Figure 3. Bacterial adaptation to environmental stress.

Schematic diagram explaining how bacteria adapt to environmental stresses: In the presence of environmental stress, bacteria have several adaptive strategies such as programmed cell death (PCD) in certain cells of the population to provide nutrients and recyclable metabolic remnants for the survivors. They also provide genetic material and post-lysis signals capable of modifying the expression of resistance determinants. Another option is the overexpression of autolysins to produce protoplasts or unwalled cells, which are unable to proliferate due to oxidative damage brought on by the buildup of reactive oxygen species (ROS), from aerobic respiration products. L-forms are created when mutations that lower ROS levels work in conjunction with enhanced membrane production to allow development without the cell wall. L-forms can multiply without ftsZ (key gene in bacterial cell division) and give rise to asymmetric progeny with different numbers of chromosomes. It should be noted that a monoderm bacteria is depicted in this design. PG, peptidoglycan; IM, inner membrane.