Discuss microbes under the following: a)Structural features of bacteria. b)Bacteria classification by Gram Stain. c)Bacteria shapes. d)Yeast characteristics. e)Pichia pastoris microbe.

Discuss microbes under the following:
a)Structural features of bacteria.
b)Bacteria classification by Gram Stain.
c)Bacteria shapes.
d)Yeast characteristics.
e)Pichia pastoris microbe.

Answers

Structural Features of Bacteria;
• Small (1–5 µm).
• No nucleus; DNA is contained in a single, circular chromosome.
• May contain plasmids.
• Cell wall that surrounds plasma membrane contains peptidoglycan; provides rigidity for protection.
• Some bacteria contain an outer layer of carbohydrates in a structure called a capsule.

Bacteria are classified by the Gram stain
1. Gram + bacteria stain purple.
• Have simple cell walls rich in peptidoglycan.
2. Gram – bacteria stain pink.
• Have complex cell wall structures with less peptidoglycan.
• Bacteria vary in size and shape.

Most common shapes;
• Cocci – spherical cells.
• Bacilli – rod-shaped cells.
• Spiral – corkscrew-shaped cells.

Other bacteria characteristics.
• Single, circular chromosome is relatively small.
• 2–4 million base pairs.
• Some bacteria contain plasmids as well.
• Plasmids often contain genes for antibiotic resistance and genes encoding proteins that form connecting tubes called pili.
• Plasmids are an essential tool for biotechnology.
• Bacteria grow and divide rapidly.
• Divide every 20 minutes or so.
• Millions of cells can be grown on small dishes of agar or in liquid culture media.
• Easy-to-make mutant strains to be used for molecular and genetic studies.

Yeast.
– single-celled eukaryotic microbes; fungi.
• Sources of antibiotics and drugs that lower cholesterol.
• Mechanisms of gene expression resemble those in human cells.
• Can grow in the presence of oxygen (aerobic) or in the absence of oxygen (anaerobic).

Pichia pastoris.
• Grows to a higher density in liquid culture than other yeast strains.
• Has a number of strong promoters that can be used for production of proteins.
• Can be used in batch processes to produce large number of cells.

jim items answered the question on March 28, 2019 at 12:04

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Discuss microbes under the following: a)Structural features of bacteria. b)Bacteria classification by Gram Stain. c)Bacteria shapes. d)Yeast characteristics. e)Pichia pastoris microbe.

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