Formaldehyde extends the CLS.

Wild-type cells were grown on methanol media containing 0.25% ammonium sulphate or 0.25% MA. Upon reaching the stationary phase, the ammonium sulphate containing culture was supplemented with 37.8 mM formaldehyde. The MA cultures were kept in the same medium as a control. Bars indicate the standard error of mean of 2 experiments.