Preliminary Isolation And Identification Of Extracellular Algicidal Substances From Algae-lysing Bacteria

Researchers confronting with the serious eutrophication have invited Miscellaneous methods to control and finally deal with the problem. Biological methods of algae-bloom management are the most promising compared with the physical, chemical methods.We have produced a algicidal powder via spray drying process with the fermentation supernatant liquid of actinomycete AN02.The powder has acquired distinct algicidal effect at Lake Dian, Yunnan. The aim of the study is to isolate and identify the active substances in the powder by preliminary treatment and then HPLC. The HPLC condition has been identified by optimization.The chromatogram was detected at 198 nm, the mobile phase is water/methanol in ration of 85/15(v/v) with Agilent XDB-C18,5um,4.6×250mm;the flow rate is 0.4/min.The fraction of 7-8min has showed high algicidal effect by time-lapse collection.From the fraction of 7-8min I also grant a single peak with the molecular weight of 645.2.Using powder to treat DS, We find that DS has swum to the bottom before it becomes xanthic. If we add the powder supernatant treated by ethanol to DS at a ration of high activity, we can find that DS will sink between the 1st day and the 3ed day, this suggests that the time from the 1st day to the 3ed day is a crucial juncture for DS to sink to the bottom.On the premise of high effect at some powder additional rate, we find that the number of the active DS alga has decrease shapely since the 11th day. This suggests the 11th day may be an important time when the powder supernatant treated by ethanol has been added.