Insight of microbial interactions in silage inoculation for amending fermentation quality and antioxidant capacity based on combination of modern multi-sensor technology, molecular microbiological methods, and optimal selection modelling

• Applicants: Professor Dr. Wolfgang Büscher; Professor Dr. André Lipski
• Subject Area: Animal Breeding, Animal Nutrition, Animal Husbandry ; Microbial Ecology and Applied Microbiology
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 514571158

Silage is worldwide the most important feedstuff for farm ruminants and substrate for biogas i.e. bioenergy production. Various biological/chemical additives have been applied for both amending fermentation quality and antioxidant capacity of silage over the last three decades. For deeper understanding of microbial roles of biological silage additives, it is critical to get insight of microbial interaction in silage inoculation, focused on optimal ensiling and optimal selection of lactic acid bacteria (LAB). This proposal presents an interdisciplinary fundamental study, combined with multi-sensor-fusion measurement, molecular microbiological analyses, biochemical LAB fermentation under optimal control theory and optimal insolation of LAB from common silage crops. Two research teams of Bonn University will cooperate together for the proposed study: one leaded by Prof. Dr. W. Büscher responsible for in situ screening of microbial activities by using multi-sensor technology and one leaded by Prof. Dr. A. Lipski responsible for molecular microbiological interpretation. The highlights of this study can be characterized as follows: ● The sounded works of preliminary study (novel experimental methods and first reported experimental data) about the optimal preselection of the strains of LAB and optimal LAB fermentation are presented from both teams. ●A series of advanced multi-sensor instruments for in situ measurement of CO2, Ethanol, O2, pH and temperature from or within silage, under anaerobic, semi-aerobic and aerobic experimental conditions, this ensures to precisely track/screen microbial activities/ metabolism during the process of LAB anaerobic fermentation and the aerobic decomposition of lactic acid in silage during aerobic experiment. ● Mathematical modelling associated with the generalized problem of Bolza equation (a basic equation of optimal control theory in applied mathematics), and to conduct the proposed experiment will result in optimal insolation and selection of LAB’s strains. ● The analyses of co-cultures of isolates from silage to detect mutualistic interactions between strains during ensiling biochemical activities. Growth rates and acid production will be analyzed for single strains and co-cultures. For characterizing the interactions the synthesis and effects of quorum sensing autoinducers will be analyzed as well as transcriptome analyses of co-cultures to detect regulatory interactions. The mutualistic activities of co-cultures will be quantified and analyzed in detail by means of the developed multi-sensor mini bioreactor system.

• DFG Programme: Research Grants