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Microbial Habitat
BY: DR WAN ZUHAINIS BT MOHD SAAD BY: DR WAN ZUHAINIS BT MOHD SAAD
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Microbial Habitat and its Microbial Inhabitants
- Three major divisions
a) atmosphere
b) hydrosphere c)
lithosphere
- Influenced by physical and chemical characteristics
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b) Allochthonous (foreign)
transient members great variation in length of time of survival
- M/os can be
a) autochthonous (indigenous) adaptive features
functional (metabolically active) competitive
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Hydrosphere
- Ecosystem hich contains ater
- !eneral characteristics of m/os that survive in atera) gro at lo nutrient concentrations
b) motile
c) some e"hibit unusual shapes
- #ivided into
a) freshater habitat
b) marine habitat
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General influencing factors in aquatic
environments:
a) Light
- #etermine the rate of photosynthesis
- #ependent on clarity of ater$ season and latitude
b) Temperature
- #etermined by the latitude and eather condition- #istribution of heat dependent upon mi"ing of
ater
- %arge body of ater more stable in temperature
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- Inland ater (not important)$ oceans (important)
- Increases & atm ith each &' m in depth
- Affects metabolism of organisms and dissociation of
carbonic acids
decrease in p
c) Pressure
- aries*+e"tremely lo to high+
d) utrient
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e) !issolved gas
- To most important gasses,
i+ "ygen, for aerobic biological processes
ii+ . , for photosynthetic processes
p e0uilibrium
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"#ygen
- #eep a0uatic environment lo diffusion
environment+- Thin ater film high diffusion environment
- in ater,
i) 1lo diffusion
ii) Influencing factor, temperature and pressure+
- 2ate of usage is faster than it can be replenished
- Aeration facilitated by surface turbulence
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$"%
- Increase in . ill decrease p
- 1olubility affected by temperature
- 1olubility is 3" higher than
- 4 gas, 4 source for 4 fi"ers
1olubility is half of
- Methane, aste product
least soluble among the gasses+
"ther gases
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&resh'ater habitats
- .lassification
a) lentic habitats b) lotic habitats
- 5ith higher vertical gradients over much shorter
distances
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The neuston layer of fresh'ater habitat
- 4euston layer
uppermost layer of hydrosphere interface beteen hydrosphere and atmosphere
- Microbial populations
photoautotrophic m/os
aerobic heterotropic m/os
- 6sually &' to &''-fold higher than underlaying ater
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- 7 8ones based on penetration of sunlight
La(esPonds
a) %ittoral 8one
b) %imnetic 8one
c) %ight compensation level
d) 9rofundal 8one
.ombination : euphotic 8one
ith photosynthetic
activity
- ;eyond the depth of effective
light penetration
- 4ot observed in shallo ponds
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a) %ittoral 8one
-
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d) 9rofundal 8one
- ery lo penetration of sunlight
- igh in organic nutrients
- Mostly anaerobic heterotrophs
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- =onation of la>es based on temperature
a) epilimnion
- arm and rich b) thermocline
- rapid decrease of temperature
c) hypolimnion- belo thermocline
- lo temperature
- lo concentrations- poor light penetration
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- =onation of la>es based on temperature
a) epilimnion
- arm and rich b) thermocline
- rapid decrease of temperature
c) hypolimnion- belo thermocline
- lo temperature
- lo concentrations- poor light penetration
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1tratification and productivity• during summer stratification, phytoplankton confined to
epilimnion
• phytoplankton (free-floating algae) contribute most ofprimary production
• productivity dependent on nutrient inputs to lake
(ground- and surface-water inputs), and nutrientrecycling in epilimnion
• decomposition rates typically high in epilimnion(aerobic environment)
• rapid nutrient uptake by phytoplankton results in lownutrient availability in epilimnion
• dead organic matter sinks to hypolimnion
– decay depletes O2, causing anaerobic environment
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&actors affecting gro'th of mos in ponds
and la(es
a+ Temperature ('-&''o.) moderate temperature
b+ p preferable neutral
c+ "ygen
? %imiting factor
d+ 1unlight penetration
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e+ 4utrients
- ligotrophic
4utrient-poor
saturated
lo microbial population
- Eutrophic nutrient-rich
4utrient-rich
1ediments of organic matter
Epilimnion, aerobic
ypolimnion, anaerobic
La(e *osto(
http://en.wikipedia.org/wiki/Image:Lake_Vostok_Map.jpg
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-5ater is clear - #eep
-
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- Eutrophication nutrient-enrichment
- 1timulates groth of plants$ algae and bacteria
Eutrophication is apparent as increased
turbidity in the northern part of theCaspian Sea, imaged from orbit.
http://www.answers.com/topic/turbidityhttp://www.answers.com/topic/caspian-seahttp://www.answers.com/topic/caspian-sea-from-orbit-jpghttp://www.answers.com/topic/caspian-seahttp://www.answers.com/topic/turbidity
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Effects of
eutrophication u t r i e
n t s
i n r u n o f f
utrients fertili,e small
floating aquatic plants
Light penetration is reduced
-educed
submerged
aquatic
vegetation
Plants die off decompose
depletion of "% in 'ater
Lac( of "% animals die
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'
&'
'
# e p t h ( m )
+pilimnion
"%
.yanobacteria
Chlorobiaceae and
Chromatiaceae
.olorless sulfur
bacteria and sulfate-
reducing organisms
H%.
Hypolimnion
eterotrophic
bacteria
$omposition and /ctivity of Microbial $ommunities in La(esPonds
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- 1urface ith full light penetration autochthonous
photoautotrophic bacteria e+g+ cyanobacteria
- 9hotoautotrophic members e+g+ Chlorobiaceae andChromatiaceae
- eterotrophic bacterial are distributed throughout
- In the sediments,
Anaerobic photoautotrophic bacteria
Anaerobic bacteria e+g+ Pseudomonas
bligate anaerobic bacteria e+g+ endospore formingClostridium spp+$ methanogenic bacteria and Desulfovibrio
spp+
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- ther microorganisms
Algae autochthonous$ contribute most of the organic .
9roto8oa autochthonous$ gra8e on algae and bacteria+
Allochthonous m/os e+g+ cellulolytic form of fungi
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utrient cycles in La(es and Ponds
- 9hytoplan>ton gro and fi" . to form organic matter$ ac0uire 4
and 9 from ater+- ;iomass of phytoplan>tonenter microbial loop
- 9hytoplan>ton release dissolved organic matter (#M)+
- #M
used by heterotrophic bacteria
transformed to bacteria @particulate organic matter (9M)+
- eterotrophic bacteria (9M) consumed and digested by large
predators release . as . and other nutrients recycled to
phytoplan>ton+
.
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9hytoplan>ton
.
4$ 9
#M
eterotrophic
bacteria/9M
9roto8oa
=ooplan>ton
Top consumers
.$ 4$ 9and
minerals
MICROBIAL
LOO
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rincipa! eco!ogica! functions of
microorganisms in fresh "ater en#ironments$
• ecompose dead organic matter
• !ssimilate and reintroduce O"
• #erform mineral cycling activities
• $ontribute to primary production
•%erve as a food source for gra&ers
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.treams and -ivers
- 1ufficient ater movement minimi8e
vertical stratification
- Most microbial biomass is attached to surfaces
-1ource of nutrient,a) In-stream production
b) utside the stream
- %imited capacity to process added organic matterE+g+ point source of pollution
nonpoint source of pollution cause
depletion of
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.treams and -ivers
- 1ufficient ater movement minimi8e
vertical stratification
- Most microbial biomass is attached to surfaces
-1ource of nutrient,a) In-stream production
b) utside the stream
- %imited capacity to process added organic matterE+g+ point source of pollution
nonpoint source of pollution cause
depletion of
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Marine environments
- BC D of earths ater
- igh pressure refrigerator
- 9ressure & atm/&' meters depth F ;arophiles
- 1alinity, appro"+ 3GD
- p H+3-H+G
Hori,ontal .tratification of Marine Habitats
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Hori,ontal .tratification of Marine Habitats
# e p t h ( > m
)
&
3
G
C
Euphotic 8one
Aphotic 8one
Intertidal 4eretic
ceanic
.ontinental
shelf .ontinental
slope
.ontinental
rise
Abyssal plain
cean trench
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a+) Intertidal 8one
- interface beteen marine ecosphere and litosphere
- at seashore
- ith alternate periods of flooding and drying
b+) 4eritic 8one
- nearshore 8one
- from lo tide mar> to edge of continental shelf
- average depth is less than '' m
c+) .ontinental slope (or bathyl region)
- 1loping from edge of continental shelf and drops don to the
sea floor (abyssal plain)
about $''' m
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d+) cean trench (or hadal region)
- E"tend don to &&$''' m in depth
JJ +uphotic ,one
- Area ith effective light penetration
- ;elo euphotic 8one is aphotic 8one
*ertical .tratification of Marine Habitats
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*ertical .tratification of Marine Habitats
# e p t h ( m )
''
&'''
'''
Epipelagic
8one
;athypelagic
8one
%and
%ittoral
8one
1ublittoral8one
9elagic 8one
;enthic 8one
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a+) 9elagic 8one
- .an be divided into
i) Epipelagic 8one
' to '' m
euphotic and arm
ii) Mesopelagic
''-&'''m
iii) ;athypelagic 8one
&''' - 7''' m
aphotic and cold ith e"treme
pressure
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& t ff ti th f i
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&actors affecting gro'th of mos in
marine environment:
a0 Hydrostatic pressure 1barophiles)b0 Light
- #ifferent avelengths at different depths+
Light absorbed !epth2ed
range
Kello
!reen
;lue
Increase
- nly euphotic 8one (top &'' m) primary productivity
G F 3' m
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c0) Temperature
d0) utrient
- 6sually lo at surface ater
- Increase beneath the euphotic 8one
- 1urface nutrient improve only during upelling
process
%and
.ontinental slope
5ind-driven surface
current
6pelling to replace
surface ater
utrient recycling in marine environment
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- 2ecycling of mineral nutrients e"tremely slo
- #ead organisms from euphotic epipelagic 8one bathypelagic benthic 8one liberated in the
process+
- 4utrients returned to surface
by upelling currents(usually at continental slope)
- 9rimary production in euphotic 8one limited by
nutrients
4utrient-rich deep aters lac> light energy for
photosynthetic primary production
utrient recycling in marine environment
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&eatures of autochthonous mos of the
marine environment
a) !roth at high salinity+ AdaptationsLL
b) !roth at lo-nutrient concentrations+
Adaptations, absorb to algal surfaces or increase
surface area
c) !roth at lo temperature+ AdaptationsLL
d) 5ithstand great hydrostatic pressure F barotolerant
bacteria
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$omposition of Marine Microbial $ommunities
- 9elagic marine habitat macro- and m/os but lac>
higher plants+- All primary production by microscopic algae and
bacteria
- Microbial numbers relatively high in nearshore andupelling aters
- eterotrophic bacteria associate ith algal surfaces
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$omposition of Marine Microbial $ommunities
- 9elagic marine habitat macro- and m/os but lac>
higher plants+- All primary production by microscopic algae and
bacteria
- Microbial numbers relatively high in nearshore andupelling aters
- eterotrophic bacteria associate ith algal surfaces
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Marine microbial community
Mostly gram negative bacteria e+g+ Pseudomonas,
Vibrio, Flavobacterium
!ram positive e+g+ Bacillus in marine sediments
Desulfovibrio in sediments (reduce sulfate to 1)
Methanogens in sediments
.hemolithotropic bacteria e+g+ Nitrosococcus,
Nitrosomonas, Nitrospina, Notrococcus, Nitrobacter (4cycling)
Marine algae of various divisions
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Phaeophyta (bron algae) upper littoral 8one to
sublittoral 8one (at a depth of ' m in clear tropical
ater)
Marine plan>ton (Chlorophyta and Chrysophyta) at
upper region of ocean ('-G' m)
!reen algae (above 3' m)
Marine proto8oa
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- %and masses (roc>s and soil)
- Most important terrestrial habitat soil
- #ifferent inorganic and organic components+ Influence
by,a+) eathering of roc>s
b+) decomposition of plants
c+) redistribution of materials by ater
movement+
Lithosphere
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.oil- s
- .lassified by relative proportions of clay$ silt$ and sand
particles+
- A good soil
able to hold sufficient ater sufficient drainage
sufficient gas-filled pores
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Physicochemical conditions 'hich affect the
microbial populations,
/0) .urfaces- 1mooth difficult for adherence
- 5ith enough nutrients (organic or minerals) and
moisture e+g+ clay- .lay particles
contain minerals e+g+ >aolinite$ montmorillonite
and illite coated ith metal hydro"ides and ses0uio"ides
carry polari8ed but electronegative charges m/os
can absorb
2 ) 3 t 1 M i t )
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20) 3ater 1 Moisture)
- Thin ater films at high level and easily
replenish
- 1oil particle as small as mm can be aerobic outside
and anaerobic inside
- #ependent on rainfall particle si8e
drainage
- Affects movement of m/os beteen pores and particles+
) T t
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c0) Temperature
- #etermine the composition of soil microflora
- aries depending on
latitude and altitude
depth
d ) / idit d /l( li it
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d0) /cidity and /l(alinity
- 6sually p 7-H+G (bacteria p -H molds any
p/acidic)- Influenced by
a) microbial metabolic activity
b) time of the year
c) climate
d) previous cropping history e+g+ type of litter and
fertili8er
2ain leaches bases soil
acidic
) . il t h
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e0) .oil atmosphere
- 5ell-drained soil ell aerated
- Influenced by soil particle si8e
1mall particles more sealed voids microbial
respiration occur decline$ . and othergaseous metabolites increase
depth
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Population of the soil:
? Microorganisms
? 2oots of plant
? Invertebrate animals (nematodes$
earthor>s$ snails$ insects and etc+)
Highest innumber
.oil Population 4 2acteria
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.oil Population 4 2acteria- ;acteria most numerous (&'-&'B viable cells per cm-3)
- Aerobic bacteria - C'D
Anaerobic bacteria - &7D
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A ton of microscopic bacteria may be acti#e in each acre of soi!.
Credit: Michael T. Holmes, Oregon State University, Corvallis
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'acteria dot the surface of strands of fungal hyphae
Credit: R. Campbell. In R. Campbell. 1985. #lant "icrobiology. Edward Arnold; London. P. 149.
Reprinted with the permission of Cambride !ni"ersit# Press.
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A$tinom#$etes, such as this %treptom#$es, give soil its earthy smell
Credit: &o. 14 from %oil "icrobiology and 'iochemistry %lide %et. 19'(. ).P. *artin+ et al.+ eds. %%%A+ *adison+ ,I
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%odu!es formed "here Rhizobium bacteria infected soybean roots.Credit: Stehen Temle, !e" Me#ico State University
.oil Population 4 &ungi
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.oil Population &ungi
-
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&ree roots 'bro"n( are connected to the symbiotic mycorrhi)a! structure
'bright "hite( and funga! hyphae 'thin "hite strands( radiating into the soi!.
Credit: Randy Molina, Oregon State University, Corvallis
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Fungus beginning to decompose leaf veins in grass clippings.
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Ectomycorrhizae are important for nutrient absorption by tree and grape roots.
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The dark, round masses inside the cells of this clover root are vesicules
for the arbuscular mycorrhizal fungus (AM.
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.oil Population 4 Proto,oa
- Minority
- 2ole, 9redators of soil bacteria
- 9roto8oa, e"posed outer surface of surface
particle (top &G cm)
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%otice the si)e of the spec*+!i*e bacteria net to the o#a!
proto)oa and !arge, angu!ar sand partic!e.
Credit: $laine R. %ngham
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Bacteria ingested by an amoeba.
Credit: !o. &' (rom Soi! Microbio!ogy and Biochemistry S!ide Set. )*+. -.. Martin, et al., eds.
SSS/, Madison, 0%
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Flagellates have one or t!o flagella !hich they use to propel or pull their !ay
through soil. A flagellum can be seen e"tending from the protozoan on the left.
The tiny specks are bacteria.
Credit: Elaine R. Ingham
. il P l i " h
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.oil Population 4 "thers
-.yanobacteria$ algae
- iruses
- Allochthonous m/os from ater$ ind$ dust$
plants$ animal sources
.ources of substrates for microbial gro'th
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.ources of substrates for microbial gro'th
a) Inorganic sources
- btained from minerali8ation of plant or
animal residue by microbial population
-
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b) rganic matter
- .
- .rop residues - cellulose$ lignins$ pectins$
proteins and etc+
- Animal residues - glycogen$ proteins$ fats
- 9lant root e"udates F simple sugar$ a+a$
organic acids
+nergy flo' in soil
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.rop and animal residues
#egradation to produce
simpler molecules
1ource of nutrient for
m/os and plants
Minerali8ation
gy
/nimal as a habitat
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/nimal as a habitat
- 9otential microbial coloni8ation surfaces, s>in$ oral
cavity$ gastrointestinal$ respiratory$ urinogenital
- Access via contact$ ingestion or inhalation
&actors affecting the composition of the flora
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a+) Anatomical and physical characteristics- Each location ith different environmental
conditions
- ral cavity, food mi"ed ith saliva
- Alimentary tract, reduced particle si8e$ presence of
proteolytic en8ymes$ bile salt$ secretions from
intestinal cells
- 9rivilege if m/os can adhere to surfaces
e+g+ lactobacilli adhere to s0uamous epithelium of
stomach$ yeasts to secretory epithelium of stomach
and etc+
Advantages of adherence
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- 1>in,
%o ater availability
1tratum corneum is regularly shedded
9ermanent sites hair follicles and seat
or sebaceous glands
Advantages of adherence
a) prevent being ash out from the gut
b) formation of biofilm optimum nutrient benefit
Advantages of adherence
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- 1>in,
%o ater availability
1tratum corneum is regularly shedded
9ermanent sites hair follicles and seat
or sebaceous glands
Advantages of adherence
a) prevent being ash out from the gut
b) formation of biofilm optimum nutrient benefit
b ) / bi i
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b0) /naerobiosis
- Alimentary tract tension varies
- 1>in high tension aerobic m/os
- %umen of hair follicles$ seat and sebaceous glands
ano"ic environment
facultative and strictlyanaerobic bacteria
c0) Temperature
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p
- 5arm blooded animal not much influence on
microbial population
- 9oi>ilothermal animals changes of microbial
population depending on environmental
temperature
d0) /cidity
- ral cavity, p C-C+G (regulate by saliva)
- 1tomach hydrochloric acid p to -3
- 1>in p G+'-+G
- Also influenced by diet
e0) "smotic pressure
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- smolality varies ith type of food eaten
- igh volume of ater$ osmotic pressure falls
f0) 3ater availability
- !roth limiting factor for s>in m/os
- 9referably high humidity areas
Microbial $ontributions to /nimal utrition
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a) Predation of Mos by /nimals
- !ra8ing on fecal pellet by coprophagousanimals
- #igestion during &st passage incomplete+
- E"creted fecal material decomposed byremnants of intestinal m/os and m/os from
environment
- 2eingestion of fecal material more
complete utili8ation of the food resource+
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- 1nails slime trails bacterial$ fungal$ and algal
populations coloni8e
- Animals retrace their trac>s gra8e on the
microbial populations
b) $ultivation of Mos by /nimals for &ood and
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) y
utrition
- erbivorous animals m/os to degrade plant
materials and produce substances that they can
assimilate
- 2umen m/os convert cellulose$ starch into .$ $
methane$ organic acids
- .ontribution of rumen microbial,
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i+ #igest plant materials
ii+ 1ource of nutrient for animals
- .ontribution of host animal
i+ .ontinuous supply of substrate
ii+ 2umination provides increased surface area
iii+ Movement of ruminant stomach sufficient mi"ing
iv+ .ontinuous removal of lo
m acids from rumen facilitate microbial
groth