What type of colony growth forms a surface membrane that floats on top of liquid culture?

Pellicle growth refers to a type of colony formation observed in liquid cultures where a film or membrane develops on the surface of the liquid. This phenomenon occurs with some bacteria that produce substances that facilitate the formation of a surface film, allowing them to float on the liquid. The development of a pellicle is often associated with the presence of oxygen in the environment, as many microorganisms that form pellicles are aerobic and require oxygen to thrive.

The other growth forms listed do not produce a surface membrane. Uniform fine turbidity indicates that the liquid culture is evenly cloudy due to suspended microbial cells throughout the medium. Translucent growth does not specifically describe a colony or growth on the surface; instead, it may refer to the appearance of colonies that are somewhat clear. Filiform growth describes a type of growth pattern where the colonies appear long and thin, often associated with specific types of bacterial growth on solid media, rather than exhibiting any surface film in a liquid culture.

Understanding these distinct forms of growth helps microbiologists identify and characterize various microbial species based on their growth behaviors in different environments.