Biotechnology and Bacteria: A Comprehensive Overview

Posted on Nov 4, 2024 in Biology

Biotechnology

Introduction

Biotechnology developed after the discovery of DNA. It is a science involved in understanding the genetic composition of organisms and implementing processes to improve productivity for human benefit.

Genetically Modified Organisms (GMOs)

GMOs are living organisms that have been genetically modified to improve productivity, enhance resistance to pathogens (viruses, bacteria, fungi, etc.), and increase tolerance to various climatic factors. This process utilizes restriction enzymes of bacterial origin, which recognize short DNA sequences, multiply them, and incorporate them into the target organism.

Methods of Genetic Modification

Restriction Enzymes

To obtain transgenic organisms, restriction enzymes are used. These enzymes recognize short DNA sequences and cut them at specific locations. The isolated gene is then multiplied and inserted into the target organism.

Projectiles

Small, solid spheres of material are used as projectiles to enter the cell. These projectiles carry copies of the desired gene.

Injection

DNA can be directly injected into the cell using a very fine needle.

Virus-Mediated Transfer

Viruses can “inject” their DNA into the cell. Viruses are macromolecules that contain DNA or RNA and only exhibit metabolic activity inside a cell, making them obligate parasites.

Bacteria

Structure

DNA: A closed circular molecule.

Cell Wall: Thin and rigid.

Capsule: Surrounds the cell wall and protects against water loss.

Flagella: Enables mobility.

Pili: Involved in conjugation.

Ribosomes: Synthesize proteins.

Fimbriae: Connect bacteria to each other and to cell membranes.

Mesosome: Assists with metabolism and cell division.

Plasmid: Encodes proteins that provide resistance to antibiotics.

Cytoplasm: Contains water, DNA, ribosomes, and, in autotrophic bacteria, pigments that capture light.

Plasma Membrane: The cell membrane of bacteria.

Bacterial Growth

  1. Latency: The period where bacteria adapt to environmental conditions.
  2. Exponential: Accelerated multiplication under optimal conditions.
  3. Stationary: Growth slows down as nutrients are depleted and waste products accumulate.
  4. Decline: Increased bacterial mortality, leading to extinction.

Bacterial Reproduction

  1. Transformation: Involves the insertion of free DNA fragments from destroyed bacteria.
  2. Transduction: A DNA fragment is transferred via a virus.
  3. Conjugation: A protein bridge (pilus) connects bacteria. A plasmid strand opens and transfers to the recipient bacterium, where it replicates. Alternatively, a chromosomal DNA strand with an integrated plasmid can be transferred and replicated.

Bacterial Cell Wall Components

Teichoic Acid: A strong negative charge attracts cations, providing rigidity to the cell wall and regulating cell growth.

Peptidoglycan: Provides stiffness to the cell wall, maintains shape, and helps control internal pressure.

Bacterial Shapes

  • Spherical: Coccus (isolated), Diplococcus (pairs), Streptococcus (chains), Staphylococcus (clusters).
  • Rod-shaped: Bacillus (isolated, with or without flagella), Streptobacillus (chains), Vibrio (spiral).

Benefits and Harms of Bacteria

Positive Utility

  • Part of the intestinal flora, synthesizing vitamins like vitamin K.
  • Used in food production (yogurt, cheese, alcohol).
  • Used in the production of transgenic organisms.
  • Fix atmospheric nitrogen, converting it to nitrates for protein synthesis.
  • Used in bioleaching, recovering copper from scrap.

Negative Effects

  • Pathogenic bacteria cause diseases and food spoilage.
  • Contribute to bad smells and the process of eutrophication (decreased oxygen in water due to waste accumulation).

Disease Classification

Infectious and Contagious Diseases

  • Syphilis
  • Influenza
  • AIDS
  • Leprosy

Sexually Transmitted Diseases (STDs)

  • AIDS
  • Herpes
  • Gonorrhea

Hereditary Diseases

  • Down Syndrome
  • Daltonism
  • Mental illnesses (e.g., Bulimia, Epilepsy)

Metabolic or Functional Diseases

  • Diabetes
  • Cretinism

Trauma-Related Diseases

  • Fractures
  • Sprains

Degenerative Diseases

  • Cancer
  • Tumors
  • Leprosy

Social Diseases

  • Alcoholism
  • Smoking

Food-Related Diseases

  • Anorexia
  • Obesity

Parasitic Diseases

  • Worms
  • Lice
  • Pubic lice