GENETICALLY ENGINEERED MICROBES FOR HYDROCARBON BIOREMEDIATION: ADVANCES AND APPLICATIONS, RISKS, GLOBAL CASE STUDIES, AND PROSPECTS FOR OIL-POLLUTED AFRICAN ECOSYSTEMS

Abstract

Hydrocarbon contamination from petroleum activities poses a persistent global environmental threat, with particularly severe impacts in Africa's oil-producing regions. This review explores the advances in genetically engineered microbes (GEMs) as a powerful bioremediation strategy, detailing molecular tools (e.g., CRISPR-Cas9, synthetic biology), metabolic pathway optimizations, resilience enhancements, and innovative gene delivery systems that enable superior degradation of aliphatic hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), and total petroleum hydrocarbons (TPHs) compared to native consortia. Applications span laboratory demonstrations, pilot trials, and synergistic integrations with biostimulation, nanomaterials, and phytoremediation, yielding efficiency gains of up to 95% in controlled settings. However, deployment is tempered by ecological risks (e.g., community shifts, biodiversity loss), biosafety concerns (e.g., horizontal gene transfer, antibiotic resistance spread), human health implications, and stringent regulatory frameworks. Global case studies highlight contained successes in North America and Asia, contrasted with Europe's precautionary stance and limited field data. For Africa's hotspots, including the Niger Delta, Libya, Angola, Algeria, and emerging producers, GEMs offer tailored prospects for tropical, saline, and heterogeneous environments, promising community empowerment, alignment with Sustainable Development Goals, and cost-effective restoration. Overarching challenges encompass technical stability, monitoring, and equitable partnerships, bridged by interdisciplinary AI, metagenomics, and climate modeling. Ultimately, realizing GEM potential in Africa demands ethical, collaborative innovation to transform hydrocarbon legacies into sustainable renewal, balancing bold advancement with rigorous precaution.