Bioremediation of heavy metals from aquatic environment through microbial processes: A potential role for probiotics?

Abstract

Heavy metals can cause disastrous effects on any living organisms. Probiotics have the ability to reduce metal toxicity. Bioremediation of polluted waters using these bacteria could be an alternative to conventional remediation methods. The aim of this study was to isolate and characterize heavy metal resistant probiotics. Soil samples were collected for the isolation of probiotics. Morphological, biochemical, and molecular characterization was performed for the isolates. In addition, a preliminary heavy metal minimum inhibitory concentration test was done followed by atomic absorption spectrometry (AAS) analysis analysis. Four Enterococci (BT1, BT2, MC1, and MC2) and Bacillus acidiproducens (SM1 and SM2) were isolated. Moreover, all the isolates demonstrated probiotic characteristics. BT1 and BT2 were able to tolerate mercury (Hg), cadmium (Cd), lead (Pb), and chromium (Cr) but they demonstrated poor Hg removal abilities (0.75-1.42%). MC1 and MC2 isolates could grow in medium supplemented with Cd, Pb, and Cr, respectively. MC1 showed the highest level of Pb removal (43.00% ± 0.776%) and Cd removal (46.19% ± 7.651%) from broth media. Yet, SM1 and SM2 isolates tolerated only Pb and Cr. SM2 had the ability to remove the highest amount of Cr (43.06% ± 7.991%). These reasonable heavy metal removal abilities could be further studied for efficient use in bioremediation.

Development, Optimization & Application of Corn Cobs as Cost Effective Matrix for Immobilization of Fungal Strains Paecilomyces sinensis and Geotrichum pseudocandidum

“…Literary works on bioremediation analysis using AAS technique have a wide time span. A thorough studies on the instrument and its application in different time periods in the late 1977 till present time (Huet & Puchooa, 2017;Sperling, 1977) and as recent as in research (Kamarudheen, 2020) & review on AAS instrument (Akash & Rehman, 2020) have been the basis of present study.…”

Potential probiotic strains with heavy metals and mycotoxins bioremoval capacity for application in foodstuffs

“…The reduction was 32 ppm of Cr and 64 ppm of Pb after 72 h. The Cr removal by B. coagulans after 1, 2 and 3 days in MRS broth after inoculation was reported as 60%, 77% and 94%, respectively. B. acidiproducens SM2 was also a potent bacterium in removing Cr (45%) from water (Huët & Puchooa, 2017). Also, B. coagulans eliminated Pb after 1, 2 and 3 days in broth by 53%, 72% and 87%, respectively (Belapurkar et al, 2016).…”

“…Enterococcus faecium strains (BT1 and BT2) showed low Hg reduction capability (1.5%), whereas Ent. hirae MC1 represented the highest metals removal level for Pb (44%) and Cd (47%) from water (Huët & Puchooa, 2017).…”

Lead biosorption efficiency of Levilactobacillus brevis MZ384011 and Levilactobacillus brevis MW362779: A response surface based approach

“…Previous research provides the information about the HM biosorption potential of various microorganisms including probiotics ( Monachese et al, 2012 , Aryal and Liakopoulou-Kyriakides, 2015 , Limcharoensuk et al, 2015 , Huet and Puchooa, 2017 ). Probiotics are living microbes which when administrated in sufficient concentration, have a significant positive impact on the health of hosts ( FAO/WHO, 2001 ).…”