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Screening and Characterization of Lipid inclusions in Bacteria by Fluorescence Microscopy and Mass Spectrometry as a Source for Biofuel Production


  • Department of Microbiology and Biotechnology, Jnanabharathi campus, Bangalore University, Bangalore - 560056, Karnataka, India


Objectives: To screen and characterize lipid inclusions found mostly in the cytoplasm of soil bacteria as a source for biofuel production. Methods: In the present study, five bacterial isolates, from soil were observed under phase contrast microscope to study their morphology later stained with lipid specific dye, Nile red and the fluorescence intensity determined by Zen blue software. Lipid extraction was performed using chloroform: methanol(2:1) and quantified gravimetrically. The extracted lipids were further resolved by TLC with Triolein and Linoleic acid as standards. Lipid with highest yield was analysed by MALDI-TOF. Findings: The analysis has been of immense importance in selection of the highest neutral lipid accumulating isolate, where Rhodococcus pyridinivorans strain OB1 yielded the highest amount of lipid (40mg/100ml).TLC profile showed TAG spots correlating with standards. MALDI-TOF spectra showed many peaks corresponding to Mono and diacylglycerols, a predominant peak at m/z 907corresponding to 54:3 TAG. Novelty: This report is the first on the analysis of several soil bacterial strains for their lipid accumulating ability and has provided a thorough profile of lipid classes.


Nile red, Fluorescence microscopy, Lipid inclusions, TLC, MALDI-TOF

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