Microbial Biotechnology Lecture 6 (BIO322) Fall 2024 PDF

Microbial Biotechnology (BIO322) Lecture 6 Fall 2024 Presented By: Dr. Hossam Taha Mohamed Associated Professor of Molecular Biology and Microbiology 1: Fundamentals of Microbiology 2: Microbial Physiology and Metabolism 3: Microbial Genetics and...

Microbial Biotechnology (BIO322) Lecture 6 Fall 2024 Presented By: Dr. Hossam Taha Mohamed Associated Professor of Molecular Biology and Microbiology 1: Fundamentals of Microbiology 2: Microbial Physiology and Metabolism 3: Microbial Genetics and Biotechnology 4: Microbial Biotechnology Applications Module 3: Microbial Genetics and Biotechnology  Fertility Plasmid (F Plasmid) o The F plasmid is a type of conjugative plasmid found in certain bacterial species, primarily Escherichia coli. o It plays a pivotal role in bacterial conjugation, a process through which genetic material is transferred from one bacterium (the donor) to another (the recipient) via direct contact. o This plasmid contains genes that encode the machinery required for conjugation, making it a key factor in horizontal gene transfer and genetic diversity in bacterial populations.  Components of the F Plasmid 1. Tra Genes: These genes encode proteins that form the conjugative pilus (sex pilus), a hair- like structure that connects donor and recipient cells. They also facilitate the transfer of the F plasmid during conjugation. 2. OriT (Origin of Transfer): A specific sequence where the plasmid begins to transfer to the recipient cell during conjugation. 3. Rep Genes: Responsible for the replication of the plasmid within the host cell. 4. Insertion Sequences (IS Elements): These mobile genetic elements allow the plasmid to integrate into the host's chromosome, creating an Hfr (High-frequency recombination) strain. 5. Tn1000 (Transposon): Provides mobility to the plasmid and may carry antibiotic resistance or other adaptive genes.  Types of Bacterial Cells Based on F Plasmid Presence 1. F+ Cells: Contain the F plasmid as an episome (a separate, non-integrated entity). Capable of forming sex pili and acting as donors during conjugation. 2. F- Cells: Lack of the F plasmid. Serve as recipients in the conjugation process. 3. Hfr Cells (High-frequency Recombination): The F plasmid is integrated into the host's chromosomal DNA. These cells can transfer chromosomal genes to F- cells during conjugation. 4. F' Cells: Arise when the F plasmid excises incorrectly from the chromosome, carrying some host genes with it. Act as donors and can transfer both plasmid and chromosomal genes.  Types of Bacterial Cells Based on F Plasmid Presence 1. F+ Cells: Contain the F plasmid as an episome (a separate, non-integrated entity). Capable of forming sex pili and acting as donors during conjugation. Conjugation F- / F- F- / F- 2. F- Cells: F+ / F- F+ / F+ Lack of the F plasmid. F+ / F+ F+ / F+ Serve as recipients in the conjugation process. Hfr / F- Hfr / F- Hfr / Hfr Hfr / Hfr 3. Hfr Cells (High-frequency Recombination): F' / F- F' / F' The F plasmid is integrated into the host's chromosomal DNA. F' / F' F' / F' These cells can transfer chromosomal genes to F- cells during conjugation. 4. F' Cells: Arise when the F plasmid excises incorrectly from the chromosome, carrying some host genes with it. Act as donors and can transfer both plasmid and chromosomal genes. Types of Bacterial Cells Based on F Plasmid Presence Electron microscope Photo of conjugated Bacteria  Uses of F Plasmid 1. Genetic Exchange: Facilitates the transfer of genetic material, increasing genetic diversity and adaptability in bacterial populations. 2. Study of Gene Function: Used in research to investigate gene expression and regulation by transferring specific genes between cells 3. Biotechnological Applications: Plays a role in genetic engineering, enabling scientists to introduce or manipulate genes in bacterial systems. 4. Antibiotic Resistance Spread: Sometimes carries antibiotic resistance genes, aiding in the dissemination of resistance traits among bacterial communities. Thank You For your Attention