Bacteria and fungi share the characteristics of all living creatures in that they are composed of cells, reproduce and respire, but there are many differences between the two creatures. Fungi are often large and made up of many cells, while bacteria are always microscopic and are single-celled. Their methods of reproduction and their cell structures are different as is the way they take in nutrition.
Different Cellular Makeup
Bacteria are simple single-celled organisms viewable only through a microscope. Fungi are more complex organisms. Yeast is a single-celled fungus; however, most fungi are multicelled organisms like mushrooms. The cells of a fungus are organized into branching tubes called hyphae, which together make up the mycelium. The bacterial cell has a cell membrane containing cytoplasm. Bacterial DNA is loosely organized in one area in the cytoplasm called the nucleotide. The fungal cell has a membrane-bound nucleus to contain its DNA. The fungal cell also has organelles such as endoplasmic reticulum to produce complex proteins. The bacterial cells lack organelles.
Bacteria undergo binary fission, an asexual process in which the cell replicates its own DNA and splits in two, thus creating an identical copy of the original. Under ideal conditions they reproduce quickly, creating visible colonies in Petri dishes in 24 hours. A fungus is capable of reproducing both sexually and asexually using spores, budding and fragmentation. Specialized cells, gametes, unite to form a unique spore, a process that is considered a form of sexual reproduction. Spores may also be produced asexually on the tip of hyphae. Fragmentation occurs when cells of the hyphae split off to form a new fungus. A single fungus cell may split in two to form a new individual in a process called budding.
Bacteria have three basic shapes dictated by the rigid cell wall. Coccus bacteria are round, bacillus is rod shaped and spirillum is spiral. Certain bacteria called mycoplasma have no cell wall and no definite shape. Fungi exist in many shapes and forms from large mushrooms and shelf fungus to microscopic yeast and mold.
Fungi cannot produce their own food. They produce digestive enzymes that break down nutrients contained on the substrate they grow on. Once the nutrients are dissolved, the fungus absorbs them. Bacteria are capable of producing food. Their cell wall allows for the transport of nutrients from the outside into the cell. The periplasmic space assists in this function.