Materi Mikro microorganism interactions and microbial ecology
I
icroorganism
Inte!'actions and
Microbial Ecology
Concepts
.
.
.
Most microorganisms in complex communities have not
been grorvn or characterized. This has limited our understanding of microorganism interactions and their roles in
nature and disease. Molecular techniques are providing a
better uncierstanding of these uncultured organisms.
The term syrnbiosis, or "together-life," can be used to describe many of the interactions between microorganisms,
and also microbial interactions with higher organisms. ingtuding plants and animals. These interactions may be positive or negative.
Microbiai ecology is the study of microbial relationships
+
with other organisms and also with their nonliving environr..er+s. ihese relationships, based on interactive uses of
.
resources, have effects extending to the global scale.
Symbiotic interactions includd' mutualism, cooperation,
commensalism. parasitism, predation, amensalism, and
competition- These interactions are important in natural
processes and in the occurrence of disease. The interactions can vary depending or the envi;'cnment and
changes in ihe interaciing organisms.
l,'i;:'ccrga',s.ias, a! :1e, ir:eral:,
. rltcl:ti.,rli:i-,. Sr,-,rilh
gcnetics' and molecular
nlL'labolisnl'
ln
iridrtion.
been discti::cd.
har.e been degenoniics'
inciuding
micrilorganisms.
ol
aspects
Jl.i.rn.,rg"tii.;tl-. inciuiiiilg lh:
scribeci.Intiiirch;.ipier.riliertlbiliiintcr'ictiotl.rrithbilththephl,s.
ical environtlle nl itnd g ilil t'r.her t'rrgatristtl: rr ili be contidcred'
FoUNDATIoNS oF MlcRoBlAL EcoLoGY
be developed in this chapter: (1) the nau ith other living organisrns' or the
relationship:
ture of microbial
tl-ic
intc'ractitlns ot- tile.e organisms
tl
r
and
nature of sl.mbioses.
phy'sical environment' or
nonliYing
$
ith
their
and
other
rriih each
Tuo major therllc>
riill
Diversitl & E'cologl'
28.1i. The ternr sl,rnbiosis is usecl in its original brr.iJcst
sen:e. fr
its an association of t\\'o ()r ntore clillerent species r)i trrganisl-lls. ,\rlJ\
as susgestecl br H. A. cleBary in 1879.
;; V"
as populations t)l 11\\i i.llirlrtgt':'rt
or ttlixture> trf c1itl'erent
communities.
sirnilar
hrLr e e voir ed
tllicrotlrganistrts
These
populations.
rnicr,--rbial
rvirh
higher trrand
*'orld
inorganic
the
rvith
while interacting
ganisrns. and thel' Iar-ue11' play beneficial and Yital rtrle:: disease-
\licroorcanisnls function
organisnts. ancl as
causi,tg organisnis are rtnly a minor colllponent ol the rlicrobial
world. if,licroorganisnts. as thcy inte ract u ith tlther trr{;.lt.tisttts arid
their enr.ironnlellt. also contribute to the ful-rctit'rnin: of ecos)'stems. or self-regulating biological cotllutunitics an'i their phl:icai enr.ironnrent (pp. 603_.+). Knou'leclge ot- litcse i1i3;1161ipn: is
important in understanding both microbial cotttribr,iiiolls tt-r tire
natural u'orld and nricrobial roles in disease processi:'
.\ major prtiblet-tl in understandin-rr nricrobial interr'-iit]ns is lhi]t
most microscctpicalll, obserVablc nticrclorganisnls cannrrt be -9ro$'n.
The ,lifl'erences between observable and culturable nicroorsenisms. $,hich limit this field even today. har,e been notei tbr at least
nli70 years. This problem $.as discussed in I 1931 textbcxrk ort soil
streptoof
er:r
discor
the
waksrnan,
bl.Selman
u.ritten
crobiology
mYcin. anci advances continue in this in-rponant :Ircl '-\rg -rc'( ''i()ri
valuable in6.-5). \''lolecular rechniclues and sequence data provitle
tbmrution on rhc-re uncultured nlicr!)olganislrlr Pr.,be: .dn be u>r-d
to bt-rrh identit-r specitrc t'rlrirnisn>r;$ilqk{ r-ttrr]er'tlnd phi:i-'rii
relationships het* een nticrohes. (ttentpt!y'r,r :lrtr* liiesc uticulrnicroL'.iui ecol.Sr
tured micr.tes re'rains r cL-rltrirl .ffiln
t4 P'c0a-b'vw 1nt {/
n prci n,it. chaptcri nitcrt>ors.rnirtns usuallr h:* e io-en
Fzar
\,
the area of n.ricrobial ecologv (Nlicrobial
I=ZeZ MICROBIAL INTERACTIONS
\,'ry
Ir{icroorganislns can b,-- phl'sicallr ass0ciatt:ti ri:ih oiher '-rrganisrns in a varietr oi r"ltr.s. One org]ni:rll cirtl n-- lrr''11!-d t'n
ttre :urfacc rrl-lnotltcr. ls rin ectosl nrhiont' i1i illi' ;l.:'c'' !h' 'Jtosl'mbiont usuailr is a snlalier organism located on the surtace
of a larger orsanisnt. ofren. clissinrilar tlrranisn'.\ (rl'sirnilar
size are in phlsical c()lllllcl. The rerrl consortium can br- u>cd
to describc' this phrsical relationship. Consortia ir aqurttic cnvironments are frequentll complex. involrin-u nluit'iplc lircrs
of similar-looking rnicroorganisms that oiten haie conlplementar)'ph1 siological properties. In contrast' Lrr' (r-!lLnL\nl
can be located rrithin another organisnl as an endosl'mbiont'
There also are rllanv cases in uhich microorgenitms lire on
both the inside and rhe outside of another or-eanism- a phert\rrllenon calleti ecto/endos)'mbiosis. Irlteresting erarnple: of
ecto/endosvlrlbioscs i ncl Lrcle it T h i rtt h r i-r specics' ; :ulfur-''r' i n g
bacteriurn. $ hich is ettached to the surface oi ri navtlr lar!a
and u'hich itscll'corttairls a parasitic biicterium' Fungi as''"iated u,ith plant roots (nrvcorrhiz-al fungi) often contain endosl mbiotic bacteria. as ri,e11 as havinc bacteria 1ir ing on their
surfaces (see PP. 6-t-t--t6).
These phlsical associations can be interrnittent and c"clic
E,xarnples of intermittent and c}'clic associatitlns
permanent.
or
u'ith plants and marine animais are shorvn
microorganisms
of
)
Microbial lnteractio.i
28.3
v \rersus
579
r$
Environment
The ternr "microbial ecology"' is nor used in a gcncral *'av to describe
the presence and contributions of microorglLnirnls. through their actil'ities, to the places uhere they'are l'ound. Studtnts of microbiologl'
should be a\\'are that mr-rch of the intbrnration rx microbial presence
and contributions to soils. \\'aters. anrl associittions *'ith plants. non described bl this term. u.ould havc bL'L'n con\iLiL-red as "enr ironment:rl
nricrobiologl" in the past. Thornas D. Brock. rhe discorerer of Tlu:r'
ntus utluaticus, rvhich is kno*n the ri'orld o\-r as the source of IarT
pr:rl1'nrerase for the poll merasc chain reaction r PCR). hl.s civell a de t'-
inition oimicrobial ecologl'that n3\'be useiui: "\licrobial ecologf
is
the studl' of the behavior and actir itics of nricr.rorganisms in their natural environments." The important operator in this sentence is r/reir environment instead of lle environnrent. To emphesize this poinr. Bro:k
ha.s noted that "microbes are small: their environments also are small."
In these small environments or "micr
icroorganism
Inte!'actions and
Microbial Ecology
Concepts
.
.
.
Most microorganisms in complex communities have not
been grorvn or characterized. This has limited our understanding of microorganism interactions and their roles in
nature and disease. Molecular techniques are providing a
better uncierstanding of these uncultured organisms.
The term syrnbiosis, or "together-life," can be used to describe many of the interactions between microorganisms,
and also microbial interactions with higher organisms. ingtuding plants and animals. These interactions may be positive or negative.
Microbiai ecology is the study of microbial relationships
+
with other organisms and also with their nonliving environr..er+s. ihese relationships, based on interactive uses of
.
resources, have effects extending to the global scale.
Symbiotic interactions includd' mutualism, cooperation,
commensalism. parasitism, predation, amensalism, and
competition- These interactions are important in natural
processes and in the occurrence of disease. The interactions can vary depending or the envi;'cnment and
changes in ihe interaciing organisms.
l,'i;:'ccrga',s.ias, a! :1e, ir:eral:,
. rltcl:ti.,rli:i-,. Sr,-,rilh
gcnetics' and molecular
nlL'labolisnl'
ln
iridrtion.
been discti::cd.
har.e been degenoniics'
inciuding
micrilorganisms.
ol
aspects
Jl.i.rn.,rg"tii.;tl-. inciuiiiilg lh:
scribeci.Intiiirch;.ipier.riliertlbiliiintcr'ictiotl.rrithbilththephl,s.
ical environtlle nl itnd g ilil t'r.her t'rrgatristtl: rr ili be contidcred'
FoUNDATIoNS oF MlcRoBlAL EcoLoGY
be developed in this chapter: (1) the nau ith other living organisrns' or the
relationship:
ture of microbial
tl-ic
intc'ractitlns ot- tile.e organisms
tl
r
and
nature of sl.mbioses.
phy'sical environment' or
nonliYing
$
ith
their
and
other
rriih each
Tuo major therllc>
riill
Diversitl & E'cologl'
28.1i. The ternr sl,rnbiosis is usecl in its original brr.iJcst
sen:e. fr
its an association of t\\'o ()r ntore clillerent species r)i trrganisl-lls. ,\rlJ\
as susgestecl br H. A. cleBary in 1879.
;; V"
as populations t)l 11\\i i.llirlrtgt':'rt
or ttlixture> trf c1itl'erent
communities.
sirnilar
hrLr e e voir ed
tllicrotlrganistrts
These
populations.
rnicr,--rbial
rvirh
higher trrand
*'orld
inorganic
the
rvith
while interacting
ganisrns. and thel' Iar-ue11' play beneficial and Yital rtrle:: disease-
\licroorcanisnls function
organisnts. ancl as
causi,tg organisnis are rtnly a minor colllponent ol the rlicrobial
world. if,licroorganisnts. as thcy inte ract u ith tlther trr{;.lt.tisttts arid
their enr.ironnlellt. also contribute to the ful-rctit'rnin: of ecos)'stems. or self-regulating biological cotllutunitics an'i their phl:icai enr.ironnrent (pp. 603_.+). Knou'leclge ot- litcse i1i3;1161ipn: is
important in understanding both microbial cotttribr,iiiolls tt-r tire
natural u'orld and nricrobial roles in disease processi:'
.\ major prtiblet-tl in understandin-rr nricrobial interr'-iit]ns is lhi]t
most microscctpicalll, obserVablc nticrclorganisnls cannrrt be -9ro$'n.
The ,lifl'erences between observable and culturable nicroorsenisms. $,hich limit this field even today. har,e been notei tbr at least
nli70 years. This problem $.as discussed in I 1931 textbcxrk ort soil
streptoof
er:r
discor
the
waksrnan,
bl.Selman
u.ritten
crobiology
mYcin. anci advances continue in this in-rponant :Ircl '-\rg -rc'( ''i()ri
valuable in6.-5). \''lolecular rechniclues and sequence data provitle
tbmrution on rhc-re uncultured nlicr!)olganislrlr Pr.,be: .dn be u>r-d
to bt-rrh identit-r specitrc t'rlrirnisn>r;$ilqk{ r-ttrr]er'tlnd phi:i-'rii
relationships het* een nticrohes. (ttentpt!y'r,r :lrtr* liiesc uticulrnicroL'.iui ecol.Sr
tured micr.tes re'rains r cL-rltrirl .ffiln
t4 P'c0a-b'vw 1nt {/
n prci n,it. chaptcri nitcrt>ors.rnirtns usuallr h:* e io-en
Fzar
\,
the area of n.ricrobial ecologv (Nlicrobial
I=ZeZ MICROBIAL INTERACTIONS
\,'ry
Ir{icroorganislns can b,-- phl'sicallr ass0ciatt:ti ri:ih oiher '-rrganisrns in a varietr oi r"ltr.s. One org]ni:rll cirtl n-- lrr''11!-d t'n
ttre :urfacc rrl-lnotltcr. ls rin ectosl nrhiont' i1i illi' ;l.:'c'' !h' 'Jtosl'mbiont usuailr is a snlalier organism located on the surtace
of a larger orsanisnt. ofren. clissinrilar tlrranisn'.\ (rl'sirnilar
size are in phlsical c()lllllcl. The rerrl consortium can br- u>cd
to describc' this phrsical relationship. Consortia ir aqurttic cnvironments are frequentll complex. involrin-u nluit'iplc lircrs
of similar-looking rnicroorganisms that oiten haie conlplementar)'ph1 siological properties. In contrast' Lrr' (r-!lLnL\nl
can be located rrithin another organisnl as an endosl'mbiont'
There also are rllanv cases in uhich microorgenitms lire on
both the inside and rhe outside of another or-eanism- a phert\rrllenon calleti ecto/endos)'mbiosis. Irlteresting erarnple: of
ecto/endosvlrlbioscs i ncl Lrcle it T h i rtt h r i-r specics' ; :ulfur-''r' i n g
bacteriurn. $ hich is ettached to the surface oi ri navtlr lar!a
and u'hich itscll'corttairls a parasitic biicterium' Fungi as''"iated u,ith plant roots (nrvcorrhiz-al fungi) often contain endosl mbiotic bacteria. as ri,e11 as havinc bacteria 1ir ing on their
surfaces (see PP. 6-t-t--t6).
These phlsical associations can be interrnittent and c"clic
E,xarnples of intermittent and c}'clic associatitlns
permanent.
or
u'ith plants and marine animais are shorvn
microorganisms
of
)
Microbial lnteractio.i
28.3
v \rersus
579
r$
Environment
The ternr "microbial ecology"' is nor used in a gcncral *'av to describe
the presence and contributions of microorglLnirnls. through their actil'ities, to the places uhere they'are l'ound. Studtnts of microbiologl'
should be a\\'are that mr-rch of the intbrnration rx microbial presence
and contributions to soils. \\'aters. anrl associittions *'ith plants. non described bl this term. u.ould havc bL'L'n con\iLiL-red as "enr ironment:rl
nricrobiologl" in the past. Thornas D. Brock. rhe discorerer of Tlu:r'
ntus utluaticus, rvhich is kno*n the ri'orld o\-r as the source of IarT
pr:rl1'nrerase for the poll merasc chain reaction r PCR). hl.s civell a de t'-
inition oimicrobial ecologl'that n3\'be useiui: "\licrobial ecologf
is
the studl' of the behavior and actir itics of nricr.rorganisms in their natural environments." The important operator in this sentence is r/reir environment instead of lle environnrent. To emphesize this poinr. Bro:k
ha.s noted that "microbes are small: their environments also are small."
In these small environments or "micr