Zellaufbau mariner Primärproduzenten (Archaeen, Bakterien, Algen, Pilze)

Biologie für die Geowissenschaften

Algen sind wichtige Gesteinsbildner!

Kreidefelsen (Rügen)

Rock Formation

Coccolithophoriden

Oxygenation of the Atmosphere

Oldest stromatolite

Biomarker evidence for cyanobacteria

Petroleum Formation

Microorganisms are important sources

of fossil fuel!

Role of Microorganisms in the Geological Context

• Biomineralization

• Microbial weathering

• Sources of fossil fuels

• Cycling of nutrients

• Development of life

• Reconstruction of past environments

Carbon cycle Nitrogen cycle Sulfur cycle

Climate!

Fossils

Mikrofossilien Molekulare Fossilien

Mikroorganismen Biomoleküle

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Stigmasterol

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Stigmastanol

Makroorganismen

Makrofossilien

Zeit

Biomarkers

Land plants: • Long chain alkyl lipids (e.g. C27, C29, C31 n-alkanes) • Triterpenoids • Lignin

Algae: • Alkenones (haptophyte algae) • Heterocyst glycolipids (Cyanobacteria) • 4Me-Sterol (Dinoflagellates) • HBIs (Diatoms)

Bacteria: • Isorenieratene (green sulfur bacteria) • Brachned glycerol dialkyl glycerol tetraethers (brGDGTs, soil bacteria)

• Archaea: • Isoprenoid GDGTs (isoGDGTs)

Alkenones

Alkenone sind eine Klasse

der Ketone

Besitzen einen

unterschiedlichen Grad der

Unsättigung, welcher

Temperaturabhängig ist

Aus dem Verhältnis der

einzelnen Alkenone

zueinander lassen sich

Paläotemperaturen

bestimmen → Uk37

Distribution of C37-

C39 alkenones in an

axenic culture of E.

huxleyi.grown at 10°C

(A) and 25°C (B). In

addition, gas

chromatograms

showing the

distribution of

alkenones in

sediments from the

coastal region off

southern Washington

state (C) and the

tropical North Pacific

(D) are shown. Note

the good match

between alkenone

distribution pattern in

cultures and natural

environments of similar

temperature.

Alkenones

10 °C 25 °C

[C37:2] – [C37:4]

[C37:2 + C37:3 + C37:4] UK

37 =

[C37:2]

[C37:2] + [C37:3] UK’

37 =

Alkenones

Alkenones

Relationship between Life

Bacteria

16S rRNA

Kingdoms:

Domains: Bacteria Archaea

Bacteria Archaea

Woese 1977

Microscopy Biochemistry Metabolism

Prokaryotes

Phylogenetic Tree of Life

pro = vor karyon = Kern Lebewesen ohne Zellkern

eu = echt karyon = Kern Lebewesen mit Zellkern

Common Ancestor

Classification Scheme

= Eukaryota

= Protista

= Prymnesiophyceae

= Isochrysidales

= Noelaerhabdaceae

= Emiliania

= Emiliania huxleyi

Bacteria

Bacteria (Greek: bacterion = cane) constitute a large domain of prokaryotic microorganisms. Currently ca. 9,300 species (Bacteria + Archaea) are known but it is estimated that bacterial diversity ranges from 107 to 109 species. Most Bacteria are unicellular and either show a rod-shaped (bacilli) or spherical (cocci) form. Other forms are also common, e.g. spiral-shaped (spirilla), tightly coiled (spirochaetes), tetrahedral or cuboidal shape.

Bacteria are rather small and typically 0.5-5.0 µm in length. Some species, such as Thiomargarita namibiensis is about ~0.5 mm long and Epulopiscium fishelsoni reaches up to 0.7 mm. Some of the smallest bacteria belong to the genus Mycoplasma, which measures only 0.3 µm and is thus as small as the largest virus.

BAct

Bacteria

The cell membrane (=cytoplasmic membrane, plasma membrane) is a bilayer consisting of phospolipids with fatty acid tails bound via an ester linkage to a glycerol.

Bacteria

Gram-negative (e.g. Pseudomonas aeruginosa)

Gram-positive (e.g. Bacillus cereus)

Bacteria

Archaea

Archaea (Greek = ancient things) are unicellular prokaryotes that in size and shape are very similar to Bacteria. Rods, spheres, sprials or plates are most common. They usually range from 0.1 µm to over 15 µm in diameter. Archaea occur in most of Earth‘ s habitats. They have first been described from various extrem environments such as black smokers at hydrothermal vents, geysers and oil wells but also from highly saline, acidic or alkaline waters. Yet, many Archaea are mesophiles that grow in mild conditions, in swamps, sewage, soils, freshwater in the ocean and the interstinal tract of animals. The number of species cannot be estimated with any accurarcy at present. The number of phyla may range from 18 to 23 and only 8 have representatives that are in culture and can directly be studied.

M. thermoautotrophicus N. maritimus Sulfolobus

Halobacteria Hot spring Haloquadratum

Archaea

N. maritimus Sulfolobus

Halobacteria Hot spring

Archaea

Extremophiles Mesophiles

(Hyper-) Thermophiles

Halophiles Alkaliphiles Acidophiles

Halobacterium Salinity >20-25%

Thermophiles >45 °C Hyperthermophiles >80 °C

pH ~ 8.5-11 optimum ~ 10

pH <2 Picophilus torridus grows at pH =0

Nitrosopumilus spp. abundant in the ocean

Archaea

The Euryarchaeota host numerous extremophiles that thrive under harsh environmental conditions including (hyper)thermophiles, acidophiles and halophiles. They also contain members of the methanophiles.

Archaea

The Crenarchaeota were initially thought to be sulfur-dependent extremophiles, some of which have the ability to grow up to 113 °C. They are either rod-, cocci-, filamentous or oddly shaped cells. Sulfolobus solfataricus lives at 80°C and a pH 2-4.

Archaea

The phylum Thaumarchaeota was first introduced in 2008 after the genome of Cenarchaeum symbiosum was sequenced, which differed significantly from other members of the Crenarchaeota. All organisms of this lineage are chemolithoautotrophic ammonia-oxidizers. As they constitute ca. 20% of the world‘s picoplankton they may play an important role in the marine nitrogen and carbon cylces.

Archaea

Hot spring

Archaea TA

CK

A

stga

rd

Archaea

Archaea

GDGT-0 (Caldarchaeol) GDGT-1

GDGT-2 GDGT-3

GDGT-4 (Crenarchaeol)

+VI

Archaea

Archaea

Archaea

Thaumarchaeota may constitute up to 20% of the world‘s picoplankton.

Archaea

Eukaryotes

Eukaryotes

Eukaryotes

Property Archaea Bacteria Eukarya

Cell Membrane Ether-linked lipids,

Pseudopeptidoglycan

Ester-linked lipids,

peptidoglycan

Ester-linked lipids, various

structures

Gene Structure Circular

chromosomes, similar

translation and

transcription to

Eukarya

Circular

chromosomes,

unique translation

and transcription

Multiple, linear chromosomes,

similar translation and

transcription to Archaea

Internal Cell

Structure

No membrane-bound

organelles or nucleus

No membrane-

bound organelles

or nucleus

Membrane-bound organelles

and nucleus

Metabolism Various, with

methanogenesis

unqiue to Archaea

Photosynthesis,

aerobic and

anaerobic

respiration,

fermentation,

autotrophy

Photosynthesis and cellualr

respiration

Reproduction Asexual reproduction,

horizontal gene

transfer

Asexual

reproduction,

horizontal gene

transfer

Sexual and asexual

reproduction

Characteristics of the different domains of life

The principal taxa of algae (primary producers) that are found over most of the world‘s oceans are diatoms, coccolithophorids, dinoflagellates, cyanobacteria, green algae, silicoflagellates. They generally range in size between 2 µm in e.g. unicellular species such as Chlorella or diatoms to 50 min giant kelp (a brown algae)

Algae

Nanoplankton (diatoms, coccolithophorids)

Ultrananoplankton (cyanobacteria, green sulfur bacteria (e.g. Chlorobium)

Macroplankton (seaweed, brown algae)

Dinoflagellaten

Diatomeen

Grünalgen

Cyanobakterien

Braunalgen

Haptophyta

Algae

Diatoms are a major group of algae and with ca. 45 % are responsible for most of

the primary production in the present-day oceans. A characteristic feature of

diatom cells is that they are encased within a unique cell wall made of silica and

pectin, often with complex sculptured surfaces and range in size from 2 to 200

μm. The silica cell wall is also called frustule, which usually shows a wide diversity

in form, but consists of two asymmetrical sides with a split between them.

There are more than 200 genera with 6000 species of living diatoms but it is

estimated that there are approximately 100,000 extant species. Most diatoms live

pelagically in open waters but they are found in the oceans, freshwater, in soils

and on damp surfaces

Diatomeen

Dinoflagellates constitute the second most abundant algal group in the present-

day ocean. They occur as single cells, either as naked cells or within cellulose

cell walls that range in size from 0.001 to 0.1 mm. They are cosmopolites that

occur in oceans, freshwater, brackish water, glaciers, sea ice, etc.

Dinoflagellates are planktonic, drifting with the water, although many species

use flagella to move. The majority of all dinoflagellates is found in the marine

realm with the largest variety of species restricted to the tropics.

Peridinium sp.

Ceratium sp. Ceratium pentagonum

Dinoflagellaten