RT Journal Article
T1 Bacterial EPS in Agarose Hydrogels Directs Mineral Organization in Calcite Precipitates: Species-Specific Biosignatures of Bacillus subtilis, Mycobacterium phley, Mycobacterium smagmatis, and Pseudomonas putida EPS
A1 Yin, Xiaofei
A1 Weitzel, Florian
A1 Griesshaber, Erika
A1 Fernández Díaz, Lurdes
A1 Jiménez López, Concepción
A1 Ziegler, Andreas
A1 Rodríguez Navarro, Alejandro
A1 Schmahl, Wolfgang W.
AB Hydrogels present model systems for biopolymer matrices in biological structural materials, as their fabric and physicochemical properties can be tailored to mimic characteristics of polymer matrices in biological hard tissues. However, hydrogels comprise synthetic compounds and lack attributes of native biopolymers, in contrast to extracellular polymeric substance (EPS) actively secreted by microbes for protection and enhancement of physiological activities. For testing the directing influence of native biopolymers on mineralization, we precipitated calcite/gel composite aggregates from agarose gels containing EPS of Bacillus subtilis, Mycobacterium phley, Mycobacterium smagmatis, or Pseudomonas putida, respectively. We characterized the aggregates with Fourier transform infrared spectroscopy, field-emission scanning electron microscopy imaging, and electron backscatter diffraction. Relative to reference aggregates devoid of EPS, aggregates containing EPS are reduced in size and show distinctive morphologies directed by the EPS of a specific bacterium. In P. putida and M. phley composites, occluded polymers are present as membranes, for M. smagmatis and B. subtilis occluded polymers are mainly developed as networks of fibrils. Precipitate crystal subunit formation in EPS-containing composites is extensive compared to the reference crystal; subunits vary in shape, size, and organization: for M. smagmatis and B. subtilis, subunit organization is radial to spherulitic; for P. putida, it is random; for M. phley, it is coaligned in all three dimensions (single-crystal-like). Bacterial EPS changes mineral microstructure/texture in a species-specific manner, a characteristic that, when developed further, might be used as an identification tool for bacterial calcification in present/past environments.
PB Elsevier
SN 1528-7483
YR 2020
FD 2020
LK https://hdl.handle.net/20.500.14352/7551
UL https://hdl.handle.net/20.500.14352/7551
LA eng
NO Ministerio de Ciencia e Innovación (MICINN)
NO Deutsche Forschungsgemein- schaft,
DS Docta Complutense
RD 5 may 2024