A Nonribosomal Peptide Synthetase Gene tzw1 Is Involved in Zwittermicin A Biosynthesis in Bacillus thuringiensis G03 - Tiemei Shao; Linquan Bai; Jie Zhang; Guangjun Wang; Daqun Liu; Zhuofu Li; Jianmi Liu; Fuping Song; Dafang Huang (Current Microbiology, 2008)