Microbiology Lecture 31: Microbial Interactions With Other Organisms

Front 1

Symbiosis is usually restricted to BLANK, but may be extended to include BLANK and BLANK.

Back 1

mutualism; parasitism and commensalism

Front 2

Symbiosis may be divided into two groups:

1. BLANK microorganisms grow within the host cells
2. BLANK microorganisms attach but remain outside of host cell.

Back 2

endosymbiosis

ectosymbiosis

Front 3

What is it called when both organisms benefit from the associations?

What are some examples (7)?

Back 3

Mutualism

Examples of mutualism: nitrogen fixation, lichen, mycorrhizae, flashlight fishes, symbionts of protozoa, symbionts of insects, and symbiosis in ruminants.

Front 4

Some gram-negative heterotrophic soil bacteria BLANK form symbiotic association with plants of the BLANK family to accomplish BLANK BLANK.

Back 4

Rhizobia

legume

Nitrogen Fixation

Front 5

Some actinomycetes like BLANK also form symbiotic association with BLANK BLANK plants such as BLANK, BLANK, and BLANK etc.

This is to accomplish BLANK BLANK

Back 5

Frankia; non-leguminous actinorhizal plants

alder (Alnus), the California lilac (Ceanothus), the Australian pine (Casuarina)

Nitrogen fixation

Front 6

Microsymbiont BLANK forms symbiotic association with the water fern BLANK to accomplish BLANK BLANK.

Back 6

Anabaena

Azolla

Nitrogen fixation

Front 7

In the nitrogen fixation process, BLANK is reduced to BLANK (N≡N → NH3) by the enzyme complex BLANK.

BLANK consists of two separate proteins components: BLANK and BLANK BLANK

Back 7

N2; ammonium; nitrogenase

Nitrogenase; dinitrogenase; dinitrogenase reductase

Front 8

Both components dinitrogenase and dinitrogenase reductase contain the metals BLANK and dinitrogenase contains BLANK.

The metals are contained in a cofactor known as BLANK.

Back 8

iron (Fe); molybdenum (Mo)

FeMo-co

Front 9

Nitrogenase is irreversibly destroyed when exposed to BLANK.

In rhizobia-legume symbiosis, BLANK binds and removes BLANK from the vicinity of nitrogenase.

Back 9

oxygen

leghemoglobin; oxygen

Front 10

The genes for dinitrogenase and dinitrogenase reductase in BLANK BLANK were well studied.

The 20 identified genes of the BLANK cluster are grouped into 7 BLANK BLANK.

Nitrogenase (BLANK) and nitrogenase reductase (BLANK) are formed independently to make up the BLANK BLANK.

Back 10

Klebsiella pneumoniae

nif; nif operons

Component I; Component II; nitrogenase complex

Front 11

Nitrogenase also reduces BLANK, BLANK, and several other triply bounded compounds.

The reduction of BLANK to BLANK is used for BLANK the activity of nitrogenase.

Back 11

cyanide (CN-), acetylene (HC≡CH)

acetylene (C2H2); ethylene (C2H4); assaying

Front 12

What is an organism that results from the symbiosis between a fungus and an alga or a cyanobacterium?

Where are these organisms found?

What is the most common fungi involved?

Back 12

Lichen

Lichen are found in such diverse places as deserts and the Arctic and Antarctic.

Ascomycota

Front 13

Lichen can grow in very inhospitable environments-- on rocks, sides and branches of trees, gravestones and therefore function as BLANK BLANK of BLANK BLANK.

Fungus in lichen gives it a tightly woven BLANK that provides protection to the BLANK.

Back 13

primary colonizers; stressful habitats

mycelium; algae

Front 14

What are the 3 types of fungi? Describe them.

Fungi in lichen absorbs BLANK and BLANK and sends it to the algae, which leads to BLANK. The algae gives BLANK back to fungus.

Back 14

1. Crustose (crust like)
2. Foliose (leaf like)
3. Fruticose (scrub like)

water and minerals; photosynthesis; carbon

Front 15

Lichens are also the BLANK of animals such as BLANK and BLANK.

Lichens are very sensitive to BLANK BLANK, especially sulfur and nitrogen, and so they are natural indicators of BLANK BLANK

Lichens grow extremely slowly usually BLANK to BLANK millimeters per year

Back 15

food; reindeer and caribou

air pollution; air quality

1 to 2 millimeters

Front 16

What is an example of symbiosis between fungi and plants called?

What are the two major types of mycorrhizae found in nature?

Plants obtain BLANK BLANK from fungi and fungi obtain BLANK for their correspondence growth in the association.

Back 16

Mycorrhizae

ectomycorrhiza & endomycorrhiza

mineral nutrients; carbohydrates

Front 17

What plants form ectomycorrhizae with fungi?

The mycelium of ectomycorrhizal fungi forms a BLANK or BLANK around the roots of the symbiont plant.

From the BLANK, a hyphal network called the BLANK BLANK extends into the root between the cells, but does not penetrate into the BLANK BLANK.

Back 17

Many woody plants, such as pine, oak and birch

sheath or mantle

mantle; Hartig net; cortical cells

Front 18

How many vascular plants for endomycorrhizae?

In endomycorrhizae, fungi penetrate into root BLANK BLANK and form special structures such as BLANK within the BLANK BLANK.

Endomycorrhizae are further divided into BLANK, BLANK, and BLANK mycorrhizae based on their morphology and host plants.

Back 18

80%

cortical cells; arbuscular; cortical cells

arbuscular, orchid and ericoid

Front 19

What are flashlight fishes?

What is the purpose of the light?

What bacteria is involved?

The fishes use quorum sensing with what chemical?

Back 19

Symbiotic relationships involving luminescent bacteria and fishes of the family Anomalopidae.

The light emitted is used to communicate, lure prey and confuse predators.

Vibrio fisheri

N-acyl homoserine

Front 20

Bacteria can be endosymbionts of what protozoa?

The bacteria are highly BLANK BLANK and infection appears to depend on one or two BLANK BLANK in the protozoa.

Endosymbiotic bacteria produce BLANK and assist protozoa in BLANK BLANK.

Back 20

Paramecium aurelia and amoebas

host specific; specific genes

cellulose; cellulose digestion

Front 21

Some bacteria are endosymbionts to different types of insects such as wood-eating BLANK and BLANK.

The bacterial endosymbionts probably play an important role in the degradation of BLANK BLANK.

The enzymes used are BLANK.

Back 21

cockroaches and termites

wood cellulose

cellulase +

Front 22

Certain microorganisms form mutualistic relationships with BLANK which animals such as cows, goats, giraffes, camels, and sheep that eat BLANK.

The microbial symbionts decompose BLANK and other plant materials and are also source of BLANK and BLANK for these animals.

The BLANK provides favorable environments for microbial growth.

Back 22

ruminants; plants

cellulous; vitamin and proteins

rumen

Front 23

What is a symbiotic relationship between two organisms in which one species called the BLANK benefits for growth and reproduction to the harm of the other species called the BLANK called?

Microorganisms such as BLANK, BLANK, BLANK, and BLANK can act as BLANK of plants and animals that cause disease of their host organisms.

Back 23

parasite; host; parasitism

viruses, bacteria, protozoa and fungi; parasites

Front 24

What plant disease lead to the epidemics that destroyed potato crops in Europe in the 1840s and caused mass starvation?

What was this epidemic called? How could the disease have been avoided?

One million people died in the three years from 1846 to 1849, about 12% of the population. Another one million are estimated fled as refugees to Great Britain, the United States, Canada, and Australia.

Back 24

Potato late blight

“The great Irish famine” (1845-1849); could have been avoided partially by crop rotation.

Front 25

BLANK BLANK like viruses, bacteria, fungi, and protozoa can invade humans and cause diseases that kill BLANK of people every year.

BLANK is caused by BLANK BLANK of the genus BLANK, causes disease in approximately 400 million people and kills between one and three million, most of them young children in Sub-Saharan Africa.

Back 25

Pathogenic microorganisms; millions

Malaria; protozoan parasites; Plasmodium

Front 26

What bacterial phylum causes disease in birds and in human and other mammals? They are BLANK BLANK pathogens.

BLANK are unable to synthesize their own high-energy compounds, but benefit from their BLANK of the host’s BLANK BLANK.

Back 26

Chlamydiae; obligate intracellular pathogens

Chlamydiae; parasitism; metabolic energy

Front 27

--Examples of Chlamydiae--
BLANK BLANK is isolated from a child and is also seen in young adults or teens.

Associated with community acquired BLANK.

Leads to BLANK

Treated with BLANK.

Back 27

Chlamydia pneumoniae

pneunomia

bronchitis

ethromycin

Front 28

--Examples of Chlamydiae--
BLAKN BLANK causes chalmidioses where there are 50 cases in US a year.

Usually seen in....

The organisms remain viable in BLANK of the bird for a while.

Develop BLANK BLANK and see flu like symptoms. Can lead to rare disease called BLANK and is fatal.

Treated with BLANK.

Back 28

Chlamydia psittaci

pigeon or bird handlers, vets, etc

feces

parrot fever; endocortidis

ethromycin

Front 29

--Examples of Chlamydiae--
BLANK BLANK is the worst of this family

Causes BLANK in males and BLANK in females and leads to BLANK BLANK disease.

Obtained from BLANK and can also cause BLANK.

Treated with BLANK.

Back 29

Chlamydia trachomatis

NGU; cervicitis; pelvic inflammatory disease

STDs; blindness

ethromycin

Front 30

What is a curved gram-negative bacterium that preys on gram-negative bacteria?

How does it work?

How are the progeny released?

Back 30

Bdellovibrio

Bores through the outer membrane and cell wall of the host bacterium and divides in the periplasm.

After cell division, the progeny bdellovibrios are released as the host cell lysis.

Front 31

What is a symbiotic relationship in which one organism is benefited and the other organism is unaffected?

Many of the microorganisms in the human microflora are BLANK.

Back 31

Commensalisms

commensalistic

Front 32

Mutualism, commensalism and parasitism are dynamic relationships that can change depending on BLANK BLANK and therefore are BLANK BLANK.

The line between mutualism or commensalism and parasitism is very fine and can be altered in hosts when they have other BLANK, are administered broad spectrum BLANK, or immune system has been impaired by BLANK or BLANK.

Back 32

environmental conditions; Dynamic Relationships

infections; antibiotics; disease or treatment