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The upcoming discussion will update you about the difference between Gram-Positive and Gram-Negative Bacteria.
Difference # Gram-Positive Bacteria:
1. Cell wall thick (150-200 A thick), straight, single layered and outer membrane is absent in gram-positive bacteria.
2. Cell wall of gram-positive bacteria contains less % of lipids (2-4%).
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3. Striking simplicity of amino acids i.e., walls have relatively few amino acids.
4. Large amount of muramic acid is present in the cell wall of gram-positive bacteria.
5. Teichoic acid is present in the cell wall of gram-positive bacteria.
6. Lipopolysaccharides absent in cell wall of gram-positive bacteria.
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7. Sialic acid absent in cell wall of gram-positive bacteria.
8. Polar flagella absent in gram-positive bacteria.
9. Sensitive to penicillin
10. Resistant to alkalies, not dissolved by 1% KOH
11. Isoelectric range pH 2-5 -4
12. Gram-Positive bacteria contain magnesium ribonucleate.
13. Porins are absent in gram-positive bacteria.
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14. Many examples are cocci or spore forming rods e.g., Staphylococcus, streptococcus, Pneumococcus, Pneumococcus. Bacillus, Clostridium, Mycobacterium, Streptomyces (exception Lactobacillus).
Difference # Gram-Negative Bacteria:
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1. Cell wall thin (75-120 A thick) heavy and two layered. The outer membrane is absent in gram-negative bacteria.
2. Lipids % is higher up to 20%.
3. All the amino acids are present in gram-negative bacteria.
4. Less muramic acid is present in the cell wall of gram-negative bacteria.
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5. Teichoic acid is absent in gram-negative bacteria.
6. Lipopolysaccharides is present in gram-negative bacteria.
7. Sialic acid is present in gram-negative bacteria.
8. Polar flagella is present in gram-negative bacteria.
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9. Gram-negative bacteria is sensitive to streptomycin.
10. Sensitive to alkalies, dissolved by 1% KOH.
11. Isoelectric range pH 4-5-5-5.
12. Magnesium Ribonucleate is absent in gram-negative bacteria.
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13. Porins or hydrophilic channels occur in other membrane.
14. Usually non spore forming rods e.g., Salmonella, E. coli, Pseudomonas, Vibrio and Azotobacter, (exceptions Neisseria, a cocci).
