An inhibitory compound produced byPseudomonaswith effectiveness onVibrio harveyi

Abstract

Persistence of the antivibrio property of the potential antagonistic probiotics, Pseudomonas MCCB 102 and 103, at di¡erent temperatures, pH and in organic solvents was studied. The antivibrio compound was extracted, puri¢ed and characterized using thin-layer chromatography, high-pressure liquid chromatography, liquid chromatography-mass spectroscopy, UVV is and nuclear magnetic resonance spectroscopy and identi¢ed as N-methyl-1-hydroxyphenazine, a phenazine antibiotic. The toxicity of the compound was tested in Penaeus monodon haemocyte culture and the IC 50 value was found to be1.4 AE 0.31mg L À 1 . The compound was found to be bacteriostatic at 0.5 mg L À 1 . Its stability to varying temperature, pH, organic solvents, prolonged shelf-life and vibriostatic nature point to its suitability for prophylatic aquaculture application.Solvent extraction was performed using 1-butanol, ethyl acetate, dichloromethane, chloroform and hex- Aquaculture Research, 2010 An inhibitory compound againstVibrio harveyi R Preetha et al.

Application of primary haemocyte culture of Penaeus monodon in the assessment of cytotoxicity and genotoxicity of heavy metals and pesticides

“…Studies on the application of haemocyte culture or any other primary cultures of shrimp in cytototoxicity and especially the genotoxicity of drugs, management chemicals and pollutants in aquaculture systems have been rarely cited in literature. The P. monodon heamocyte culture has been applied for assessing cytotoxicity of N-methyl-1-hydroxyphenazine, a proposed aquaculture drug (Preetha et al, 2010) and benzalkonium chloride, an aquaculture management chemical employing MTT assay. Sung et al (2003) examined the effects and toxicity of phthalate esters on the isolated haemocytes of Macrobrachium rosenbergii utilising haemocytic adhesion, pseudopodia formation, superoxide anion production and phenoloxidase activity.…”

Antagonistic effect of Pseudomonas aeruginosa isolates from various ecological niches on Vibrio species pathogenic to crustaceans

“…Toxicity assessments in brine shrimp showed pyocyanin to be non-toxic at concentrations up to 100 mg/L, and the LC 50 values were (296.65依18.15) mg/ L and (215.312依35.660) mg/L for the exposure times of 12 h and 24 h respectively. The cytotoxicity (IC 50 ) of pyocyanin from environmental isolates of P. aeruginosa in primary haemocyte cultures from Penaeus monodon was found to be (1.40依0.31) mg/L, and on V. harveyi at 0.5 mg/L, it showed static effect and cidal at 1.0 mg/L [16] . NMR spectroscopic study confirmed that the extracted compound, antagonistic to Vibrio, was pyocyanin.…”

“…Pyocyanin produced from environmental isolate of P. aeruginosa has been identified as the key molecule that inhibits growth of vibrios in aquaculture systems [16] . It has also been demonstrated that environmental isolate of Pseudomonas can control vibrios and improve larval survival in shrimp hatchery systems [15] .…”

“…Specifically, the versatile and ubiquitous bacterium, Pseudomonas aeruginosa [10,11] ( P. aeruginosa ) has recently been recognized as an active antagonist of pathogenic Vibryo harveyi (V. harveyi) and thus as a candidate probiotic in aquaculture systems [12][13][14][15] . The anti-vibrio compound produced by P. aeruginosa was proved to be pyocyanin [16] , a blue-green chloroform-soluble phenazine pigment, which possessed broad-spectrum antibacterial [17] , anti-fungal [18,19] and antiprotozoan activities [20] .…”

Antivibrio compounds produced by Pseudomonas sp. W3: characterisation and assessment of their safety to shrimps

“…(Alavandi et al 2004;Preetha et al 2009). Therefore, exploring for new bioactive compounds against shrimp bacterial disease agents like V. harveyi is an urgent priority.…”