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Selected microbial degradation of saturated methyl branched-chain fatty acid isomers

Ngo, Helen L., Ashby, Richard D., Nunez, Alberto
Journal of the American Oil Chemists' Society 2012 v.89 no.10 pp. 1885
Pseudomonas, bacteria, biodegradation, branched chain fatty acids, carbon, feedstocks, gas chromatography, isomers, microbial growth, spectroscopy
Three strains of Pseudomonas bacteria were screened for their capabilities of degrading chemically synthesized saturated branched-chain fatty acids (sbc-FAs). Mixtures of sbc-FAs with the methyl-branch located at various locales along the fatty acid were used as a carbon feedstock in shake-flask culture. Utilization (and hence degradability) of the sbc-FAs was monitored based on positive bacterial growth, fatty acid recovery rates and chromatographic (GC and GC-MS) analysis of the recovered carbon source. Pseudomonas (P.) putida KT2442 and P. oleovorans NRRL B-14683 were both able to grow on sbc-FAs utilizing 35% and 27% of the carbon source, respectively after 144 h. In contrast, P. resinovorans NRRL B-2649 exhibited the most efficient use of the carbon source by utilizing 89% of the starting material after 96 h resulting in a cell dry weight (CDW) of 3.1 g/L. GC and GC-MS analysis of the recovered carbon source revealed that the bacterial strains selectively utilized the isostearic acid in the sbc-FA mixture and a new group of short chain fatty acids (approximately 4 to 29%) were formed during degradation.