TYPES OF BACTERIA
1. On the basis of their shape:
(i) Coccus (pl: Cocci) – Spherical shaped, e.g., Streptococcus lactis
(ii) Bacillus (pl: Bacilli) – Rod shaped, e.g., E. coli, Lactobacillus
(iii) Spirillum (pl: Spirilla) – Spiral shaped bacteria, e.g., Spirillum volutans, Spirochete.
(iv) Vibrium (pl: vibrium) – Comma shaped, e.g., Vibrio cholerae
(v) Pleomorphic bacteria – Variable in shape, e.g., Rhizobium.