Visual signal transduction for environmental stewardship: A novel biosensing approach to identify and quantify chlorpyrifos-related residues in aquatic environments.

The pervasive presence of organophosphate pesticides (OPs), such as chlorpyrifos (CPF), in aquatic ecosystems underscores the urgent need for sensitive and reliable detection methods to safeguard environmental and public health. This study addressed the critical need for a novel biosensor capable of detecting CPF and its toxic metabolite, 3,5,6-trichloro-2-pyridinol (TCP), with high sensitivity and selectivity, suitable for field applications in environmental monitoring. The study engineered a whole-cell biosensor based on E.

Biosynthesis of Indigo Dyes and Their Application in Green Chemical and Visual Biosensing for Heavy Metals.

Fermentative production of natural colorants using microbial strains has emerged as a cost-effective and sustainable alternative to chemical synthesis. Visual pigments are used as signal outputs in colorimetric bacterial biosensors, a promising method for monitoring environmental pollutants. In this study, we engineered four self-sufficient indigo-forming enzymes, including HbpAv, bFMO, cFMO, and rFPMO, in a model bacterium .

Visual arsenic detection in environmental waters: Innovating with a naked-eye biosensor for universal application.

Arsenic contamination in environmental water sources poses a significant threat to human health, necessitating the development of sensitive and accessible detection methods. This study presents a multidimensional optimization of a bacterial biosensor for the susceptible and deoxyviolacein (DV)-based visual detection of arsenic. The research involved screening six different arsenic resistance (ars) operons and optimizing the genetic circuit to minimize background noise.

Detection of Cadmium in Human Biospecimens by a Cadmium-Selective Whole-Cell Biosensor Based on Deoxyviolacein.

Cadmium poses a severe health risk, impacting various bodily systems. Monitoring human exposure is vital. Urine and blood cadmium serve as critical biomarkers.

Synthetic bacteria designed using ars operons: a promising solution for arsenic biosensing and bioremediation.

The global concern over arsenic contamination in water due to its natural occurrence and human activities has led to the development of innovative solutions for its detection and remediation. Microbial metabolism and mobilization play crucial roles in the global cycle of arsenic. Many microbial arsenic-resistance systems, especially the ars operons, prevalent in bacterial plasmids and genomes, play vital roles in arsenic resistance and are utilized as templates for designing synthetic bacteria.

High-throughput screening of human mercury exposure based on a low-cost naked eye-recognized biosensing platform.

Whole-cell biosensors could be helpful for in situ disease diagnosis. However, their use in analyzing biological samples has been hindered by unstable responses, low signal enhancement, and growth inhibition in complex media. Here, we offered a solution by building a visual whole-cell biosensor for urinary mercury determination.

Tailored bacteria tackling with environmental mercury: Inspired by natural mercuric detoxification operons.

Mercury (Hg) and its inorganic and organic compounds significantly threaten the ecosystem and human health. However, the natural and anthropogenic Hg environmental inputs exceed 5000 metric tons annually. Hg is usually discharged in elemental or ionic forms, accumulating in surface water and sediments where Hg-methylating microbes-mediated biotransformation occurs.

Designed bacteria based on natural pbr operons for detecting and detoxifying environmental lead: A mini-review.

Lead (Pb), a naturally occurring element, is redistributed in the environment mainly due to anthropogenic activities. Pb pollution is a crucial public health problem worldwide due to its adverse effects. Environmental bacteria have evolved various protective mechanisms against high levels of Pb.

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

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.

A panel of visual bacterial biosensors for the rapid detection of genotoxic and oxidative damage: A proof of concept study.

The emergence of new compounds during the past decade requires a high-throughput screening method for toxicity assay. The stress-responsive whole-cell biosensor is a powerful tool to evaluate direct or indirect damages of biological macromolecules induced by toxic chemicals. In this proof-of-concept study, nine well-characterized stress-responsive promoters were first selected to assemble a set of blue indigoidine-based biosensors.

Metabolic engineering of the carotenoid biosynthetic pathway toward a specific and sensitive inorganic mercury biosensor.

The toxicity of mercury (Hg) mainly depends on its form. Whole-cell biosensors respond selectively to toxic Hg(ii), efficiently transformed by environmental microbes into methylmercury, a highly toxic form that builds up in aquatic animals. Metabolically engineered () have successfully produced rainbow colorants.

Anthocyanin biosynthetic pathway switched by metalloregulator PbrR to enable a biosensor for the detection of lead toxicity.

Environmental lead pollution mainly caused by previous anthropogenic activities continuously threatens human health. The determination of bioavailable lead is of great significance to predict its ecological risk. Bacterial biosensors using visual pigments as output signals have been demonstrated to have great potential in developing minimal-equipment biosensors for environmental pollutant detection.

Metabolic engineering of the violacein biosynthetic pathway toward a low-cost, minimal-equipment lead biosensor.

Metabolic engineered bacteria have been successfully employed to produce various natural colorants, which are expected to be used as the visually recognizable signals to develop mini-equipment biological devices for monitoring toxic heavy metals. The violacein biosynthetic pathway has been reconstructed in Escherichia coli (E. coli).

Differential Detection of Bioavailable Mercury and Cadmium Based on a Robust Dual-Sensing Bacterial Biosensor.

Genetically programmed biosensors have been widely used to monitor bioavailable heavy metal pollutions in terms of their toxicity to living organisms. Most bacterial biosensors were initially designed to detect specific heavy metals such as mercury and cadmium. However, most available biosensors failed to distinguish cadmium from various heavy metals, especially mercury.

Detection of environmental pollutant cadmium in water using a visual bacterial biosensor.

Cadmium (Cd) contamination in water and soil is considered an environmental pollutant. Food crops can absorb and accumulate bioavailable Cd. Continuous monitoring of Cd levels in the environment can minimize exposure and harm to humans.

Recent advances in bacterial biosensing and bioremediation of cadmium pollution: a mini-review.

Cadmium (Cd) pollution has become a global environmental issue because Cd gets easily accumulated and translocated in the food chain, threatening human health. Considering the detrimental effects and non-biodegradability of environmental Cd, this is an urgent issue that needs to be addressed through the development of robust, cost-effective, and eco-friendly green routes for monitoring and remediating toxic levels of Cd. This article attempts to review various bacterial approaches toward biosensing and bioremediation of Cd in the environment.

Detection of Bioavailable Cadmium by Double-Color Fluorescence Based on a Dual-Sensing Bioreporter System.

Cadmium (Cd) is carcinogenic to humans and can accumulate in the liver, kidneys, and bones. There is widespread presence of cadmium in the environment as a consequence of anthropogenic activities. It is important to detect cadmium in the environment to prevent further exposure to humans.

Indigoidine biosynthesis triggered by the heavy metal-responsive transcription regulator: a visual whole-cell biosensor.

During the last few decades, whole-cell biosensors have attracted increasing attention for their enormous potential in monitoring bioavailable heavy metal contaminations in the ecosystem. Visual and measurable output signals by employing natural pigments have been demonstrated to offer another potential choice to indicate the existence of bioavailable heavy metals in recent years. The biosynthesis of the blue pigment indigoidine has been achieved in E.

Development of a bioavailable Hg(II) sensing system based on MerR-regulated visual pigment biosynthesis.

Engineered microorganisms have proven to be a highly effective and robust tool to specifically detect heavy metals in the environment. In this study, a highly specific pigment-based whole-cell biosensor has been investigated for the detection of bioavailable Hg(II) based on an artificial heavy metal resistance operon. The basic working principle of biosensors is based on the violacein biosynthesis under the control of mercury resistance (mer) promoter and mercury resistance regulator (MerR).

Versatile artificial mer operons in Escherichia coli towards whole cell biosensing and adsorption of mercury.

Mercury exists naturally and mainly as a man-made pollutant in the environment, where it exerts adverse effects on local ecosystems and living organisms. It is important to develop an appropriate synthetic biological device that recognizes, detects and removes the bioavailable fraction of environmental mercury. Both single-signal and double-signal output mercury biosensors were assembled using a natural mer operon as a template.

Development of Cadmium Multiple-Signal Biosensing and Bioadsorption Systems Based on Artificial Operons.

The development of genetic engineering, especially synthetic biology, greatly contributes to the development of novel metal biosensors. The operon encoding cadmium resistance was previously characterized from . In this study, single-, dual-, and triple-signal output Cd(II) biosensors were successfully developed using artificial translationally coupled operons.

Genetic control of violacein biosynthesis to enable a pigment-based whole-cell lead biosensor.

Environmental risks continue to grow due to heavy metal contamination caused by anthropogenic activities. Accumulation of harmful quantities of lead poses a threat to aquatic organisms, plants, and human beings. Whole-cell biosensors, which can proliferate independently, can detect the bioavailable fraction to assess the effect of target heavy metal on the environmental ecosystem.

Construction of a RFP-lacZα bicistronic reporter system and its application in lead biosensing.

The combination of a fluorescent reporter and enzymatic reporter provides a flexible and versatile way for the study of diverse biological processes, such as the detection of transcription and translation. Thus, there is an urgent need to develop this novel bifunctional reporter system. This study reports the design, construction, and validation of a new dicistronic mCherry-lacZα reporter system by artificial lac operon and pbr operon models in lacZM15-producing E.

Improved Monitoring of Low-Level Transcription in by a β-Galactosidase α-Complementation System.

Genetically encoded reporter proteins are important and widely used tools for the identification and capture of a promoter, tracking the dynamic behavior of transcription, and the quantification of promoter activity. The sensitivity of the reporter gene is a critical factor for an ideal reporter system because weak transcriptional signal has usually failed to be detected using classical reporters. In this study, we present a novel reporter system for improved monitoring of transcription in based on β-galactosidase α-complementation.

Development of a novel bacterial surface display system using truncated OmpT as an anchoring motif.

Objectives: An efficient bacterial surface display system based on the anchoring motif derived from Escherichia coli (E. coli) outer membrane protease OmpT was developed in this study.

Results: Referring to the classical Lpp-OmpA (LOA) display system, the signal peptide and nine amino acids of mature Lpp were fused to the transmembrane domain comprising five β-strands of truncated OmpT to generate a novel Lpp-OmpT (LOT) display system.