Nanobes - a mysterious life form

Nanobacteria are the smallest cell-walled organisms on Earth,
the existence of which is the center of great controversy. A
nanobacterium is by definition one billionth of a meter in
diameter (1/10 the size of bacteria), leaving some to question
whether or not an organism of this size has enough room to
house necessary cell components such as DNA, RNA, and
plasmids.
Nanobes are small features found in organisms and rocks. It is
debatable if nanobes are living entities. This more general term
does not imply that the structures are or have been left behind
by nano-sized bacteria.
While nanobes and nanobacteria are sometimes used as distinct
terms, they are often used interchangably. These terms will be
used interchangably in this text.
Where are Nanobes Found?
Nanobes are thought to exist everywhere! Nanobe structures have
been found within organisms as well as rocks. While their existence
is relatively new knowledge, some speculate that nanobes may
even outnumber bacteria by an order of magnitude!
Nanobes may also exist on other planets! Martian meteorites such
as (https://go.nasa.gov/3w1xhkU) ALH84001 (https://bit.ly/3I03ETC)
have been speculated to contain trace fossils of nanobacteria. The
softball-sized igneous meteorite shows microscopic worm-like and
"ovid" nanofossils.
Nanobacteria are thought to have been found in human blood and
may be related to health issues such as the formation of kidney
stones due to their biomineralizaton processes. This has been met
with some resistance, as some argue that this biomineralization is
caused by the nucleation of (https://bit.ly/3Kyq6EQ) non-living
biological molecules (https://bit.ly/3I51Vwo).
Robert Folk, a sedimentary geologist from Austin, Texas, is known
as the "father of nanobacteria" (although he prefers the spelling
nannobacteria to conform with geological usage). Folk asserts that
nanobacteria are key players in mineral formation and that their
activities aid in the formation of geological strata (e.g. soil
formation). Using acid etching and gentle gold shadowing techniques,
he was the first to demonstrate the presence of 0.05-0.2 µm spherical
structures in an assortment of geologic materials.
Dr. Philippa Uwins, a sedimentary geologist from the University of
Queensland, Australia, discovered nanobes in Jurassic and Triassic
sandstones from Australia in 1996. She and her research team are
hesitant to term their nanobes "nanobacteria" until they are more
certain of their evolutionary history and their general nature. She
and her team have recently performed molecular analyses of these
nanobes and found evidence for the presence of DNA as indicated
by DAPI, Acridine Orange (https://bit.ly/3J6BSpK), and Feulgen
staining (https://bit.ly/3KF6Zt6). In addition, they appear to be
membrane-bound structures that are possibly surrounded by cytoplasm
and nuclear area and are composed of C, N, and O, chemical
constituents associated with living biota (https://bit.ly/3CAFWMG)
Uwins, et al., 1998 (https://bit.ly/35Q01m9).
In 1996, a group of scientists led by David McKay of NASA's Johnson
Space Center published a paper speculating the existence of
nanobacterial trace fossils on Martian meteorite ALH84001. If these
structures were indeed left behind by nanobacteria and if
nanobacteria are true organisms, their findings would imply the
existence of life on Mars at one point in the planet's history.
In 1998, Finnish scientists Olavi Kajander and Neva Ciftcioglu
published a paper in the Proceedings of the U.S. National Academy
of Science about the isolation, culturing, and partial characterization
of ribosomal RNA (rRNA) for nanobacteria in human and cow blood
and commercial blood serum. Their cultured nanobacteria were made
up of apatite, a mineral composed of calcium and phosphate, which
is found in teeth and bones. However, the reliability of their study
results is questionable. The sequenced rRNA from their culture is
almost identical to that of Phyllobacterium mysinacearum, a common
contaminant of the reagents used in sequence analyses. In addition,
other studies have shown that the nanobe culturing media has been
found to spontaneously generate particles that resemble nanobe cells
and "dwelling structures" when inorganic calcium and phosphate
salts are combined with organic materials.
Implications for Nanobacterial Life
Although the existence of nanobacteria would alter our perception
of what qualities are essential for life, the following implications
would be probable if nanobes are indeed alive:
- Organisms may be smaller than previously thought. Proceedings from
a workshop (https://bit.ly/3IjCHup) hosted by the National Academy
of Sciences in 1998 suggested that the simplest organism would need
to be 0.2-0.3µm (200-300 nm) in diameter to hold the molecular
pieces necessary for life (e.g. RNAs, ribosome, protein).
- If nanofossils exist in Martian meteorites, this may indicate the
existence of water at one point in Mars' history. According to
current knowledge, water is thought to be essential for life to
exist.
Nanobacteria may mediate processes currently thought to be controlled
by inorganic chemical reactions, such as low-temperature precipitation
of dolomite, oxidation of iron, and the formation of clay minerals
(https://bit.ly/35T3Hn1) Folk, 1993 (https://bit.ly/3w27vNB).
- Nanobacteria may build essential parts of larger organisms or play
a role in disease in the same organisms. Biomineralization could
result in the formation of bones, shells, teeth, and kidney stones,
and arterial plaque.
Nanobe studies challenge our perception of life. Microbes have
already expanded our understanding of the harsh conditions that
can support life (https://bit.ly/3KFoauw). So, if nanobes do exist
as living biota, they will broaden our perspective on the scale
of life.