Growth characteristics of bacteria on the medium

1, solid mediumspecimens or liquid cultures are drawn to the surface of a solid culture, individual bacteria can be divided and reproduced to form a group of bacteria, called colony"text-align: center;"img src""alt"""bacterial growth characteristics on the medium" title""(1) the morphological characteristics of the colonies:size, shape (dew,circular, circular, Dishes, irregularities, etc.), protrusions or flatness, dents, edges (smooth, waveforms, serrated, curly, etc.), colors (red, gray-white, black, green, colorless, yellow, etc.), surfaces (smooth, rough, etc.), transparency (opaque, translucent, transparent, etc.) and viscosity, etcAccording to the different surface characteristics of bacterial colonies, the colonies can be divided into 3 types:(1) smooth colonies (S-type colonies): the colony surface smooth, moist, neat edges, newly separated bacteria are mostly smooth-type colonies(2) rough colonies (R-type colonies): the surface of the colonies is rough, dry, wrinkled or grainy, mostofly untidy edgesR-type colonies are mostly s-type s-type bacteria mutation loss bacteria surface polysaccharides or protein formationThe R-type bacterial antigen is incomplete, and its virulence and anti-swallowing ability are weaker than that of Type S bacteriaBut there are also a few bacteria newly isolated toxic strains are R-type, such as Bacillus anthrax spores, TB branches and so on(3) mucus-type colonies (M-type colonies): the colonies are sticky, shiny, and water-likeIt is found in thick film or rich mucus layer of bacteria, tb bacteria, etc(2) colony hemolytic characteristics:colony hemolytic blood has the following 3 conditions:(1) alpha hemolytic blood: also known as grass-green hemolytic blood, colonies around the medium of 1 to 2mm grass green ring, caused by high-iron hemoglobin;(2) beta-soluble Hemolysis: also known as complete lysis, the colony around the formation of a completely clear and transparent hemolytic ring, is the bacteria produced by hemolytic blood cells to completely dissolve the cause; (3) pigment: Some bacteria produce water-soluble pigment, so that the colonies and surrounding media appear green, golden, white, orange, lemon color and other colors, the resulting pigment has water-soluble or fat-soluble (4) odor: some bacteria can produce special odors after growth and reproduction in the medium, such as copper-green pseudomonas (the smell of ginger), morphite bacteria (chocolate-burning odor), anaerobic clostridium (the bad smell of corruption), white pseudofima yeast (yeast taste) and line bacteria (earthy taste), etc 2, liquid medium bacteria in the liquid medium has three growth phenomena: most bacteria in the liquid culture medium growth and reproduction of uniform turbidity; 3, semi-solid medium semi-solid medium is mainly used for bacterial power testing, in addition to the growth of bacteria along the puncture line, in both sides of the puncture line can also be seen feather-shaped or cloud-like cloudy growth Whip-free bacteria can only grow in a clear line along the puncture line, and the media on both sides of the puncture line are still clarified transparent, negative for the power test