1. Laboratory of Soil and Environmental Microbiology, Division of Systems Bioengineering, Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, Fukuoka, Japan
2. Indonesian Oil Palm Research Institute, Medan, North Sumatera, Indonesia
3. Soil Science Department, Faculty of Agriculture, Gadjah Mada University, Yogyakarta, Indonesia