Bacteria are single-cell organisms can appear everywhere. The bacteria live in every climate and location on Earth (in the air, water or land...). When prompted to "bacteria", many people assume that it means negative, but the bacteria perform many important functions for the organism and the environment. The majority of bacteria harmful to humans but still have some kind of beneficial. In the gastrointestinal tract of humans, the good bacteria that aid digestion, producing vitamins and immune booster. Bacteria have three basic shapes: the rod (Bacillus), spherical (Pneumococcus), or spiral (spirilla). The bacteria can also be classified as Gram-positive or gram-negative. (1)
The purpose of the experiment was to identify the causative agent …show more content…
For gram stain, the gram-positive bacteria have thick cell wall, this substance has the ability to retain the Crystal Violet-iodine complex. Meanwhile, the peptidoglycan cell wall of gram-negative bacteria thinner and usually have more lipopolysaccharide (LPS) membrane on the outside; this substance does not have ability to retain the crytal-idodine complex, so it will be washed away and bacteria will appear pink. Catalase test is an enzyme capable of decomposing hydrogen peroxide (H2O2) into water (H2O) and oxygen (O) 2H2O2 + 2H2O + O2 → catalase. Drop 1 small drop of 3% H2O2 cover up the bacteria and observed the formation of bubbles. (1) If the result give strong bubbles immediately after 1 drop, then this bacterium can be considering as catalase (+). In contract, if after drop H2O2 and bubbles not form then the bacteria is catalase (-). The main ingredients of MSA environment include peptone, beef extracts, Mannitol, NaCl and Phenol Red. The salt concentrations in the environment are quite high (7.5%) will inhibit the growth of several species of microorganisms. Mannitol is sources of Carbohydrates, the unique fermentation bacteria. (1) In Mannitol salt agar environment, s. aureus bacteria able to ferment mannitol and it will growth with the color changed from red to yellow; s. epidermidis cannot ferment mannitol and the bacteria will growth without changing
The purpose of the experiment was to identify the causative agent …show more content…
For gram stain, the gram-positive bacteria have thick cell wall, this substance has the ability to retain the Crystal Violet-iodine complex. Meanwhile, the peptidoglycan cell wall of gram-negative bacteria thinner and usually have more lipopolysaccharide (LPS) membrane on the outside; this substance does not have ability to retain the crytal-idodine complex, so it will be washed away and bacteria will appear pink. Catalase test is an enzyme capable of decomposing hydrogen peroxide (H2O2) into water (H2O) and oxygen (O) 2H2O2 + 2H2O + O2 → catalase. Drop 1 small drop of 3% H2O2 cover up the bacteria and observed the formation of bubbles. (1) If the result give strong bubbles immediately after 1 drop, then this bacterium can be considering as catalase (+). In contract, if after drop H2O2 and bubbles not form then the bacteria is catalase (-). The main ingredients of MSA environment include peptone, beef extracts, Mannitol, NaCl and Phenol Red. The salt concentrations in the environment are quite high (7.5%) will inhibit the growth of several species of microorganisms. Mannitol is sources of Carbohydrates, the unique fermentation bacteria. (1) In Mannitol salt agar environment, s. aureus bacteria able to ferment mannitol and it will growth with the color changed from red to yellow; s. epidermidis cannot ferment mannitol and the bacteria will growth without changing