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.
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 Ni2+
and urea, pH value,
and culture time were analyzed through orthogonal tests. The favored calcite precipitation culture conditions
were as follows: the concentration of Ni2+
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.
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.