MIXED MICROBIAL FERMENTATIONS AND METHODOLOGIES FOR THEIR INVESTIGATION DEN N IS S . N I ELSEN, N I LS ARN EBORG, A N D LEN E J ESPER SEN

Numerous microbiological interactions take place during mixed fermentations, such as (i) interactions between microorganisms and substrate; (ii) interactions between microorganisms and metabolites; and (iii) interactions between different microbiological groups at both species and strain level. In addition, the microbiological processes during fermentation induce biochemical and/or physical changes in the substrate which also influence the fermentation.