Screening And Identification Of Myxobacteria And Its Antibiotic Matter

Myxobacteria is the prokaryote, glissadic and strictly aerobic.It is Gram-Negativebacillus and has multiplicity cell's behavior. Not only Myxobacteria is possessed of theimportant position on cytodifferentiation and development but also considerable attention hasbeen paid to Myxobacteria recently because of producting more abundant and useful secondarymetabolism, including antibacterial, antifungal, anticancer and thrombolysis compounds. But it isvery difficult handle and time-consuming to purification and characterization ofMyxobacteria, as well as harding culture.All these confine overwhelmingly the exploitationof Myxobacteria.So the exploratory development to Myxobacteria falls behind the othermicro-organism. Therefore, it is very important looking for the better method of purification andcharacterization of Myxobacteria.In these researching, the pure grazing hare dungs was used in order to screening theMyxobacteria. During the screening of Myxobacteria, Duo Junling, curling factor andcanesten were used to inhibit production of fungus. Heating treatment was used toinhibit production of heat-labile mixed bacteria and freezing treatment were used toinhibit vermes's production and production of bacteria that can't bear thefreeze-thawing again and again. In addition, selective medium such as VY/4 medium,Cellulose medium and WCX medium were used for enriching Myxobacteria.During the researching three strains have been obtained. In order to identify the Myxobacteria,VY/4 culture medium, Cellulose culture medium, WCX culture medium andelectronmicroscope and LB medium were used. These strains were preliminaryclassified as Angiococcus generic according with their morphologic characters,including fruiting bodies, colony, myxospores and vegetative cells.All these strainsof Myxobacteria were new strains of Myxobacteria because they have not beenreported until today.It is discovered that Duo Junling, curling factor and canesten all inhibits productionof fungus and the inhibition effect of Duo Junlin is better. Duo Junling is agriculturemedication and it is cheaper, easy to obtain and little toxicity than actinone that was reportedprevious.So Duo Junling is worth spreading.In this researching,the No.1 Myxobacteria(Angiococcus sp.) was studied andresearched mainly.It is discovered that its logarithmic phase is from 3.5 hours to 11 hoursand the optimum initial pH is 7.22 and the optimal temperature is 34℃. At the sametime, the antibiotic of its cell's interior and exterior was detected by filter papermethod. Both the interior and exterior matter of cell has antibacterial activity andthey have different antibiogram. The cell's exterior matter inhibits the growth ofGram-positive bacteria strongly.The cell's interior matter inhibits both the growth ofsome Gram-positive bacteria and Gram-negative bacteria,such as Escherichiacoli,but the bacteriostatic activity to Gram-negative bacteria is morepowerful.Neither the interior nor exterior matter of the Angiococcus sp.cell inhibitsfungus.After the cell's exterior matter was evaporation to dryness on 60℃,it is dissolved indistilled water.And then the antibiotic of the No.1 strain's exterior was isolated byliquid phase extractions,thin-layer chromatography(TLC) and silica gel columnchromatography. An anti-Streptomyces microflavus active single component wasobtained. In order to identify the active component,many methods were used,such asspectroscopy, biuret method, polyacrylamide gel electrophoresis(PAGE), trichloroacetic acidsediment,Molisch reaction, anthrone reaction,and so on.It is discovered that there is themaximum photo-absorption onλ=270nm and it is preliminary classified as derivate of aldehyde group or ketone group.Because of the better heat resistance,the better stability,the better water solubility,thepowerful resistance to Gram-positive bacteria and having activity after 3 months in 4℃refrigerator, the cell's exterior matter of No.1 strains is very worth studying andresearching.It is also found that the cell's interior matter of the No.3 strains can inhibit theproduction of Escherichia coli too.All these indicate that the researching work of the 3Myxobacteria strains is a kind of useful and original work..