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Introduction Chromobacterium violaceum is a Gram-negative bacillus often found in soil and water of tropical and subtrop-ical regions. Human infection by this bacterium is rare; however, when it occurs, it is associated with high mor-tality rates if not diagnosed or treated correctly or early enough. A study car-ried out between 1971 and 2005 high-lighted that human infection by this microorganism could yield mortality rates between 60 % and 80%. Systemic clinical symptoms include sepsis and visceral abscesses in the liver. The combination of percutaneous drainage of abscesses and systemic antibiotic therapy remains the most common treatment. Currently, it is believed that diagnosis via computed tomography scan and ultrasound-guided aspira-tion must be done before beginning antibiotic therapy. We report a case of C. violaceum infection in Brazil in a pa-tient who had rapid evolution of signs and multiple liver abscesses. Treat-ment consisted of interventional ra-†‹‘Ž‘‰› ƒ† ‹’”‘ Ў‘šƒ ‹ ™‹–Š‘—– –Š‡ need for surgical intervention.

The biosynthesis of lignarenones 1 and 2, the major polyketides of the Mediterranean mollusc Scaphander lignarius is described. The process is primed by benzoic acid and requires acetate and propionate as extender units. The labeling pattern suggests PKS-like synthesis of an unusual E,Z,E-triene chain and origin of the benzoate unit from phenylalanine. 13C-13C NMR COSY has been used to establish the labeling positions due to incorporation of 13C2-acetate.

Summary • In recent years, oxylipins (lipoxygenase-derived oxygenated fatty acid products) have been reported in several bloom-forming marine diatoms. Despite increasing attention on the ecophysiological role of these molecules in marine environments, their biosynthesis is largely unknown in these microalgae. • Biochemical methods, including tandem mass spectrometry, nuclear magnetic resonance and radioactive probes were used to identify structures, enzymatic activities and growth-dependent modulation of oxylipin biosynthesis in the pennate diatom Pseudo-nitzschia delicatissima. • Three major compounds, 15S-hydroxy-(5Z,8Z,11Z,13E,17Z)-eicosapentaenoic acid (15S-HEPE), 15-oxo-5Z,9E,11E,13E-pentadecatetraenoic acid and 13,14-threo-13R-hydroxy-14S,15S-trans-epoxyeicosa-5Z,8Z,11Z,17Z-tetraenoic acid (13,14-HEpETE), were produced by three putative biochemical pathways triggered by eicosapentaenoic acid-dependent 15S lipoxygenase. Oxylipin production increases along the growth curve, with remarkable changes that precede the demise of the culture. At least one of the compounds, namely 15-oxoacid, is formed only in the stationary phase immediately before the collapse of the culture. • Synthesis and regulation of phyco-oxylipins seem to correspond to a signaling mechanism that governs adaptation of diatoms along the growth curve until bloom termination. Factors triggering the process are unknown but synthesis of 15-oxoacid, constrained within a time-window of a few days just before the collapse of the culture, implies the involvement of a physiological control not directly dependent on distress or death of diatom cells.