The common microorganisms in general water bodies, wastewater, and sewage treatment include: bacteria Bacteria, fungi Fungi, algae Aglae, protozoa Protozoa, rotifers Rotifers, crustaceans Crustaceans, and worms (nematodes Nematodes and flatworms Flatworms).
The main testing items include total bacterial count, total yeast count, total mold count, total Escherichia coli count, etc.
1. Total bacterial count determination
1.1After diluting the biochemical pool water sample by 103 times, 104 times, 105 times, 106 times, and 107 times, 1mL of each dilution solution was taken and inoculated into a culture dish, poured onto a plate, and cultured in a biochemical incubator at 37 ℃ for 24 hours. Culture samples with a colony count between 30-300 were selected for counting, and 5 parallel samples were taken for each dilution ratio.
1.2Take 100mL of water sample and soak it in a water bath until a small amount of water remains. Dry it in a 105 ℃ oven until constant weight is reached. Weigh the dry weight of activated sludge in the water sample and calculate the total number of bacteria per gram of dry sludge in the biochemical tank water sample.
2. Total yeast count determination
2.1After diluting the biochemical pool water sample by 102 times, 103 times, 104 times, and 105 times, 1mL of each dilution solution was taken and inoculated into a culture dish. The dish was then poured onto a plate and cultured in a 30 ℃ biochemical incubator for 48 hours. Culture samples with a colony count between 30 and 300 were selected for counting, and 5 parallel samples were taken for each dilution ratio.
2.2Take 100mL of water sample and soak it in a water bath until a small amount of water remains. Dry it in a 105 ℃ oven until constant weight is reached. Weigh the dry weight of activated sludge in the water sample and calculate the total number of yeast cells per gram of dry sludge in the biochemical tank water sample.
3. Determination of total mold count
3.1After diluting the biochemical pool water sample by 102 times, 103 times, 104 times, and 105 times, 1mL of each dilution solution was taken and inoculated into a culture dish. The dish was then poured onto a plate and cultured in a 30 ℃ biochemical incubator for 72 hours. Culture samples with a colony count between 30 and 300 were selected for counting, and 5 parallel samples were taken for each dilution ratio.
3.2Take 100mL of water sample and soak it in a water bath until a small amount of water remains. Dry it in a 105 ℃ oven until constant weight is reached. Weigh the dry weight of the activated sludge in the water sample and calculate the total number of molds per gram of dry sludge in the biochemical tank water sample.
4. Determination of total coliform bacteria count
4.1Initial fermentation test: Using aseptic operation, inoculate 10 milliliters of sewage sample into 5 fermentation tubes each containing 5 milliliters of 3-fold concentrated lactose peptone culture medium. Inoculate 1 milliliter of sewage sample into 5 fermentation tubes each containing approximately 10 milliliters of single lactose peptone culture medium. Then inoculate 1 milliliter of 1:10 diluted sewage sample (equivalent to 0.1 milliliter of original sewage sample) into 5 fermentation tubes each containing approximately 10 milliliters of single lactose peptone culture medium. Place these 15 inoculated fermentation tubes in a 37 ℃ constant temperature incubator and incubate for 24 hours.
4.2Plate separation: After 24 hours of cultivation, the fermentation tubes that produce acid and gas, as well as those that only produce acid and do not produce gas, are inoculated onto either Eosin Meilan medium or fuchsin sodium sulfite medium, and incubated at 37 ° C for 18-24 hours. Select colonies that meet the following characteristics, take a small portion of the colonies, and perform smear, Gram staining, and microscopic examination.
In the process of colony count inspection, various experimental plates are encountered for colony counting, such as pouring method plates, spiral inoculation plates, 3M colony count test paper sheets, filter membrane method plates, etc. Moreover, manual counting not only consumes time and manpower, but also increases with the fatigue of individuals. Some staff members even hastily complete the task in order to reduce workload.
The Xunshu fully automatic colony counter has statistical functions for different types of petri dishes, and can save petri dish images and databases for verification. The Xunshu colony analysis instrument adopts colony enlargement image shooting, high-resolution 10 million pixel CCD digital imaging technology, and Colonfast colony intelligent recognition technology.
1. Regarding the determination of total bacterial count
In terms of automatic colony counting, the instrument can quickly complete the automatic colony counting and concentration calculation of various pouring method plates, coating method plates, filter membrane method plates, air settling method plates, spiral inoculation plates, 3M paper sheets, and other samples containing bacteria, molds, yeasts, etc. The speed of automatic colony counting is higher than 500 colonies per second, and the smallest distinguishable colony diameter can reach 0.01mm. Counting templates can be constructed to adapt to complex laboratory environments, with counting errors controlled within 10%.
2. Targeting yeast and mold
The rapid counting colony analysis instrument has a special algorithm built-in, which supports automatic counting and concentration calculation of colonies on various pouring method plates, coating method plates, filter membrane method plates, and spiral inoculation plates containing mold and yeast samples.
3. Targeting Escherichia coli
The automatic colony counting capability of the rapid counting instrument can help experimenters quickly and accurately select the "colony count"VRBA tablets ranging from 30 to 150; Using color high-resolution CCD imaging and intelligent recognition software such as Colonfast, the rapid counting colony analyzer can quickly identify "purple red, sediment ring, and diameter not less than 0.5 millimeters" Escherichia coli colonies, and calculate the number of typical Escherichia coli colonies in just 1 second.
4. Some special wastewater also contains highly pathogenic microorganisms, such as Bacillus subtilis var. niger spores.
Detection method:
1）Take an appropriate amount of Bacillus subtilis var. niger spore suspension, mix it into a collection tank, and make the final concentration of bacterial liquid in the sewage reach (2-8) × 104/mL
2）Perform chemical disinfection and physical disinfection in sequence according to the sewage treatment procedure.
3）Boil and disinfect the filter membrane in distilled water for 3 times, each time for 15 minutes; The filter is sterilized with pressure steam (121 ℃, 20min).
4）Testing and sampling: After disinfection treatment, use a graduated pipette to draw 100mL of sewage to be discharged from the sampling port of the sewage collection tank, and filter it through a microporous membrane under sterile conditions.
5）Wash the filter membrane with 50mL PB buffer to remove residual disinfectant.
6）Collect the washing solution and filter it through a microporous membrane under sterile conditions.
7）Place the microporous membrane under sterile conditions on a pancreatic soybean agar plate for bacterial cultivation. The filter membrane should be tightly attached to the culture medium without leaving any bubbles.
8）Invert the sampling petri dish and incubate at 35 ± 0.5 ℃ in a incubator for 24 ± 2 hours, then count the bacterial colonies of Bacillus subtilis.
For colony counting on filter membranes, 3M paper sheets, and other materials, the intelligent colony recognition technology of Fast Count can identify colony characteristics and achieve rapid automatic counting.
Hangzhou Xunshu Technology Co., Ltd. is a high-tech company specializing in microbial analysis and testing technology research and instrument equipment production. At present, we mainly produce automatic colony counter, spiral inoculation microbial colony analyzer, and inhibition zone measuring instrumentβ_Products such as lactam analyzer, antibiotic potency analyzer, algae counter, algae assisted identification system, zooplankton counter, biological microscopic analysis system, etc. The product is widely used in scientific research, inspection and quarantine, quality supervision, environmental monitoring, disease control centers, drug and biological product testing, food and drug daily chemical production, as well as steel, petrochemical, chemical and power industries.
At present, the company's products have become the products of thousands of domestic enterprises and institutions, such as the Chinese Academy of Sciences, the Chinese Academy of Agricultural Sciences, the Chinese Academy of Inspection and Quarantine Sciences, the China Institute for the Control of Pharmaceutical and Biological Products, the China Center for Animal Health and Epidemiology, the National Aquatic Product Quality Supervision and Inspection Center, the National Oceanic Administration, and Shanghai Baosteel, Lanzhou Petrochemical. And successfully served AustraliaAMSDrug resistance monitoring in laboratories, water quality testing by Veolia Water Group in France, bacterial resistance analysis by DSM Group in the Netherlands, toxicology center testing by WuXi AppTec in the United States, and automatic detection of antibiotic potency by Pfizer Pharmaceuticals in the United States. The company's products and excellent after-sales service have been widely praised and welcomed both domestically and internationally.（Xunshu Technology:）