Liquid culture medium transfer technology

Liquid culture medium transfer technology

For the enrichment of pure bacteria and to observe the growth characteristics of bacteria in a liquid environment (cloudy growth, surface growth or sedimentary growth)
(1)Material
broth medium
Slant cultures (Escherichia coli, Streptococcus pyogenes, Bacillus subtilis)
(2) Method
① Take the inoculation loop, burn it on a flame, sterilize it, and cool it.
② In the “double-tube transplantation method”, the left hand holds two test tubes of bacterial slant culture and broth medium, and the right hand holds the inoculation loop. Take a small amount of bacteria according to the aseptic operation method, gently smear and grind the bacteria-contaminated inoculation ring on the inclined tube wall close to the liquid level, and stand the test tube upright so that the bacteria attached to the tube wall are submerged in the liquid. After inoculation, the cells were incubated in a 37°C incubator.
(3) Results
①The turbid growth of Escherichia coli bacteria liquid is uniform and turbid, and there is a small amount of precipitation at the bottom of the tube.
② Precipitate growth of Streptococcus pyogenes bacteria with sediment at the bottom of the tube, and no obvious turbidity in the bacterial liquid.
③ Bacterial film growth The surface of Bacillus subtilis bacteria liquid forms a film.