## 1 Introduction  
Microbial Induced Carbonate Precipitation (MICP) through a ureolytic pathway is nowadays a subject of intense research interest in the field of biogeochemical as it provides solutions to a wider range of engineering applications. Several studies have demonstrated that MICP can be employed to improve the mechanical properties of weak porous materials [1] and cater to a number of technological applications including ground reinforcement, slope stabilization, liquefaction prevention, erosion prevention of dams and levees, toxic metals removal from contaminated wastewaters/waters, immobilization of hazardous contaminants in soil, and CO\({}_{2}\) sequestration, among others [2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16]. Recently, this mechanism has been suggested as a novel approach towards erosion mitigation of sandy soils in nearshore regions as it is a minimal disturbance to natural coastal environment. Loose beach sands generally show high erodibility under strong wave action, rising sea levels, as well as under strong wind currents closer to the surface. Conventional engineering solutions such as construction of sea walls, dykes, embankments, groins, and breakwaters have succeeded in combatting the beach sand erosion problem over decades [17; 18]. However, they are associated with continual and costly maintenance work, large visual impact lowering the recreational values of beaches and downdrift erosion in the presence of alongshore currents [18]. Chemical grouting is another commonly applied technique in civil engineering to stabilize weaker sands/soils. However, most of the chemical grouts are toxic to humans and require comparatively high cost [1]. Greener solutions such as vegetation belts, sand supply, and artificial dunes are not primary solutions but mere additional measures to protect beaches [17]. The myriad of issues associated with conventional engineering solutions have necessitated a search for alternative measures and, markedly, MICP has gained a lot of attention due to its economical and ecological sustainability. Albeit in limited amounts, previous studies have already shown possible avenues for loose beach sand stabilization for coastal zone management through MICP-based biogeochemical approaches [19; 20; 21; 22; 23]. MICP is based on a set of complex biochemical reactions which ultimately produce calcium carbonate (CaCO\({}_{3}\)) crystals that physically bond the loose sand grains together thereby improving mechanical and geotechnical engineering properties of treated sand [24]. In MICP, microbial enzyme urease (urea amidohydrolase; EC 3.5.1.5) catalyzes hydrolysis of urea (CO(NH\({}_{2}\))\({}_{2}\)) to ammonia and carbonic acid (H\({}_{2}\)CO\({}_{3}\)) (Equations (1) and (2)). The resulting ammonia and carbonic acid equilibrate to form HCO\({}_{3}\)\({}^{-}\) (Equation (3)) and NH\({}_{4}\)\({}^{+}\) (Equation (4)) with equilibrium constants of pK\({}_{1}\) 6.3 and pK\({}_{4}\) 9.3, respectively [25]. This phenomenon creates a high carbonate alkalinity in the micro environment around the cell [26] which favors the formation of carbonate ions (Equation (5)). In the presence or supply of a calcium source, Ca\({}^{2+}\) ions will be attracted towards negatively charged bacterial cell walls, resulting a localized state of super saturation with respect to calcium carbonate. Subsequently, calcium carbonate will be precipitated on cell surfaces which also act as nucleation sites (Equation (6)) once a certain level of supersaturation is achieved [13].