Abstract:In this paper， strains with high agarase yield were screened from Porphyrɑ. Their morphology and 16S rRNA gene sequence were analyzed and phylogenetic tree was constructed. The optimal enzyme production conditions were obtained through single factor and orthogonal tests， and the degradation effect of the enzyme on cell wall of Porphyrɑ 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 conditions， 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 Porphyrɑ and the content of reducing sugar and total sugar after degradation of Porphyrɑ showed that the agarose-producing strain could degrade agar to agaro- oligosaccharides with the extension of degradation time. In summary， the marine bacterium Wang-1 isolated and screened from the Porphyrɑ culture area of Lianyungang was identified as Pseudoɑlteromonɑs Wang-1， and the agarase-producing strain had high activity.