Wickerhamomyces psychrolipolyticus f.a., sp. nov., a novel yeast species producing two kinds of lipases with activity at different temperatures

Wickerhamomyces corioli f.a., sp. nov., a novel yeast species discovered in two mushroom species

Two yeast strains, designated as 19-39-3 and 19-40-2, obtained from the fruiting bodies of Trametes versicolor and Marasmius siccus collected in Yunwu Mountain Forest Park, PR China, have been identified as representing a novel asexual ascomycetous yeast species. From the results of phylogenetic analyses of the sequences of the D1/D2 domains of the large subunit (LSU) rRNA, small subunit (SSU) rRNA and translation elongation factor 1-α (TEF1) genes, it was determined that these strains represent a member of the genus Wickerhamomyces, with Wickerhamomyces alni and Candida ulmi as the closest relatives. The novel species exhibited 6.6 and 6.7% differences in the D1/D2 domains compared with W. alni and C. ulmi, respectively. Additionally, distinct biochemical and physiological differences were observed between the novel species and its related counterparts. No sexual reproduction was observed in these strains, leading to the proposal of the name Wickerhamomyces corioli f.a., sp. nov. for this newly discovered species.

Diversity of Wickerhamomyces (Wickerhamomycetaceae, Saccharomycetales) in China with the description of four new species

Wickerhamomyces is a well-known genus of the family Wickerhamomycetaceae in the class Ascomycetes. These fungi can survive in a variety of substrates and environments and perform many valuable roles in both industrial processes and the natural ecosystems. During our investigation of yeast diversity associated with plant materials, 53 Wickerhamomyces isolates were obtained from rotting wood and plant leaves collected in Fujian, Guizhou, Henan, and Yunnan Provinces of China. Isolates were identified as 14 Wickerhamomyces species, including 1 species known previously to occur in China (W. anomalus), 9 new record species in China (W. arborarius, W. ciferrii, W. edaphicus, W. lynferdii, W. pijperi, W. subpelliculosa, W. xylosica, W. strasburgensis, and W. sydowiorum), and 4 novel species (W. guiyangensis sp. nov., W. paramyanmarensis sp. nov., W. quanzhouensis sp. nov., and W. phyllophilus sp. nov.). This study presents a detailed account of these new species, illustrating their morphology and analyzing their phylogenetic relationships with other Wickerhamomyces species. Our study is the first comprehensive study on Wickerhamomyces species associated with plant materials from tropical and subtropical China. The results of this study update our understanding of the phylogenetic relationships, systematics, and ecology of Wickerhamomyces.

Wickerhamomyces sinyiensis f.a., sp. nov., a new ascomycetous yeast species in the Wickerhamomyces clade isolated in Taiwan

This study describes Wickerhamomyces sinyiensis, a new anamorphic ascomycetous yeast species, four strains of which were isolated from soil and the fruiting body of a mushroom in Taiwan between 2006 and 2007. Analysis of the sequences of the large-subunit rRNA, small-subunit rRNA and elongation factor-1α identified this species as a member of the Wickerhamomyces clade. The yeast strains of W. sinyiensis exhibited a 0–3 nucleotide difference in the sequences of the D1/D2 domain of the large subunit rRNA when compared to one another and a 10 and 11 nucleotide difference when compared to Candida sp. BG99-11-14-10-4-1 and NRRL Y-7574, the closest undescribed species, respectively. The yeast strains differed by 77 and 78 nucleotides from W. orientalis and W. bispora, the close Wickerhamomyces species, respectively. The internal transcribed spacer sequences of the four isolates exhibited a divergence of 106–108 substitutions from the recognized species W. xylosivorus. No sexual reproduction was observed. The strains differed from those of related species in terms of their carbon and nitrogen assimilation patterns. Therefore, this study proposes W. sinyiensis f.a., sp. nov. to accommodate these four strains, with W. sinyiensis BCRC 23185T (isotype CBS 11432T; MycoBank number MB563484) as the holotype.

Extremophilic lipases for industrial applications: A general review

With industrialization and development in modern science enzymes and their applications increased widely. There is always a hunt for new proficient enzymes with novel properties to meet specific needs of various industrial sectors. Along with the high efficiency, the green and eco-friendly side of enzymes attracts human attention, as they form a true answer to counter the hazardous and toxic conventional industrial catalyst. Lipases have always earned industrial attention due to the broad range of hydrolytic and synthetic reactions they catalyse. When these catalytic properties get accompanied by features like temperature stability, pH stability, and solvent stability lipases becomes an appropriate tool for use in many industrial processes. Extremophilic lipases offer the same, thermostable: hot and cold active thermophilic and psychrophilic lipases, acid and alkali resistant and active acidophilic and alkaliphilic lipases, and salt tolerant halophilic lipases form excellent biocatalyst for detergent formulations, biofuel synthesis, ester synthesis, food processing, pharmaceuticals, leather, and paper industry. An interesting application of these lipases is in the bioremediation of lipid waste in harsh environments. The review gives a brief account on various extremophilic lipases with emphasis on thermophilic, psychrophilic, halophilic, alkaliphilic, and acidophilic lipases, their sources, biochemical properties, and potential applications in recent decades.

An Updated Global Species Diversity and Phylogeny in the Genus Wickerhamomyces with Addition of Two New Species from Thailand

Ascomycetous yeast species in the genus Wickerhamomyces (Saccharomycetales, Wickerhamomycetaceae) are isolated from various habitats and distributed throughout the world. Prior to this study, 35 species had been validly published and accepted into this genus. Beneficially, Wickerhamomyces species have been used in a number of biotechnologically applications of environment, food, beverage industries, biofuel, medicine and agriculture. However, in some studies, Wickerhamomyces species have been identified as an opportunistic human pathogen. Through an overview of diversity, taxonomy and recently published literature, we have updated a brief review of Wickerhamomyces. Moreover, two new Wickerhamomyces species were isolated from the soil samples of Assam tea (Camellia sinensis var. assamica) that were collected from plantations in northern Thailand. Herein, we have identified these species as W. lannaensis and W. nanensis. The identification of these species was based on phenotypic (morphological, biochemical and physiological characteristics) and molecular analyses. Phylogenetic analyses of a combination of the internal transcribed spacer (ITS) region and the D1/D2 domains of the large subunit (LSU) of ribosomal DNA genes support that W. lannaensis and W. nanensis are distinct from other species within the genus Wickerhamomyces. A full description, illustrations and a phylogenetic tree showing the position of both new species have been provided. Accordingly, a new combination species, W. myanmarensis has been proposed based on the phylogenetic results. A new key for species identification is provided.

Cold Active Lipases: Biocatalytic Tools for Greener Technology

Lipases are enzymes that catalyze the ester bond hydrolysis in triglycerides with the release of fatty acids, mono- and diglycerides, and glycerol. The microbial lipases account for $400 million market size in 2017 and it is expected to reach $590 million by 2023. Many biotechnological processes are expedited at high temperatures and hence much research is dealt with thermostable enzymes. Cold active lipases are now gaining importance in the detergent, synthesis of chiral intermediates and frail/fragile compounds, and food and pharmaceutical industries. In addition, they consume less energy since they are active at low temperatures. These cold active lipases have not been commercially exploited so far compared to mesophilic and thermophilc lipases. Cold active lipases are distributed in microbes found at low temperatures. Only a few microbes were studied for the production of these enzymes. These cold-adapted enzymes show increased flexibility of their structures in response to freezing effect of the cold habitats. This review presents an update on cold-active lipases from microbial sources along with some structural features justifying high enzyme activity at low temperature. In addition, recent achievements on their use in various industries will also be discussed.