Effect of growth substrate on thermal death of thermophilic bacteria.
The heat sensitivity of gram-negative, hydrocarbon-utilizing thermophilic bacteria was altered by a change in growth substrate. Thermophilic strains CC-6, BI-1, and LEH-1, grown with acetate or n-heptadecane as the carbon source, had a higher survival rate when incubated 5 degrees C above their maximum growth temperature than cells of the same organism after growth on glucose or glycerol. There was a correlation between the growth substrated, heat resistance, and the ratios of cellular n-hexadecanoic acid/branched hexadecanoic acid and n-heptadecanoic acid/branched heptadecanoic acid. The bacterial cells that were more heat resistant had ratios of straight-chain/branched-chain fatty acids above 1.0, whereas the heat-sensitive cells had ratios below 0.6.
D000085:Acetates / Q000378:metabolism; D000473:Alkanes / Q000378:metabolism; D001419:Bacteria / Q000254:growth & development* / Q000378:metabolism; D003470:Culture Media; D005227:Fatty Acids; D005947:Glucose / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D006358:Hot Temperature
D000085:Acetates; D000473:Alkanes; D003470:Culture Media; D005227:Fatty Acids; D005947:Glucose; D005990:Glycerol