2004 Denver Annual Meeting (November 7–10, 2004)
Paper No. 28-3
Presentation
Time: 2:00 PM-2:15 PM
SHOULD ORGANIC COMPOUNDS FOUND IN ASSOCIATION WITH MINERALS BE
CALLED BIOMINERALS?
PERRY, Randall S.1, BRASIER, Martin D.2, ENGEL, Michael H.3, GREEN, Owen R.4, GORBUSHINA, Anna A.5, KOLB, Vera M.6, KRUMBEIN, Wolfgang E.5, PERRY, Carole C.7, CAMPBELL, Kathleen8, and STALEY, James T.9, (1) Earth Sciences, Oxford Univ and Planetary
Sci Institute, Parks Road, Oxford, OX1 3PR, United Kingdom, perry@psi.edu, (2) Earth
Sciences, Univ of Oxford, Parks Road, Oxford, OX1 3PR, United Kingdom, (3)
School of Geology and Geophysics, Univ of Oklahoma, 100 East Boyd St, Norman,
OK 73019-1009, (4) Earth Sciences, Univ of Oxford, Parks Rd, Oxford, OX8 1HL,
United Kingdom, (5) Geomicrobiology, ICBM Carl von Ossietzky Univ, Oldenburg,
26111, Germany, (6) Chemistry, Univ of Wisconsin-Parkside, 900 Wood Rd,
Kenosha, WI 53141-2000, (7) Chemistry Division, The Nottingham Trent Univ,
Clifton Lane, Nottingham, NG11 8NS, (8) Department of Geology, Univ of
Auckland, pb 92019, Auckland, New Zealand, (9) Department of Microbiology,
School of Medicine, Univ of Washington, Seattle, WA 98195-1310
Most
higher organisms form exo- or endoskeletons by the direct precipitation of
minerals (e.g. silica, calcite, apatite), a process called biomineralization.
This involves the selective uptake of elements and their incorporation into
macro-molecular mineral structures under direct biological control. However,
minerals are also biologically induced. The recognition of biominerals (or
their remnant chemical signatures) in ascertaining the presence of past life is
important when considering the veracity of Archaean fossils, life preserved in
meteorites, or microbial deposits (e.g. Metallogenium).
Can we clearly define which minerals are indicators of life? Does the presence
of organic compounds support the existence of past life? While studying desert
varnish, silica sinter and silica glazes, DNA, amino acids, pigments, and
polymorphic organic compounds were identified along with silica and metal
oxides. For instance, many researchers have identified living microorganisms on
rock coatings. However, there have been only few, if any, viable models for a
direct microbial contribution in producing, for example desert varnish.
Formation of these “biologically-induced” silica-related coatings through
non-biological means poses the question: can any of these deposits be called
biominerals? Life-related organics have measurable effects (biosignatures) when
found in association with minerals, but when living cells are not directly
responsible, existing terminology can be misleading. Biomineralization is a
useful descriptive term. However, the indirect formation of minerals by
organisms, such as by the alteration of local Eh-pH conditions, the contribution of biological organic compounds
to altering biogeochemical reactions and the fossilized biopolymers, could be
more appropriately be termed organominerals. This term has been used in the
hydrocarbon and agricultural industries but has not generally been applied to
natural minerals that are of special interest to microbiologists,
paleontologists, and astrobiologists. We propose that the term organomineral
provides a more succinct definition of minerals not produced directly by
organisms, but formed with organopolymers, bio(organic), and/or organic
compounds without the direct evidence of skeleton or intracellular formation.
2004
Denver Annual Meeting (November 7–10, 2004)
General
Information for this Meeting
Session No.
28
Geomicrobiology:
Microbe-Mineral Interactions, Life in Extreme Environments, and Early Microbial
Life on Earth
Colorado
Convention Center: 703
1:30
PM-5:30 PM, Sunday, November 7, 2004
Geological Society of America Abstracts with Programs, Vol. 36, No. 5, p. 87