anaerobiosis

This term is a specialized scientific descriptor used primarily in microbiology and biochemistry. It describes a metabolic state or a biological capability rather than a general condition, distinguishing organisms that can survive without oxygen from those that require it (aerobiosis).

As a technical term for a biological process, it is treated as an uncountable noun. It does not refer to individual instances of the process but to the phenomenon itself, meaning it is not used in plural forms or with indefinite articles in standard scientific discourse.