Several detection methods of microbial growth

related topics
summary:The detection of microorganism
, whether in theoretical research or in production practice, is of great significance, in this paper, the growth measurement method, microbial counting method, physiological index method and commercial rapid microbial detection briefly introduced the use of microbial weight, volume, size, physiological metabolites and other indicators of more than 20 commonly used detection methods, briefly introduced the principles of these methods, application scope and advantages and disadvantages.summary:microbial cells in the right external conditions, constantly absorb nutrients, and according to their own metabolic methods of metabolism. If the speed of assification exceeds the alienation effect, the total amount of protons (weight, volume, size) increases, and the growth of individuals occurs. If this is a balanced growth, i.e. when the cellular parts are increased at an appropriate proportion, reproduction occurs to a certain extent, resulting in an increase in the number of individuals, at which point the original individual has developed into a group. As individuals in the group grow further, this group grows, as measured by its volume, weight, density or concentration. The growth of microorganisms is different from the growth of other organisms, and the individual growth of microorganisms is difficult in scientific research, and usually has no practical significance. Microbes win by quantity, so the growth of microorganisms usually refers to the expansion of populations. The growth and reproduction of microorganisms is a comprehensive reflection of their interaction with various environmental factors inside and outside. Therefore, growth and reproduction can be used as an important index to study various physiological
notogenics and bio-chemicals
and genetic problems, at the same time, microorganisms in the production practice of various applications or disease-caused, the prevention and treatment of moldy microorganisms are closely related to their growth inhibition. Therefore, it is necessary to introduce the detection method of microbial growth. Since growth means an increase in protonic content, the method of assays are also directly or indirectly based on secondary, while the measurement of reproduction is based on counting. Microbial growth can be measured by its weight, volume, density, concentration, and indicators.growth measurement method isvolume measurement method: also known as mycelium concentration method.the growth of microorganisms
measured
amount of mycelium contained in a certain volume and culture solution. The method is to take a certain amount of culture fluid to be tested (e.g. 10 ml) placed in a scaled centrifuge tube, set a certain centrifugal time (e.g. 5 minutes) and speed (e.g. 5000 rpm), centrifugation, poured out of the night, measured the volume of the upper clear night is v, then the concentration of mycelium is (10-v)/10. Mycelium concentration determination is an important monitoring index of microbial growth in large-scale industrial fermentation production. This method is extensive, simple and fast, but needs to set consistent treatment conditions, otherwise the deviation is very large, because the centrifugal sediment is mixed with some solid nutrients, the result will be a certain deviation.weighing method: thecan be determined by centrifugation
or
filtration method. Generally dry weight is 10-20% wet weight. In centrifugation method, a certain volume of culture fluid to be measured is poured into the centrifugal tube, set a certain centrifugal time and speed, centrifugation, and with water centrifugation washing 1-5 times,
drying
. Drying can be done in an oven at 105 degrees C or 100 degrees C, or in infrared drying, or in a vacuum at 80 degrees C or 40 degrees C, after drying weighing. Such as the use of filtration method, silk
fillus
can be filtered with filter paper,
bacteria
can be filtered with acetic acid fiber membrane and other membranes, filtered with a small amount of water washing, vacuum drying at 40 degrees C. Weighing and re-eding is cumbersome, and is often used when obtaining microbial products as bacterials, such as active dry
yeast
(activity dry yeast, ADY), some feed and fertilizers with microbial bacteria as active substances.than turbidity method:of microorganisms caused by the increase in turbidity of cultures. The absorption value
a certain wavelength
was determined by the ultraviolet ion terroelometer to determine the growth of microorganisms. A special triangular flanter with side arms may be used to keep a timed track of the growth of bacteria in a culture. By inserting the side arm into the color base hole of the photoelectromeometer, its growth can be determined at any time without the need for fungicides. This method is mainly used for the monitoring of the growth of fermented industrial fungi. As I use UNICO's ultraviolet-visible tradiscometer, the absorbance value of the fermentation fluid OD600 is timed at a wavelength of 600nm to monitor the growth and induction time of
E.Coli
.Mycelium length measurement method:for silky fungi and some line-letting bacteria, you can determine the length of mycelium growth over a certain period of time on the
-culture base
, or use a thin glass tube with an opening at one end, into a suitable culture base, lie down, inoculated microorganisms at one end of the opening, after a period of time to record the growth length of the mycelium microorganisms, to measure the growth of silk microorganisms.。