Abstract: Amino oligomers were produced by fermentation of Pseudomonas sp. VIIIT39. The optimal composition(g/L) of the medium at a flask scale was: chitosan 2.5, MgSO4.7H2O 0.5,KH2PO4 0.5, KCl 0.5, FeSO4.7H2O 0.01and Tween20 0.5mL.Optimal temperature and initial pH for production were 28℃ and 6.5 respectively. When Pseudomonas sp. VIIIT39 was cultivated on arotary shaker(120r/min) at 28 ℃ for 84hrs. in a 250mL flask containing 125mL of medium,the results showed that 4.5 μ mol/mL of amino oligomers were accumulated(31% yield from chitosan).

Key words: Pseudomonas sp., Amino oligomers