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Updated: Jun 23, 2026
From a Natural Product to Its Biosynthetic Gene Cluster: A Demonstration Using Polyketomycin from Streptomyces diastatochromogenes Tü6028
Published on: January 13, 2017
[Antibacterial activity of Porphyra spp. epiphytic bacteria and polyketide synthase I gene screening]
Wenya Fang1, Rui Yang, Peng Zhu
1Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ningbo 315211, China. fangwenya1984@163.com
Objective:
Based on the antibacterial analysis, we screened Polyketide synthase (PKS I) gene from the epiphytic bacteria of Porphyra spp., in order to obtain the PKS I positive strains and detect the potential connection between the PKS pathway and the antibacterial mechanisms.
Methods:
A total of 31 bacteria with broad-spectrum antibacterial activity were screened by agar-screening methods. The 16S rDNA and the Ketosynthase gene were amplified from the genome DNA of these bacteria, which were cloned into pMD19-T vector for sequencing analysis.
Results:
Porphyra spp. epiphytic bacteria showed broad-spectrum antibacterial activity. Three PKS I positive epiphytic bacteria were obtained from Wenzhou rotten Porphyra spp. samples which had high antibacterial activity. The BLAST results indicated that the Ketosynthase fragments of PKS I from the strains of WPhG3, WPySwl and WPySw2 shared highest similarity (98%, 99%, 98%) to the strains of Bacillus subtilis subsp. Subtilis str. 168 (NP_389602), Bacillus subtilis (ABR19776) and Aspergillus carbonarius (AAZ99721), respectively. Furthermore, the phylogenetic analysis based on 16S rDNA sequences indicated that they belonged to the genus of Bacillus.
Conclusion:
The flora of Porphyra spp. epiphytic bacteria was complex, which regulated the phycosphere in many ways. The PKS I pathway might be a performance of antibacterial function of Bacillus from Wenzhou rotten samples.
