1. Key Laboratory for Industrial Biocatalysis of the Ministry of EducationDepartment of Chemical EngineeringTsinghua UniversityBeijing 100084P. R. China
2. Center for Synthetic and Systems BiologyTsinghua UniversityBeijing 100084P. R. China
3. Department of Chemical EngineeringMassachusetts Institute of TechnologyCambridgeMA 02139USA