Studies On Physiological And Biochemical Mechanism Of Inhibition Of Alkaloid Narciclasine To Yeast Growth

The plant alkaloids, as the secondary metabolism products, play a key role in environment adaptation of plants.The effects of narciclasine (NCS) isolated from Narcissus tazetta bulb on the growth of two model microorganisms, E.coli and Ceteuisiae fermentum, were studied in this paper. The results revealed that the growth of Ceteuisiae fermentum was obviously inhibited by 20μ.g/mL NCS. The inhibition was about 51%. However, the inhibition of NCS to E.coli growth was hardly observed. Based on the above results, the physiological and biochemical mechanism of NCS inhibition to the growth of Cereuisine fermentum was further studied. The main results as follow:1. The cell configuration of Cereuisine fermentum treated with NCS was almost no significant difference compared to the control. And the inhibitory effect of NCS on Cereuisine fermentum growth could be resumed.2. The result of the SDS-PAGE showed that the protein content of Cereuisine fermentum cell dramatically decreased in the present of 20μg/mL NCS. It was only 68% of the control. The protein synthesis of Ceteuisiae fermentum cell was inhibited by NCS when they were cultured in the medium with ³⁵S-Met.3. The Ceteuisiae fermentum cells treated with NCS were mostly in G1 stage during the cell cycle measurement. The amount of cells in Gl stage increased about 20% compared to the control. These data suggested that the process of protein synthesis may be inhibited or prolonged by NCS. The further study found that the death rate of Cetruisine fermentum was hardly affected by NCS.4. The respiratory rate of Ceteuisine fermentum cell was significant increase in the present of NCS. It may be due to the amount of cell in G1 stage increased after treated with NCS since the cells in Gl stage have higher life activity.From above results, NCS inhibited the growth of eukaryote, but did not affected the growth of prokaryote. The inhibition of NCS to eukaryote growth may be due to prolong the cell division and prevent protein synthesis. The inhibition of NCS to Cetruisine fermentum growth was not seem to kill cells and NCS inhibition could be resumed.