Energy-efficient crop storage - Bioconservation


Sugarbeets and grains grown in Sweden are two crops that may be used as raw materials for domestic production of bioethanol, and also for biogas fermentation. To make this economically feasible, the amount of energy expended for storage and preservation should be minimised. Today, grains are normally dried before storage, at high energy cost, and are then soaked in water before use. Sugarbeets are stored in heaps covered by tarpaulins and are rapidly spoiled due to infestation by soil microorganisms within a few months, limiting the availability of beets for ethanol production. The current project is focused on biopreservation, that is, the use of microoganisms to prevent growth of spoilage moulds and bacteria. Moist grain can be stored in air tight systems but any air leakage may permit the growth of spoilage moulds. Research at the Department of Microbiology has earlier identified Pichia anomala as a biocontrol yeast that can compete with the moulds for oxygen and nutrients, thus increasing the storage stability. 



The main issues under investigation are:


  1. Use of Pichia anomala biocontrol yeast for storage of grain.
  2. Use of Pichia anomala in combination with lactic acid bacteria to improve long term storage.
  3. Use of Pichia anomala to increase the storage time for sugar beets, either be using air tight storage of unbroken beets or by ensiling sugarbeet pulp.





Karin Jacobsson, Department of Microbiology, SLU, Box 7025, 750 07 Uppsala, tel +46 (0) 18 673255