The advantages and disadvantages of each species preservation method

1． Slope low temperature preservation method
(1) inoculated the bacteria in a suitable solid slope
culture
base, to be fully grown, the cotton plug part with oil paper wrapped, moved to 2-8 degrees C refrigerator storage.
(2) storage time is different according to the type of
microbial
, mold, line bacteria and bacteria with spores are preserved for 2-4 months, the seed is transferred once.
yeast
two months, the bacteria are best moved once a month.
This method is commonly used in laboratory and factory bacteria storage method, the advantage is simple operation, easy to use, no special equipment, can check at any time whether the stored strains are dead, mutation and contamination of germs. The disadvantage is that it is easy to mutate, because the physical and chemical properties of
mostyl
are not strictly constant, and repeated transmission will change the metabolism of microorganisms, and affect the characteristics of microorganisms;
2． Liquid paraffin preservation method (1) the liquid paraffin is packed in a triangular flavott, stuffed with cotton plugs, and wrapped in verse paper, 1.05 kg/cm2, 121.3 degrees C sterilized for 30 minutes, and then placed in a 40 degrees C temperature tank, so that the water vapor evaporated, spare.
(2) will need to be stored in the species, cultured in the most suitable slope medium, so that the robust bacteria or spores.
(3) using sterilized straw to absorb sterilized liquid paraffin, injected into the slope of the bacteria has been long, its dosage is 1cm higher than the top of the slope, so that the bacteria and air isolation.
(4) store the test tube upright at low or room temperature (some microorganisms last longer at room temperature than in the refrigerator).
this method is practical and effective. Mold, line bacteria, spore bacteria can be stored for more than 2 years not dead, yeast can be stored for 1-2 years, the general spore-free bacteria can also be stored for about 1 year, and even with the general method is difficult to preserve meningococcal bacteria, in the temperature box at 37 degrees C, can also be stored for up to 3 months. The advantage of this method is that it is simple to make, does not require special equipment, and does not need to be moved frequently.
disadvantage is that it must be placed upright when saved, take up a larger position, but also inconvenient to carry. After removing the culture from under the liquid paraffin, when the inoculation ring burns on the flame, the culture is easy to fly with the residual liquid paraffin splash, special attention should be paid.
3． Filter paper preservation method(1) cut the filter paper into a small strip of 0.5×1.2cm, loaded into 0.6×8cm
ampoules
tubes, each tube 1-2 sheets, stuffed with cotton plugs, 1.05kg/cm2, 121.3c sterilization for 30 minutes.
(2) will need to be preserved in the species, cultured on a suitable sloped culture base, so that full growth.
(3) take sterilized skimmed cow's milk 1-2 ml drops added to the sterilized petri dish or test tube, take a number of ring moss mixed in the cow's milk, to make a strong suspension.
(4) with sterilized tweezers from the ampoule tube to take the filter paper into the bacterial suspension, so that it is full, and then put back into the ampoule tube, plugged with cotton plugs.
(5) put the ampoule tube into a
drive
with phosphorus oxide as a absorbent and pump the gas to dry with
spoil pump

(6) stuffed cotton into the tube, sealed with flame, stored at low temperatures.
(7) need to use bacteria, resurrection culture, the ampoule tube mouth can be burned on the flame, drop a drop of cold water in the hot part, so that the glass breaks, and then knock off the glass at the end of the mouth with tweezers, after the ampoule tube opened, take out the filter paper, put into the liquid medium, in the temperature tank culture.
bacteria, yeasts, silky
fillies
can be protected with this method, the first two can be 2 years or so, some silky fungi can even be 14-17 years. This method is simpler than liquid nitrogen and freeze-drying method, and does not require special equipment.