Nanostructure of palygorskite/sepiolite in Texas caliche: Possible bacterial origin

Abstract

In a caliche from west Texas, watermelon-shaped calcite crystals arc.coated with fibers of palygorskite/sepiolite clay, which also extend out into pore spaces as spiky filaments. Some filaments arc smooth and capped by ovoid 30 -1OOnm beads. Other filaments arc made of rosary-like chains of beads. These objcets arc seen both in gold-coated and carbon-coated samples, thus are not artifacts. Wc suggest that these minute features were cells of nannobacteria (dwarf forms) that precipitated the clay filaments, in a similar manner as larger bacteria that accumulate clay minerals on their negatively-charged cell walls.

Signatures of biologically influenced CaCo3 and Mg–Fe silicate precipitation in hot springs: Case study from the Ruidian geothermal area, western Yunnan Province, China

“…Notably, ACC was absent in areas that lacked EPS and/or filamentous microbes. Jones & Peng () pointed out that the nanoparticles that form ACC are morphologically similar to the nannobacteria that have been widely reported from many different settings (Folk, ; Folk & Rasbury, ). Nevertheless, these authors argued that ACC can form abiotically by rapid precipitation from supersaturated fluids and that the constituent nanoparticles need not be indicative of calcified nannobacteria.…”

Spotlight on the Association Between Nanobacteria and Some Human Diseases

“…They are also known as calcifying nanoparticles (CNPs). In 1997 Folk proposed that nanobacteria are the foremost operators of precipitation of all minerals and crystals on Earth formed in fluid water, that they moreover cause all oxidation of metals, which are abundant in many biological specimens (Folk, 1993, 2005, Folk & Rasbury, 2007. The nature of these obscure cellculture contaminants and their role in human organ disease has raised a lot of attention in therapeutic and human health research over the final decades (Kajander .…”