Aureobasidium melanogenum: a native of dark biofinishes on oil treated wood

Abstract

The genus Aureobasidium, which is known as a wood staining mould, has been detected on oil treated woods in the specific stain formation called biofinish. This biofinish is used to develop a new protective, self-healing and decorative biotreatment for wood. In order to understand and control biofinish formation on oil treated wood, the occurrence of different Aureobasidium species on various wood surfaces was studied. Phenotypic variability within Aureobasidium strains presented limitations of morphological identification of Aureobasidium species. PCR amplification and Sanger sequencing of ITS and RPB2 were used to identify the culturable Aureobasidium species composition in mould stained wood surfaces with and without a biofinish. The analysed isolates showed that several Aureobasidium species were present and that Aureobasidium melanogenum was predominantly detected, regardless of the presence of a biofinish and the type of substrate. A.melanogenum was detected on wood samples exposed in the Netherlands, Cameroon, South Africa, Australia and Norway. ITS-specific PCR amplification, cloning and sequencing of DNA extracted from biofinish samples confirmed results of the culturing based method: A. melanogenum is predominant within the Aureobasidium population of biofinishes on pine sapwood treated with raw linseed oil and the outdoor placement in the Netherlands.Electronic supplementary materialThe online version of this article (doi:10.1007/s10482-016-0668-7) contains supplementary material, which is available to authorized users.

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

“…In 2014, this variety was defined as a separate species named A. melanogenum (Gostinčar et al, 2014). Aureobasidium melanogenum is a pleomorphic fungus that shows phenotypic plasticity, meaning that the fungus grows in different shapes and is able to change morphology, physiological state, and/or behavior (Slepecky & Starmer, 2009;Van Nieuwenhuijzen et al, 2016). Aureobasidium melanogenum has both a yeast-like and a hyphal growth mode.…”

“…Aureobasidium melanogenum is found on many different surfaces, for instance, on leafs (McGrath & Andrews, 2007), wood, painted material (Harvath et al, 1976;Shirakawa et al, 2002), and rocks (Urzì et al, 1999). Recently, it was found that A. melanogenum is the main fungus in dark-colored biofilms on oil-impregnated wood (Van Nieuwenhuijzen et al, 2016).…”

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

“…The A. melanogenum isolate CBS 140241, obtained from the Westerdijk Fungal Biodiversity Centre, was used for all growth experiments. This isolate originates from oil‐treated wood in the initial stage of biofinish formation (Van Nieuwenhuijzen, Houbraken, et al, ). An Aureobasidium inoculum was made with young hyaline yeast‐like cells.…”

“…Till now, the growth mechanisms of dark wood staining fungi on the surface of oil‐treated wood are poorly understood. Recent studies show the common presence of Aureobasidium melanogenum , formerly known as Aureobasidium pullulans variety melanogenum (Gostinčar et al, ), in natural biofinishes of wood (Van Nieuwenhuijzen, Houbraken, Meijer, Adan, & Samson, ). Also the impact of other fungal species, such as Superstratomyces , has to be considered (Van Nieuwenhuijzen et al, ; Van Nieuwenhuijzen, Houbraken, et al, ; Van Nieuwenhuijzen, Miadlikowska, et al, ).…”

“…Recent studies show the common presence of Aureobasidium melanogenum , formerly known as Aureobasidium pullulans variety melanogenum (Gostinčar et al, ), in natural biofinishes of wood (Van Nieuwenhuijzen, Houbraken, Meijer, Adan, & Samson, ). Also the impact of other fungal species, such as Superstratomyces , has to be considered (Van Nieuwenhuijzen et al, ; Van Nieuwenhuijzen, Houbraken, et al, ; Van Nieuwenhuijzen, Miadlikowska, et al, ). Although many parameters define the growth conditions on the surface of a material outdoors, for example, rain, air temperature, or solar radiation, one of the controllable parameters is the type of vegetable oil used for the wood impregnation.…”