Microbial Transformation of Fecal Pellet Lipids During Sedimentation

摘要: Abstract Changes in the composition and distribution of fecal pellet lipids during sedimentation were investigated laboratory experiments. Fecal pellets collected from marine copepod Calanus helgolandicus fed on dinoflagellate Scrippsiella trochoidea , split into fractions, treated one three ways (antibiotics, poisoned or untreated controls). Pellets incubated dark at 10°C using revolving cylinders to allow continual sinking, for up 16 days. Bacterial numbers monitored surrounding water by epifluorescence microscopy extracted analyzed capillary gas chromatography chromatography-mass spectrometry. Significant differences lipid observed among all treatments compared with freshly pellets, largest changes occurring pellets. Fatty acids showed greatest shift, substantial variations odd branched chain fatty acids. In “aged” five days, small amounts hop-17(20)-ene present which increased concentration aged The algal sterols only slight incubation period treatments, suggesting that sterol distributions are not substantially altered microbial activity upper oceanic waters over relatively short (16 days) time periods.