Definition of Bacteria 

Bacteria are unicellular, prokaryotic organisms, that lack a true nucleus and contain a few membrane-less cell organelles.

1. Bacteria appear about 3.5 billion years ago on earth, hence they were the first organism on earth.
2. Bacteria can be autotrophs or heterotrophs depends on the species. Some of them get their nutrition from photosynthesis whereas others get their nutrients from the host cell.
3. Their size shape, color, and habitats are variable.
4. There are threes shape of bacteria such as spherical (e.g., cocci), rod-shaped (e.g., Vibrio), and spiral (e.g., Spirochetes).
5. They reproduce by binary fission or conjugation.
6. Bacteria are divided into two groups based on their nature of cell walls such as Gram-positive and Gram-negative bacteria.
7. All bacteria are not pathogenic some of them are harmless or even beneficial.
8. Some harmless or beneficial bacteria help in the decomposition of organic matters and also helps in the industrial processing of cheese, curd, and yogurt, or other fermented products.
9. The harmful bacteria can cause tuberculosis, salmonella, strep throat, and spoilage of food.
10. The components of bacteria are; Glycocalyx, Nucleoid, Pilus, Mesosomes, Flagellum, Cell Wall, Fimbriae, Inclusion/Granules, Ribosomes, Cell membrane, Endospore.

Definition of Fungi

Fungi are multicellular eukaryotic organisms that don’t produce their food on their own and are characterized by the chitinous cell wall.

• They appear on earth about 900 million years ago and are derived from the protists.
• They contain hyphae, it is a thread-like structure.
• They form mycelium when their hypha grows and forms a thick mass.
• They reproduce sexually as well asexually.
• Fungi get their nutrients from autotrophs and as well as from the dead and decaying materials.
• There are present both harmful and harmless fungi. The harmless fungi are used for the production of antibiotics or as a food and for making bread.
• In ecosystem, they help in the conversation of complex organic compounds to simple inorganic compounds.
• They can be free-living or may appear in a parasitic or symbiotic relationship with others.
• The components of fungi are; Nucleus, Cytoplasm, Mitochondria, Golgi Apparatus, Lysosomes and peroxisomes, Endoplasmic Reticulum, Cell Wall, Cytoplasmic Membrane/Plasma Membrane, and Ribosomes.

Key Differences Between Bacteria and Fungi

Topic	Bacteria	Fungi
Definition	Bacteria are unicellular, prokaryotic organisms, that lack a true nucleus and contain a few membrane-less cell organelles.	Fungi are multicellular eukaryotic organisms that don’t produce their food on their own and are characterized by the chitinous cell wall.
Prokaryotes/Eukaryotes	Bacteria are Prokaryotic cell.	Fungi are Eukaryotic cell.
Single-celled/Multi-celled	Bacteria are Single-celled.	Fungi are Multi-celled.
Organelles	Absent	Present
Nucleus	Absent	Present
Cell wall Composition	Made up of peptidoglycan.	Made up of chitin.
Cell Membrane	Present below the cell wall.	Present.
Shapes	Three shapes are found such s spiral, round, and rod shape.	Vary in shapes, but most of them are in the form of the thread-like structure called hyphae.
Reproduction	Asexual.	Sexually or asexually.
Motility	Move through flagellum.	They are non-motile.
Derive energy from	Bacteria obtain energy from sugars, proteins, and fats.	Fungi obtain their energy from the used and pre-existing sources present in an environment.
Presence of sterol	Absent, except mycoplasma	Present in cell membrane.
Mode of nutrition	Can be autotrophs, but usually heterotrophs.	Heterotrophs, usually feed on the dead and decayed matter.
Optimum pH for Growth	Neutral 6.7- 7	Acidic Atmosphere 4-6
Producer/Decomposer	Can be both producer and decomposer	Decomposer
Resistance	Griseofulvin	Antibiotics such as Penicillium, chloramphenicol, etc.
Host	They do not need a host to grow.	They grow their own.
Disease caused by them	Tuberculosis, rabies, leprosy, tetanus, diphtheria, strep throat, leprosy, pertussis, cholera.	Athlete’s foot, aspergillosis, aspergilloma, allergic bronchopulmonary, etc.
Example	Coccus, Bacillus, Spirillum, Rickettsia, and Mycoplasma, etc.	yeasts, rusts, smuts, mildews, molds, and mushrooms.

Further Reading

• Top 22 Difference Between Bacteria and Virus
• Difference Between Virus and Viroids
• Differences Between Viroids and Prions