1. Ultrafast removal of toxic Cr(VI) by the marine bacterium Vibrio natriegens.
- Author
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Shi, Xiao-Chen, Wang, Kefan, Xue, Miao, Mao, Weijia, Xu, Kai, Tremblay, Pier-Luc, and Zhang, Tian
- Subjects
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MARINE bacteria , *VIBRIO , *CHARGE exchange , *VIBRIONACEAE , *VIBRIO harveyi , *HEAVY metals - Abstract
The fastest-growing microbe Vibrio natriegens is an excellent platform for bioproduction processes. Until now, this marine bacterium has not been examined for bioremediation applications, where the production of substantial amounts of biomass would be beneficial. V. natriegens can perform extracellular electron transfer (EET) to Fe(III) via a single porin-cytochrome circuit conserved in Vibrionaceae. Electroactive microbes capable of EET to Fe(III) usually also reduce toxic metals such as carcinogenic Cr(VI), which is converted to Cr(III), thus decreasing its toxicity and mobility. Here, the performance of V. natriegens was explored for the bioremediation of Cr(VI). At a density of 100 mg/mL, V. natriegens removed 5–20 mg/L Cr(VI) within 30 s and 100 mg/L Cr(VI) within 10 min. In comparison, the model bacterium Escherichia coli grown to a comparable cell density removed Cr(VI) 36 times slower. To eliminate Cr(VI), V. natriegens had to be metabolically active, and functional outer-membrane c -type cytochromes were required. At the end of the Cr(VI) removal process, V. natriegens had reduced all of it into Cr(III) while adsorbing more than half of the metallic ions. These results demonstrate that V. natriegens , with its fast metabolism, is a viable option for the rapid treatment of aqueous pollution with Cr. [Display omitted] • The fast-growing microbe Vibrio natriegens can reduce and adsorb toxic chromium. • High-density V. natriegens removed 5–20 mg/L Cr(VI) within 30 s. • V. natriegens at the same density also removed 100 mg/L Cr(VI) within minutes. • Cr(VI) was reduced extracellularly and Cr(III) was adsorbed by the microbes. • A porin-cytochrome complex is likely involved in Cr(VI) conversion. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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