Antibacterial activity of Porphyra spp. epiphytic bacteria and polyketide synthase I gene screening

• Published in: Wei sheng wu hsüeh pao Vol. 49; no. 2; p. 153
• Main Authors: Fang, Wenya, Yang, Rui, Zhu, Peng, Shan, Yuanyuan, Yan, Xiaojun
• Format: Journal Article
• Language: Chinese
• Published: China 01.02.2009
• Subjects: Amino Acid Sequence; Antibiosis; Bacillus - classification; Bacillus - enzymology; Bacillus - isolation & purification; Bacillus - physiology; Bacterial Proteins - chemistry; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; DNA, Bacterial - genetics; DNA, Ribosomal - genetics; Molecular Sequence Data; Phylogeny; Polyketide Synthases - chemistry; Polyketide Synthases - genetics; Polyketide Synthases - metabolism; Porphyra - microbiology; RNA, Ribosomal, 16S - genetics; Sequence Alignment
• ISSN: 0001-6209

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. 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. 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 carb