Microflora dynamics in earthworms casts in an artificial soil (biosynthesol) containing lactic acid oligomers

Abstract

Studies were performed to appreciate the presence of micro-organisms able to degrade OLA, in earthworms casts or in the surroundings. Worms were grown in biosynthesol, an artificial soil. The counting of bacteria and fungi in earthworms casts and in biosynthesol without earthworms suggested that earthworms ate some of the microorganisms. The main filamentous fungi genera found were Aspergiilus, Trichoderma, Fusarium and Pénicillium. Previous results in the literature have shown that some species from the Aspergiilus and Fusarium genera were able to degrade OLA and other aliphatic esters. It could be suggested that these two genera and some bacteria were responsible for the pre-degradation of OLA, and that earthworms might eat them.