Isolation,Identification and the Bacteria Colony Characteristic of Thermo-acidophilic Bacteria in the Apple Juice Concentrate
In order to understand and control thermo-acidophilic bacteria in apple juice concentrate,a strain of thermo-acidophilic bacteria was screened,isolated,and purified from the apple juice concentrate in expansion bags.The thermo-acidophilic bacteria were identified by cell morphology,colony morphology,16S rDNA test with phylogenetic tree analysis.The result showed that the homology of isolated strain and standard bacteria ATCC 49025 reached to 99.51％.The isolated strain was identified as Aiyclobacillus acidoterrestris.The thermal stability and acid-base stability of the strain were examined by heat and acid-base treatment.Orthogonal experiment was carried out on the base of single factor experiments,and it was found that the optimal sterilization parameter was to heat treat at 105 ℃ for 20 min at pH 6.0.Under this parameter,the number of colonies growing on the plate was 0.The result indicated that the extraction conditions have good rationality and reliability.The conclusion provided a theoretical basis for the control of thermo-acidophilic bacteria in apple juice concentrate.
Apple juice concentratescreening and isolationthermo-acidophilic bacteriaseparation and identificationmicrobial characteristics
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