scholarly journals Yeast Biodiversity in Fermented Doughs and Raw Cereal Matrices and the Study of Technological Traits of Selected Strains Isolated in Spain

2020 ◽  
Vol 9 (1) ◽  
pp. 47
Author(s):  
Rosana Chiva ◽  
Lorena Celador-Lera ◽  
José Antonio Uña ◽  
Ana Jiménez-López ◽  
María Espinosa-Alcantud ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Yeast Species ◽  
Dough Rheology ◽  
Phenotypic Traits ◽  
Fermentation Time ◽  
Yeast Strains ◽  
Wide Range ◽  
Wild Strains ◽  
Food Matrices ◽  
Comprehensive Study

Bakers use pure microorganisms and/or traditional sourdoughs as the leavening agent for making bread. The performance of each starter and the substances produced by the microorganisms greatly affect the dough rheology and features of breads. Modern sourdoughs inoculated with selected lactic acid bacteria and yeasts are microbiologically stable, safer than traditional sourdoughs, and easy to use. However, the commercial repertoire of baker’s yeasts is still limited. Therefore, there is a demand for new strains of yeast species, capable of conferring distinctive traits to breads made from a variety of agri-food matrices, in the design of innovative starters. In this context, we report the first comprehensive study on yeasts isolated from a wide range of fermented doughs, cereal flours, and grains of Spain. Nine yeast species were identified from 433 isolates, which were distributed among separate clades. Moreover, phenotypic traits of potential technological relevance were identified in selected yeast strains. Mother doughs (MDs) showed the greatest yeast biodiversity, whereas commercial Saccharomyces starters or related and wild strains often dominated the bakery doughs. A metataxonomic analysis of wheat and tritordeum MDs revealed a greater richness of yeast species and percentage variations related to the consistency, flour type, and fermentation time of MDs.

scholarly journals Candida cabralensis sp. nov., a yeast species isolated from traditional Spanish blue-veined Cabrales cheese

2010 ◽  
Vol 60 (11) ◽  
pp. 2671-2674 ◽  
Author(s):  
Ana Belén Flórez ◽  
Carmela Belloch ◽  
Pablo Álvarez-Martín ◽  
Amparo Querol ◽  
Baltasar Mayo
Keyword(s):  
Lactic Acid ◽  
Yeast Species ◽  
Rrna Gene ◽  
The Novel ◽  
Physiological Characterization ◽  
Yeast Strains ◽  
Unknown Species ◽  
Traditional Cheese ◽  
26S Rrna ◽  
Cabrales Cheese

Three yeast strains, 1AD8T, 3AD15 and 3AD23, belonging to a previously unknown yeast species were isolated from two independent batches of the Spanish blue-veined Cabrales cheese, a traditional cheese manufactured without the addition of starter and mould cultures. Physiological characterization revealed that the unknown yeast is not fermentative and does not assimilate lactose; rather it assimilates dl-lactic acid and ethanol, major end products of lactic acid bacteria metabolism in cheese. The novel yeast is anamorphic. Phylogenetic tree reconstruction based on nucleotide sequence comparison of the D1/D2 region of the 26S rRNA gene showed that Pichia terricola and Pichia fermentans are the closest relatives of the unknown species. The name Candida cabralensis sp. nov. is proposed, and the isolate 1AD8T (=CECT 13027T =CBS 11679T) is the type strain of this novel taxon.

scholarly journals Yeasts producing zeatin

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6474 ◽  
Author(s):  
Rostislav A. Streletskii ◽  
Aleksey V. Kachalkin ◽  
Anna M. Glushakova ◽  
Andrey M. Yurkov ◽  
Vladimir V. Demin
Keyword(s):  
Plant Hormone ◽  
Yeast Species ◽  
The Arctic ◽  
Alpine Zone ◽  
Yeast Strains ◽  
Dry Biomass ◽  
Screening Study ◽  
Sporobolomyces Roseus ◽  
Wild Strains ◽  
Temperate Climates

The present paper describes the first screening study of the ability of natural yeast strains to synthesize in culture the plant-related cytokine hormone zeatin, which was carried out using HPLC-MS/MS. A collection of 76 wild strains of 36 yeast species (23 genera) isolated from a variety of natural substrates was tested for the production of zeatin using HPLC-MS/MS. Zeatin was detected in more than a half (55%) of studied strains and was more frequently observed among basidiomycetous than ascomycetous species. The amount of zeatin accumulated during the experiment varied among species and strains. Highest zeatin values were recorded for basidiomyceteSporobolomyces roseusand ascomyceteTaphrinasp. that produced up to 8,850.0 ng and 5,166.4 ng of zeatin per g of dry biomass, respectively. On average, the ability to produce zeatin was more pronounced among species isolated from the arctic-alpine zone than among strains from tropical and temperate climates. Our study also demonstrated that epiphytic strains and pigmented yeast species, typically for phyllosphere, are able to more often produce a plant hormone zeatin than other yeasts.

scholarly journals Candida baotianmanensis sp. nov. and Candida pseudoviswanathii sp. nov., two ascosporic yeast species isolated from the gut of beetles

2015 ◽  
Vol 65 (Pt_10) ◽  
pp. 3580-3585 ◽  
Author(s):  
Yong-Cheng Ren ◽  
Long-Long Xu ◽  
Lin Zhang ◽  
Feng-Li Hui
Keyword(s):  
Type Strain ◽  
Yeast Species ◽  
Novel Species ◽  
Phenotypic Traits ◽  
Rrna Gene ◽  
Candida Maltosa ◽  
Yeast Strains ◽  
Lsu Rrna Gene ◽  
Candida Viswanathii ◽  
Lsu Rrna

Four yeast strains were isolated from the gut of beetles collected on Baotianman Mountain and People's Park of Nanyang in Henan Province, China. These strains produced unconjugated asci with one or two ellipsoidal to elongate ascospores in a persistent ascus. Phylogenetic analysis of the D1/D2 domains of the LSU rRNA gene sequences indicated that the isolates represent two novel sexual species in the Candida/Lodderomyces clade. Candida baotianmanensis sp. nov. was located in a statistically well-supported branch together with Candida maltosa. Candida pseudoviswanathii sp. nov. formed a subclade with its closest relative Candida viswanathii supported by a strong bootstrap value. The two novel species were distinguished from their most closely related described species, Candida maltosa and Candida viswanathii, in the D1/D2 LSU rRNA gene and internal transcribed spacer (ITS) sequences and in phenotypic traits. The type strain of Candida baotianmanensis sp. nov. is NYNU 14719T ( = CBS 13915T = CICC 33052T), and the type strain of Candida pseudoviswanathii sp. nov. is NYNU 14772T ( = CBS 13916T = CICC 33053T). The MycoBank numbers for Candida baotianmanensis sp. nov. and Candida pseudoviswanathii sp. nov. are MB 812621 and MB 812622.

scholarly journals Brewers’ spent grain as substrate for dextran biosynthesis by Leuconostoc pseudomesenteroides DSM20193 and Weissella confusa A16

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Prabin Koirala ◽  
Ndegwa Henry Maina ◽  
Hanna Nihtilä ◽  
Kati Katina ◽  
Rossana Coda
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Raw Materials ◽  
Degree Of Polymerization ◽  
Raw Material ◽  
Fermentation Time ◽  
Viscosity Increase ◽  
Spent Grain ◽  
Leuconostoc Pseudomesenteroides ◽  
Weissella Confusa

Abstract Background Lactic acid bacteria can synthesize dextran and oligosaccharides with different functionality, depending on the strain and fermentation conditions. As natural structure-forming agent, dextran has proven useful as food additive, improving the properties of several raw materials with poor technological quality, such as cereal by-products, fiber-and protein-rich matrices, enabling their use in food applications. In this study, we assessed dextran biosynthesis in situ during fermentation of brewers´ spent grain (BSG), the main by-product of beer brewing industry, with Leuconostoc pseudomesenteroides DSM20193 and Weissella confusa A16. The starters performance and the primary metabolites formed during 24 h of fermentation with and without 4% sucrose (w/w) were followed. Results The starters showed similar growth and acidification kinetics, but different sugar utilization, especially in presence of sucrose. Viscosity increase in fermented BSG containing sucrose occurred first after 10 h, and it kept increasing until 24 h concomitantly with dextran formation. Dextran content after 24 h was approximately 1% on the total weight of the BSG. Oligosaccharides with different degree of polymerization were formed together with dextran from 10 to 24 h. Three dextransucrase genes were identified in L. pseudomesenteroides DSM20193, one of which was significantly upregulated and remained active throughout the fermentation time. One dextransucrase gene was identified in W. confusa A16 also showing a typical induction profile, with highest upregulation at 10 h. Conclusions Selected lactic acid bacteria starters produced significant amount of dextran in brewers’ spent grain while forming oligosaccharides with different degree of polymerization. Putative dextransucrase genes identified in the starters showed a typical induction profile. Formation of dextran and oligosaccharides in BSG during lactic acid bacteria fermentation can be tailored to achieve specific technological properties of this raw material, contributing to its reintegration into the food chain.

scholarly journals Controlling Teleportation-Based Locomotion in Virtual Reality with Hand Gestures: A Comparative Evaluation of Two-Handed and One-Handed Techniques

Electronics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 715
Author(s):  
Alexander Schäfer ◽  
Gerd Reis ◽  
Didier Stricker
Keyword(s):  
Virtual Reality ◽  
Virtual Worlds ◽  
User Preferences ◽  
Interaction Techniques ◽  
Hand Gestures ◽  
Wide Range ◽  
Effectiveness And Efficiency ◽  
High Degree ◽  
Additional Hardware ◽  
Comprehensive Study

Virtual Reality (VR) technology offers users the possibility to immerse and freely navigate through virtual worlds. An important component for achieving a high degree of immersion in VR is locomotion. Often discussed in the literature, a natural and effective way of controlling locomotion is still a general problem which needs to be solved. Recently, VR headset manufacturers have been integrating more sensors, allowing hand or eye tracking without any additional required equipment. This enables a wide range of application scenarios with natural freehand interaction techniques where no additional hardware is required. This paper focuses on techniques to control teleportation-based locomotion with hand gestures, where users are able to move around in VR using their hands only. With the help of a comprehensive study involving 21 participants, four different techniques are evaluated. The effectiveness and efficiency as well as user preferences of the presented techniques are determined. Two two-handed and two one-handed techniques are evaluated, revealing that it is possible to move comfortable and effectively through virtual worlds with a single hand only.

scholarly journals Relationship between the Stereocomplex Crystallization Behavior and Mechanical Properties of PLLA/PDLA Blends

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1851
Author(s):  
Hye-Seon Park ◽  
Chang-Kook Hong
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Crystallization Behavior ◽  
Mechanical Analysis ◽  
X Ray Diffraction ◽  
Nucleation Agent ◽  
Scanning Calorimetry ◽  
Nucleation Sites ◽  
Wide Range ◽  
Degree Of Crystallization

Poly (l-lactic acid) (PLLA) is a promising biomedical polymer material with a wide range of applications. The diverse enantiomeric forms of PLLA provide great opportunities for thermal and mechanical enhancement through stereocomplex formation. The addition of poly (d-lactic acid) (PDLA) as a nucleation agent and the formation of stereocomplex crystallization (SC) have been proven to be an effective method to improve the crystallization and mechanical properties of the PLLA. In this study, PLLA was blended with different amounts of PDLA through a melt blending process and their properties were calculated. The effect of the PDLA on the crystallization behavior, thermal, and mechanical properties of PLLA were investigated systematically by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), polarized optical microscopy (POM), dynamic mechanical analysis (DMA), and tensile test. Based on our findings, SC formed easily when PDLA content was increased, and acts as nucleation sites. Both SC and homo crystals (HC) were observed in the PLLA/PDLA blends. As the content of PDLA increased, the degree of crystallization increased, and the mechanical strength also increased.

P0031AURINE METABOLOMICS: AN EMERGING TOOL FOR DISSECTING BIOLOGICAL ABERRATIONS UNDERLYING RENAL DYSFUNCTION IN BARDET-BIEDL SYNDROME

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Miriam Zacchia ◽  
Emanuela Marchese ◽  
Marianna Caterino ◽  
Margherita Ruoppolo ◽  
Giovambattista Capasso
Keyword(s):  
Lactic Acid ◽  
Kidney Disease ◽  
Renal Disease ◽  
Renal Dysfunction ◽  
Metabolic Pathways ◽  
Healthy Subjects ◽  
Hexadecenoic Acid ◽  
Kidney Dysfunction ◽  
Bardet Biedl Syndrome ◽  
Wide Range

Abstract Background and Aims Bardet Biedl Syndrome (BBS) is a rare genetic disorder characterized by a wide range of organ dysfunction, including kidney disease. The severity of renal dysfunction is highly variable in this setting, ranging from tubular defects to the end stage renal disease, with poor genotype-phenotype correlation. Proteomics and metabolomics are powerful tools able to contribute to the better understanding of molecular basis of disease conditions. Our previous studies demonstrated that the urinary proteomic pattern of BBS patients differed from that of healthy subjects, with a set of deregulated proteins including cell adhesion and extracellular matrix organization proteins (1). The present study aims to characterize urine metabolomic profile of BBS patients, in order to identify both 1) potential disease biomarkers and 2) aberrant metabolic pathways underlying renal disease Method To this end, in the pilot study urine samples have been collected from 14 adult BBS patients and have been compared with healthy volunteers, using an untargeted strategy. In the confirmation study, 24 BBS patients with wide range of kidney dysfunction have been enrolled, and additional control groups, besides healthy subjects, were included: 1) age-gender-matched chronic kidney disease patients by other causes and 2) obese individuals. Results Several metabolites were de-regulated in BBS patients compared with normal subjects (lactic acid, glycolic acid,3-Hydroxypropionic acid, pyruvic acid, 3-hydroxyisobutyric acid, 2-ethyl-3-hydroxy-propionic acid, succinic acid, fumaric acid, erythropentonic acid, 2-hydroxyglutaric acid, 4-hydroxyphenyllactic acid, 3,4-pyridinedicarboxylic acid, retinoic acid, 4-hydroxyphenylacetic acid, palmitic acid, 9-Hexadecenoic acid, oleic acid and 9-Octadecenoic acid). The clusterization performed by MetaboAnalyst tool, revealed a possible deregulation of different metabolic pathways, including glycolysis, TCA cycle, pyruvate metabolism, lipids biosynthesis and glutamate metabolism (p-value <0.01) (figure 1); some of these pathways were described as de-regulated in other ciliopathies (2). In the confirmation study (on-going studies) some metabolites, including lactic acid and intermediates of Krebs cycle, correlated with kidney dysfunction only in the BBS group. Conclusion These findings suggest that urine metabolomic fingerprint of BBS patients is different from that of healthy subjects and indicate a possible deregulation of several metabolic pathways; some urinary molecules correlated with kidney dysfunction only in BBS patients, suggesting the specificity of these results.

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