Megazyme/AZCL-Chitosan/I-AZCHAN/4 grams

ThemicrobialcommunitiesinsomeAntarcticregionsstillhavenotextensivelyinvestigated.Inthepresentstudy,weisolated24bacterialstrainsunderaerobicconditionsfromterrestrialsamplesattwolocationsinmaritimeAntarctica:DeceptionIslandandGalindezIsland.Phylogeneticanalysisbasedonthe16SrRNAgenesequencingrevealedaffiliationoftheAntarcticisolatestoGammaproteobacteria(54.2%),Betaproteobacteria(8.3%),Firmicutes(20.8%),andActinobacteria(16.7%).Themajorityofisolates(92%)arepsychrotolerant,and75%arehalotolerant.About63%ofisolatedAntarcticbacteriawereabletoproducehydrolyticenzymessuggestingimportantroleofthestrainsincarbonandnitrogencyclingintheirhABItats.Amongisolates,producersofproteases(58.3%),ureases(45.8%),polygalacturonases(41.6%),β-glucosidases(33.3%),phytases(20.8%)andribonucleases(16.6%)weredetected.TheresultsrevealedhigherpotentialofisolatesfromDeceptionIslandtoproducehydrolyticenzymesthanthosefromGalindezIsland.Tothebestofourknowledge,thisisthefirstreportforpolygalacturonaseproductionbyAntarcticbacteriaandβ-glucosidaseproductionbyculturableAntarcticBurkholderiastrain.TheresultsobtainedcontributetobetterunderstandingofthediversityofculturableheterotrophicbacteriainmaritimeAntarcticaandtheirpotentialforproductionofhydrolyticenzymesallowingdetectionofpromisingpsychrotolerantproducersofindustriallyimportantenzymes.

Anewmoderatelyhalophilic,strictlyaerobic,Gram-negativebacterium,strainSX15^T,wasisolatedfromhypersalinesurfacesedimentofthesouthernarmofGreatSaltLake(Utah,USA).Thestraingrewonanumberofcarbohydratesandcarbohydratepolymerssuchasxylan,starch,carboxymethylcelluloseandgalactomannan.Thestraingrewatsalinitiesrangingfrom2to22%NaCl(w/v).Optimalgrowthoccurredinthepresenceof7–11%NaCl(w/v)atatemperatureof35°CandapHof6.7–8.2.Majorwhole-cellfattyacidswereC16:0(30.5%),C18:0(14.8%),C18:1ϖ7c(13.1%)andC12:0(7.8%).TheG+CcontentoftheDNAwas60±0.5mol%.By16SrRNAgenesequenceanalysis,strainSX15^TwasshowntobeaffiliatedtomembersofthegammaproteobacterialgenusMarinimicrobiumwithpairwiseidentityvaluesof92.9–94.6%.Thepheno-andgenotypicpropertiessuggestthatstrainSX15^TrepresentsanovelspeciesofthegenusMarinimicrobiumforwhichthenameMarinimicrobiumhaloxylanilyticumisproposed.ThetypestrainisSX15^T(=DSM23100^T=CCUG59572^T).

Fungus-growing(attine)antsandtheirfungalsymbiontspassedthroughseveralevolutionarytransitionsduringtheir50millionyearoldevolutionaryhistory.Thebasalattinelineagesoftenshiftedbetweentwomaincultivarclades,whereasthederivedhigher-attinelineagesmaintainedanassociationwithamonophyleticcladeofspecializedsymbionts.Inconjunctionwiththetransitiontospecializedsymbionts,theantsadvancedincolonysizeandsocialcomplexity.Hereweprovideacomparativestudyofthefunctionalspecializationinextracellularenzymeactivitiesinfungusgardensacrosstheattinephylogeny.Weshowthat,relativetosisterclades,gardensofhigher-attineantshaveenhancedactivityofprotein-digestingenzymes,whereasgardensofleaf-cuttingantsalsohaveincreasedactivityofstarch-digestingenzymes.However,theenzymeactivitiesoflower-attinefungusgardensaretargetedprimarilytowardpartialdegradationofplantcellwalls,reflectingaplesiomorphicstateofnondomesticatedfungi.Theenzymeprofilesofthehigher-attineandleaf-cuttinggardensappearparticularlysuitedtodigestfreshplantmaterialsandtoaccessnutrientsfromlivecellswithoutmajorbreakdownofcellwalls.Theadaptivesignificanceofthelower-attinesymbiontshiftsremainsunclear.Oneoftheseshiftswasobligate,butdigestiveadvantagesremainedambiguous,whereastheotherremainedfacultativedespiteprovidinggreaterdigestiveefficiency.

Introduction:Inwood-dwellingfungus-farmingweevils,theso-calledambrosiabeetles(Curculionidae:ScolytinaeandPlatypodinae),woodintheexcavatedtunnelsisusedasamediumforcultivatingfungibythecombinedactionofdigginglarvae(whichcreatemorespaceforthefungitogrow)andofadultssowingandpruningthefungus.Thebeetlesareobligatelydependentonthefungusthatprovidesessentialvitamins,aminoacidsandsterols.However,towhatextentmicrobialenzymessupportfungusfarminginambrosiabeetlesisunknown.Herewemeasure(i)13plantcell-walldegradingenzymesinthefungusgardenmicrobialconsortiumoftheambrosiabeetleXyleborinussaxesenii,includingitsprimaryfungalsymbionts,inthreecompartmentsoflaboratorymaintainednests,atdifferenttimepointsaftergalleryfoundationand(ii)fourspecificenzymesthatmaybeeitherinsectormicrobiallyderivedinX.saxeseniiadultandlarvalindividuals.Results:Wediscoveredthattheactivityofcellulasesinambrosiafungusgardensisrelativelysmallcomparedtotheactivitiesofothercellulolyticenzymes.Enzymeactivityinallcompartmentsofthegardenwasmainlydirectedtowardshemicellulosecarbohydratessuchasxylan,glucomannanandcallose.Hemicellulolyticenzymeactivitywithinthebroodchamberincreasedwithgalleryage,whereasirrespectiveoftheageofthegallery,thehighestoverallenzymeactivityweredetectedinthegallerydumpmaterialexpelledbythebeetles.Interestinglyendo-β-1,3(4)-glucanaseactivitycapableofcallosedegradationwasidentifiedinwhole-bodyextractsofbothlarvaeandadultX.saxesenii,whereasendo-β-1,4-xylanaseactivitywasexclusivelydetectedinlarvae.Conclusion:Similartocloselyrelatedfungiassociatedwithbarkbeetlesinphloem,themicrobialsymbiontsofambrosiabeetleshardlydegradecellulose.Instead,theirenzymeactivityisdirectedmainlytowardscomparativelymoreeasilyaccessIBLehemicellulosecomponentsoftheray-parenchymacellsinthewoodxylem.FurThermore,thedetectionofxylanolyticenzymesexclusivelyinlarvae(whichfeedonfunguscolonizedwood)andnotinadults(whichfeedonlyinfungi)indicatesthatonlylarvae(pre-)digestplantcellwallstructures.ThisimpliesthatinX.saxeseniiandlikelyalsoinmanyotherambrosiabeetles,adultsandlarvaedonotcompeteforthesamefoodwithintheirnests-incontrast,larvaeincreasecolonyfitnessbyfacilitatingenzymaticwooddegradationandfunguscultivation.

PenicilliumochrochloronBiourge,whichwasisolatedfromrottensweetpotato,canproduceplantcellwalldegradingenzymes(PCWDEs)withhighviscosityreducingcapabilityforethanolproductionusingfreshsweetpotatotubersasfeedstock.Theenzymepreparationwascharacterizedbyabroadenzymespectrumincluding13kindsofenzymeswiththeactivitytohydrolyzecellulose,hemicellulose,pectin,starchandprotein.Themaximumviscosityreducingcapabilitywasobservedwhentheenzymepreparationwasobtainedafterfivedaysfermentationusing20g/Lcorncobassolecarbonsource,4.5g/LNH₄NO₃assolenitrogensource,andaninitialmediumpHof6.5.Thesweetpotatomashtreatedwiththeenzymepreparationexhibitedmuchhigherfermentationefficiency(92.58%)comparedwithcommercialcellulase(88.06%)andcontrol(83.5%).Theenzymeproductionwasthenscaledupto0.5,5,and100L,andtheviscosityreducingrateswerefoundtobe85%,90%,and91%,respectively.Thus,P.ochrochloronBiourgedisplayspotentialviscosityreducingcapabilityforethanolproduction.

Chineseliquorisoneoftheworld"sbest-knowndistilledspiritsandisthelargestspiritcategorybysales.Theuniqueandtraditionalsolid-statefermentationtechnologyusedtoproduceChineseliquorhasbeenincontinuoususeforseveralthousandyears.Thediverseanddynamicmicrobialcommunityinaliquorstarteristhemaincontributortoliquorbrewing.However,littleisknownabouttheecologicaldistributionandfunctionalimportanceofthesecommunitymembers.Inthisstudy,metatranscriptomicswasusedtocomprehensivelyexploretheactivemicrobialcommunitymembersandkeytranscriptswithsignificantfunctionsintheliquorstarterproductionprocess.Fungiwerefoundtobethemostabundantandactivecommunitymembers.Atotalof932carbohydrate-activeenzymes,includinghighlyexpressedauxiliaryactivityfamily9and10proteins,wereidentifiedat62°Cunderaerobicconditions.Somepotentialthermostableenzymeswereidentifiedat50,62,and25°C(maturestage).Increasedcontentandoverexpressedkeyenzymesinvolvedinglycolysisandstarch,pyruvateandethanolmetabolismweredetectedat50and62°C.Thekeyenzymesofthecitratecyclewereup-regulatedat62°C,andtheirabundantderivativesarecrucialforflavorgeneration.Here,themetabolismandfunctionalenzymesoftheactivemicrobialcommunitiesinNFliquorstarterwerestudied,whichcouldpavethewaytoinitiateimprovementsinliquorqualityandtodiscovermicrobesthatproducenovelenzymesorhigh-valueaddedproducts.