Low-Molecular-Weight, Biologically Active Compounds from Marine Pseudoalteromonas Species

Abstract

We have examined the ability of marine Proteobacteria from the Pseudoalteromonas genus and Alteromonas macleodii to produce low-molecular-weight, biologically active compounds with antimicrobial and surface-active properties. A new marine bacterium, Pseudoalteromonas issachenkonii, exhibited a high level of biological activity and produced antifungal and hemolytic compounds. A detailed spectroscopic investigation based on UV, IR, high-resolution mass spectrometry, and 2D 1H and 13C nuclear magnetic resonance revealed that the former was indole-2,3-dione (isatin). The chemical structure of red-brown pigment (C9H7N3OS3) responsible for hemolytic activity remained unclear. Four of the 15 strains studied (P. luteoviolacea, P. rubra, P. undina, and P. issachenkonii) produced cell-bound, two (P. elaykovii and P. carrageenovora) produced extracellular, and one strain (P. citrea) produced cell-bound and extracellular fatty acids and phospholipids with surface activity. Neither peptides nor glycolipids with surface activity were detected.

Purification and characterization of antibacterial compounds of Pseudoalteromonas flavipulchra JG1

“…Both the non-halogenated and the halogenated compounds showed inhibitory activity against different target organisms. For example, Pseudoalteromonas phenolica produced a brominated biphenyl compound (3,39,5,59-tetrabromo-2,29-diphenyldiol) inhibitory to meticillin-resistant S. aureus strains (Egan et al, 2002;Isnansetyo & Kamei, 2003), and the non-halogenated compound isatin (indole-2,3-dione) found in the EtOAc extracts of Pseudoalteromonas issachenkonii (Kalinovskaya et al, 2004) showed an antifungal activity. Most of the bioactive compounds have a cyclic or benzene ring structure, implying that they may share some structural features.…”

Characterization of culturable bacterial flora in yolk sac larvae of Atlantic halibut (Hippoglossus hippoglossus L.) with

“…Several probiotic studies include strains of spore forming Bacillus that possess adhesion abilities, capable of producing bacteriocins (antimicrobial peptides) (Cherif et al, 2001;Cladera-Olivera et al, 2004;Duc et al, 2004) and their presence could be associated to modular response linked to the probiotic functions of the Bacillus genera. In the same way, Pseudoalteromonas is usually reported as belonging to the normal flora and not related to pathogenic events in fish due to their capability of producing biologically active compounds with antibacterial, algicidal, antifungal, agarolytic, cytotoxic and antiviral activities (Holmstrom & Kjelleberg, 1999;Kalinovskaya et al, 2004). However, some species like P. undina, have also been reported as a pathogen for marine fish (Pujalte et al, 2007).…”

Beneficial effects of 2,4-diacetylphloroglucinol- producing pseudomonads on the marine alga Saccharina latissima

“…Three further isolates were chosen from the collection of Pseudomonas spp. strains obtained in 2010 by the following procedure: The algae were homogenised, and the suspensions of different dilution series as well as the rhizosphere suspension were plated on 3 different media: (1) Medium G, GSP agar according to Kielwein (1971), (2) Medium P prepared according to Kalinovskaya et al (2004) and modified by supplementation with 18 g Tropic Marin sea salt (Dr. Biener) and 15 g Bacto agar in 1 l deionised water, pH 7.6, and (3) Medium C, a Pseudomonas selective agar base supplemented with Pseudomonas CFC selective supplement (Merck), pH 7.2. Incubation was carried out in the dark at 28°C for 5 d. The light regime of the sampling site was not considered as a parameter for setting the culture conditions.…”