Sulfolipid and Phospholipd in Soils and Sewage Sludges in Iowa

Abstract

Abstract The distribution of sulfolipid S and phospholipid P in 10 surface soils and 12 sewage sludges in Iowa is reported. Expressed as percentage of total S in soils and sewage sludges studied, sulfolipid S ranged from 0.29 to 0.45% (avg = 0.37%) and from 6.2 to 38.1% (avg = 20.8%), respectively. Expressed as percentage of organic P, the phospholipid P ranged from 0.27 to 0.79% (avg = 0.50%) in soils and ranged from 0.24 to 8.84% (avg = 2.18%) in sewage sludges. Fractionation of the sulfolipid S extracted from soils showed that HI‐reducible S (expressed as percentage of total lipid S) ranged from 20.2 to 39.6% (avg = 29.2%) and that Raney Ni‐reducible S ranged from 6.1 to 72.7% (avg = 40.7%). The remaining sulfolipid S extracted from soils (from 0 to 58.9%; avg = 30.1%) could not be identified. On the other hand, expressed as percentage of total lipid S in sewage sludges, from 42.0 to 89.3% (avg = 76.2%) was reducible by HI, from 60.4 to 98.0% (avg = 83.4%) by Raney Ni, and from 0.4 to 15.7% (avg = 3.5%) by HCl. Comparison of the results of the S fractions in the lipid extracted from soils and sewage sludges suggests that the nature of the sulfolipid in the two sources is different.