powerpoint presentation - soi bacteria - soil science at...

Soil Organisms

• Classification schemes for organisms• Basis for classification• How classifications relate to each other• What classification says about an

organism’s role in environmental processes and vice versa

How are life forms and their activity in soil categorized?

• Physical identification of organisms, their description and naming

• Biochemical characterization of organisms and naming (microbes)

• Identification of soil processes and organisms’ role(s) in these

• Ecosystem function – producers, consumers

• Trophic (physiological) group– e.g., aerobe, anaerobe, denitrifiers, etc.

• Phylogenetic/taxonomic identification– e.g., Proteobacteria, Pseudomonas, etc.

Categories

Organic material

Carbon dioxide, inorganic materials

Ecosystem function

Ecological classification: Producers

– Generate organic materials that consumers and decomposers feed on

• Plants • Green algae, Cynaobacteria (Blue-green algae)• Mineral-oxidizing bacteria (lithotrophs)

Ecological classification: Consumers

– Feed directly on plants or on other consumers

– Animals including• Macrofauna (moles, snakes)• Mesofauna (ants, worms)• Microfauna (nematodes, protozoa)

Ecological classification: Decomposers

Microflora• Bacteria (including actinomycetes)• Fungi (including yeasts)

Trophic categories

• Defined by:– Source of carbon for cell synthesis – mechanisms used to generate energy

• Define majority of transformations that comprise element cycles

Organic carbonCarbon dioxide

Autotrophs

Heterotrophs

(Producers)

(Consumers & Decomposers)

Carbon source categories

• Energy harnessed during the movement of electrons (e-)– Requires a reduced e- donor & oxidized e-

acceptor• Dissimilatory reaction

– Energy is extracted – Materials are released (oxidized e- donor,

reduced e- acceptor)

Energy generation

Energy generation categories: Electron donor types

• Organotroph– Organic compounds

• Consumers and decomposers• Invariably use organics for cell synthesis


• Lithotroph – Inorganic compounds

• Producers• Invariably use carbon dioxide for cell synthesis


• Phototroph– Light

• Producers• Invariably use CO2 for cell synthesis

Trophic category summary

• Organoheterophs– Often abbreviated to “heterotroph”

• Photoautotrophs– Often abbreviated to “phototroph”

• Lithoautotrophs– Often abbreviated to “autotroph”

• Oxygen • Oxidized forms of:

– nitrogen– sulfur– metals

• Halogenated organic compounds

Energy generation categories: Electron acceptor types

• Aerobes• Facultative anaerobes• Anaerobes

Energy generation categories based on electron acceptor use

• Use of oxygen only• “obligate” or “strict”

– Includes:• Macro-, meso- , micro-fauna• Microflora: most fungi, many bacteria including

all actinomycetes

Aerobes

• Use O2 if available• If O2 is absent, use alternate acceptor or

ferment• Alternate electron acceptors include

– Nitrate (most common)– Iron/manganese/sulfate (less common)

• Includes:– Bacteria– Eukaryotes (capable of limited fermentation)

Facultative anaerobes

• Unable to use O2 as electron acceptor• Use:

– oxidized metals (Fe, Mn, others), S– CO2– Halogenated organics

• Lack protection against toxic oxygen species• “obligate” or “strict”• Include Bacteria and Archaea

Anaerobes

PLANT DEBRIS

FUNGI BACTERIANEMATODES

MITES PROTOZOANS

PREDATORY NEMATODES

PREDATORY MITES

OLIGOCHAETES

MAMMALS/ BIRDS

PLANT ROOTS

NEMATODESCOLLEMBOLA

PREDATORY COLLEMBOLA

PREDATORY COLLEMBOLA

PLANT-FEEDING

PREDATORY INSECTS

ROOT DEPOSITIONS

Soil organisms & ecosystem function: Bottom-up

primary

secondary

tertiary

Autotroph Heterotroph

Phototroph Lithotroph Organotroph Organotroph

Producer Producer Consumer Decomposer

AerobeBacteriaEukarya

Fac. AnerobeBacteria

Anaerobe Bacteria

AerobeBacteriaArchaea

Fac. AnerobeBacteria

Anaerobe

Aerobe Eukarya

AerobeBacteria PEukarya

Fac. AnerobeBacteriaEukaryaArchaea

AnaerobeBacteriaArchaea

BacteriaArchaea

Integrated functional and taxonomic classification road maps link food chain, trophic, and

biogeochemical functions with common and genomic names of biological community members

OBLIGATE AEROBES

* Photosynthetic:

Oxygenic Water oxidizers

* Nonphotosynthetic :

Org C oxidizers

* O2

reducers

* Plants. Eukarya :

* Green algae. Eukarya :

Chlamydomonas ,

Chlorella

* Diatoms. Eukarya :

* Cyanobacteria. Bacteria:

Anabaena, Calothrix ,

Gloeocapsa , Microcystis ,

Nostoc

FACULTATIVE ANAEROBES

* Photosynthetic (only anaerobic):

Anoxygenic H2

, Sulfide, S0

oxidizers


H2

, Org C oxidizers

* O2

reducers if O2

present;

Org C

reducers if no O2

* Purple S bacteria. Bacteria:

Chromatium , Thiocapsa

OBLIGATE ANAEROBES

* Photosynthetic:

Anoxygenic H2

, Sulfide, S0

oxidizers


H2

, Org C

oxidizers

* Org C

reducers

* Green S bacteria. Bacteria:

Chorobium , Pelodictyon

OBLIGATE AEROBES

* H2

, CO oxidizers

* O2

reducers. Bacteria: Acidovorax ,

Hydrogenophaga , Paracoccus ,

Variovorax

* Sulfide, S0

oxidizers

* O2

reducers

* Bacteria : Beggiatoa , Bosea ,

Thiobacillus

* Archaea : Acidianus

* Ferrous, Manganous oxidizers

* O2

reducers. Bacteria : Gallionella ,

Leptothrix , Planctomyces ,

Spharotilus , Thiobacillus

* Ammonium to nitrite oxidizers

* O2

reducers. Bacteria :

Nitrosococcus , Nitrosomonas,

Nitrosospira

* Nitrite oxidizers

* O2

reducers. Bacteria : Nitrobacter ,

Nitrospira


* H2

oxidizers

* O2

reducers if O2

present;

Nitrate denitrifiers if no O2

.

* Bacteria : Bacillus , Paracoccus

* Sulfide, S0

oxidizers

* O2

reducers if O2

present;


.

* Bacteria : Thiobacillus ,

Thiomicrospira

OBLIGATE ANAEROBES

* H2

oxidizers

* Thiosulfate , S0

reducers

* Bacteria :

Desulfurococcus

* Archaea : Archeoglobus ,

Pyrobaculum

* CO2

reducing methanogens

* Archaea : Methanobacterium ,

Methanococcus , Methanosaeta ,

Methanosarcina ,

* CO2

reducing acetogens

* Bacteria: Acetobacterium ,

Clostridium, Sporomusa

OBLIGATE AEROBES

* Org C

oxidizers

* O2

reducers

* Fungi. Eukarya :

* Oomycetes : Pythium ,

Phytophthora ,

Saprolegnia

* Zygomycetes :

Glomus ,

Mucor , Rhizopus

* Ascomycetes /

Deuteromycetes :

Acremonium ,

Alternaria ,

Aspergillus ,

Blastomyces ,

Chaetomium ,

Cladosporium ,

Coccidioides ,

Colletotrichum ,

Fusarium ,

Histoplasma ,

Paecilomyces ,

Penicillium ,

Rhizoctonia ,

Sclerotium ,

Trichoderma

* Basidiomycetes:

Mushrooms, Lignin

degraders

* Yeasts. Eukarya :

C andida, Rhodotorula


* Org C

oxidizers

* O2

reducers if O2

present;

Org C reducers if no O2

* Yeasts. Eukarya :

Saccharomyces

OBLIGATE AEROBES

* Org C

oxidizers

* O2

reducers. Actinomycetes . Bacteria:

Actinomadura , Micromonospora ,

Nocardia , Rhodococcus , Streptomyces ,

Frankja

* Org C, H2

oxidizers

* O2

reducers. Bacteria2

: Acidovorax ,

Alcaligenes , Agrobacterium , Agromyces ,

Arthrobacter , Cellulomonas , Cytophoga ,

Deinobacter , Flexibacter , Haloferax ,

Myxococcus , Paracoccus ,

Pedomicrobium , Planctomyces ,

Pseudomonas, Xanthomonas

Azoarcus , Azospirillum , Azotobacter ,

Bradyrhizobium , Rhizobium

* Org C1

oxidizers

* O2

reducers. Bacteria3

: Methylobacillus


* Org C, H2

oxidizers

* O2

reducers if O2

present;

* Nitrate denitrifiers i f no O2

.

* Bacteria4

: Acidovorax , Bacillus,

Haloferax , Paracoccus

* Archaea : Haloferax

* Nitrate denitrifiers , Ferric, Manganic , Org C

reducers i f no O2

. Bacteria: Shewanella

* Org C oxidizers ± H2

producers

* O2

reducers if O2

present;

Nitrate, Org C reducers i f no O2

* Bacteria5

: Erwinia , Escherichia,

Pantoea , Proteus, Prosthecobacter ,

Serratia , Verrumicrobium ,

Aeromonas , Bacillus, Klebsiella

OBLIGATE ANAEROBES


producers

* Org C, Org Cl , Org N, Nitrate, Proton

reducers. Bacteria: Acidobacterium ,

Clostridium, Dehalobacter ,

Dehalococcoides , Dehalospirillum ,

Fibrobacter , Lactobacillus, Sarcina ,

Clostridium

* Sulfate, S0

reducers

* Bacteria6

Desulfotomaculum ,

Desulfovibrio ,

* Org Cl reducers. Bacteria :

Desulfitobacterium , Desulfomile ,

Desulfuromonas ,

* Archaea : Archeoglobus , Pyrobaculum ,

Sulfolobus

* Org C1

oxidizers

* Org C1ox


* Archaea7

: Methanobacterium ,

Methanosaeta , Methanosarcina

* Acetate splitting methanogens

* Archaea : Methanosarcina


* Photo & nonphotosynthetic

Anoxygenic Org C, CO, H2

,

Sulfide, S0

oxidizers


O2

reducers if O2

present;

Org C

, Heavy metal (Se,

Te) anion reducers if no O2

* Purple non S bacteria

* Bacteria:

Rhodobacter ,

Rhodopseudomonas ,

Rhodospirillum ,

Rhodovibrio

* Photosynthetic (only

anaerobic)

Anoxygenic Org C oxidizers


Org C oxidizers

* O2

reducers if O2

present;

Org C

reducers if no O2

* Filamentous green bact

* Bacteria:

Chloroflexus ,

Heliothrix

OBLIGATE ANAEROBES



* Nonphotosynthetic

* Org C

reducers

* Bacteria with bchl g

* Bacteria:

Heliobacillus

Organisms producing organic C for biomass by reducing

CO2

( autotrophs ) with inorganic e-

donors ( lithotrophs )

Organic Matter Producers

PRIMARY

PRODUCERS

BIOLOGICAL COMMUNITY

Plants, Algae, Bacteria

CHEMO

PRODUCERS

DECOMPOSERS CONSUMERS

Animals1

Fungi, Yeasts Actinomycetes , Bacteria Bacteria Bacteria

MIXOTROPHS

1 Animals : OBLIGATE AEROBES, Org C

oxidizers, O

2 reducers. Eukarya .

Macrofauna : Groundhogs, Moles, Snakes

Mesofauna : Ants, Centipedes, Grubs, Millipedes, Mites, Spiders, Springtails, Worms

Microfauna : Nematodes:

Protozoa: Small flagellates, Naked amoebae, Slime molds - Dictyostelium , Physarum , Ciliates, Testacea

2 Also, Acetobacter , Flavobacterium , Hyphomicrobium , Kocuria , Leptohtrix , Pirella , Sphaerotillus , Xanthomonas

3

Also, Methylobacter , Methylobacterium , Methylocystis , Methylomonas , Methylophaga , Methylosinus

4 Also, Blastobacter , Brachymonas , Bradyrhizobium , Halomonas , Hyphomicrobium , Jonesia , Roseobacter , Thiomicrospira

5

Also, Enterobacter ,

6 Also, Desulfobacterium , Desulfobulbus , Desulfohalobium , Desulfonatrum , Desulfurella , Desulfurococcus , Desulfuromonas

7

Also, Methanococcus , Methanocorpusculum , Methanoculleus , Methanospirillum ,

Organisms using organic C for biomass ( heterotrophs ) , and mineralizing it to

CO2

as organic e-

donor ( organotrophs ) for chemical energy ( chemotrophs )

Organisms using light as primary

energy ( phototrophs ), and

supplemental chemical energy with

endogenous org or inorg e-

donors

Organisms using chemical

energy ( chemototrophs ) with

inorganic e-


Food-ingesting

organisms

Predigested food-

absorbing organisms

Color coding

Green: C assimilators, and

N2

fixing organisms

Red: e-

donor oxidizers

Blue: e- acceptor reducers

CO2

Regenerators

How might organo(hetero)trophic soil microbes obtain carbon?

Passive acquisition from by-products

Active acquisition

How might decomposers obtain carbon from producers?

• Passivelly from dead biomass, excretions and secretions– Saprotrophs

• Actively from living biomass– Necrotrophs, attack and decay biomass – Biotrophs, obtain carbon from plant in

exchange for a microbe-supplied nutrient

Saprotrophs

• Consume inanimate organic material – Plant: litter, exudates– Animal: bodies, excretions– Microbial: cells, exudates

Necrotrophs

• Plant pathogens• Attack and decompose living plant parts• Fungi (Pythium)• Bacteria (Erwinia)

Biotrophs

• Plant symbionts• Bacteria = Nitrogen fixation

– Rhizobia (legumes)– Actinorhiza (trees)

• Fungi = Phosphorus uptake– Mycorrhizal fungi (woody and non-woody

plants)

Learning Goals

• Classification schemes for organisms• Basis for classification• How classifications relate to each other• What classification says about an

organism’s role in environmental processes and vice versa

• What can we infer from element’s redox transitions in biogeochemical cycles about the microbial driving force underlying the individual transformations?– What do the microbes get out of reaction?– What ecological/ tropic categories of would

mediate such a reaction?

Coupled Redox Reactions and Oxidation Numbers

•Dissimlatory processes: Oxidation of one element is coupled to reductionof another.

•Recognizing which element is oxidized and which is reduced allows identification of trophic classification.

•Knowing the trophic classification is key to understanding the microbiology and biochemical basis of any transformation.

•The oxidation number indicates the relative oxidation state of an element andcan be used to identify electron donor/electron acceptor pairs

Classification according to growth characteristics

• Two general pools of organic carbon in soil

• Resistant to degradation– Soil organic matter (humus, humic materials)– Amounts are relatively constant

• Labile to degradation– Fresh inputs(root exudates, soluble components released from

dead cells)– Amounts are highly variable (spatially and temporally)

• Soil organisms may adapt to exploit one or the other of these pools

Zymogenous v. autochthonous Winogradski (~1900)

•zymogenous: “ferment-producers”

•Attack readily available carbon sources

•Population densities fluctuate widely

•Large (1-3 um diam), spore-forming bacilli

•autochthonous: “self-feeders of the earth”, “humus degraders”

•Attack more resistant materials

•Population densities are relatively stable.

• Small (1-1.5 um diam), cocci

.

Oligotrophs and copiotrophs(Sources?)

•Copiotrophs (aka, eutrophs): “abundant [resource] feeders”.

•Activity adapted for the presence of abundant, readily-available carbon sources.

•Oligotrophs: “scant [resource] feeders”. •Activity adapted for the presence of low amounts of readily-degradable carbon sources or compounds not readily-degradable.

•Aerobic, but lack catalase and/or superoxid dismutase, • lack full protection against toxic oxygen species

•High nutrient uptake capacity• high surface/volume (S/V) ratio (small diameter) • high density of transporter sites

•Efficient nutrient management to allow growth• formation of reserve polymers (poly--hydroxybutyrate)• biosynthesis regulation

Characteristics of an oligotroph

Arthrobacter: a possible soil oligotroph

Morphology: coccoid cells (high S/V) under low nutrient conditions, rod-shaped (lower S/V) under high nutrient levels.

Uptake systems favor organic acids, amino acids. Reduces competition for sugars

Endogenous metabolism of starving cells 10% of that of starving copiotrophs (e.g., E. coli, Pseudomonas)

Cells are resistant to dessication (% survival similar to Bacillus endospores)

Morphology transition in Arthrobacter

r- and K-strategists

• Mathematical model developed from studies on population dynamics of animals and plants

• r = rate of population increase, K = carrying capacity of the environment (carrying capacity = density of organisms that can be supported

•K -strategists: optimized to function at high population sizes (high K), but low growth rate (low r).

•r-selected: optimized to function at low population sizes (low K), but high growth rates (high r)

Organism type r value K value

r-strategist high low

K-strategist low high

rate of population

growth

population densityresource density (availability)

lowhigh

highlow

rI

rII

KI KII

competitive cross-over density

r-strategist favored when resources are high relative to populationK-strategist favored when resources are low relative to population

r wins K wins

Growth types: Equivalent terms

Zymogenous = copiotroph = r-strategist

Autochthonous = oligotroph = K-strategist

Integrated functional and taxonomic classification road maps link food chain, trophic, and

biogeochemical functions with common and genomic names of biological community members

OBLIGATE AEROBES

* Photosynthetic:

Oxygenic Water oxidizers


Org C oxidizers

* O2

reducers

* Plants. Eukarya :

* Green algae. Eukarya :

Chlamydomonas ,

Chlorella

* Diatoms. Eukarya :

* Cyanobacteria. Bacteria:

Anabaena, Calothrix ,

Gloeocapsa , Microcystis ,

Nostoc


* Photosynthetic (only anaerobic):

Anoxygenic H2

, Sulfide, S0

oxidizers


H2

, Org C oxidizers

* O2

reducers if O2

present;

Org C

reducers if no O2

* Purple S bacteria. Bacteria:

Chromatium , Thiocapsa

OBLIGATE ANAEROBES

* Photosynthetic:

Anoxygenic H2

, Sulfide, S0

oxidizers


H2

, Org C

oxidizers

* Org C

reducers

* Green S bacteria. Bacteria:

Chorobium , Pelodictyon

OBLIGATE AEROBES

* H2

, CO oxidizers

* O2

reducers. Bacteria: Acidovorax ,

Hydrogenophaga , Paracoccus ,

Variovorax

* Sulfide, S0

oxidizers

* O2

reducers

* Bacteria : Beggiatoa , Bosea ,

Thiobacillus

* Archaea : Acidianus

* Ferrous, Manganous oxidizers

* O2

reducers. Bacteria : Gallionella ,

Leptothrix , Planctomyces ,

Spharotilus , Thiobacillus

* Ammonium to nitrite oxidizers

* O2

reducers. Bacteria :

Nitrosococcus , Nitrosomonas,

Nitrosospira

* Nitrite oxidizers

* O2

reducers. Bacteria : Nitrobacter ,

Nitrospira


* H2

oxidizers

* O2

reducers if O2

present;


.

* Bacteria : Bacillus , Paracoccus

* Sulfide, S0

oxidizers

* O2

reducers if O2

present;


.

* Bacteria : Thiobacillus ,

Thiomicrospira

OBLIGATE ANAEROBES

* H2

oxidizers

* Thiosulfate , S0

reducers

* Bacteria :

Desulfurococcus

* Archaea : Archeoglobus ,

Pyrobaculum

* CO2


* Archaea : Methanobacterium ,

Methanococcus , Methanosaeta ,

Methanosarcina ,

* CO2

reducing acetogens

* Bacteria: Acetobacterium ,

Clostridium, Sporomusa

OBLIGATE AEROBES

* Org C

oxidizers

* O2

reducers

* Fungi. Eukarya :

* Oomycetes : Pythium ,

Phytophthora ,

Saprolegnia

* Zygomycetes :

Glomus ,

Mucor , Rhizopus

* Ascomycetes /

Deuteromycetes :

Acremonium ,

Alternaria ,

Aspergillus ,

Blastomyces ,

Chaetomium ,

Cladosporium ,

Coccidioides ,

Colletotrichum ,

Fusarium ,

Histoplasma ,

Paecilomyces ,

Penicillium ,

Rhizoctonia ,

Sclerotium ,

Trichoderma

* Basidiomycetes:

Mushrooms, Lignin

degraders

* Yeasts. Eukarya :

C andida, Rhodotorula


* Org C

oxidizers

* O2

reducers if O2

present;

Org C reducers if no O2

* Yeasts. Eukarya :

Saccharomyces

OBLIGATE AEROBES

* Org C

oxidizers

* O2

reducers. Actinomycetes . Bacteria:

Actinomadura , Micromonospora ,

Nocardia , Rhodococcus , Streptomyces ,

Frankja

* Org C, H2

oxidizers

* O2

reducers. Bacteria2

: Acidovorax ,

Alcaligenes , Agrobacterium , Agromyces ,

Arthrobacter , Cellulomonas , Cytophoga ,

Deinobacter , Flexibacter , Haloferax ,

Myxococcus , Paracoccus ,

Pedomicrobium , Planctomyces ,

Pseudomonas, Xanthomonas

Azoarcus , Azospirillum , Azotobacter ,

Bradyrhizobium , Rhizobium

* Org C1

oxidizers

* O2

reducers. Bacteria3

: Methylobacillus


* Org C, H2

oxidizers

* O2

reducers if O2

present;

* Nitrate denitrifiers i f no O2

.

* Bacteria4

: Acidovorax , Bacillus,

Haloferax , Paracoccus

* Archaea : Haloferax

* Nitrate denitrifiers , Ferric, Manganic , Org C

reducers i f no O2

. Bacteria: Shewanella


producers

* O2

reducers if O2

present;

Nitrate, Org C reducers i f no O2

* Bacteria5

: Erwinia , Escherichia,

Pantoea , Proteus, Prosthecobacter ,

Serratia , Verrumicrobium ,

Aeromonas , Bacillus, Klebsiella

OBLIGATE ANAEROBES


producers

* Org C, Org Cl , Org N, Nitrate, Proton

reducers. Bacteria: Acidobacterium ,

Clostridium, Dehalobacter ,

Dehalococcoides , Dehalospirillum ,

Fibrobacter , Lactobacillus, Sarcina ,

Clostridium

* Sulfate, S0

reducers

* Bacteria6

Desulfotomaculum ,

Desulfovibrio ,

* Org Cl reducers. Bacteria :

Desulfitobacterium , Desulfomile ,

Desulfuromonas ,

* Archaea : Archeoglobus , Pyrobaculum ,

Sulfolobus

* Org C1

oxidizers

* Org C1ox


* Archaea7

: Methanobacterium ,

Methanosaeta , Methanosarcina

* Acetate splitting methanogens

* Archaea : Methanosarcina



Anoxygenic Org C, CO, H2

,

Sulfide, S0

oxidizers


O2

reducers if O2

present;

Org C

, Heavy metal (Se,

Te) anion reducers if no O2

* Purple non S bacteria

* Bacteria:

Rhodobacter ,

Rhodopseudomonas ,

Rhodospirillum ,

Rhodovibrio

* Photosynthetic (only

anaerobic)



Org C oxidizers

* O2

reducers if O2

present;

Org C

reducers if no O2

* Filamentous green bact

* Bacteria:

Chloroflexus ,

Heliothrix

OBLIGATE ANAEROBES



* Nonphotosynthetic

* Org C

reducers

* Bacteria with bchl g

* Bacteria:

Heliobacillus

Organisms producing organic C for biomass by reducing

CO2

( autotrophs ) with inorganic e-


Organic Matter Producers

PRIMARY

PRODUCERS

BIOLOGICAL COMMUNITY

Plants, Algae, Bacteria

CHEMO

PRODUCERS

DECOMPOSERS CONSUMERS

Animals1

Fungi, Yeasts Actinomycetes , Bacteria Bacteria Bacteria

MIXOTROPHS

1 Animals : OBLIGATE AEROBES, Org C

oxidizers, O

2 reducers. Eukarya .

Macrofauna : Groundhogs, Moles, Snakes

Mesofauna : Ants, Centipedes, Grubs, Millipedes, Mites, Spiders, Springtails, Worms

Microfauna : Nematodes:

Protozoa: Small flagellates, Naked amoebae, Slime molds - Dictyostelium , Physarum , Ciliates, Testacea

2 Also, Acetobacter , Flavobacterium , Hyphomicrobium , Kocuria , Leptohtrix , Pirella , Sphaerotillus , Xanthomonas

3

Also, Methylobacter , Methylobacterium , Methylocystis , Methylomonas , Methylophaga , Methylosinus

4 Also, Blastobacter , Brachymonas , Bradyrhizobium , Halomonas , Hyphomicrobium , Jonesia , Roseobacter , Thiomicrospira

5

Also, Enterobacter ,

6 Also, Desulfobacterium , Desulfobulbus , Desulfohalobium , Desulfonatrum , Desulfurella , Desulfurococcus , Desulfuromonas

7

Also, Methanococcus , Methanocorpusculum , Methanoculleus , Methanospirillum ,

Organisms using organic C for biomass ( heterotrophs ) , and mineralizing it to

CO2

as organic e-

donor ( organotrophs ) for chemical energy ( chemotrophs )

Organisms using light as primary

energy ( phototrophs ), and

supplemental chemical energy with

endogenous org or inorg e-

donors

Organisms using chemical

energy ( chemototrophs ) with

inorganic e-


Food-ingesting

organisms

Predigested food-

absorbing organisms

Color coding

Green: C assimilators, and

N2

fixing organisms

Red: e-

donor oxidizers

Blue: e- acceptor reducers

CO2

Regenerators

powerpoint presentation - soi bacteria - soil science at...

Documents