Characterization of Biominerals in Cacteae Species by FTIR

A biomineral is a crystalline or amorphous mineral product of the biochemical activity of an organism and the local accumulation of elements available in the environment. The cactus family has been characterized by accumulating calcium oxalates, although other biominerals have been detected. Five species of Cacteae were studied to find biominerals. For this, anatomical sections and Fourier transform infrared, field emission scanning electron microscopy and energy dispersive x-ray spectrometry analyses were used. In the studied regions of the five species, they presented prismatic or spherulite dihydrate calcium oxalate crystals, as the predominant biomineral. Anatomical sections ofAstrophytum asteriasshowed prismatic crystals andEchinocactus texensisamorphous silica bodies in the hypodermis. New findings were forAriocarpus retusussubsp.trigonuspeaks assigned to calcium carbonate and forMammillaria sphaericapeaks belonging to silicates.