Clay-armored bubbles show minerals played key role in origin of life

WASHINGTON - The discovery of inorganic, semipermeable clay vesicles has shed light on how minerals could have played a key role in the origins of life.

The study by a team of applied physicists at Harvard’s School of Engineering and Applied Sciences (SEAS), Princeton, and Brandeis found that semipermeable vesicles are formed from inorganic clay stating that the clay vesicles provide an ideal container for the compartmentalization of complex organic molecules.

It has opened the possibility that primitive cells might have formed inside inorganic clay microcompartments.

“We have now provided a complete physical mechanism for the transition from a two-phase clay-air bubble system, which precludes any aqueous-phase chemistry, to a single aqueous-phase clay vesicle system creating a semipermeable vesicle from materials that are readily available in the environment,” said lead author Anand Bala Subramaniam, a doctoral candidate at SEAS.

‘Clay-armored bubbles’ form naturally when platelike particles of montmorillonite collect on the outer surface of air bubbles under water.hen the clay bubbles come into contact with simple organic liquids like ethanol and methanol, which have a lower surface tension than water, the liquid wets the overlapping plates. As the inner surface of the clay shell becomes wet, the disturbed air bubble inside dissolves.

The resulting clay vesicle is a strong, spherical shell that creates a physical boundary between the water inside and the water outside.

Microscopic pores in the vesicle walls create a semipermeable membrane that allows chemical building blocks to enter the ‘cell,’ while preventing larger structures from leaving.

Scientists have studied montmorillonite, an abundant clay, for hundreds of years, and the mineral is known to serve as a chemical catalyst, encouraging lipids to form membranes and single nucleotides to join into strands of RNA.

Because liposomes and RNA would have been essential precursors to primordial life, researchers have suggested that the pores in the clay vesicles could do double duty as both selective entry points and catalytic sites.

The findings have been published in the journal Soft Matter. (ANI)