Development of an improved E. coli bacterial strain for green and sustainable concrete technology

Development of smart bioconcrete materials has recently become an emerging area of research for construction. Here, the silica leaching attribute transferred to an E. coli bacterial strain, has been utilized for higher strength and more durable concrete structures. The silica leaching gene was fished out from the BKH2 bacterium (GenBank accession no.: KP231522), amplified by the PCR technique and cloned into E. coli bacteria via a suitable T-vector to develop a bio-engineered E. coli strain. The transformed bacterial cells when incorporated directly into mortar specimens produced high performance biocomposite materials. Improvements on the compressive strength (>30%), ultrasonic pulse velocity (>5%), and decrease in the water absorption capacity were noted in the bacteria amended mortars. FESEM analysis revealed rod-like crystalline structures within the mortar matrices, and XRD analysis confirmed the development of a new silicate phase (gehlenite). The bioengineered E. coli cells can be directly explored for green and sustainable high performance composites in the near future.