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Methodsofscreening,culturing,improvementandstorageofmicroorganisms...
tabletcontainingadditionallysodiumbicarbonateandcitricacid,
whichsupplementtheanaerobicatmospherewithhydrogen.
Disposable,commerciallyavailablechemicalanaerobicgas
generatorssuchasGasPak,AnaeroGenorAnaerocultarewidely
usedandtheyaremostlyintheformofsachetsorenvelopes
placedinsidetheculturejars.Inordertocontroltheanaerobic
conditionsintheanaerostate,appropriateindicatorsareoften
introduced,e.g.basedonthereactionofmethyleneblue,which
occursinoxidisedforminblueandbecomescolourlesswhen
hydrogenisadded.
Oneofthestandardsofobtaininganaerobicconditions
byphysicalmethodsistheANOXOMATsystem,whichis
basedonadevicethatallowspreparationoftheculturein
anaerobicconditionsorwithlowoxygencontentbymeansof
afullyautomatedmechanismofairpumpingandatmospheric
compositionexchangeinanaerobicjars.Theprocessofachieving
thedesiredgrowthconditionsformicroorganismsthatare
sensitivetodiferentoxygenconcentrationintheenvironment,is
controlledateachstageoftheprocessthroughamicroprocessor
system,ensuringprecise,fastandreproducibleachievementand
maintenanceofanaerobicorlowoxygenconditions.
Anaerobicchambersarealsowidelyusedinanaerobic
cultures,whichminimisetheexposureofanaerobic
microorganismstooxygen.Anaerobicchambersareequipped
withspecialisedsystemssupportingcontroloftheprocessof
creatingandmaintaininganaerobicatmosphere.Theyarealso
equippedwithsetsofsleevesorcufsattachedtohandaccess
portsandasluiceformaterialinsertionandremoval.
Inaddition,bioreactorsarealsousedforanaerobicculture,
mainlyduetothecontinuousfeedingofsubstratesandremoval
ofby-products,whichallowsstableconditionstobeachieved
formicroorganismgrowth,whilereproducingthenatural
environmentalconditions.
Manymethodsofanaerobescultivationarebasedon
modificationsofalreadyexistingtechniques,whichoftenboil
downtotheseparationofspecificgroupsofmicroorganisms.
Theseimprovementsincludechangesinthecompositionof
culturemedia(e.g.theuseofantibioticstofacilitatethegrowth
ofmethanogenicarchaeons),theintroductionofnewcocultures
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