Tests for nanobacteria.

Robert Clark rgclark at my-deja.com
Mon Apr 9 11:09:16 EST 2001

 A recent paper on biogenic phosphate isotopes may provide
a means of testing the hypothesis that nanobacteria are
the cause of kidney stones as Kajander et. al. maintain:

Nanobacteria: An alternative mechanism for pathogenic intra-
and extracellular calcification and stone formation
Proc. Natl. Acad. Sci.,Vol. 95, Issue 14, 8274-8279, July 7,

or whether the observed mineralization was due to inorganic processes,
as Cisar et. al. maintain:

An alternative interpretation of nanobacteria-induced biomineralization
Proc. Natl. Acad. Sci., Vol. 97, Issue 21, 11511-11515, October
10, 2000

 The paper was able to determine if apatite had a biogenic
origin by measuring its phosphate isotope ratios:

Oxygen isotope ratios of PO4: An inorganic indicator of
enzymatic activity and P metabolism and a new biomarker
in the search for life
Proc. Natl. Acad. Sci., Vol. 98, Issue 5, 2148-2153,
February 27, 2001

 Another possibility is to use the chiral labeled release
experiment of Gil Levin:

An Unambiguous Martian Life Detection Experiment

 Kajander et.al. mentioned in their article that they
measured respired gases as a marker of the nanobacteria.
Perhaps this can be adapted to use nutrients containing
only left-handed and right-handed amino acids separately.

 Another possibility was discussed by Lin Chao at a NASA

Defining Life

 Chao notes that life has the ability to evolve when
exposed to new environments. He suggests successively
transferring the putative life forms to a new nutrient
batch and observing whether or not they become more
efficient at utilizing the nutrients.
 Kajander et.al. discussed transferring a portion of the
nanobacteria to a fresh medium, but it's not clear to me
that they were observing increased efficiency in utilizing
the medium, such as by faster reproduction times, larger
biofilm produced or increased measured respiration rates.
 Also, the transfer should take place after the supposed
nanobacteria have used up all the nutrient in order to
use the effect of the more evolved forms crowding out the
old forms. One problem though is the much slower reproduction
rates of the nanobacteria. This might make it difficult to
observe the number of generations that would be expected
for them to evolve to more efficient forms.

 It is interesting to note that there has been a separate
observation of filterable, highly-resistant bacteria with
mineral coats:

Bacteria pressed into service as living transistors

  This occurred in electronic clean-rooms. The researchers
found the bacteria were getting through in the ultra-pure
water that was specially treated to eliminate bacterial contamination.
The water was exposed to UV and oxidants to
kill any bacteria present, but it was later found some
bacteria were able to survive the treatment.
 I wrote the researchers and was told the bacteria were
able to even pass through very small filters with pore
sizes on the nanometer scale. This is interesting in that
the bacteria they found were normal sized, but the pore
sizes of the filters were on the order of tens of nanometers.
One suggestion was that the bacteria were able to "grow"
through the filters, but I don't think they have a clear
idea of how they were able to do it.
 This might explain the mineralization Cisar et.al. observed
even with sterile solutions:

"Serum or saliva components that are potential nucleators of
biomineralization in primary nanobacterial cultures would
eventually be diluted out on subculture, and thus, these
components may not account for the long-term transferability of
biomineralization to fresh medium. However, apatite is also a nucleator
In fact, we found that this mineral, formed
from sterile solutions of CaCl2 and NaHPO4 in DMEM, promoted
further apatite formation, even after repeated dilution
(i.e., 1:10) of the DMEM/apatite suspension to fresh DMEM. In addition,
SEM of apatite formed under such conditions and,
scraped from the culture flask, revealed clusters of small
coccoid-shaped particles (Fig. 4 c-e) and dwelling-like
structures (Fig. 4f) that closely resembled putative
nanobacteria cultured either from saliva (Fig. 2a), FBS
(6), or human kidney stones (9). Thus, the effect of apatite
on metastable concentrations of calcium and phosphate ions
in DMEM is sufficient to account for both the sustained,
life-like transferability of biomineralization and the wide
range of morphological forms previously attributed to
nanobacteria (6)."
An alternative interpretation of nanobacteria-induced biomineralization
Proc. Natl. Acad. Sci. USA, Vol. 97, Issue 21, 11511-11515, October 10, 2000

          Bob Clark


 "In science, everything is significant."
      - Bob Clark

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