Ethylene Production by Pseudomonas solanacearum

Abstract

ETHYLENE is known to be produced by different tissues of many plants and by a few fungi^1,2. So far as we are aware, ethylene production by bacteria has not been noted. We considered that ethylene might be involved in the apparent early ripening of banana fruits that is characteristic of infection by P. solanacearum E. F. Sm. This type of early ripening consists of a change of peel colour from green to yellow with little associated starch hydrolysis and sweetening of the pulp. The gas inside banana fruits was removed by a vacuum technique and collected in a funnel in a system immersed in water. 10–20 c.c. of gas were evolved per fruit. Measurement of ethylene by a gas chromatographic method³ (Cary vibrating reed electrometer with a Loenco flame ionization detector) revealed that infected banana fruit did indeed produce more ethylene than healthy fruit of comparable age. This increased ethylene production was as high as 3 p.p.m. in the internal atmosphere of severely infected fruit that had not yet commenced to yellow, and 20 p.p.m. in fruit half-yellow. No ethylone was detectable in uninfected green fruit.