Abstract
Cells of Streptococcus laths grown at 10°C and harvested were disintegrated and lyphoilized for extraction of total lipids. The extracted lipids were separated into neutral and complex lipids by silicic acid column chromatography and recovered to determine their yields. Complex lipids were fractionated into glycolipids and phospholipids by silicic acid column chromatography and on silicic acid-impregnated papers. Total lipid contents in dried cells of the bacterium amounted to about 5%, and the proportion of neutral to complex lipids was about 20 to 80, irrespective of growth temperatures (10 and 30°C). Seven components in complex lipids were divided into three of glycolipids and four of phospholipids on the chromatogram. The variations in the yields of the components were due to the growth medium composition. It was found that glycolipid contents of bacterial cells were considerably higher. The fatty acid composition of neutral lipids and phospholipids was clearly affected by growth temperatures, and at 10°C, unsaturated acids (C1=l6 and C1=18) increased and lactobacillic acid (cy-C13) decreased.
