scholarly journals Yeast Species Associated with Orange Juice: Evaluation of Different Identification Methods

2002 ◽  
Vol 68 (4) ◽  
pp. 1955-1961 ◽  
Author(s):  
Covadonga R. Arias ◽  
Jacqueline K. Burns ◽  
Lorrie M. Friedrich ◽  
Renee M. Goodrich ◽  
Mickey E. Parish
Keyword(s):  
Orange Juice ◽  
Restriction Pattern ◽  
Partial Sequence ◽  
Rrna Gene ◽  
Correct Identification ◽  
Internal Transcribed Spacer Region ◽  
Accurate Identification ◽  
Hanseniaspora Uvarum ◽  
Classical Methodology ◽  
26S Rrna

ABSTRACT Five different methods were used to identify yeast isolates from a variety of citrus juice sources. A total of 99 strains, including reference strains, were identified using a partial sequence of the 26S rRNA gene, restriction pattern analysis of the internal transcribed spacer region (5.8S-ITS), classical methodology, the RapID Yeast Plus system, and API 20C AUX. Twenty-three different species were identified representing 11 different genera. Distribution of the species was considerably different depending on the type of sample. Fourteen different species were identified from pasteurized single-strength orange juice that had been contaminated after pasteurization (PSOJ), while only six species were isolated from fresh-squeezed, unpasteurized orange juice (FSOJ). Among PSOJ isolates, Candida intermedia and Candida parapsilosis were the predominant species. Hanseniaspora occidentalis and Hanseniaspora uvarum represented up to 73% of total FSOJ isolates. Partial sequence of the 26S rRNA gene yielded the best results in terms of correct identification, followed by classical techniques and 5.8S-ITS analysis. The commercial identification kits RapID Yeast Plus system and API 20C AUX were able to correctly identify only 35 and 13% of the isolates, respectively. Six new 5.8S-ITS profiles were described, corresponding to Clavispora lusitaniae, Geotrichum citri-aurantii, H. occidentalis, H. vineae, Pichia fermentans, and Saccharomycopsis crataegensis. With the addition of these new profiles to the existing database, the use of 5.8S-ITS sequence became the best tool for rapid and accurate identification of yeast isolates from orange juice.

Naumovozyma baii sp. nov., an ascomycetous yeast species isolated from rotten wood in a tropical forest

2012 ◽  
Vol 62 (Pt_12) ◽  
pp. 3095-3098 ◽  
Author(s):  
Wan-Qiu Liu ◽  
Pei-Jie Han ◽  
Jun-Zhi Qiu ◽  
Qi-Ming Wang
Keyword(s):  
Gene Sequence ◽  
Yeast Species ◽  
Morphological Characteristics ◽  
18S Rrna Gene ◽  
Rrna Gene ◽  
Internal Transcribed Spacer Region ◽  
Ascomycetous Yeast ◽  
Rotten Wood ◽  
D2 Domain ◽  
26S Rrna

Two strains isolated from rotten wood were included in the Saccharomyces group based on morphological characteristics. However, rRNA gene sequence analyses (including the 18S rRNA gene, 26S rRNA gene D1/D2 domain and internal transcribed spacer region) indicated that these two strains represent a novel species of Naumovozyma, for which the name Naumovozyma baii sp. nov. is proposed (type strain: BW 22T = CGMCC 2.04520T = CBS 12642T). The MycoBank number of the new species is MB800484.

scholarly journals The mutL Gene as a Genome-Wide Taxonomic Marker for High Resolution Discrimination of Lactiplantibacillus plantarum and Its Closely Related Taxa

2021 ◽  
Vol 9 (8) ◽  
pp. 1570
Author(s):  
Chien-Hsun Huang ◽  
Chih-Chieh Chen ◽  
Yu-Chun Lin ◽  
Chia-Hsuan Chen ◽  
Ai-Yun Lee ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Target Genes ◽  
Marker Genes ◽  
Rrna Gene ◽  
Accurate Identification ◽  
Discrimination Power ◽  
Sequence Identity ◽  
Genome Wide ◽  
A Genome

The current taxonomy of the Lactiplantibacillus plantarum group comprises of 17 closely related species that are indistinguishable from each other by using commonly used 16S rRNA gene sequencing. In this study, a whole-genome-based analysis was carried out for exploring the highly distinguished target genes whose interspecific sequence identity is significantly less than those of 16S rRNA or conventional housekeeping genes. In silico analyses of 774 core genes by the cano-wgMLST_BacCompare analytics platform indicated that csbB, morA, murI, mutL, ntpJ, rutB, trmK, ydaF, and yhhX genes were the most promising candidates. Subsequently, the mutL gene was selected, and the discrimination power was further evaluated using Sanger sequencing. Among the type strains, mutL exhibited a clearly superior sequence identity (61.6–85.6%; average: 66.6%) to the 16S rRNA gene (96.7–100%; average: 98.4%) and the conventional phylogenetic marker genes (e.g., dnaJ, dnaK, pheS, recA, and rpoA), respectively, which could be used to separat tested strains into various species clusters. Consequently, species-specific primers were developed for fast and accurate identification of L. pentosus, L. argentoratensis, L. plantarum, and L. paraplantarum. During this study, one strain (BCRC 06B0048, L. pentosus) exhibited not only relatively low mutL sequence identities (97.0%) but also a low digital DNA–DNA hybridization value (78.1%) with the type strain DSM 20314T, signifying that it exhibits potential for reclassification as a novel subspecies. Our data demonstrate that mutL can be a genome-wide target for identifying and classifying the L. plantarum group species and for differentiating novel taxa from known species.

scholarly journals Inocybe brijunica sp. nov., a New Ectomycorrhizal Fungus from Mediterranean Croatia Revealed by Morphology and Multilocus Phylogenetic Analysis

2021 ◽  
Vol 7 (3) ◽  
pp. 199
Author(s):  
Armin Mešić ◽  
Danny Haelewaters ◽  
Zdenko Tkalčec ◽  
Jingyu Liu ◽  
Ivana Kušan ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
National Park ◽  
Hot Spot ◽  
Phylogenetic Reconstruction ◽  
Ectomycorrhizal Fungus ◽  
Alkaline Solutions ◽  
Rrna Gene ◽  
28S Rrna ◽  
Internal Transcribed Spacer Region ◽  
Biogeographical Region

A new ectomycorrhizal species was discovered during the first survey of fungal diversity at Brijuni National Park (Croatia), which consists of 14 islands and islets. The National Park is located in the Mediterranean Biogeographical Region, a prominent climate change hot-spot. Inocybe brijunica sp. nov., from sect. Hysterices (Agaricales, Inocybaceae), is described based on morphology and multilocus phylogenetic data. The holotype collection was found at the edge between grassland and Quercus ilex forest with a few planted Pinus pinea trees, on Veli Brijun Island, the largest island of the archipelago. It is easily recognized by a conspicuous orange to orange–red–brown membranaceous surface layer located at or just above the basal part of the stipe. Other distinctive features of I. brijunica are the medium brown, radially fibrillose to rimose pileus; pale to medium brown stipe with fugacious cortina; relatively small, amygdaliform to phaseoliform, and smooth basidiospores, measuring ca. 6.5–9 × 4–5.5 µm; thick-walled, utriform, lageniform or fusiform pleurocystidia (lamprocystidia) with crystals and mostly not yellowing in alkaline solutions; cheilocystidia of two types (lamprocystidia and leptocystidia); and the presence of abundant caulocystidia only in the upper 2–3 mm of the stipe. Phylogenetic reconstruction of a concatenated dataset of the internal transcribed spacer region (ITS), the nuclear 28S rRNA gene (nrLSU), and the second largest subunit of RNA polymerase II (rpb2) resolved I. brijunica and I. glabripes as sister species.

scholarly journals Real-Time PCR Assay for Detection and Enumeration of Dekkera bruxellensis in Wine

2003 ◽  
Vol 69 (12) ◽  
pp. 7430-7434 ◽  
Author(s):  
Trevor G. Phister ◽  
David A. Mills
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Pcr Primers ◽  
Rrna Gene ◽  
Dekkera Bruxellensis ◽  
Pcr Assay ◽  
Specific Pcr ◽  
Spoilage Yeast ◽  
Pcr Method ◽  
26S Rrna

ABSTRACT Traditional methods to detect the spoilage yeast Dekkera bruxellensis from wine involve lengthy enrichments. To overcome this difficulty, we developed a quantitative real-time PCR method to directly detect and enumerate D. bruxellensis in wine. Specific PCR primers to D. bruxellensis were designed to the 26S rRNA gene, and nontarget yeast and bacteria common to the winery environment were not amplified. The assay was linear over a range of cell concentrations (6 log units) and could detect as little as 1 cell per ml in wine. The addition of large amounts of nontarget yeasts did not impact the efficiency of the assay. This method will be helpful to identify possible routes of D. bruxellensis infection in winery environments. Moreover, the time involved in performing the assay (3 h) should enable winemakers to more quickly make wine processing decisions in order to reduce the threat of spoilage by D. bruxellensis.

scholarly journals Water quality and antifungal susceptibility of opportunistic yeast pathogens from rivers

2016 ◽  
Vol 75 (6) ◽  
pp. 1319-1331 ◽  
Author(s):  
M. E. Monapathi ◽  
C. C. Bezuidenhout ◽  
O. H. J. Rhode
Keyword(s):  
Water Quality ◽  
Antifungal Susceptibility ◽  
Principal Component ◽  
Water Sources ◽  
Health Concern ◽  
Rrna Gene ◽  
Biochemical Tests ◽  
Livestock Farming ◽  
Physico Chemical ◽  
26S Rrna

Yeasts from water sources have been associated with diseases ranging from superficial mucosal infections to life threatening diseases. The aim of this study was to determine the water quality as well as diversity and antifungal susceptibility of yeasts from two rivers. Yeast levels and physico-chemical parameter data were analyzed by principal component analysis to determine correlations between physico-chemical data and yeast levels. Yeast morphotypes were identified by biochemical tests and 26S rRNA gene sequencing. Disk diffusion antifungal susceptibility tests were conducted. Physico-chemical parameters of the water were within target water quality range (TWQR) for livestock farming. For irrigational use, total dissolved solids and nitrates were not within the TWQR. Yeast levels ranged between 27 ± 10 and 2,573 ± 306 cfu/L. Only non-pigmented, ascomycetous yeasts were isolated. Saccharomyces cerevisiae and Candida glabrata were most frequently isolated. Several other opportunistic pathogens were also isolated. A large number of isolates were resistant to azoles, especially fluconazole, but also to other antifungal classes. Candida species were resistant to almost all the antifungal classes. These water sources are used for recreation and religious as well as for watering livestock and irrigation. Of particular concern is the direct contact of individuals with opportunistic yeast, especially the immune-compromised. Resistance of these yeast species to antifungal agents is a further health concern.

scholarly journals Multiplex End-Point PCR for the Detection of Three Species of Ophiosphaerella Causing Spring Dead Spot of Bermudagrass

Plant Disease ◽  
2019 ◽  
Vol 103 (8) ◽  
pp. 2010-2014 ◽  
Author(s):  
J. Francisco Iturralde Martinez ◽  
Francisco J. Flores ◽  
Alma R. Koch ◽  
Carla D. Garzón ◽  
Nathan R. Walker
Keyword(s):  
Rna Polymerase Ii ◽  
Elongation Factor ◽  
Temperature Cycling ◽  
Molecular Technique ◽  
Correct Identification ◽  
Internal Transcribed Spacer Region ◽  
Spring Dead Spot ◽  
End Point ◽  
Specificity And Sensitivity ◽  
Species Specific

A multiplex end-point polymerase chain reaction (PCR) assay was developed for identifying the three-fungal species in the genus Ophiosphaerella that cause spring dead spot (SDS), a devastating disease of bermudagrass. These fungi are difficult to identify by morphology because they seldom produce pseudothecia. To achieve species-specific diagnosis, three pairs of primers were designed to identify fungal isolates and detect the pathogen in infected roots. The internal transcribed spacer region, the translation elongation factor 1-α, and the RNA polymerase II second-largest subunit were selected as targets and served as templates for the design of each primer pair. To achieve uniform melting temperatures, three to five random nucleotide extensions (flaps) were added to the 5′ terminus of some of the designed specific primers. Temperature cycling conditions and PCR components were standardized to optimize specificity and sensitivity of the multiplex reaction. Primers were tested in multiplex on DNA extracted from axenic fungal cultures and from field-collected infected and uninfected roots. A distinct amplicon was produced for each Ophiosphaerella sp. tested. The DNA from Ophiosphaerella close relatives and other common bermudagrass pathogens did not amplify during the multiplex assay. Metagenomic DNA from infected bermudagrass produced species-specific amplicons while DNA extracted from noninfected roots did not. This multiplex end-point PCR approach is a sensitive and specific molecular technique that allows for correct identification of SDS-associated Ophiosphaerella spp. from field-collected roots.

scholarly journals Production and Optimization of Xylanase and α-Amylase from Non-Saccharomyces Yeasts (Pichia membranifaciens)

2021 ◽  
pp. 452-461
Author(s):  
Hala A. Salah ◽  
Hanan A. Temerk ◽  
Nivin A. Salah ◽  
Saeed Rafa Zara Alshehri ◽  
Jazi A. Al-Harbi ◽  
...  
Keyword(s):  
Culture Medium ◽  
Potato Starch ◽  
Pcr Amplification ◽  
Soluble Starch ◽  
Relative Activity ◽  
Rrna Gene ◽  
Pichia Membranifaciens ◽  
Ph Values ◽  
26S Rrna ◽  
Saccharomyces Yeasts

The xylanolytic and amylolytic yeasts were qualitatively determined by Cong red xylan agar and soluble starch agar plates, respectively. The most xylanase and α-amylase inducible strain (AUN-02) was selected and identified using PCR amplification of 26S rRNA gene and sequence analysis. The comparison of the alignment results and phylogenetic analysis of the sequences of the isolated yeast to published rRNA gene sequences in GenBank, confirmed the identification of the isolate as Pichia membranifaciens. Xylanase and α-amylase production by isolated P. membranifaciens were investigated at different pH values (4-8), temperature degrees (20-45°C), incubation time (1-7 days) and various substrates.A higher production of xylanase (38.8 U/mL) and a-amylase (28.7 U/mL) was obtained after 4 days of fermentation of P. membranifaciens. Higher activity of xylanase (36.83 U/mL) and a-amylase (27.7 U/mL) was obtained in the fermentation of P. membranifaciens in a culture medium adjusted to pH 7.0. The optimum temperature showed maximum xylanase and a-amylase activity (42.6 and 32.5 units/mL, respectively) was estimated at 35 °C. The xylanase and a-amylase activities of P. membranifaciens were estimated and compared for the different substrates tested. The strain revealed 100% relative activity of xylanase and a-amylase on beechwood and potato starch, respectively. The affinity of enzymes towards substrate was estimated using Km values. The Km values of xylanase and α-amylase increased in the order of pH’s 7.0, 6.0 and 4.5 (0.85, 1.6 and 3.4 mg xylan/mL and 0.22, 0.43 and 2.8 mg starch/mL, respectively). the yeast P. membranifaciensis is suitable for produce neutral xylanase and α-amylase enzymes. So, it could be used as a promising strain for production of these enzymes in industrial field.

scholarly journals Occurrence and molecular characterization of cyst nematode species (Globodera spp.) associated with potato crops in Colombia

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0241256
Author(s):  
Daniela Vallejo ◽  
Diego A. Rojas ◽  
John A. Martinez ◽  
Sergio Marchant ◽  
Claudia M. Holguin ◽  
...  
Keyword(s):  
Management Strategies ◽  
Nematode Species ◽  
Globodera Pallida ◽  
Rrna Gene ◽  
Potato Cyst Nematodes ◽  
28S Rrna ◽  
Cyst Nematodes ◽  
Nucleotide Substitutions ◽  
Internal Transcribed Spacer Region ◽  
The Status

Potato cyst nematodes (PCN) from the genus Globodera spp. cause major losses in the potato (Solanum tuberosum) industry worldwide. Despite their importance, at present little is known about the status of this plant pathogen in cultivated potatoes in Colombia. In this study, a total of 589 samples collected from 75 geographic localities in nine potato producing regions of Colombia (Cundinamarca, Boyacá, Antioquia, Nariño, Santander, Norte de Santander, Tolima, Caldas and Cauca) were assayed for the presence of potato cyst nematodes. Fifty-seven percent of samples tested positive for PCN. Based on phylogenetic analysis of the internal transcribed spacer region (ITS1-5.8S-ITS2) of the rRNA gene and D2-D3 expansion segments of the 28S rRNA gene, all populations but one were identified as Globodera pallida. Sequences of G. pallida from Colombia formed a monophyletic group closely related to Peruvian populations, with the lowest average number of nucleotide substitutions per site (Dxy = 0.002) and net nucleotide substitutions per site (Da = 0.001), when compared to G. pallida populations from Europe, South and North America. A single sample formed a well-supported subclade along with G. rostochiensis and G. tabacum from Japan, USA and Argentina. To our knowledge this is the first comprehensive survey of Globodera populations from Colombia that includes genetic data. Our findings on species diversity and phylogenetic relationships of Globodera populations from Colombia may help elucidate the status and distribution of Globodera species, and lead to the development of accurate management strategies for the potato cyst nematodes.

scholarly journals Yeasts Associated with Various Amazonian Native Fruits

2020 ◽  
Vol 69 (3) ◽  
pp. 251-261
Author(s):  
CARLOS VEGAS ◽  
AMPARO I. ZAVALETA ◽  
PAMELA E. CANALES ◽  
BRAULIO ESTEVE-ZARZOSO
Keyword(s):  
Fragment Length Polymorphism ◽  
Lipolytic Activity ◽  
Debaryomyces Hansenii ◽  
Its Region ◽  
Rrna Gene ◽  
Yeast Strains ◽  
Citrus Medica ◽  
Amazonian Rainforest ◽  
Phenotypic Methods ◽  
26S Rrna

Yeasts, commonly present on the surface of fruits, are of industrial interest for the production of enzymes, flavorings, and bioactive compounds, and have many other scientific uses. The Amazonian rainforest may be a good source of new species or strains of yeasts, but their presence on Amazonian fruits is unknown. The aim of this study was to identify and characterize yeasts isolated from Amazonian native fruits using molecular and phenotypic methods. In total, 81 yeast isolates were obtained from 10 fruits species. Rep-PCR showed 29 strain profiles. Using a combination of restriction-fragment length polymorphism (RFLP) of the 5.8S-ITS region and D1/D2 sequencing of the 26S rRNA gene, 16 species were identified belonging to genera Candida, Debaryomyces, Hanseniaspora, Kodamaea, Martiniozyma, and Meyerozyma. The most dominant species were Candida tropicalis, Debaryomyces hansenii, Hanseniaspora opuntiae, and Hanseniaspora thailandica. H. opuntiae and H. thailandica showed the highest number of the strain profiles. Phenotypic profiles were variable between species, and even among strains. Screening for hydrolases showed lipolytic activity in only one isolate, while proteolytic, cellulolytic and amylolytic capabilities were not detected. Yeast presence among fruits varied, with cidra (Citrus medica) and ungurahui (Oenocarpus bataua) having the highest number of species associated. This investigation broadens the understanding and possible biotechnological uses of yeast strains obtained from Amazonian native fruits.

Sign in / Sign up

Export Citation Format

Share Document