Oil type and cross‐linking influence growth of Aureobasidium melanogenum on vegetable oils as a single carbon source

Abstract

Aureobasidium melanogenum is the main fungus found in a spontaneously formed biofilm on a oil-treated wood. This dark colored biofilm functions as a protective coating. To better understand biofilm formation, in this study A. melanogenum was cultured on olive oil and raw linseed oil. Metabolic activity and oil conversion were measured. The results show that A. melanogenum is able to grow on linseed oil and olive oil as a single carbon source. The fungus produces the enzyme lipase to convert the oil into fatty acids and glycerol. Metabolic activity and oil conversion were equal on linseed oil and olive oil. The fungus was not able to grow on severe cross-linked linseed oil, meaning that the degree of cross-linking of the oil is important for growth of A. melanogenum. Dark coloring of the colony was seen on linseed oil, which might be a stress response on the presence of autoxidation products in linseed oil. The colony on olive oil showed delayed melanin production indicating an inhibitory effect of olive oil on melanin production.

Vegetable oils as carbon and energy source for Aureobasidium melanogenum in batch cultivation

“…The demonstration of oil‐related population growth and accumulation of fatty acids in A. melanogenum cells indicates that the tested olive oil, raw linseed oil, and stand linseed oil provide a carbon and energy for the growth of the biofinish‐inhabiting fungus in shake flak cultivation. The finding of oil‐related A. melanogenum growth when using raw linseed or olive oil as carbon‐based nutrient is in line with the findings of Peeters et al (). Although the methods to demonstrate growth differed, it indicates that various types of raw linseed oil or olive oil are suitable sources of carbon and energy for A. melanogenum .…”

“…This could be explained by the degree of cross‐linked molecules. Stand linseed oil has a higher degree of cross‐linked triglycerides than raw linseed and olive oil (Zovi et al, ), and cross‐linking can influence the growth of A. melanogenum on oil (Peeters et al, ). The lipases produced by A. melanogenum might be unable to act on big molecules of cross‐linked triglycerides.…”

“…Stand linseed oil has a higher degree of cross-linked triglycerides than raw linseed and olive oil (Zovi et al, 2011), and cross-linking can influence the growth of A. melanogenum on oil (Peeters et al, 2018).…”

“…In the case of the yeast Saccharomyces cerevisiae , contradicting results have been found on its ability to grow on lipid substrates (Darvishi, ; Shirazi, Rahman, & Rahman, ). In the study of Peeters, Huinink, Voogt, and Adan (), colony growth of A. melanogenum was demonstrated on layers made of a raw linseed and olive oil. Thus far, it is unknown if A. melanogenum can use all types of linseed and olive oil as carbon and energy source for growth.…”

Bioinspired Living Coating System in Service: Evaluation of the Wood Protected with Biofinish during One-Year Natural Weathering

“…One of the most attractive aspects of using A. pullulans as a living coating system is an induced self-healing ability of such a finished surface. Biofinish is solely composed of natural substances and it is considered a fully sustainable wood treatment solution with minimal environmental impact and low maintenance requirements [42]. Timber products are currently treated at an industrial scale and the do-it-yourself (DIY) coating formulation is available on the market [43].…”