In this paper,strains with high agarase yield were screened from Porphyra.Their morphology and 16S rRNA gene sequence were analyzed and phylogenetic tree was constructed.The optimal enzyme produc-tion conditions were obtained through single factor and orthogonal tests,and the degradation effect of the en-zyme on cell wall of Porphyra was investigated.The results of growth curve showed that 8 h of inoculation was a logarithmic phase,and OD600 could reach 0.776.The optimal conditions for agarase production by the strain were culture temperature 28℃,initial pH7.5,culture time 24 h,and inoculum size 1%.Under these condi-tions,the highest agarase activity could reach 67.933 U/mL.Morphological observation results showed that the strain was milky white,round or oval,and viscous and moist in texture.The results of biological microscope observation on the degradation effect of the strain on Porphyra and the content of reducing sugar and total sugar after degradation of Porphyra showed that the agarose-producing strain could degrade agar to agaro-oligosac-charides with the extension of degradation time.In summary,the marine bacterium Wang-1 isolated and screened from the Porphyra culture area of Lianyungang was identified as Pseudoalteromonas Wang-1,and the agarase-producing strain had high activity.
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