Microbiology

Introduction

Microbiology is the study of microorganisms, which are microscopic organisms too small to be seen with the naked eye. They include bacteria, viruses, fungi, and protozoa.

Types of Microorganisms

• Bacteria: unicellular prokaryotes. Example: Escherichia coli, Clostridium tetani.
• Viruses: acellular, consist of DNA or RNA in a protein coat. Example: Influenza virus, HIV.
• Fungi: eukaryotic, may be unicellular (yeast) or multicellular (molds). Example: Saccharomyces cerevisiae, Rhizopus stolonifer.
• Protozoa: unicellular eukaryotes. Example: Plasmodium, Amoeba.

Structure & Reproduction

Bacteria: cell wall, cell membrane, cytoplasm, nucleoid, plasmids, flagella. Reproduce by binary fission.

Viruses: protein coat (capsid) and nucleic acid. Replicate inside host cells.

Fungi: have hyphae and mycelium; reproduce sexually and asexually via spores.

Protozoa: single-celled with nucleus, cytoplasm, cilia/flagella. Reproduce by binary fission or sexual reproduction.

Beneficial Roles

• Decomposition and nutrient recycling.
• Food production (yogurt, cheese, bread).
• Production of antibiotics (Penicillin).
• Genetic research and biotechnology applications.
• Bioremediation: using microbes to clean pollutants.

Harmful Roles

• Cause diseases in humans, animals, and plants.
• Food spoilage.
• Crop damage and reduced agricultural yield.

Microbial Diseases

• Humans: Cholera, Tuberculosis, Malaria, Influenza.
• Animals: Foot-and-mouth disease, Anthrax.
• Plants: Late blight of potato, Rice blast.

Laboratory Safety

• Use gloves, lab coat, and protective eyewear.
• Work in a sterile environment to avoid contamination.
• Properly sterilize instruments and dispose of microbial waste.
• Never eat, drink, or touch the face in the lab.
• Wash hands thoroughly after handling microorganisms.

Practice Questions & Answers

• Q: Define microbiology.
  A: Study of microscopic organisms, including bacteria, viruses, fungi, and protozoa.
• Q: Name four types of microorganisms.
  A: Bacteria, viruses, fungi, protozoa.
• Q: Explain the difference between bacteria and viruses.
  A: Bacteria are unicellular prokaryotes that reproduce independently. Viruses are acellular, require a host to replicate, and have DNA/RNA in a protein coat.
• Q: List three beneficial roles of microorganisms.
  A: Decomposition, food production, antibiotics production.
• Q: List three harmful roles.
  A: Cause diseases, food spoilage, crop damage.
• Q: Mention four lab safety precautions.
  A: Use protective equipment, work sterile, sterilize instruments, wash hands.