Biocontrol activity of Meyerozyma guilliermondii against mould growth and a study of local post-harvest systems for maize in Cameroon

Abstract: Post-harvest loss is a major problem for farmers in sub-Saharan Africa. Substantial amountsof cereal grain are lost each year due to factors such as exposure to rain, extreme drought,physical damage and invasion of microorganisms. This decreases the availability of food/feedwhich in turn increases prices and the consumption of unsafe food. Therefore storage systemsneed to be developed to ensure a safe food supply with low losses.The project aimed to evaluate the inhibiting effects of Meyerozyma guilliermondii against mould growth on maize under local conditions in Cameroon. This was in order to determine if M. guilliermondii could be used for biocontrol storage of moist maize under airtight conditions. Previous studies have shown this system, together with the yeastWickerhamomyces anomalus as biocontrol, to be very effective for grain preservation.Mini silos were inoculated with different moulds and yeasts. W. anomalus was used as a control since it has previously been shown to have an inhibiting effect on mould growth. Furthermore the project aimed to study local post-harvest systems for maize in two different areas of Cameroon. This was done by means of visiting farms and interviewing farmers. The new biocontrol system of moist grain was also explained to the farmers in orderto introduce the idea to them and see if they were willing to try a new storage system. A hygiene study of the storages was also done by microbial quantification and calculation of colony forming units (CFU).No inhibition of mould growth was detected for either M. guilliermondii or W. anomalus.Several factors such as low moisture content, too much mould and the size and the material of the mini silos made the results questionable. More studies need to be made regarding the biocontrol activity of M. guilliermondii.The storage method and hygiene varied between different farms in the Nforya-Bamenda area. However none of the local storage systems seemed to have better hygienic status foryeasts and moulds. The biocontrol system seemed suitable for introduction in Nforya-Bamenda for several practical and socio-economic reasons. With current storage technology it would be no use increasing yield per hectare for maize in this region since farmers already produce more than they can store. Moreover, the change in maize storage technology could prove essential to improving women and children’s health in Cameroon, since many farmers smoke their maize indoors using fire-wood.