Development of microorganisms during storage of wet brewery waste under aerobic and anaerobic conditions

Abstract

This research study was conducted to evaluate, by means of microbiological analyses, the preservation of wet brewery waste stored under aerobic and anaerobic conditions, regarding the development of filamentous fungi, yeasts and lactic-acid bacteria. The following treatments were used: untreated brewery waste, pre-dried brewery waste silage, brewery waste silage with effluent drainage and BW silage without effluent drainage. Silos made of PVC and equipped with Bunsen valves to allow gases to escape were used. Dry matter (DM), crude protein (CP), temperature (°C) and pH in the untreated BW, in the stored brewery waste and in the brewery waste silage upon silo opening, after 60 days of ensilage were analyzed. A completely randomized design was used. The data were subjected to analysis of variance, and the means were compared by the Tukey test at the 5% probability level. The preservation of brewery waste packaged under aerobic conditions was not appropriate due to the development of filamentous fungi and yeasts; however, storage under anaerobic conditions proved to be an effective conservation process.

Keywords

• filamentous fungi
• lactic acid bacteria
• silage
• yeasts