The diversity and extracellular enzymatic activities of yeasts isolated from water tanks of Vriesea minarum, an endangered bromeliad species in Brazil, and the description of Occultifur brasiliensis f.a., sp. nov.

Abstract

The diversity of yeast species collected from the bromeliad tanks of Vriesea minarum, an endangered bromeliad species, and their ability to produce extracellular enzymes were studied. Water samples were collected from 30 tanks of bromeliads living in a rupestrian field site located at Serrada Piedade, Minas Gerais state, Brazil, during both the dry and rainy seasons. Thirty-six species were isolated, representing 22 basidiomycetous and 14 ascomycetous species. Occultifur sp., Cryptococcus podzolicus and Cryptococcus sp. 1 were the prevalent basidiomycetous species. The yeast-like fungus from the order Myriangiales, Candida silvae and Aureobasidium pullulans were the most frequent ascomycetous species. The diversity of the yeast communities obtained between seasons was not significantly different, but the yeast composition per bromeliad was different between seasons. These results suggest that there is significant spatial heterogeneity in the composition of populations of the yeast communities within bromeliad tanks, independent of the season. Among the 352 yeast isolates tested, 282 showed at least one enzymatic activity. Protease activity was the most widely expressed extracellular enzymatic activity, followed by xylanase, amylase, pectinase and cellulase activities. These enzymes may increase the carbon and nitrogen availability for the microbial food web in the bromeliad tank of V. minarum. Sequence analyses revealed the existence of 10 new species, indicating that bromeliad tanks are important sources of new yeasts. The novel species Occultifur brasiliensis, f.a., sp. nov., is proposed to accommodate the most frequently isolated yeast associated with V. minarum. The type strain of O. brasiliensis, f.a., sp. nov. is UFMG-CM-Y375(T) (= CBS 12687(T)). The Mycobank number is MB 809816.

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

“…mucoides showed low endoglucanase activity. This yeast species has never been reported to produce endoglucanase, while some strains of P. laurentii and M. guilliermondii have been reported to produce this enzyme (Gomes et al 2015); however, none of the P. laurentii and M. guilliermondii strains obtained in this study produced this enzyme. We found that β-glucosidase was produced by only three strains of Cryp.…”

Pattersoniomyces tillandsiae gen. et comb. nov.: linking sexual and asexual morphs of the only known smut fungus associated with Bromeliaceae

“…The teleomorphic stage of Pattersoniomyces tillandsiae follows the occurrence of the host plants Tillandsia flabellata and Tillandsia leiboldiana, both restricted to Central America (www.gbif.org/species/ 2694789; www.gbif.org/species/2694764). The anamorphic stage of this fungus is reported in an area of Atlantic rain forest of northeast Brazil associated with the endemic species Canistrum improcerum (Martinelli et al 2008), and in a small area in southeast Brazil associated with the endemic and endangered species Vriesea minarum (Versieux 2011;Gomes et al 2015). Considering the usually high level of host specificity of smut fungi in the teleomorphic stage (e.g., Hendrichs et al 2005;Piątek et al 2011Piątek et al , 2013Piątek et al , 2016Li et al 2017), it is not likely to find the teleomorph of P. tillandsiae outside its current area of host distribution.…”

“…(Albu et al 2015). However, several other ascomycetous or basidiomycetous yeasts were found to be consistently associated with bromeliads (Landell et al 2010(Landell et al , 2015Safar et al 2013;Gomes et al 2015Gomes et al , 2016 but it is currently unknown which factors are responsible for such a habitat preferences of these yeast species.…”

“…Processing of the Brazilian yeast strains, including the sequencing the LSU and ITS rDNA regions, was performed as described previously (White et al 1990;O'Donnell 1993;Lachance et al 1999;Gomes et al 2015). DNA sequences determined for this study were deposited in GenBank, accession numbers are given in Tables 1 and 2 and Fig.…”

Physiological adaptations of yeasts living in cold environments and their potential applications

“…laurentii and Cr. nemorosus (Gomes et al 2015), Tetracladium (Abdullah 1989), in Mrakia species isolated from Arctic puddles (Pathan et al 2010), in Cr. victoriae, D. fristingensis, Leuconeurospora sp., M. blollopis and M. psychrophila, isolated from sub-Antarctic region (Carrasco et al 2012).…”