Microbiology Miscellaneous


Microbiology Miscellaneous

  1. The lipopolysaccharides present in bacterial cell wall has lipid A which is connected to ​​









  1. View Hint View Answer Discuss in Forum

    The Gram negative cell envelope contains an additional outer membrane composed by phospholipids and lipopolysaccharides which face the external environment. The highly charged nature of lipopolysaccharide confers an overall negative charge to the Gram negative cell wall. Lipopolysaccharide is comprised of a hydrophilic polysaccharide and a hydrophobic component known as lipid A which is responsible for the major bioactivity of endotoxin. Lipopolysaccharide can be recognized by immune cells as a pathogen-associated molecule through Toll-like receptor 4. Lipid A usually gets attached to the core polysaccharide of Gram negative cell wall. ​

    Correct Option: B

    The Gram negative cell envelope contains an additional outer membrane composed by phospholipids and lipopolysaccharides which face the external environment. The highly charged nature of lipopolysaccharide confers an overall negative charge to the Gram negative cell wall. Lipopolysaccharide is comprised of a hydrophilic polysaccharide and a hydrophobic component known as lipid A which is responsible for the major bioactivity of endotoxin. Lipopolysaccharide can be recognized by immune cells as a pathogen-associated molecule through Toll-like receptor 4. Lipid A usually gets attached to the core polysaccharide of Gram negative cell wall. ​


  1. Match the cell structures in Group I with the organismsin Group II. ​​
    Group I​
    P.​Endospores
    Q.​Bipolar flagella ​​
    R.​Pseudomurine ​​​in cell wall​ ​​
    S.​Periplasmic flagella ​​
    Group II ​​
    1.​ Methanobacterium ​​
    2. ​Treponema ​​
    3. Spirillum
    ​​4. ​Clostridium









  1. View Hint View Answer Discuss in Forum

    Clostridium is a genus of Gram-positive bacteria, belonging to the Firmicutes. They are obligate anaerobes capable of producing endospores. Spirillum is genus of spiral-shaped bacteria of the family Spirillaceae. Spirillum is microbiologically characterized as a gram-negative, motile helical cell with tufts of whiplike flagella at each end. Treponemes are helically coiled, corkscrew-shaped cells, 6 to 15 µm long and 0.1 to 0.2 µm wide. They have an outer membrane which surrounds the periplasmic flagella, a peptidoglycan-cytoplasmic membrane complex, and a protoplasmic cylinder. Multiplication is by binary transverse fission. Methanobacteria are methane producing microorganisms (methanogens) and have pseudomurine in their cell wall. ​

    Correct Option: A

    Clostridium is a genus of Gram-positive bacteria, belonging to the Firmicutes. They are obligate anaerobes capable of producing endospores. Spirillum is genus of spiral-shaped bacteria of the family Spirillaceae. Spirillum is microbiologically characterized as a gram-negative, motile helical cell with tufts of whiplike flagella at each end. Treponemes are helically coiled, corkscrew-shaped cells, 6 to 15 µm long and 0.1 to 0.2 µm wide. They have an outer membrane which surrounds the periplasmic flagella, a peptidoglycan-cytoplasmic membrane complex, and a protoplasmic cylinder. Multiplication is by binary transverse fission. Methanobacteria are methane producing microorganisms (methanogens) and have pseudomurine in their cell wall. ​



  1. Match the commercial microbial sources in Group I with the products in Group II. ​​
    Group I​
    ​​P.​ Corynebacteriumlilium ​​
    Q.​ Klebsiellaoxytoca​ ​​
    R.​ Aspergillusniger
    ​​S.​ Alcaligeneseutrophus ​​​
    Group II ​​
    1.​ 2,3-Butane di-ol ​​
    2. ​Poly-β-hydroxybutyric acid
    ​​3.​ Glutamic acid ​​
    4.​ Citric acid ​​









  1. View Hint View Answer Discuss in Forum

    Mostly, Glutamic acid is produced by the species of Corynebacterium particularly Corynebacterium lilium. Klebsiella oxytoca produces butanol and in this case 2, 3-butane-diol. Citric acid is a common product of fermentation of the fungi Aspergillus niger. Alkaligenes eutrophus commonly produces butyric acids along with other derivatives through its fermentation. ​

    Correct Option: B

    Mostly, Glutamic acid is produced by the species of Corynebacterium particularly Corynebacterium lilium. Klebsiella oxytoca produces butanol and in this case 2, 3-butane-diol. Citric acid is a common product of fermentation of the fungi Aspergillus niger. Alkaligenes eutrophus commonly produces butyric acids along with other derivatives through its fermentation. ​


  1. Phylum proteobacteria is subdivided into  α-, β-, δ-and ε-proteobacteria based on ​​









  1. View Hint View Answer Discuss in Forum

    The phylum Proteobacteria is the largest and most diverse group of bacteria. They have many different shapes and ways of living. Some are free-living, some are parasitic, and others form mutualistic relationships with other organisms, such as those found in the rumen. Many Proteobacteria are responsible for diseases in animals and humans. The largest and most diverse Bacterial phylum is the Proteobacteria. All are Gram-negative and show relationship based on 16s RNA comparison. ​

    Correct Option: D

    The phylum Proteobacteria is the largest and most diverse group of bacteria. They have many different shapes and ways of living. Some are free-living, some are parasitic, and others form mutualistic relationships with other organisms, such as those found in the rumen. Many Proteobacteria are responsible for diseases in animals and humans. The largest and most diverse Bacterial phylum is the Proteobacteria. All are Gram-negative and show relationship based on 16s RNA comparison. ​



  1. Which of the following essential element(s) is/are required as major supplement to enhance the bioremediation of oil spills by the resident bacteria? ​​









  1. View Hint View Answer Discuss in Forum

    Oil spills in seas and oceans can be remedied by the use of certain special kinds of bacteria which degrade polyhydrocarbons. Such bacteria are utilized in the process of bioremediation to prevent serious impacts on marine environment caused by spillage. Such bacteria require nitrogen and phosphorus as major supplement for enhancing the rate of degradation of saturated and unsaturated hydrocarbons.

    Correct Option: B

    Oil spills in seas and oceans can be remedied by the use of certain special kinds of bacteria which degrade polyhydrocarbons. Such bacteria are utilized in the process of bioremediation to prevent serious impacts on marine environment caused by spillage. Such bacteria require nitrogen and phosphorus as major supplement for enhancing the rate of degradation of saturated and unsaturated hydrocarbons.