Abstract
Heavy metal-resistant bacteria can be efficient bioremediators of metals and might provide an alternative method for metal removal in contaminated environments. The present study aims to isolate bacteria from the aquatic environment and evaluate their potential tolerance to copper metal, aiming at bioremediation processes. Also, compare co-resistance to heavy metal and antibiotics. The morphology of isolates was observed, and sequence analysis (16S ribosomal DNA) revealed that isolated strains were closely related to species belonging to the genera Enterococcus and Bacillus. Bacterial isolates were resistant to CuSO4, with a minimum inhibitory concentration of 0.78 mg ml-1. Enterococcus lactis was resistant to a combination of copper and tetracycline. The other tested isolates were sensitive to the tested antimicrobials. The metal removal ability of these isolates was assayed using atomic absorption spectroscopy, and the strains 27, 23, and E. lactis were best at removing heavy metals, at 87.7%. Enterococcus casseliflavus EC55 was 62%, followed by Bacillus aerius (18.4%), E. casseliflavus EC70 (10%) and Bacillus licheniformis (10%). Based on our findings, Enterococcus sp and Bacillus sp. have potential applications in enhanced remediation of contaminated environments.
Highlights
IntroductionIt is known that the increased use of metals and chemicals in the process industries has resulted in the generation of large amounts of effluents containing toxic heavy metals and these effluents can accumulate in the environment, due to their non-degradable nature (Gautam, Gautam, Banerjee, Chattopadhyaya, & Pandey, 2016)
Toxic metals can accumulate along the food chain, causing chronic toxicity to the aquatic environment and in humans (Pugazhendhi, Ranganathan, & Kaliannan, 2018)
Cu-resistant bacteria were isolated by the serial dilution method in saline water (0.85% w v-1)
Summary
It is known that the increased use of metals and chemicals in the process industries has resulted in the generation of large amounts of effluents containing toxic heavy metals and these effluents can accumulate in the environment, due to their non-degradable nature (Gautam, Gautam, Banerjee, Chattopadhyaya, & Pandey, 2016). Toxic metals can accumulate along the food chain, causing chronic toxicity to the aquatic environment and in humans (Pugazhendhi, Ranganathan, & Kaliannan, 2018). Several microorganisms that live in these environments adopt different mechanisms to adapt to these heavy metal and antibiotics stresses. This occurs because some mechanisms for heavy metal resistance function in a similar way of those for resistance to antibiotics. It is very important to elucidate the bacterial resistance to both in detail for further understanding the bacterial cross-resistance and its ecological risk (Zhou et al, 2015)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
