The power of CRISPR rests on its molecular logic. At its core, the system pairs a programmable guide RNA with a Cas nuclease, allowing researchers to target almost any DNA or RNA sequence with single-base precision. Since the foundational demonstration that Cas9 can be directed by a dual-RNA guide to cleave chosen genomic sites, the toolbox has expanded dramatically. Base editors now rewrite individual letters of the genetic code without making double-strand breaks, prime editors perform search-and-replace genome surgery without donor DNA templates, and dead Cas proteins fused to regulatory domains can silence or activate genes without cutting at all. RNA-targeting variants such as Cas13 extend the approach to transcriptomes, while Cas12a’s collateral cleavage activity has become the engine of a generation of ultrasensitive diagnostic platforms. This versatility is precisely what makes the technology attractive for environmental applications, where targets are diverse, distributed, and constantly evolving.

Perhaps the most mature environmental application involves turning CRISPR against its own microbial relatives. Because guide RNAs can be designed to discriminate between strains at the level of single nucleotides, CRISPR-Cas systems can be deployed as sequence-specific antimicrobials that eliminate pathogenic or antibiotic-resistant bacteria while sparing benign members of a microbial community. Studies have shown that genome-targeting CRISPR-Cas constructs can programmatically remove defined bacterial strains from mixed populations, offering a selectivity that broad-spectrum antibiotics and disinfectants cannot match. Engineered bacteriophages carrying CRISPR payloads can deliver these constructs directly into target cells, and combinations of CRISPR-Cas9 with nanoparticle delivery systems are being explored against stubborn biofilm-driven infections. Researchers have also documented the flip side: bacteria can mount resistance to CRISPR antimicrobials, and anti-CRISPR proteins found in mobile genetic elements can neutralize the systems, underscoring that deployment strategies must anticipate evolutionary pushback.

Antibiotic resistance genes represent a particularly insidious form of biological pollution because they spread horizontally through water systems, soils, and food chains. The review highlights how CRISPR-based interventions could excise or disrupt resistance genes directly in environmental microbial communities, while CRISPR-enabled diagnostics provide the surveillance backbone needed to track them. Field-deployable assays that pair Cas12a or Cas13a with isothermal amplification methods such as LAMP and RPA have already been used to detect antibiotic resistance genes like ermB in wastewater and to identify SARS-CoV-2 in sewage, sometimes on paper-based devices read by smartphone. These platforms turn what once required a fully equipped molecular laboratory into tests that can run at the entrance of a treatment plant or in a monitoring van, closing the feedback loop between detection and intervention.

Pathogen surveillance extends beyond resistance genes. The authors describe CRISPR diagnostic platforms, sometimes called CRISPR-Dx, as complementary tools for identifying and tracking biological contaminants in real time. Portable plasmonic biosensors coupled with Cas12a have been used for genotyping SARS-CoV-2 in sewage, and one-pot, amplification-free RNA detection has been demonstrated with the newer Cas12a2 variant. Work from the review’s own research group, including the WATER NEWS field approach for sustainable pathogen detection in wastewater and optimized monitoring scenarios for resistance genes in urban water cycles, illustrates how these diagnostics can be tuned for routine environmental practice. In a world still digesting the lessons of pandemic wastewater monitoring, the ability to read the genetic signature of contamination quickly, cheaply, and on site is a quiet revolution in public health infrastructure.

Against invasive and harmful species, CRISPR offers interventions of a different scale. Gene drive systems, which bias inheritance to spread engineered traits through wild populations, have been built to target female reproduction in the malaria mosquito Anopheles gambiae and have produced complete population suppression in caged mosquito experiments. Precision-guided sterile insect approaches have eliminated malaria vectors in laboratory trials and been demonstrated in flies, while split drive designs targeting the doublesex gene are being pursued against the invasive malaria vector Anopheles stephensi and the global fruit pest Drosophila suzukii. Similar logic applies to agricultural pests: CRISPR-Cas9 has been used to validate spermatogenesis genes as targets in the fall armyworm, one of the world’s most damaging invasive insects, and to edit fall armyworm genomes for future population control.

Plants are being recruited to the same fight, but from the defensive side. Rather than attacking pathogens directly, CRISPR edits crop genomes to remove susceptibility genes that pathogens exploit. Editing the MLO gene family in soybean, the PMR4 gene in tomato, and the CsLOB1 promoter region in grapefruit have all yielded resistance to powdery mildew, bacterial diseases, and citrus canker respectively, while edits in tomato Bs5 genes and rice OsETR haplotypes confer resistance against Xanthomonas and bacterial blight. Editing the TOM1 gene in tobacco confers resistance to tobacco mosaic virus. In several cases, Cas12a ribonucleoprotein delivery has produced transgene-free, canker-resistant citrus lines, sidestepping some regulatory and public acceptance issues associated with introducing foreign DNA. The review frames these crop edits as a form of biological pollution control that reduces pesticide dependence and the ecological damage that follows chemical-intensive disease management.

Yet the authors are explicit that laboratory success does not translate automatically into environmental impact. Delivery remains the central technical bottleneck: getting CRISPR components to the right cells in a lake, a soil horizon, or an insect population in the open field is vastly harder than transfecting a cell culture. Viral vectors, polymer nanocomplexes, and nonviral nanoparticles, including high-loading porous silicon and polymer systems capable of in vivo Cas9 delivery, are promising but unproven at ecosystem scale. Off-target editing risks harming non-target organisms, and even perfectly targeted edits can have unpredictable consequences when released into complex ecological networks. Horizontal gene transfer, resistance evolution, and the sheer heterogeneity of environmental matrices all compound the difficulty. The review also stresses governance: gene drives in particular demand regulatory frameworks capable of assessing irreversible, cross-border ecological interventions, and public trust will hinge on transparency, containment strategies such as daisy-chain and split drives that limit spread, and responsible oversight.

Looking forward, the authors identify three converging directions. High-precision editing tools, including improved base editors with widened targeting range and engineered Cas variants with expanded PAM compatibility and higher fidelity, will reduce collateral damage. Intelligent delivery systems, potentially combining engineered phages, nanoparticles, and biosensors that release payloads only upon detecting their targets, will improve spatial and temporal control. And emerging artificial intelligence approaches, from deep learning models that predict guide RNA efficiency to AI-designed editor proteins, could accelerate the design of environmentally tailored systems. Together with a maturing governance discourse, these advances suggest a pathway from demonstration projects to genuine deployment, provided researchers treat ecological uncertainty as a design constraint rather than an afterthought.

The significance of the review lies less in any single result than in the synthesis it offers. Biological pollution is compounding: resistance genes accumulate in water cycles, invasive pests reshuffle global agriculture, and pathogens exploit every corridor of trade and climate change. Conventional chemical and physical controls are reaching their limits, often trading one harm for another. CRISPR, the authors argue, is the first technology that matches this problem’s defining feature, which is specificity, allowing interventions aimed precisely at the pathogen, the resistance gene, or the invader while leaving the surrounding biological community intact. Whether that promise survives contact with real ecosystems will depend on the coming decade of field trials, regulatory imagination, and public engagement, but the review makes clear that the tools are no longer the limiting factor. The limiting factor is learning to use them responsibly at scale.

Subject of Research: Application of CRISPR gene-editing and diagnostic technologies for controlling environmental biological pollution, including pathogens, antibiotic resistance genes, and invasive species.

Article Title: Advances and challenges in the application of CRISPR technology for environmental biological pollution control

Article References: Zheng, X.-F., Cheng, Z.-H., Yu, H.-Q., & Liu, D.-F. (2026). Advances and challenges in the application of CRISPR technology for environmental biological pollution control. ENGINEERING Environment, 20(12), Article 187. https://doi.org/10.1007/s11783-026-2287-5

Image Credits: AI Generated

DOI: 10.1007/s11783-026-2287-5

Keywords: CRISPR-Cas, gene editing, biological pollution, antibiotic resistance, pathogen detection, invasive species, gene drive, wastewater surveillance, environmental biotechnology, bioremediation, crop disease resistance, CRISPR diagnostics