Pb(II)-inducible proviolacein biosynthesis enables a dual-color biosensor toward environmental lead

Frontiers in Microbiology

Microbiology

Ming-qi Liu¹  De-long Zhu¹  Hao Luo¹  Chang-ye Hui²  Bing-chan Ma³  Yong-qin Lin⁴  Nai-xing Zhang⁴  Yan Guo⁴  Hai-jun Wang⁴  Chao-xian Gao⁴ 

[1] School of Public Health, Guangdong Medical University, Dongguan, China;School of Public Health, Guangdong Medical University, Dongguan, China;Shenzhen Prevention and Treatment Center for Occupational Diseases, Shenzhen, China;School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China;Shenzhen Prevention and Treatment Center for Occupational Diseases, Shenzhen, China;

关键词: whole-cell biosensors;    proviolacein biosynthesis;    lead pollution;    bioavailability;    ecotoxicity;   

DOI  :  10.3389/fmicb.2023.1218933

 received in 2023-05-08, accepted in 2023-07-10,  发布年份 2023

来源: Frontiers

【 摘 要 】

With the rapid development of synthetic biology, various whole-cell biosensors have been designed as valuable biological devices for the selective and sensitive detection of toxic heavy metals in environmental water. However, most proposed biosensors are based on fluorescent and bioluminescent signals invisible to the naked eye. The development of visible pigment-based biosensors can address this issue. The pbr operon from Klebsiella pneumoniae is selectively induced by bioavailable Pb(II). In the present study, the proviolacein biosynthetic gene cluster was transcriptionally fused to the pbr Pb(II) responsive element and introduced into Escherichia coli. The resultant biosensor responded to Pb(II) in a time- and dose-dependent manner. After a 5-h incubation with Pb(II), the brown pigment was produced, which could be extracted into n-butanol. Extra hydrogen peroxide treatment during n-butanol extract resulted in the generation of a stable green pigment. An increased brown signal was observed upon exposure to lead concentrations above 2.93 nM, and a linear regression was fitted from 2.93 to 3,000 nM. Extra oxidation significantly decreased the difference between parallel groups. The green signal responded to as low as 0.183 nM Pb(II), and a non-linear regression was fitted in a wide concentration range from 0.183 to 3,000 nM. The specific response toward Pb(II) was not interfered with by various metals except for Cd(II) and Hg(II). The PV-based biosensor was validated in monitoring bioaccessible Pb(II) spiked into environmental water. The complex matrices did not influence the regression relationship between spiked Pb(II) and the dual-color signals. Direct reading with the naked eye and colorimetric quantification enable the PV-based biosensor to be a dual-color and low-cost bioindicator for pollutant heavy metal.

【 授权许可】

Unknown   
Copyright © 2023 Zhu, Guo, Ma, Lin, Wang, Gao, Liu, Zhang, Luo and Hui.