Application of Food Grade Agar for Preparation as Media Using in Microbiological Laboratory Learning
Abstract
Background : Because the analytical-grade agar commonly used in microbiological laboratory is very expensive. The food-grade agar, the lower cost one, was introduced for preparation of commonly used media in attempt to reduce the cost of this purpose.
Objective : To assess the potentiality of the food grade agar in preparation of bacterial and fungal media for microbiological laboratory learning.
Methods : Eighty six strains of bacteria were cultivated on Nutrient agar (NA) and Sugar assimilation media, and twenty two fungal strains (19 molds, 3 yeasts) were cultivated on Sabouraud dextrose agar (SDA). These media were prepared by the food grade agar. The quality and quantity of these microorganism growth were compared to those of cultivation on media prepared by the analytical grade agar.
Results : All bacterial strains showed the similar characteristics and also biochemical and physiological properties whether cultivation on media prepared from food grade agar or analytical grade agar. Nine strains of molds showed no significant difference on both SDAs, while each of 5 strains on food grade agar-SDA were included in the less and better growth groups (Paired t-test, p<0.05). And, three yeast strains showed no different characters on both SDAs.
Conclusion : In cultivation using bacterial media (NA, Sugar assimilation media) and fungal media (SDA) prepared by food grade agar , the main characteristics of the tested microorganisms showed no difference when compared to those of media prepared by analytical grade agar. Therefore, the food grade agar could be employed for the laboratory learning purpose instead of the analytical grade agar.
Key word : bacterial media, microbiological media
