Synthetic bacteria for the detection and bioremediation of heavy metals

Abstract

Toxic heavy metal accumulation is one of anthropogenic environmental pollutions, which poses risks to human health and ecological systems. Conventional heavy metal remediation approaches rely on expensive chemical and physical processes leading to the formation and release of other toxic waste products. Instead, microbial bioremediation has gained interest as a promising and cost-effective alternative to conventional methods, but the genetic complexity of microorganisms and the lack of appropriate genetic engineering technologies have impeded the development of bioremediating microorganisms. Recently, the emerging synthetic biology opened a new avenue for microbial bioremediation research and development by addressing the challenges and providing novel tools for constructing bacteria with enhanced capabilities: rapid detection and degradation of heavy metals while enhanced tolerance to toxic heavy metals. Moreover, synthetic biology also offers new technologies to meet biosafety regulations since genetically modified microorganisms may disrupt natural ecosystems. In this review, we introduce the use of microorganisms developed based on synthetic biology technologies for the detection and detoxification of heavy metals. Additionally, this review explores the technical strategies developed to overcome the biosafety requirements associated with the use of genetically modified microorganisms.

The function of microbial enzymes in breaking down soil contaminated with pesticides: a review

“…Despite the advancements in synthetic biology and microbial engineering that have led to the creation of microorganisms with new metabolic pathways or optimization for better fitness in harsh conditions, the use of genetically altered bacteria in the environment remains controversial. The reasons are twofold: first, potential adverse genotypes can be easily mobilized in the environment, which is perceived as a negative attribute of indigenous organisms; second, the unstable nature of inserted genetic material acknowledges that the efficiency of engineered microbes is relied on their tendency to carry the genetic material [ 19 , 21 , 22 , 27 , 32 ]. As a result, despite the benefits afforded by altered microorganisms, governments such as the United States and Europe restrict the use of genetically modified organisms in the exposing environment [ 21 ].…”

Bacterial tolerance and detoxification of cyanide, arsenic and heavy metals: Holistic approaches applied to bioremediation of industrial complex wastes

“…Thus, systems biology may allow the development of specific, sustainable and efficient methods to detect and bioremediate cyanide and heavy metals. Application of synthetic biology to this purpose is still in its infancy, and although significant advances have been addressed on heavy metals (recently reviewed by Thai et al., 2023 ), some relevant issues, such as ethical concerns, biosafety and legal regulations, must be overcome.…”

“…The first step in the implementation of a bioremediation process is sensing and monitoring the presence of pollutants in the environment. Synthetic biology directed to heavy metal detection has allowed the development of different biosensors, but currently, there are limited examples of the use of synthetic biology for metal bioremediation due to the ethical and legal implications of the utilization and release of genetically modified organisms, and because many of the developed toolkits are relatively new (Capeness & Horsfall, 2020 ; Somayaji et al., 2022 ; Thai et al., 2023 ). Biosensors are multi‐component and modular devices with some biological circuits that include, at least, a sensing element that detects the analyte (i.e.…”

“…Biosensors are multi‐component and modular devices with some biological circuits that include, at least, a sensing element that detects the analyte (i.e. a metal‐binding protein), a signal processing module that also amplifies and tunes the signal, and an output system that allows the measurement and quantitation of the signal, usually based on fluorescence, bioluminescence, colourimetric, electrical or chemotactic detection (Kim et al., 2018 ; Singh & Kumar, 2021 ; Thai et al., 2023 ). Efficient biosensors have been developed for arsenic, copper and other heavy metals (Fan et al., 2022 ; Roggo & van der Meer, 2017 ; Thai et al., 2023 ).…”

Recent advances in the development and applications of luminescent bacteria–based biosensors

“…The design of the sensing layer in luminescent bacterial biosensors is critical to the performance of the system [42]. Recent advancements in genetic manipulation techniques have made it possible for bacteria bioreporters to serve as the core sensing element, offering several advantages such as high sensitivity and low cost [43–49]. Most importantly, bioreporters can specifically respond to certain classes of compounds, making them highly valuable tools in various applications [50].…”