Mineralization Mechanism and Application Potential of Vaterite Induced by Two Bacterial Strains

Abstract. Clarifying the bacterial mechanisms underlying vaterite biosynthesis is important for advancing biomineralization theory and expanding its applications in material science, environmental protection, and biomedicine. In this study, Bacillus velezensis LB002 and Pseudomonas putida KT2440 were used as representative bacterial strains to compare strain-dependent vaterite formation and environmental remediation performance. The biomineralization processes in the liquid medium were dynamically monitored, and the induced biominerals were characterized, with particular attention to their organic components. The differences in vaterite characteristics between both bacterial systems were evaluated, and their remediation potential was assessed using Cu²⁺ and tetracycline removal as model applications. Both strains induced vaterite formation under identical culture conditions, while B. velezensis exhibited a stronger biomineralization capacity than P. putida. In a 100 mL culture system, the Ca²⁺ mineralization percentage of B. velezensis reached 35.06 %, and the dry weights of biomineral aggregates produced by B. velezensis and P. putida were 0.36 and 0.31 g, respectively. SEM observations revealed that the vaterite induced by B. velezensis had a loose and porous surface, whereas that induced by P. putida had a relatively smooth surface. For the high concentration of Cu²⁺ at 50 mg/L, the removal rate reached 84.93 % for B. velezensis-induced vaterite, compared with 71.86 % for P. putida-induced vaterite under the same conditions. Both biominerals demonstrated similar tetracycline removal performance, with removal rates of approximately 60 %. These findings provide comparative evidence for strain-dependent vaterite formation and support the potential application of biogenic vaterite in environmental remediation.