Background: Biomineralization is a significant process performed by living organisms in which minerals are
produced through the hardening of biological tissues. Herein, we focus on calcium carbonate precipitation,
as part of biomineralization, to be used in applications for environmental protection, material technology, and
other fields. A strain GM-1,
Microbacterium
sp. GM-1, isolated from active sludge, was investigated for its
ability to produce urease and induce calcium carbonate precipitation in a metabolic process.
Results: It was discovered that
Microbacterium sp. GM-1 resisted high concentrations of urea up to 60 g/L. In order
to optimize the calcification process of
Microbacterium sp. GM-1, the concentrations of Ni
2+ and urea, pH value,
and culture time were analyzed through orthogonal tests. The favored calcite precipitation culture conditions
were as follows: the concentration of Ni
2+ and urea were 50 μM and 60 g/L, respectively, pH of 10, and culture
time of 96 h. Using X-ray diffraction analysis, the calcium carbonate polymorphs produced by
Microbacterium
sp. GM-1 were proven to be mainly calcite.
Conclusions: The results of this research provide evidence that
Microbacterium sp. GM-1 can biologically induce
calcification and suggest that strain GM-1 may play a potential role in the synthesis of new biominerals and in
bioremediation or biorecovery.
