Studies On The Isolation And Biological Characteristics Of A Pseudomonas Fluorescens Bacteriophages KS461-2

Pseudomonas fluorescens was classified in Family Pseudomonas and genus Pseudomonas. Pseudomonas fluorescens was widely applied in mass productin of 2-keto-D-gluconic acid. 2-keto-D-gluconic acid, the isomers of vitamin C, is also named as D-isoascorbic acid, lsovitamin C, crythorbicacid, D-arabinose as well as ascorbic acid. It has strongly revivification. In medicine, it has the ability of decreasing the blood pressure, diuresis, resolving toxin, promoting generation hepatic glycogen as well as pigmenting excretion. It is an important antioxidant in food industryPhages are virus, the non-cell microorganism, invading bacteria and actinom-ycetes. It is smaller and more simple than prokaryotic germ, and more primordial on evolution as well. It composes of capsid and inner nucleic acid. However, there exists only one kind of nucleic acid, i.e. DNA or RNA.Phages are ubiquitous in soil, sewage and air, where are suitable for the host bacteria, and can easily cause pollution in the production of fermentation resulting in the abnormally process. They can cause great loss and damage in economic and in the industry of fermentation respectively. Almost all the fermentation industry that using bacteria have the possibility of being invaded by the phage, including the fermentation for 2-keto-D-gluconic acid.The main results were as follows:1. Phage named KS461-2, were first separated from the abnormal fermentation broth of Pseudomonas fluorescens K1005 strain which produced 2-keto-D-gluconic acid. The KS461-2 was tadpole-like observed by electron microscope. According to ICTV, it belongs to the Siphoviridae family and is a virulent phage.2. The optimal MOI for phage KS461-2 to invade its host bacteria Pseudomonas fluorescens K1005 is about 0.01. 3. One-step growth kinetic of the phage showed that the latent period was 30min, the rise period was 145 min, and the average burst size was 24 phage particles /infected cell.4. It is more stable at pH 7.0-10.0 than pH 4.0-7.0, and is more sensitive to thermal.5. SDS-PAGE profiles indicated that KS502-2 contains five capsid proteins, and molecular weights estimated at 66.0 KD, 61.0 KD, 42.5 KD, 34.7 KD and 14.4KD respectively.6. The genome of the phage KS461-2 was about 85KB when restricted by enzyme ScaI, KpnI, XbaI.