Size matters: biochemical mineralization and microbial incorporation of dicarboxylic acids in soil

Abstract The transformation and turnover time of medium- to long-chain dicarboxylic acids (DCA) in soil is regulated by microbial uptake mineralization. However, the chain length n-alkyl lipids may have a remarkable influence on its utilization mineralization therefore formation stable organic carbon from e.g. leave- needle- root-derived matter during decomposition. To investigate their size dependent incorporation, four DCA different lengths (12–30 atoms), that were 13 C labeled at each terminal carboxylic groups, applied Ah horizon Fluvic Gleysol. Incorporation into CO 2 distinct groups classified phospholipid fatty acid (PLFA) analysis was investigated. Mineralization incorporation PLFA decreased with increasing length, rate highest first days incubation. Half-life increased 7.6 for 12 86.6 18 again 46.2 22 DCA, whereas 30 had longest half-life time. Rapid efficient as an intact molecule observable. Gram-negative bacteria incorporated higher amounts DCA-derived compared other especially actinomycetes fungi phase derived actinomycetes, steadily entire incubation time, suggesting those take up label necromass used before.