Epsilon Archive for Student Projects

Abstract

Borling, J. 2010. Preservation of moist crimped cereal grain can be achieved as a result of fermentation by lactic acid bacteria. Climatic variations make it difficult under practical farm conditions to harvest the grain at a moisture content (30-45%), suitable to ensure fermentation. Therefore the yeast Pichia anomala J121, previously found to prevent mould spoilage and improve preservation of moist grain in malfunctioning air tight silos, was added to the storage of moist crimped cereal grain in big plastic tubes. Freshly harvested barley was rolled and inoculated with 105 colony-forming units (Cfu) g-1 P. anomala, strain J121. Due to the local weather conditions, harvest was delayed and moisture content in the cereal grain had decreased to only 16-18%. Inoculation of P. anomala was done in 48 tons of barley, packed into three plastic tubes. Three additional sets of plastic tubes were packed with cereal grain without addition of P. anomala. The grain tubes were left closed for 5 months, after which feeding to cattle commenced. The population diversity of lactic acid bacteria (LAB) was very high both in the P. anomala inoculated barley and in the non-inoculated barley. A shift in the dominant LAB over the course of storage to Pediococcus pentosaceus and Lactobacillus paracasei was discernible in inoculated and non-inoculated respectively. The yeast population in the inoculated barley was totally dominated by P. anomala during the entire storage period. In the non-inoculated grain, the yeast population was more diverse, displaying shifts in the dominant species during storage. Pichia burtonii was the dominant species at the last sampling occasion. In the inoculated grain, mould numbers were reduced by approximately two log units, and the number of Enterobacteriaceae was reduced beneath detection limit. Negative effects on animal health or on weight gain were not observed.