Oral/perioral piercing may provide an ideal environment for adhesion and colonization of microorganisms. The aim of this study is to perform an “in vitro” research on the capabilities of adhesion of Candida albicans on oral piercings made of plastic and metal. Acrylic and metal piercings were incubated with Candida albicans and then were observed using scanning electron microscopy under different magnifications. A lot of irregularities and roughness were observed on the surface of the plastic piercing unlike the surface of the metal one, which is not so rough. Nevertheless, the number of Candida albicans colonies was considerably larger on the scanned metal surface in comparison to the plastic surface. In vitro the metal surface of the piercing creates better environment for the adhesion and colonization of microorganisms than the acrylic. This could be attributed to the electrostatic forces that most likely attract Candida albicans to the metal piercing in the early stages of biofilm formation.
Ultrafiltration of skim cow’s milk with a UF10-PAN membrane at volume reduction ratios (VRRs) of 2 and 3 was performed. The ultrafiltration retentates obtained were used for production of probiotic yoghurts with three different starters. A control sample was prepared using skim cow’s milk. All yoghurts were analysed according to the following parameters: titratable acidity, dry matter, organoleptic characteristics, number of specific microorganisms (Lactobacillus bulgaricus and Streptococcus thermophilus) and the total count of viable lactic acid bacteria for 28 d of storage. The results showed that the increase in the VRR during ultrafiltration increased the titratable acidity, as well as the dry matter of all yoghurts. Ultrafiltration concentration led to an increase in the count of viable lactic acid bacteria in all yoghurts which improved their functional properties. The highest values of the total number of viable lactic acid bacteria were determined in yoghurts obtained with starter 1CM, followed by starters MZ2 and ZD for both VRRs. Probiotic yoghurts with the highest organoleptic evaluation were obtained from ultrafiltration retentates at VRR = 2 and starters 1CM and MZ2.