Hits:

Indexed by:期刊论文

Date of Publication:2018-01-01

Journal:Environmental science and pollution research international

Included Journals:PubMed、SCIE

Volume:25

Issue:21,SI

Page Number:20756-20768

ISSN No.:1614-7499

Key Words:Bacterial tellurite reduction; Lysinibacillus sp.; Biogenic tellurium nanoparticles; Biogenically tailored nanomaterials; Tellurite reductases

Abstract:Although tellurite is highly toxic to organisms, elemental tellurium nanomaterials (TeNMs) have many uses. The microbe-mediated reduction of tellurite to Te(0) has been shown to be a green and cost-effective approach for turning waste into wealth. However, it is difficult to tune the morphology of biogenic nanomaterials. In this study, a series of experiments was conducted to investigate the factors influencing tellurite reduction by the tellurite-reducing bacterium Lysinibacillus sp. ZYM-1, including pH, tellurite concentration, temperature, and heavy metal ions. The optimal removal efficiency of tellurite was respectively achieved at pH8, 0.5mM tellurite, and 40°C. All of the tested metal ions retarded the reduction of tellurite, especially Cd2+ and Co2+, which completely inhibited its reduction. Further characterization of the biogenic TeNMs indicated that their morphology could be tuned by the tellurite concentration, pH, temperature, and organic solvents used. Regular Te nanosheets were produced using 5mM tellurite. The TeNMs were primarily synthesized in the cell membrane. Hexagonal Te nanoplates, nanorods, nanoflowers, and nanobranches were synthesized when combining membrane fractions with tellurite and NADH. The diverse morphologies are assumed to be induced by the synergy between the reduction kinetics and the protein structure. Therefore, this study confirmed that the bacterium can tune the morphology of TeNMs, broadening the potential application of biogenic TeNMs.