Biogenic Calcium Carbonate: Calcite Crystals of Variable Morphology by the Reaction of Aqueous Ca2+ Ions with Fungi

✍ Scribed by A. Ahmad; D. Rautaray; M. Sastry

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 408 KB
• Volume: 14
• Category: Article
• ISSN: 1616-301X
• DOI: 10.1002/adfm.200400005

✦ Synopsis

Abstract

The biological synthesis of CaCO~3~ crystals of variable morphology by challenging non‐calcareous microorganisms such as fungi with aqueous Ca^2+^ ions has been described. Many fungi are known to produce reasonable amounts of CO~2~ during growth. We show here that CO~2~ and characteristic proteins released from the fungi Fusarium oxysporum and Trichothecium sp. may be reacted with aqueous Ca^2+^ ions to produce truly biogenic CaCO~3~ crystals. While calcite crystals are obtained with both fungi, significant differences in the morphology of the crystals is observed, indicating that the proteins secreted by the fungi play a crucial role in directing the morphology of the calcite crystals. The action of specific proteins secreted by the microorganisms in directing calcite crystal morphology as well as the more complex issue of synergistic action of mixtures of proteins in directing crystal structure and morphology has been addressed.