Naslov
Biomimetic precipitation of calcium carbonate polymorphs by urease enzyme catalyzed decomposition of the urea

Autori
Sondi, Ivan ; Salopek-Sondi, Branka

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Proceedings, Seventh Multinational Congress on Microscopy (ISBN 961-6303-69-4) / Čeh, Miran ; Dražić, Goran ; Fidler, Sanja - Ljubljana : Slovene Society for Microscopy and Department for Nanostructured Materials, Jožef Štefan Institute, 2005, 535-535

Skup
Seventh Multinational Congress on Microscopy

Mjesto i datum
Portorož, Slovenija, 26.06.2005. - 30.06.2005

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
calcium carbonate polymorph; precipitation; urease-catalyzed decomposition of urea; crystal phase formation; Canavalia ensiformis; Bacillus pasteurii

Sažetak
Precipitation processes of carbonate particles of different size, shape, and surface properties have been intensely investigated due to their importance in geo- and biosciences and in numerous industrial applications. This study describes and discusses a conceptually new method for the precipitation of calcium carbonate polymorphs, effectuated through catalytic decomposition of urea by urease enzymes in solutions of calcium salts. Specifically, the influence of plant (Canavalia ensiformis) and bacterial (Bacillus pasteurii) ureases on the nucleation and growth of carbonate precipitates was investigated. The structure and morphology of the obtained precipitates were investigated using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Despite of the same catalytic function in the decomposition of urea, the two ureases exert different influence on crystal phase formation and on the development of unusual morphologies of calcium carbonate polymorphs. These differences may be explained by dissimilarities in the amino acid sequences of the two examined ureases and their different roles in nucleation and physico-chemical interactions with the surface of the growing crystals. Finally, the results of this study exemplify that different organisms in nature have the ability to produce different proteins with the same function and that, with slight variation of their primary structure, they take control over the crystal phase formation and growth processes of biogenic calcium carbonate precipitates.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Biologija

POVEZANOST RADA