Physiology of Sporeforming Bacteria Associated with Insects II. Lipids of Vegetative Cells.
Lipid composition was studied in two strains each of mid-log phase cells of Bacillus thuringiensis, B. larvae, B. popilliae, B. alvei, and B. lentimorbus. Total lipids varied from 2.5 to 3.5% of the cell dry weight of B. thuringiensis to 4.3 to 5.0% of B. popilliae. Phospholipids in the organisms examined ranged from 55 to 79% of total lipids; neutral lipids averaged from 13 to 45%. Common phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and lysophosphatidylethanolamine. 1,2-Diglycerides, methyl esters, free fatty acids, and hydrocarbons were found in all the organisms studied. Branched-chain fatty acids constituted more than 50% of the total fatty acids in B. thuringiensis, B. larvae, B. popilliae, and B. alvei, whereas, in B. lentimorbus, normal-chain acids constituted more than 50%. Anteiso-C(15) (12-methyltetradeconoate) was the most abundant acid (30 to 50%) in B. alvei, B. larvae, B. popilliae, and B. lentimorbus. In contrast, B. thuringiensis contained more iso-C(13) (7%), iso-C(15) (17%), normal-C(16) (24%), and iso-C(17) (18%) than anteiso-C(15) (6%). The distribution of individual fatty acids was similar in the phospholipids and neutral lipids of each organism. However, the total amount of iso, anteiso, and normal isomers differed.
Northern Regional Research Laboratory, Peoria, Illinois 61604.
L A
LA
Bulla
G A
GA
Bennett
O L
OL
Shotwell