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

• Published in: International journal of environmental research and public health Vol. 17; no. 6; p. 2118
• Main Authors: Li, Ming-Hao, Gao, Xue-Yan, Li, Can, Yang, Chun-Long, Fu, Chang-Ai, Liu, Jie, Wang, Rui, Chen, Lin-Xu, Lin, Jian-Qiang, Liu, Xiang-Mei, Lin, Jian-Qun, Pang, Xin
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 23.03.2020; MDPI
• Subjects: Adaptability; Alginic acid; Bacteria; Biomass; Bioremediation; Cell culture; Chromium; Communication; Contamination; Copper; Detoxification; Diatomaceous earth; Environmental health; Immobilization; Immobilized cells; Methods; Microorganisms; Morphology; Phylogenetics; Physiology; Pollution effects; Potassium; Scanning electron microscopy; Sediment pollution; Sodium alginate; Soil contamination; Soil pollution; Trivalent chromium; United States > US; China; Japan; Finland; heavy metal contamination; bioremediation; Bacillus cereus; chromium (VI); bioreduction; immobilized cells
• ISSN: 1660-4601; 1661-7827; 1660-4601
• DOI: 10.3390/ijerph17062118

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 strains with a high chromium tolerance and reduction ability, named D and 332, respectively. Both strains demonstrated a strong pH and temperature adaptability and survival under 8 mM Cr(VI). 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 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 was more efficient in immobilized cells. Our research provided valuable information and new, highly effective strains for the bioremediation of chromium pollution.