Isolation and Identification of Chromium Reducing Bacillus Cereus Species from Chromium-Contaminated Soil for the Biological Detoxification of Chromium

Abstract

Chromium contamination has been an increasing threat to the environment and to human health. Cr(VI) and Cr(III) are the most common states of chromium. However, compared with Cr(III), Cr(VI) is more toxic and more easily absorbed, therefore, it is more harmful to human beings. Thus, the conversion of toxic Cr(VI) into Cr(III) is an accepted strategy for chromium detoxification. Here, we isolated two Bacillus cereus strains with a high chromium tolerance and reduction ability, named B. cereus D and 332, respectively. Both strains demonstrated a strong pH and temperature adaptability and survival under 8 mM Cr(VI). B. cereus D achieved 87.8% Cr(VI) removal in 24 h with an initial 2 mM Cr(VI). Cu(II) was found to increase the removal rate of Cr(VI) significantly. With the addition of 0.4 mM Cu(II), 99.9% of Cr(VI) in the culture was removed by B. cereus 332 in 24 h. This is the highest removal efficiency in the literature that we have seen to date. The immobilization experiments found that sodium alginate with diatomite was the better method for immobilization and B. cereus 332 was more efficient in immobilized cells. Our research provided valuable information and new, highly effective strains for the bioremediation of chromium pollution.

Chromium Pollution in European Water, Sources, Health Risk, and Remediation Strategies: An Overview

“…Bacteria capable of reducing Cr (VI) mainly belong to nitrate-reducing, Fe (III)-reducing, and sulphate-reducing bacteria. Among the gram positive bacteria, Bacillus, Deinococcus, and Arthrobacter have shown Cr (VI) reduction capability [107,150,151]. Meanwhile, Enterococcus, Shewanella, Pseudomonas, Escherichia, Thermus, and Ochrobactrum are examples of gram-negative bacteria with potential application in bioremediation [152][153][154][155][156][157].…”

“…The best-known disposal method of wastes and wastewaters enriched in chromium is often reduction of Cr (VI) to a less mobile and less toxic form, Cr (III), because Cr in industrial wastes occurs predominantly in the hexavalent form [ 27 ]. Some strategies used for chromium pollution remediation include chemical reduction methods by reducing agents such as Fe (0) and Fe (II), precipitation, adsorption, ion exchange, electrocoagulation, or biological reduction as a result of microbial metabolism [ 21 , 25 , 107 , 108 , 109 ].…”

Aerobic Degradation Characteristics of Decabromodiphenyl ether through Rhodococcus ruber TAW-CT127 and Its Preliminary Genome Analysis

“…Physiological and biochemical analyses were performed according to the environmental engineering microorganism detection manual [ 41 , 42 ]. Gram staining experiments were performed, based on the method described by Li et al [ 43 ]. Physiological and biochemical characterizations including the Voges–Proskauer (VP), starch hydrolysis, glucose oxidative fermentation, gelatin hydrolysis, peroxidase, and contact oxidase tests were performed.…”

Insight into chromium adsorption from contaminated soil using Mg/Al LDH-zeolite

“…Yan et al (2018) [ 10 ] reported the successful remediation of chromium-contaminated soil using an electric field to mobilize and extract contaminants, employing iron-loaded activated carbon electrodes in a three-dimensional system. Bioremediation approaches have also been explored for Cr-contaminated soil, with certain bacteria, such as Bacillus cereus, identified for their ability to reduce and detoxify Cr Li et al (2020) [ 11 ]. Phytoremediation, which involves using plants to remove contaminants from the soil, has been studied for Cr(VI) contamination.…”