SURVEY AND FOURIER TRANSFORM INFRARED MICROSCOPY (FTIR) ANALYSIS OF YEASTS ISOLATED FROM DAIRY PRODUCTS IN OSOGBO METROPOLIS

Abstract

The purpose of this paper is to investigate the different yeast species in dairy products that can be harnessed industrially for biotechnological functions. Eighteen (18) different yeast species were obtained from thirty (30) different dairy products namely: yogurt, milk and cheese. pH, temperature and ethanol tolerance were conducted using standard methods while fungi isolation was done using culture-dependent methods. The antibacterial activity and FTIR analysis the yeast species were also done using standard methods. Result obtained showed that S. cerevisiae was the predominant fungi isolated (19.11%) while Chrysosporiumspp and C. fimetiwere the least with 1.47% occurrence each. All isolates showed moderate antibacterial activity on test pathogens. S. cerevisiae, C. krusei, C.glabrataand K. fragilis were analzyed for functional groups with the corresponding peaks 3439.19, 3437.26, 3439.19, 3431.48, 3417.98 and 3448.84(cm-1) respectively. All possess hydroxyl (O-H) and methylene functional group (C-H) while only D. hansenii(C-C) had an additional alkenyl group. In conclusion, representative isolate analyzed by FTIR can be employed industrially for fermentation processes while D. hanseniiis a promising organism for plastics degradation/ bioplastic production.

Keywords

• milk
• yoghurt
• cheese
• antibacterial activity
• ethanol tolerance
• s. cerevisiae
• d. hansenii