Posted: May 22nd, 2023

Animalia and Vegetabilia did not consider microorganisms

In 1735 Linnaeus classification of two Kingdoms – Animalia and Vegetabilia did not consider microorganisms, in 1866, Haeckel’s three Kingdom system – Animalia, Plantae, and Protista, in 1925, Chatton’s two groups – Eukaryote and Prokaryote, and in 1938, Copeland’s 4 Kingdoms – Animalia, Plantae, Protista, and Monera included the eukaryotic (fungi, etc) and prokaryotic microorganisms. But the revolution in the classification system came from Whittaker’s five Kingdom systems – Animalia, Plantae, Fungi, Protista, and Monera. Later, Carl Woese’s rRNA sequence homology-based classification brought forward the three-domain system of the organisms – Bacteria, Archaea, and Eukarya, including Fungi, Animals, and Plants. The Bergey’s Manual of Systematic Bacteriology also uses the term Kingdom instead of Domain for Archaea (Kingdom I-Archaeota) and Bacteria (Kingdom II-Bacteria). Based on the shape and overall morphology bacteria can be classified as Micrococcus, Diplococcus, Staphylococcus, Streptococcus, Padiococcus, Sarcina, (spheres) Bacillus, Corynebacterium, Vibrio, Spirillum (Straight or curved Rods), Atrichous (without flagella), Monotrichous (one flagellum), Cephalotrichous (many flagella at one end), Amphitrichous (one flagellum at each end), and Lophotrichous (group of flagella at each end). In naming a microorganism, like others, the genus name precedes species epithet. A genus with capitalized and species names in lower case, in the beginning, should be completely spelled in italics. Later, the genus name but not species epithet should be abbreviated.