Growth in High Osmotic Medium of an Unsaturated Fatty Acid Auxotroph of Escherichia coli K-12

A temperature-sensitive mutant of Escherichia coli K-12, which is impaired in the biosynthesis of the unsaturated fatty acids at 42 C, continues to grow and remains viable in a medium with a high osmotic pressure. Under these growth conditions, 50% of the fatty acids of the parental strain and 80% of the fatty acids of the mutant strain are saturated.