Abstract
The ubiquity of the CRISPR gene system in bacteria and archaea is
characterized by the Cas9 protein, which functions in the repression and activation of
several genes. This inherent function of the CRISPR system can find application in
bioprocess optimization in environmental and health research. Owing to the complex
and dynamic nature of microbial communities catalysing the bioremediation of urban
and industrial toxic waste effluents in wastewater treatment plant (WWTP)/common
effluent treatment plant (CETP), such sites represent a relatively untapped area for
applying the CRISPR technique. DNA editing using CRISPR can enable the sitespecific enhancement in process efficiency of bacterial remediation, which under
normal conditions is hampered by its non-selectivity and saturation of binding sites
with multiple non-targeted pollutants. Similarly, under the second generation biorefinery concept, CRISPR can serve as a powerful tool in strengthening and improving
the anaerobic bio-processes by genome editing in microbes for the heterogeneous
expression of various genes associated with anaerobic digestion. Not only has the
CRISPR system been used to insert desired genes in the host genome but also to
regulate the expression of the host-specific genes. The role of methanotrophic and
nitrogen metabolizing bacteria in shaping the atmospheric gaseous composition can
also be monitored via CRISPR aided manipulation so as to regulate the nutritional
exchange between the atmosphere and the soil. Additionally, genome editing of
targeted organisms and crops has found extensive applications in various areas ranging
from the nutrigenomics, food and pharmaceutical industry, diagnostics and
therapeutics, health and disease prevention.