Gelatine which contains Escherichia coli remains solid while the gelatine that contains Bacillus subtilis turns into liquid. This shows that Bacillus subtilis produces an enzyme called gelatinase which will turn the solid gelatine into liquid form while Escherichia coli do not produce gelatinase. The last method is plate culture whereby Escherichia coli are grown by streaking on agar plates in Petri dishes. Quadrant streaking method and S-shaped streaking method are used in this experiment. In quadrant streaking method, Escherichia coli are found to be in the form of
By what mechanism do the authors propose that the mcr-1 gene confers colistin resistance, and what evidence do they use to support this assertion? The protein sequence of mcr-1 showed its similarity to the polymyxin-producing bacterium, Paenibacillus spp., which showed the possibility of gene transfer occurring. The mcr-1 gene enables protection from polymyxin. The mechanism that the authors proposed on how the mcr-1 gene confers colistin resistance is that mcr-1 causes a modification in lipid A, present in the lipopolysaccharides of most bacteria, which leads to lessened polymyxin affinity.
(2003, 2005) identified Cytophaga sp. (YM2-23) of the Cytophaga–Flavobacterium–Bacteroides complex, which excretes the morphogenesis-inducing substance thallusin and restores the foliaceous morphology of M. oxyspermum. The authors reported that the same factor also partially promotes the formation of distromatic thalli of U. pertusa and other Ulva species, highlighting the potentially important role of thallusin for the normal development of green macroalgae. Pure thallusin strongly induced the differentiation of M. oxyspermum, even at very low effective concentrations between 1 fg mL-1 and 1 ag mL-1 (Matsuo et al., 2005; Gao et al., 2006). Although thallusin can be obtained from bacterial cultivations, Nishizawa et al.
Like OPC-67683, Nitroimidazo-oxazine is a nitroimidazole that has demonstrated bactericidal and sterilizing activity against drug-resistant and non drug-resistant TB. Nitroimidazo-oxazine has also shown activity against both active and latent TB. In a 2002 agreement with the former biotechnology company Chiron, The TB Alliance is carrying out phase II clinical testing on Nitroimidazo-oxazine (Diacon et al. ). Nitroimidazo oxaine is also active against latent TB bacteria .In a latent state, bacteria are anaerobic and else replicating very slowly and non replicating.
The swab was inoculated onto blood agar, MacConkey’s agar and nutrient agar, mannitol salt agar and Sabouraud's dextrose agar and was incubated at 370C for 24 hrs for bacterial culture and at room temperature for fungal isolates. Next day the colonies were picked up and preliminary identification was done and the bacterial isolates were identified based on standard protocols. LPCB was done for the identification of fungal isolates after 48 to 72 hrs. ANTIBIOTIC SUSCEPTABILITY TEST Antibiotic sensitivity test of the bacterial isolates was determined by the Kirby-Bauer disc diffusion method2.
We added 1 ml of distilled water to test tubes labelled 2, 3,4 and 5. . To tube 1 we added 1ml of standard protein solution and recorded the concentration of the standard protein as 10mg/ml. To tube 2 we added 1ml of standard protein solution and shake it so that it can mix well. With a fresh pipette we removed 1ml from tube number 2 and added it to tube 3 then gently shake the tube. With another fresh pipette we removed 1ml from tube 3 and added it to tube 4, shake well.
A study by Karunanithi et al. (2000) showed that the bacteria produces antibiotic compounds, for example pyrollnitrin and phenazine-1-carboxylic acid, which create inhibition zones 12mm long, and in this way it inhibits the growth of pathogens. (Ganeshan & Manoj Kumar, 2005). In addition to this function, Pseudomonas inactivates the cell wall of fungi that degrade damaged plants. Its application in bioremediation comes from its ability to increase in number and change its macro structure in response to oil contamination.
MATERIALS METHODS 1.1 MATERIALS OF MTT ASSAY The Pin1 transcript and HEK-293 cells were the main components of this experiment. Dulbecco’s Modified Eagle Medium (DMEM) was used for culturing the cells. PEI (Polyethylenimine) was used for both empty (mock) and Pin1 transcript containing vector. The MTT (3-(4,5-dimethylthiazole-2-yl)-2,5,diphenyl-tetrazolium bromide(5mg/ml) was used for detection of cell viability.
Nitrate reduction in the gram negative bacteria was conducted and when bacterium produce nitrate reductase when grown in a medium containing nitrate, the enzymes will convert the nitrate to nitrite. If nitrite is present the medium will turn red. This indicates a positive test (Goldman). If the bacterial is one of the few specials that can produce the enzyme Urase, this will be the key test that will separate this gram negative from all of the other possible candidates. Narrowing down the unknown microorganism to gram negative, this approach was helpful to take the next step, in some bacteria the cell wall is surrounded by cell enveloped called capsule, also some bacteria make capsule when faced in a harsh environment to protect them.
Catalase activity test establishes whether the bacterium produces the enzyme catalase. The eosin methylene blue test or EMB, inhibits the growth of gram positive bacteria and tests whether or not gram negative bacteria can ferment lactose. Lactose fermentation testing is done to see if the bacterium is capable of fermenting sugar by testing for acid and gas production. These are the possible tests that are needed in order to identify unknown
It starts orange and turns yellow positive for microbe 3C Klebsiella oxytoca (Professor Brady, Personal Communication). Procedure 1 Gram stain: Purpose/ Introduction: The Gram stain reveals whether a microbe is gram positive or gram negative. It also reveals the shape and arrangement of the microbe (Professor Brady, Personal Communication). Of the forty-three possible microbes the following are gram positive: Bacillus cereus, Bacillus circulans, Bacillus coagulans, Bacillus megaterium, Bacillus subtilis,
Major unknown #202 was given out by the instructor, and the unknown bacterium was streaked out on a Trypticase Soy Agar tube and plate to inoculating the bacterium and incubating. After incubated and grown the morphology was observed and several Gram stains were performed to determinate if the bacterium were gram positive or negative, and the morphology of the bacterium. The Gram Stain of my major unknown #202 was determinate to be Gram negative bacilli, and was double checked by the Gram check slide. Also I noticed that my bacterium was a facultative anaerobe and according to my results of endospore test, my bacterium has not endospores. So according to the list of possible major unknowns provided by the instructor, I narrow my bacterium thru
After incubation, a gram stain was performed one the colonies that were isolated. First, the organism was smeared onto a slide with a loop full of distilled water. The smear was heat fixed to provide the bacteria to stick to surface. Next, the staining started by using crystal violet for 60 seconds, rinsed with distilled water. Then iodine for 60 seconds, rinsed with