Does Bacillus subtilis reduce nitrate?
During anaerobic nitrate respiration Bacillus subtilis reduces nitrate via nitrite to ammonia.
Is Bacillus subtilis catalase positive?
It was renamed in 1872 by Ferdinand Cohn. Bacillus subtilis (B. subtilis) is a Gram-positive, aerobic bacterium. It is rod-shaped and catalase-positive.
Is Bacillus subtilis a mannitol fermenter?
Bacillus subtilis is not able to ferment mannitol and yet the Mannitol test yielded a positive result. The conclusion drawn from this is human error during the inoculating process. It is believed that there must have been a mannitol fermenting bacterium somewhere along the length of the inoculating loop.
Is Bacillus cereus positive for nitrate reduction?
cereus, i.e. glucose fermentation, nitrate reduction and Voges Proskauer (VP) reaction. B. cereus should be positive for all three con¢rmation reactions [13].
How do you perform a nitrate reduction test?
Procedure of Nitrate Reduction Test Add 6-8 drops of nitrite reagent A and add the 6-8 drops of nitrite reagent B. Observe for the reaction (color development) within a minute or less. If no color develops add zinc powder. Observe for at least 3 minutes for a red color to develop after addition of zinc.
Is Bacillus subtilis an obligate Aerobe?
There was a long-held belief that the gram-positive soil bacterium Bacillus subtilis is a strict aerobe. But recent studies have shown that B. subtilis will grow anaerobically, either by using nitrate or nitrite as a terminal electron acceptor, or by fermentation.
Does Bacillus subtilis produce catalase?
Strong catalase activity was secreted by Bacillus subtilis cells during stationary growth phase in rich medium but not in sporulation-inducing medium. N-terminal sequencing indicated that the secreted activity was due to the vegetative catalase KatA, previously considered an endocellular enzyme.
Which Bacillus is catalase positive?
Bacillus species are Gram-positive, rod-shaped bacteria; they can be either obligate or facultative aerobes and show positive reaction in the catalase test. Members of the genus Bacillus are known to form spores under stressful conditions.
How do you identify Bacillus subtilis?
Bacillus subtilis is a typical germ, which is rod-shaped and Gram-positive. When cultured on ordinary nutrient agar, the morphology circular colony of this bacteria is rough, opaque, fuzzy white or slightly yellow with jagged edges [1, 7].
Does Bacillus thuringiensis reduce nitrate?
thuringiensis isolates were grown in nitrite broth for 24 h at 37°C. To this broth, the Nitrate A and B reagents were added in equal proportions. The medium will turn pink or red if the organism is nitrate positive. The reaction indicates the ability of the organism to reduce nitrate (NO3) to nitrite (NO2).
Is Bacillus subtilis citrate positive or negative?
Biochemical Test and Identification of Bacillus subtilis
| Basic Characteristics | Properties (Bacillus subtilis) |
|---|---|
| Citrate | Positive (+ve) |
| Flagella | Flagellated |
| Gas | Negative (-ve) |
| Gelatin Hydrolysis | Positive (+ve) |
What is nitrate reduction test?
Nitrate reduction test is a test that determines the production of an enzyme called nitrate reductase, which results in the reduction of nitrate (NO3). Bacterial species may be differentiated on the basis of their ability to reduce nitrate to nitrite or nitrogenous gases.
What is nitrate reducing bacteria?
Nitrate-reducing bacteria are mostly heterotrophic and often facultative anaerobic, with the ability to switch between oxygen and nitrate respiration depending on the environmental conditions (Luque-Almagro et al., 2011).
Is B. subtilis an aerobe or anaerobe?
facultative anaerobe
Even though B. subtilis is still generally considered to be an obligate aerobe, several recent studies have proved that this bacterium is in fact a facultative anaerobe, which is capable of both fermentation and anaerobic respiration with either nitrate or nitrite used as the terminal electron acceptor (19, 20).
Is Bacillus subtilis positive for oxidase?
The gram-positive endospore-forming bacterium Bacillus subtilis has, under aerobic conditions, a branched respiratory system comprising one quinol oxidase branch and one cytochrome oxidase branch. The system terminates in one of four alternative terminal oxidases.
What is unique about Bacillus subtilis?
Bacillus subtilis is one of the best characterized bacteria and is used as a model organism for Gram-positive bacteria. B. subtilis is a rod-shaped bacterium, which produces endospores that allow the survival of extreme environmental conditions including heat and desiccation.
What bacteria is catalase negative?
If no bubbles appear, the bacteria are catalase negative. Staphylococcus and Micrococcus spp. are catalase positive, whereas Streptococcus and Enterococcus spp. are catalase negative.
How do you isolate Bacillus subtilis?
Bacillus subtilis can readily be isolated from various soil types with frequency of 80% in soils from garden and refuse dumps and 20% from flower bed. All the B. subtilis isolates demonstrated the potential for amylase production. This preliminary study could provide information on the isolation of B.