How are bacilli bacteria characterized?

Bacilli bacteria are characterized primarily by their rod-shaped structure. This basic morphology is a fundamental trait of bacilli, distinguishing them from other bacterial shapes, such as cocci, which are round, and spirilla, which are spiral in shape. The rod shape of bacilli allows them to have a larger surface area relative to their volume, which can be advantageous for nutrient absorption and metabolic processes. Bacilli can be found in various arrangements, such as singly, in pairs, or in chains, but their defining feature remains their elongated, rod-like structure. This characteristic plays an important role in the identification and classification of bacteria in microbiology.