Study on Fermentation Conditions and Characteristics of Antibacterial Substance Produced by Marine Microorganisms
|School||Dalian University of Technology|
|Keywords||marine bacterial bacter iostasic activity cup method fermentationcondition|
Because of their special living conditions, marine microorganisms can often yield various bioactive substances with novel functions and structures. Therefore marine microorganisms, as the new sources of bioactive substances, have received people’s great attention in recent years.In this thesis, marine bacteria strain B-42and marine fungi strain F-04produced antibacterial substance which were isolated from sea water,sea mud and maritime plant at low tide sea front in Dalian were researched.The growth characteristics, the fermentation conditions and partial characteristics of produced antibacterial substance were researched, initial identification of strain.In this thesis,according to the cup method,the optimal fermentation conditions of marine bacteria strain B-42and marine fungi strain F-04produced antibacterial substance were definited.For Staphylococcus aureus, the optimal fermentation conditions were glucose1.5%, peptone0.1%, yeast extract paste0.15%,sea water60%and (60%potato sea water leachate)100%, glucose0.5%, peptone0.8%, yeast extract paste0.2%, swing bed rotation speed were140r/min、100r/min, culture temperature were24℃、26℃; for Escherichia coli, glucose1%, peptone0.2%, yeast extract paste0.15%,sea water40%and (60%potato sea water leachate)100%, glucose1.5%, peptone0.6%, yeast extract paste0.1%, swing bed rotation speed were160r/min%120r/min, culture temperature were26℃、24℃.In this thesis, partial characteristics of marine bacteria strain B-42and marine fungi strain F-04produced antibacterial substance were researched.The antibacterial substance produced by the two strains was stably at80℃after dealing60min; the antibacterial substance produced by the two strains was stably between pH6.0and pH10.0. organic solvent extraction the antibacterial substance, the optimal effect was acetoacetate.In this thesis, according to determine biomass,the growth characteristics of two strains were definited. marine bacteria strain B-42grew well in NaCl density3%-4%and medium incipient pH7.0-8.0. marine fungi strain F-04grew well in low NaCl density and medium incipient pH7.0-8.0.The cultural characteristic, cell morphous and physiology biochemistry characteristics were researched, initial identify that marine bacteria strain B-42was Bacillus and marine fungi strain F-04was A.clavatus.