Experimental Observation On Relevant Factors Of Penicillium Citreoviridin's Toxin Production

Objective To observe the effect of simple factor of temperature, pH or cultivated time on Penicillium citreoviridin's (PCV) production of toxin in laboratory;to study the interaction of temperature and pH on Penicillium citreoviridin's toxin production.Methods PCV was cultivated in Charles culture medium in different conditions . The controlled temperature was high (30℃permanently),low (8℃permanently) and alternant temperature ( 8～30℃). The pH of culture medium was controlled in 5.0,7.0 and 9.0 by adding NaOH or HCl. The cultivated time was 5, 10, 15 and 20 days. Citreoviridin (CIT) was extracted with dichloromethane.CIT was analyzed by HPLC methods. The Hypersil SiO2 column (4.6mm×150mm,5μm) was used with mobile phase of ethyl acetate and n-hexane (7:3,V/V) . The flow rate was 1 ml/min. The detective wavelength was 383 nm. The time of detection for one sample was 10 min.Result1. observation on the effect of simple factor of temperature, pH or cultivated time on Penicillium citreoviridin's (PCV) production of toxin.(1) Quantity of CIT produced by PCV was uniform at the temperature of 30℃and 8℃(222.36～231.02μg/g medium), PCV produced more CIT in alternant temperature (P<0.05);(2) Quantity of CIT produced by PCV in deferent pH was 161.86～231.02μg/g medium, Quantity of CIT in acid culture medium was less than others(P<0.05);(3) Quantity of CIT produced by PCV in 20 days was 87.06～309.90μg/g medium, PCV produced the most amount of CIT after cultivated for 10 days(P<0.05).2. PCV produced CIT in all Charles culture medium in the second period study. Quantity of CIT was 60.30～336.10μg/g medium; The interaction of temperature and pH on PCV's toxin production was found. PCV produced more CIT at high temperature(30℃) in alkali Charles culture medium (P<0.05). Conclusion1. Temperature, pH of environment and cultivated time affect Penicillium citreoviridin's production of toxin,The production of toxin was promoted in neutral environment and alternant temperature , PCV produced more CIT cultivated for 10 days.2. The quantity of CIT produced by PCV is affected by interaction of temperature and pH.3. PCV grows and produces toxin well in the temperature of Keshan disease area.