Extracellular enzymatic activities and physiological profiles of yeasts colonizing fruit trees

Abstract

Yeasts form a significant and diverse part of the phyllosphere microbiota. Some yeasts that inhabit plants have been found to exhibit extracellular enzymatic activities. The aim of the present study was to investigate the ability of yeasts isolated from leaves, fruits, and blossoms of fruit trees cultivated in Southwest Slovakia to produce extracellular enzymes, and to discover whether the yeasts originating from these plant organs differ from each other in their physiological properties. In total, 92 strains belonging to 29 different species were tested for: extracellular protease, β-glucosidase, lipase, and polygalacturonase activities; fermentation abilities; the assimilation of xylose, saccharose and alcohols (methanol, ethanol, glycerol); and for growth in a medium with 33% glucose. The black yeast Aureobasidium pullulans showed the largest spectrum of activities of all the species tested. Almost 70% of the strains tested demonstrated some enzymatic activity, and more than 90% utilized one of the carbon compounds tested. Intraspecies variations were found for the species of the genera Cryptococcus and Pseudozyma. Interspecies differences of strains exhibiting some enzymatic activities and utilizing alcohols were also noted. The largest proportion of the yeasts exhibited β-glucosidase activity and assimilated alcohols independently of their origin. The highest number of strains positive for all activities tested was found among the yeasts associated with leaves. Yeasts isolated from blossoms assimilated saccharose and D-xylose the most frequently of all the yeasts tested. The majority of the fruit-inhabiting yeasts grew in the medium with higher osmotic pressure.

Yeasts from peat in a tropical peat swamp forest in Thailand and their ability to produce ethanol, indole-3-acetic acid and extracellular enzymes

“…All 65 yeast strains exhibited production of at least one extracellular enzyme. They all produced lipase, and while M. guilliermondii, P. flavescens, P. laurentii and R. mucilaginosa have been previously reported to produce this enzyme (Buzzini and Martini 2002;Carvalho et al 2013;Molnarova et al 2014;Wang et al 2007;Yalcin et al 2014), ours is the first report for the other species. Among the three cellulases, only three strains of Cu.…”

Use of biocontrol agents and botanicals in integrated management of Botrytis cinerea in table grape vineyards

“…[33][34][35][36][37] The yeast-like fungus A. pullulans is a BCA used in agriculture due to its great adaptability to stress conditions and its strong antagonistic activity against many pathogens, including B. cinerea. [38][39][40] Bacillus subtilis strain QST713 and Bacillus amyloliquefaciens strain D747, and the A. pullulans strains DSM14940 and DSM14941 were tested in field trials carried out in table-grape vineyards located in Apulia (southern Italy) and covered by plastic film to delay the grape harvest until December.…”

Enzymes for Wine Fermentation: Current and Perspective Applications

“…Lipolytic activities have been detected only in few wine-relevant Lactobacillus strains [28], but in different genera of yeasts isolated from natural environments [29,30]. In theory, lipases could be used for winemaking for decomposition of lipoid cell membranes, thereby improving color extraction from red grape berries ( Figure 1…”