Journal article Open Access
Neelam Hashmi, Asma Yousafzai*, Yumna Akhter, Syeda Sabila Aftab, Muhiba Janan, Razia Kanwal, Jaweria Ali Tariq, Naheed Sajjad, Kiran Rani, Faiza Nawaz, Muneeza Arbab, Imran Ali Sani, Shan Ahmed, Muhammad Murad, Nisar Ahmed
In the biosphere, chromium is widespread heavy metal occurring in trivalent chromium (Cr3+) and hexavalent chromium (Cr6+) forms. Trivalent chromium has been extensively used in different industries. Hexavalent chromium is an environmental pollutant, toxic, carcinogenic and mutagenic metal whereas trivalent form is less soluble in water and even an essential nutrient. The distinctive capability of different isolated bacterial species, to reduce hexavalent chromium into trivalent form is going to be used in bioremediation. The present study was aimed to isolate and identify chromium resistant bacteria species from chromium mines. Random samples (n= 3) were taken and biochemical test were applied to identify chromium resistant bacterial species. Four bacterial species, belonged to genus Bacillus (iso-four, seven, eight, nine) were identified as B.pumilus, B.circulans, B.subtilis and B.sphaericus respectively. Isolates belonged to genus enterobacter (iso-one and iso-five) were identified as salmonella enteric and E.arogenes respectively. Isolate belonged to genus arthrobacter (Iso-three) was identified as A. creatinolyticus. Isolate belonged to genus pseudomonas (iso-two) was identified as p.fluorescene. Isolate belonged to genus staphylococcus; (iso-six) was identified as S.aureus, while iso-ten belonged to micrococcusluteus. All the isolates showed ability to tolerate chromium but iso-eight B.subtilis showed highest resistance against chromium. Furthermore, these bacterial species alter hexavalent Cr into trivalent Cr. This ability is being used on commercial scale to remove or minimize chromium pollutants.