1-Aminocyclopropane-1-carboxylate (ACP) is a natural product found in plant tissues. It is a key intermediate in the biosynthesis of ethylene, a fruit-ripening hormone in plants. Overripening of fruits may cause economic implications. Control of ethylene biosynthesis may delay this. It has been found that several microorganisms such as the bacterium Pseudomonas sp. ACP and the yeast Williopsis saturnus contain ACP deaminase and degrade ACP to 2-oxobutanoate and ammonia ([http://www.ncbi.nlm.nih.gov/pubmed/7326243|Walsh et al., 1981]). This may be a way to reduce ethylene synthesis and delay fruit ripening.