This study comprehensively investigates the literature on using bacteria to confer self-repair abilities on concrete and mortar. Although crack-healing is the main objective, calcite-precipitating bacteria affect concrete's durability and mechanical properties. This article reviews the research on bacteria-based self-healing concrete and its developments from 1984 to 2023. This systematic review was developed by adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. R studio and Vosviewer were used to perform bibliometric analysis and visualization of the 295 documents by 874 authors affiliated with 97 sources acquired from Scopus (NY). It is vital to emphasise that the document selection was carried out by two impartial reviewers to prevent any bias. In addition to repairing cracks in the material, the data indicate that applying various self-healing bacteria improves concrete's mechanical and durability properties. A meta-analysis evaluated the summary effect size of the most cited articles. It was concluded with the statistical evidence from the meta-analysis that bacteria incorporated concrete, which shows self-healing efficiency of 5.07 and 7.29 times than that of control concrete.

Maintaining concrete structures by using bacterial agents to repair microcracks is a promising strategy for maximizing their lifespan. A non-ureolytic and alkali -tolerant B6 strain, newly isolated from paddy soil, was tested for microbiologically induced calcium carbonate precipitation (MICP) performance along with its antibacterial activity for pathogen removals. Whole genome and bioinformatic analyses showed that our B6 strain could be designated as Bacillus altitudinis with its 16S rDNA and average nucleotide identity. Field emission scanning electron microscopy (FE -SEM) and X-ray diffractometry (XRD) revealed that the B6 strain could form vaterite and produce extracellular polymeric substances, thereby contributing to excellent biofilm formation, even under high pH conditions. The MICP in the B6 cells, inoculated on cracked mortars, could repair microcracks (0.3 mm) within 14 days. The presence of vaterite and survivability by the B6 cells inside the healed area was verified using energy -dispersive X-ray spectroscopy and FE -SEM. Antibacterial activity was determined using the supernatant of the B6 cells grown in rich media at pH 8 and showed that the cell -free extract could kill Grampositive bacteria, including Staphylococcus aureus and Enterococcus faecalis, by damaging their cellular membranes. Thermostable thiocillin, a putatively secreted antibacterial compound, was identified using biosynthetic gene cluster analyses for secondary metabolites and chemical analysis using reversed -phase high-performance liquid chromatography (RP-HPLC/UV) and ultra -performance liquid chromatography (UPLC)-mass spectrometry (MS). Our data demonstrated that the MICP and antibacterial activities of the B6 strain could be promising components for repairing microcracks and controlling the pathogen contamination of concrete.