1Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand
2Walai Rukhavej Botanical Research Institute, Mahasarakam University, Mahasarakam 44150, Thailand
3Fermentation Research Center for Value Added Agricultural Products, Khon Kaen University, Khon Kaen
40002, Thailand
*e-mail: portha@kku.ac.th