bacillus sp
- Thread starter pe_nam_91
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Trịnh Thị Hồng Nhung
Senior Member
Baccilus sp nghĩa là Bacillus species phải không bạn?
Tớ nghĩ là phân lập nó cũng theo các phương pháp phân lập chung thôi.
Để tách nó ra từ một hỗn hợp canh trường nuôi cấy đơn giản thì có thể dùng phương pháp pha loãng rồi cấy zích zắc trên mặt thạch, nếu cần nhanh và chính xác hơn thì áp dụng vi thao tác tách từng tế bào.
Để thu được chủng thì lấy từ môi trường tự nhiên, trong đất, không khí sẵn có rất nhiều chủng baccilus, rồi nuôi trong canh trường có môi trường phù hợp với chủng đó.
Bạn có thể tham khảo bài viết này:
http://www.dhsphue.edu.vn/dhsphue/view/index.php?opt=fronviewdetail&iddonvi=33&idnew=975
Tớ nghĩ là phân lập nó cũng theo các phương pháp phân lập chung thôi.
Để tách nó ra từ một hỗn hợp canh trường nuôi cấy đơn giản thì có thể dùng phương pháp pha loãng rồi cấy zích zắc trên mặt thạch, nếu cần nhanh và chính xác hơn thì áp dụng vi thao tác tách từng tế bào.
Để thu được chủng thì lấy từ môi trường tự nhiên, trong đất, không khí sẵn có rất nhiều chủng baccilus, rồi nuôi trong canh trường có môi trường phù hợp với chủng đó.
Bạn có thể tham khảo bài viết này:
http://www.dhsphue.edu.vn/dhsphue/view/index.php?opt=fronviewdetail&iddonvi=33&idnew=975
Lê Tuấn Anh
Senior Member
Period 1
Materials
Soil samples from one or more midwestern sites will be available for those who didn't bring in their own sample.
One screw-capped tube containing about 12-15 ml of saline
Water bath set at 80°C
Eight 9 ml saline dilution blanks
Pipettors and sterile tips
Eight plates of Nutrient Agar
Place about half a teaspoonful of soil in the screw-capped tube of saline and mix well. Record the details about the sample you are using (source, date of collection).
Prepare four, serial decimal dilutions of the soil suspension and inoculate 0.1 ml from each of the four dilutions onto a separate spread plate of Nutrient Agar. Label the plates NOT HEAT-SHOCKED.
Screw the cap of the tube on tightly and label the cap top with an identifying mark. Completely immerse the tube in the 80°C water bath for 10 minutes.
Remove the tube (with forceps) and cool it in a glass of cold tap water for a few minutes. This heating and cooling constitute the heat-shocking procedure. (What may this procedure do besides eliminating vegetative cells and reproductive spores?)
After mixing the suspension, prepare plates from dilutions as you did in step 2. Label the plates HEAT-SHOCKED.
Incubate the plates at 30°C for 2 or more days.
------------------------------------------------------------
Period 2
Materials
Three tubes of Glucose Fermentation Broth (with Durham tubes)
One plate of Starch Agar
Dropper bottle of malachite green (5% aqueous solution, filtered)
Compare the two sets of plates (labeled heat-shocked and not heat-shocked)
Did the heat-shocking cause any noticeable effect in the variety of different types of colonies? As Bacillus colonies tend to be light or tan-colored, any brightly-pigmented colonies would be of other genera, and fuzzy, filamentous colonies would probably be molds. (Any such colonies on the heat-shocked plates may indicate faulty aseptic tech-nique!) Of the various cell types found in soil (vegetative cells, endospores, reproductive spores), what type(s) of cells could serve as colony-forming units before and after heat-shocking?
Determine the number of CFUs per ml of the suspension for both sets of plates and note any difference. When counting colonies, remember to choose one plate (having between 30 and 300 colonies) to determine the CFU/ml count. (Don't count all the plates!) Any large, spreading colony - such as the spiral-colony-forming Bacillus mycoides which can cover an entire plate in time - should be counted as one colony.
On the plates marked heat-shocked, proceed as follows, recording your observations in table form. (Save your plates until you are satisfied with your microscopic observations in step 3. You may wish to continue incubating them.)
Pick out at least three different, well-isolated colonies. Label them by number or letter and record their colonial appearances.
Then, prepare heat-fixed smears from each numbered colony for subsequent staining (step 3, below). For one of the larger colonies, prepare two smears - one from the center of the colony and one from the edge.
From each numbered colony, inoculate a tube of Glucose Fermentation Broth, and also spot-inoculate a sector of the plate of Starch Agar. (A separate plate should be obtained for any wide-spreading colony.) Incubate at 30°C.
When time permits (this period or next), stain the smears by the endospore-staining procedure
Look for the presence of rod-shaped vegetative cells (red) and circular or oval endospores (green). The endospores may be found within the vegetative cells and/or free. (If no endospores are seen, what may this mean? Consider time of incubation so far, and re-incubate your plates if necessary.)
For the smears you made from the edge and center of the same colony, explain any noticeable difference in the apparent ratio of endospores to vegetative cells between the two sites.
------------------------------------------------
Period 3
Materials
Dropper bottle of 3% hydrogen peroxide
Empty plastic petri dishes for the slide catalase test
From each of the isolates growing on the Starch Agar plates, perform the slide catalase test (method 2 on page 144; keeping the plate covered as directed!) and record the results. Discard the slide into the disinfectant and the plastic petri dish in the usual place.
For each of the isolates, note the reaction(s) of the Glucose Fermentation Broth and the amylase reaction. (Recall how you did this in Experiment 7.)
Were the overall results as expected? Between your isolates and those of your neighbors, does amylase production appear to be 100% positive? Considering the results of the glucose broth and the catalase test, was more than one oxygen relationship seen?
xem tại đây nhé:
http://inst.bact.wisc.edu/inst/index.php?module=book&func=displayarticle&art_id=277
https://docs.google.com/viewer?a=v&...Y2NkMy00MWY0LTk5NTktNzZjNTJiZTU5MWJl&hl=en_US
Materials
Soil samples from one or more midwestern sites will be available for those who didn't bring in their own sample.
One screw-capped tube containing about 12-15 ml of saline
Water bath set at 80°C
Eight 9 ml saline dilution blanks
Pipettors and sterile tips
Eight plates of Nutrient Agar
Place about half a teaspoonful of soil in the screw-capped tube of saline and mix well. Record the details about the sample you are using (source, date of collection).
Prepare four, serial decimal dilutions of the soil suspension and inoculate 0.1 ml from each of the four dilutions onto a separate spread plate of Nutrient Agar. Label the plates NOT HEAT-SHOCKED.
Screw the cap of the tube on tightly and label the cap top with an identifying mark. Completely immerse the tube in the 80°C water bath for 10 minutes.
Remove the tube (with forceps) and cool it in a glass of cold tap water for a few minutes. This heating and cooling constitute the heat-shocking procedure. (What may this procedure do besides eliminating vegetative cells and reproductive spores?)
After mixing the suspension, prepare plates from dilutions as you did in step 2. Label the plates HEAT-SHOCKED.
Incubate the plates at 30°C for 2 or more days.
------------------------------------------------------------
Period 2
Materials
Three tubes of Glucose Fermentation Broth (with Durham tubes)
One plate of Starch Agar
Dropper bottle of malachite green (5% aqueous solution, filtered)
Compare the two sets of plates (labeled heat-shocked and not heat-shocked)
Did the heat-shocking cause any noticeable effect in the variety of different types of colonies? As Bacillus colonies tend to be light or tan-colored, any brightly-pigmented colonies would be of other genera, and fuzzy, filamentous colonies would probably be molds. (Any such colonies on the heat-shocked plates may indicate faulty aseptic tech-nique!) Of the various cell types found in soil (vegetative cells, endospores, reproductive spores), what type(s) of cells could serve as colony-forming units before and after heat-shocking?
Determine the number of CFUs per ml of the suspension for both sets of plates and note any difference. When counting colonies, remember to choose one plate (having between 30 and 300 colonies) to determine the CFU/ml count. (Don't count all the plates!) Any large, spreading colony - such as the spiral-colony-forming Bacillus mycoides which can cover an entire plate in time - should be counted as one colony.
On the plates marked heat-shocked, proceed as follows, recording your observations in table form. (Save your plates until you are satisfied with your microscopic observations in step 3. You may wish to continue incubating them.)
Pick out at least three different, well-isolated colonies. Label them by number or letter and record their colonial appearances.
Then, prepare heat-fixed smears from each numbered colony for subsequent staining (step 3, below). For one of the larger colonies, prepare two smears - one from the center of the colony and one from the edge.
From each numbered colony, inoculate a tube of Glucose Fermentation Broth, and also spot-inoculate a sector of the plate of Starch Agar. (A separate plate should be obtained for any wide-spreading colony.) Incubate at 30°C.
When time permits (this period or next), stain the smears by the endospore-staining procedure
Look for the presence of rod-shaped vegetative cells (red) and circular or oval endospores (green). The endospores may be found within the vegetative cells and/or free. (If no endospores are seen, what may this mean? Consider time of incubation so far, and re-incubate your plates if necessary.)
For the smears you made from the edge and center of the same colony, explain any noticeable difference in the apparent ratio of endospores to vegetative cells between the two sites.
------------------------------------------------
Period 3
Materials
Dropper bottle of 3% hydrogen peroxide
Empty plastic petri dishes for the slide catalase test
From each of the isolates growing on the Starch Agar plates, perform the slide catalase test (method 2 on page 144; keeping the plate covered as directed!) and record the results. Discard the slide into the disinfectant and the plastic petri dish in the usual place.
For each of the isolates, note the reaction(s) of the Glucose Fermentation Broth and the amylase reaction. (Recall how you did this in Experiment 7.)
Were the overall results as expected? Between your isolates and those of your neighbors, does amylase production appear to be 100% positive? Considering the results of the glucose broth and the catalase test, was more than one oxygen relationship seen?
xem tại đây nhé:
http://inst.bact.wisc.edu/inst/index.php?module=book&func=displayarticle&art_id=277
https://docs.google.com/viewer?a=v&...Y2NkMy00MWY0LTk5NTktNzZjNTJiZTU5MWJl&hl=en_US
