The Netherlands 1

Marisse Hut (17)

City/Region: Krimpen aan den Ijssel, Zuid-Holland Hobbies: Tennis, playing the flute Career: Dietician School: Comenius College

Stefanie Koster (18)

City/Region: Rotterdam, Zuid-Holland E-mail: fam.koster@hccnet.nl Hobbies: Reading, watching TV, internet and my work at a video store Career: No career intention yet School: Comenius College

Influence of Non-biotic Factors on the Growth of Moulds

Microbial food contamination in the form of uncontrolled fungi (yeast and mould) growth still continues to this day to present today a major human health hazard. Marisse and Stefanie wanted to see how long they could contain the spread of Penicillin and Mucor moulds on food supplies. They decided that if they could determine under which circumstances these moulds grow the best, they could also determine how to limit their growth. They exposed black bread to different kinds of non-biotic factors, such as light, air, humidity and temperature. By varying one of the factors and keeping the other factors the same, the girls determined what the best situation was for each factor. Light, air and acidity they found had no particular influence on the growth of moulds though the moulds did seem to like an acid environment as much as a neutral one.