Genetic engineering to enhance microalgal-based produced water treatment with emphasis on CRISPR/Cas9: A review

Abstract

In recent years, the increased demand for and regional variability of available water resources, along with sustainable water supply planning, have driven interest in the reuse of produced water. Reusing produced water can provide important economic, social, and environmental benefits, particularly in water-scarce regions. Therefore, efficient wastewater treatment is a crucial step prior to reuse to meet the requirements for use within the oil and gas industry or by external users. Bioremediation using microalgae has received increased interest as a method for produced water treatment for removing not only major contaminants such as nitrogen and phosphorus, but also heavy metals and hydrocarbons. Some research publications reported nearly 100% removal of total hydrocarbons, total nitrogen, ammonium nitrogen, and iron when using microalgae to treat produced water. Enhancing microalgal removal efficiency as well as growth rate, in the presence of such relevant contaminants is of great interest to many industries to further optimize the process. One novel approach to further enhancing algal capabilities and phytoremediation of wastewater is genetic modification. A comprehensive description of using genetically engineered microalgae for wastewater bioremediation is discussed in this review. This article also reviews random and targeted mutations as a method to alter microalgal traits to produce strains capable of tolerating various stressors related to wastewater. Other methods of genetic engineering are discussed, with sympathy for CRISPR/Cas9 technology. This is accompanied by the opportunities, as well as the challenges of using genetically engineered microalgae for this purpose.

Advances in Environmental Biotechnology with CRISPR/Cas9: Bibliometric Review and Cutting-Edge Applications

“…Moreover, CRISPR/Cas9 has been successfully applied to enhance microalgae-based water treatment, improving biomass productivity, tolerance to abiotic stressors, and increasing lipid content for environmental biofuels [100]. Additionally, the self-sustaining method based on the CRISPR/Cas9 system shows potential for pest management, which is crucial for sustainable agricultural practices [101].…”

“…Moreover, CRISPR/Cas9 can control invasive species that threaten native biodiversity, thus maintaining ecological balance. Given the enormous potential application of CRISPR/Cas technology for species conservation and environmental sustainability [100].…”

Can bacteria and carbon-based nanomaterials revolutionize nanoremediation strategies for industrial effluents?

“…This breakthrough underlines the potential of genetic engineering to provide targeted, eco-friendly solutions for effluent treatment and promote sustainable environmental practices. Advancements in molecular engineering and synthetic biology are crucial for developing effective microbial systems capable of pinpointing and eliminating pollutants, thereby enhancing bioremediation methods, and supporting green decontamination techniques (Xue et al, 2022;Elmore et al, 2023;Hassanien et al, 2023;Wang et al, 2024a;Chen, Liu, and Liu, 2024).…”

Challenges and potential solutions of microalgae-based systems for wastewater treatment and resource recovery

“…For example, López-Sánchez et al (2022) summarized the maximum biomass concentration, COD removal, total nitrogen removal, and total phosphorus removal from different microalgae species cultivated in primary livestock wastewater as a medium, and pointed out that selection of an algal strain with high performance for wastewater treatment and resource recovery was very important. In future, selection of algal strains with excellent growth characteristics and nutrient removal capacity should be carried out by different methods, such as genetic engineering, adaptive laboratory evolution, and random mutagenesis ( Hassanien et al, 2023 ).…”