Designation:D7816−12StandardTestMethodforEnumerationofHalophilicandProteolyticBacteriainRacewayBrine,Brine-CuredHidesandSkins1ThisstandardisissuedunderthefixeddesignationD7816;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoverstheenumerationofbacteriathatcantoleratehighsaltconcentrationsorcanhydrolyzeprotein/collagen,orboth.Thistestmethodisapplicabletoracewaybrine,brine-curedhidesandskins,andpre-chargeracewayliquor.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D6715PracticeforSamplingandPreparationofFreshorSalt-Preserved(Cured)HidesandSkinsforChemicalandPhysicalTestsE177PracticeforUseoftheTermsPrecisionandBiasinASTMTestMethodsE691PracticeforConductinganInterlaboratoryStudytoDeterminethePrecisionofaTestMethod3.SummaryofTestMethod3.1Samplesofbrine-curedhidesandskins,racewaybrineorpre-chargeracewayliquorareseriallydilutedandplatedonagarcontaining7%NaClandcaseinfromskimmilk.Theplatesareincubatedunderaerobicconditionsat35°Cfor48h.Afterincubation,todeterminesalttolerant(halophilic)bacteria,allcoloniesarecounted.Todeterminebacteriathatcanhydrolyzeprotein(proteolytic),theplatesarefloodedwithdiluteacidandthecoloniesshowinga“halo”(semi-clearzones)arecounted.4.SignificanceandUse4.1Thistestmethodenumeratessalttolerant(halophilic)bacteria,andproteolyticbacteriathatarealsosalttolerant.Undertheconditionsofthistestmethodthosebacteriaareequatedashalophilicorganisms.Salttolerantproteolyticbacteriahavebeenknowntoc...
