The isolation, purification and biological activity of a novel antibacterial compound produced byPseudomonas stutzeri

Abstract

A novel compound designated zafrin [4beta-methyl-5, 6, 7, 8 tetrahydro-1 (4beta-H)-phenanthrenone] was isolated from a crude extract of a marine bacterium identified as Pseudomonas stutzeri. Zafrin showed strong antibacterial activity against both Gram-positive and Gram-negative bacteria. The compound was purified and its structure was elucidated by spectroscopic methods including 1H-nuclear magnetic resonance (NMR), 13C-NMR, 1D-NMR and 2D-NMR spectroscopy. It could be demonstrated that a purified solution of zafrin was active against several human pathogens, including Staphylococcus aureus, and Salmonella typhi. By contrast, zafrin did not inhibit the growth of eukaryotic organisms Candida albicans and Schizosaccharomyces pombe. The minimal inhibitory concentration for Gram-positive bacteria ranged from 50 to 75 microg mL(-1) and varied between 75 and 125 microg mL(-1) for Gram-negative bacteria. Zafrin lysed Bacillus subtilis cells grown in an osmotically protected medium, suggesting that it does not act upon the cell wall. Further investigation using B. subtilis indicated that the compound is bactericidal and is likely to target the cell membrane.

Bioactive substances produced by marine isolates of Pseudomonas

“…CMG1030 has antimicrobial activity. This organism was originally identiWed as P. aeruginosa, but the strain identiWcation was revised to P. stutzeri CMG1030, which produces the novel antibacterial compound zafrin [76]. Subsequently, the authors elucidated the chemical structure of zafrin and studied its antibacterial mechanism.…”

“…Marine isolates of P. stutzeri have also been reported to live in the Black Sea (southwest) at 120-m depth [69], in a deep-sea hydrothermal vent in the Galapagos Rift [62] and in the Ariake Sea tideland, Japan [40]. Strains of this species can degrade naphthalene [11-13, 60, 61], oxidize thiosulfate [69], and sulfur [62], denitrify [40], and produce urea [73] and antibiotics [1,[75][76][77]. Amachi et al [3] also have isolated Pseudomonas strain SCT, a dissimilatory iodate-reducing bacterium closely related to P. stutzeri.…”

Red Sea Microbial Diversity for Antimicrobial and Anticancer Agents

“…Isnansetyo et al [81] have isolated a novel compound, zafrin (4b-methyl-5,6,7,8-tetrahydro-1 (4b-H)-phenanthrenone), from Pseudomonas stutzeri strain, which was isolated from Gulf of Karachi, Pakistan. The bactericidal effect of Zafrin was more efficient than ampicillin, vancomycin or tetracycline against Bacillus subtilis., and bacterial membrane was the target of its bactericidal due to its amphiphilic nature, disruption of bacteria membrane like nisin or triton X-100 antibacterial agents [82]. Similarly, Al-Gendy et al [83] have also reported antibacterial compound, ayamycin, derived from secondary metabolites of Nocardia sp.…”

Bioactive Compounds from Marine Bacteria and Fungi

“…Zafrin does not target the bacterial cell wall and its pattern of lysis resembles that of compounds such as nisin (14.91 µM) and Triton X‐100, which disrupt the cell membrane. It was suggested that the mode of action of zafrin is via the disruption of the cytoplasmic membranes, since the molecule is amphiphilic (Uzair et al ., 2008).…”