1. University of Plovdiv “Paisii Hilendarski”, Department of Biochemistry and Microbiology, Plovdiv, Bulgaria
2. Institute of Engineering, UABC, Mexicali, B.C., Mexico
3. University of Food Technologies, Department of Technology of Wine and Brewing, Plovdiv, Bulgaria
4. Technological Institute of Mexicali, Mexicali, B.C., Mexico
5. University of Food Technologies, Department of Biotechnology, Plovdiv, Bulgaria
6. University of Plovdiv „Paisii Hilendarski”, Department of Mathematical Analysis, Plovdiv, Bulgaria