17 12月 代写论文：一种新的抗细菌大肠杆菌素的发现
After analyzing the micro-flora human gut, a new strain of E-coli cells than can also destroy other E-coli cells has been discovered. In order to analyze and obtain this new strand, a method was adopted by which culture spreading was done of the chosen strain of E-coli over a sensitive bacteria lawn. First, bacteria were cultured from the guts of human beings over a Petri dish from which single stranded E-coli was selected for generation of pure clones. This further grew into individual clones and sensitive cells plates. This new cell was termed as Strain A and it was observed that wherever these Strain A cells grew it led towards clearance of that zone depicting that the strand A was secreting a substance which was poisonous for other cells but not for that strand A(Braun et al 1994). Further testing was done by using a Fredericq’s modified agar stab test for colicinogeny. All the strained were grown under a nutrient of liquid broth by keeping it for all night. Inoculation of the Agar plated through stab of needles led towards broth cultures of every strain to form leading towards incubation at 37 degree Celsius for 20 hours. The bacterium plates after being exposed to vapor of chloroform were killed and on all the plates thin soft agar layers were over laid inclusive of 10 to the power 7 times the broth culture of a fresh strain indicator. At 37 degree Celsius the incubation of the plates took place. When the X cells strains were growing, it was observed that the region was cleared due to some toxic substance release. After adding trypsin however, the effect of soft agar was not evidently seen to depict that trypsin could digest the toxic substance and therefore it can be indicated as a protonated media culture.