pseudomonas aeruginosa*

ment of contaminated wastewater with heavy metals [51].

Additionally, it has been found that the adsorption of heavy metals by *Pseudomonas aeruginosa* bio flocculant is influenced by the first metal focus, the concentration of bio flocculant and the pH of the solution. The study showed that microbial potential bio flocculant has been used as a bio remedial tool in the treat-

**90**

Heavy metals pollution cause problems and effect on soil, water, plant, animal, human and ecosystem. Heavy metals cause health risks to human lead to cancer. Also, the highest removal percentage of heavy metals from environment is recorded by microorganisms and plants. Microbial community recorded high tolerance and uptake to different heavy metals such as bacteria, fungi and algae. *Pseudomonas aeruginosa* is the most potent bacterial strains which tolerating and removal heavy metals. Tolerance and removal of heavy metals occurred by different mechanisms. Additionally, *Pseudomonas aeruginosa* recorded high removal percentage from different heavy metals such as cadmium, nickel, lead, chromium, mercury, copper and zinc. Also, different studies insured that high removal recorded at optimum conditions for growth and biomass produced. Conditions included pH, temperatures, biomass dose and incubation periods. Finally, *Pseudomonas aeruginosa* can tolerate heavy metals using resistant genes and genes that carry on plasmid which play important role in increase efficacy of strain in bioaccumulation and tolerance. In future prospections, *Pseudomonas aeruginosa* will be promising in heavy metals bioremediation and bioaccumulation from environment and achieve high removal percentage after using genetic engineering and gene transfer.

### **Acknowledgements**

Firstly, **g**reat thanks and appreciation to staff of Al-Azhar **U**niversity, Faculty of Science for their supporting and encouragement.

Finally, I wish to thank my Mother, Brother, sisters, wife, sons (Khalid and Mohammed) and everyone in my family for their continual guidance.

### **Conflict of interest**

The author declares no conflict of interest.
