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The emergence of pathogenic bacteria that are multi-resistant to antibiotics lurks in today's society. In the golden age of the discovery of new antibiotic-producing microorganisms, each contribution was a step forward, but currently the progression is no longer so spectacular. The probability of finding new microorganisms and different antibiotics is lower and lower. The use of spatial statistical methods such as the Kriging technique has been shown to be suitable for this purpose, allowing us to determine areas with greater possibilities of locating these microorganisms. For a practical approach of our estimations, a total of 12 isolates capable of inhibiting the growth of several control strains (Escherichia coli, Bacillus cereus and at least one other) were analyzed. The isolates were preliminarily characterized, and subsequently identified at the species level by DNA sequence analyses (16S rDNA PCR) and protein analyses (MALDI-TOF MS). However, between soil pH values and the number of isolates capable of inhibiting the control strains. Geospatial mapping with RStudio software provide a satisfactory predictive tool for isolation of new microbial isolates.
Sergi Maicas; Jaume Segura-Garcia. Spatial distribution of antibiotic-producing bacteria in urban areas. A case study in Valencia (Spain). IEEE/ACM Transactions on Computational Biology and Bioinformatics 2020, PP, 1 -1.
AMA StyleSergi Maicas, Jaume Segura-Garcia. Spatial distribution of antibiotic-producing bacteria in urban areas. A case study in Valencia (Spain). IEEE/ACM Transactions on Computational Biology and Bioinformatics. 2020; PP (99):1-1.
Chicago/Turabian StyleSergi Maicas; Jaume Segura-Garcia. 2020. "Spatial distribution of antibiotic-producing bacteria in urban areas. A case study in Valencia (Spain)." IEEE/ACM Transactions on Computational Biology and Bioinformatics PP, no. 99: 1-1.
Antibiotic misuse is a public health problem due to the appearance of resistant strains in almost all human pathogens, making infectious diseases more difficult to treat. The search for solutions requires the development of new antimicrobials as well as novel strategies, including increasing social awareness of the problem. The Small World Initiative (SWI) and the Tiny Earth (TE) network are citizen science programs pursuing the discovery of new antibiotics from soil samples and the promotion of scientific culture. Both programs aim to bring scientific culture and microbiological research closer to pre-university students through a crowdsourcing strategy and a Service Learning (SL) educational approach, with a 2-fold objective: to encourage students to pursue careers in science and to involve them in the discovery of soil microorganisms producing new antimicrobials. SWI and TE projects were put into practice in Spain under the common name MicroMundo. [email protected] was implemented at the Universitat de València (UV) during the academic years 2017–2018 and 2018–2019. It trained 140 university students to disseminate this initiative into 23 high/secondary schools, and one primary school, involving about 900 people (teachers and students) as researchers. A total of 7,002 bacterial isolates were obtained from 366 soil samples and tested for antibiosis at UV and high/secondary school centers. About 1 or 7% of them produced inhibition halos for the Escherichia coli or Bacillus cereus target strains, respectively. Geolocation of sampling sites by an application developed ad hoc and Kriging analysis also allowed detection of soil foci of antibiotic-producing bacteria. Evaluation of the project by university, high/secondary, and primary school students revealed their strong positive perception and their increased interest in science, as a consequence of acquiring new scientific and pedagogical concepts and skills that they were able to pass on to other classmates, younger students, or relatives. To further expand the dissemination of the project in the Valencian Community, diverse extramural activities deemed to include a gender perspective and aimed at different age groups, were also carried out, obtaining very satisfactory results, increasing sensitivity and awareness to the global antibiotic crisis.
Sergi Maicas; Belén Fouz; Àngela Figàs-Segura; Jesús Zueco; Hortensia Rico; Alfonso Navarro; Ester Carbó; Jaume Segura-García; Elena G. Biosca. Implementation of Antibiotic Discovery by Student Crowdsourcing in the Valencian Community Through a Service Learning Strategy. Frontiers in Microbiology 2020, 11, 1 .
AMA StyleSergi Maicas, Belén Fouz, Àngela Figàs-Segura, Jesús Zueco, Hortensia Rico, Alfonso Navarro, Ester Carbó, Jaume Segura-García, Elena G. Biosca. Implementation of Antibiotic Discovery by Student Crowdsourcing in the Valencian Community Through a Service Learning Strategy. Frontiers in Microbiology. 2020; 11 ():1.
Chicago/Turabian StyleSergi Maicas; Belén Fouz; Àngela Figàs-Segura; Jesús Zueco; Hortensia Rico; Alfonso Navarro; Ester Carbó; Jaume Segura-García; Elena G. Biosca. 2020. "Implementation of Antibiotic Discovery by Student Crowdsourcing in the Valencian Community Through a Service Learning Strategy." Frontiers in Microbiology 11, no. : 1.
Allergy is the most common chronic disease in Europe and about 40% of the population suffers from it. Microbiota are closely linked to the immune system, with some probiotics characterized as beneficial, contributing to reductions in allergenic symptomatology. To ensure the predominance of beneficial probiotics in the gut microbiota, the use of prebiotics is very important. Among the most important prebiotics are those of marine origin, particularly the fucoidan, a polysaccharide from brown algae (Phaeophyta). The effect of fucoidan on Lactobacillus reuteri in vitro growth behavior has been studied using turbidimetry, plate count and statistical analysis. The fucoidan revealed a significant prebiotic effect, increasing L. reuteri growth (≈2 Log10 cycles after 48 h exposure). The combination of the prebiotic effect of the fucoidan with the direct action that it exerts on allergy and other health problems make this molecule a promising nutraceutical for future use.
Neus Ricós-Muñoz; Sergi Maicas; María Consuelo Pina-Pérez. Probiotic Lactobacillus Reuteri Growth Improved under Fucoidan Exposure. Proceedings 2020, 70, 106 .
AMA StyleNeus Ricós-Muñoz, Sergi Maicas, María Consuelo Pina-Pérez. Probiotic Lactobacillus Reuteri Growth Improved under Fucoidan Exposure. Proceedings. 2020; 70 (1):106.
Chicago/Turabian StyleNeus Ricós-Muñoz; Sergi Maicas; María Consuelo Pina-Pérez. 2020. "Probiotic Lactobacillus Reuteri Growth Improved under Fucoidan Exposure." Proceedings 70, no. 1: 106.
The enterobacteria that produce β-lactamases are the main focus of infections in the healthcare environment. This is due to the difficulty they present in terms of treatment, their ease of transmission, and the impact they represent at the economic and personal level. The bacteria of greatest clinical relevance are those with resistance to third and fourth generation cephalosporins, extended spectrum β-lactamase and AmpC. Currently, carbapenemics are one of the few antimicrobials effective against multi-drug resistant organisms. However, the emergence of carbapenem-resistant enterobacteria has increased health concerns. These microorganisms include K. pneumoniae, a pan-resistant bacteria with high morbidity and mortality rates in public health facilities. In this work we have carried out a review on the antimicrobial resistance genes found in its genome, as well as the resistance mechanisms involved. Finally, we will focus on the main outbreaks causing nosocomial infections during the last years.
Celeste Moya; Sergi Maicas. Antimicrobial resistance in Klebsiella pneumoniae strains: mechanisms and outbreaks. Proceedings of 1st International Electronic Conference on Microbiology 2020, 1 .
AMA StyleCeleste Moya, Sergi Maicas. Antimicrobial resistance in Klebsiella pneumoniae strains: mechanisms and outbreaks. Proceedings of 1st International Electronic Conference on Microbiology. 2020; ():1.
Chicago/Turabian StyleCeleste Moya; Sergi Maicas. 2020. "Antimicrobial resistance in Klebsiella pneumoniae strains: mechanisms and outbreaks." Proceedings of 1st International Electronic Conference on Microbiology , no. : 1.
Scientific journals have played an essential role in the diffusion of research breakthroughs. For many years there was no competition between journals, but, in recent decades they have become categorized by a careful assessment of their published contents based on several metric parameters. Of greater note, the ‘prestige index’ has become an essential tool used by public and private institutions to develop their scientific policy. Thus, the evaluation of research staffs, the concession of grants or fellowships and even the scholarly reputation and academic positions are mainly founded on a given journal's ‘quality’. As a consequence, the prestige of some journals has gone up, based on the assumption that they publish cutting-edge science, while the reputation of others has gone down. Within the field of Microbiology, we have carried out a direct analysis by monitoring several representative classic journals according to customary metric parameters over 20 years. This analysis also covers another set of journals of recent appearance (novel journals). Although a direct comparison between both groups is not possible, this approach serves to perceive the trends of publication among microbiologists. Our preliminary conclusion is that the continued existence of many so-termed classic journals devoted to Microbiology is seriously threatened.
Sergi Maicas; Ruth Sánchez-Fresneda; Juan-Carlos Argüelles. Trends in Microbiology publications: are classic scientific journals condemned to extinction? FEMS Microbiology Letters 2020, 367, 1 .
AMA StyleSergi Maicas, Ruth Sánchez-Fresneda, Juan-Carlos Argüelles. Trends in Microbiology publications: are classic scientific journals condemned to extinction? FEMS Microbiology Letters. 2020; 367 (17):1.
Chicago/Turabian StyleSergi Maicas; Ruth Sánchez-Fresneda; Juan-Carlos Argüelles. 2020. "Trends in Microbiology publications: are classic scientific journals condemned to extinction?" FEMS Microbiology Letters 367, no. 17: 1.
In recent years, vessels have been discovered that contain the remains of wine with an age close to 7000 years. It is unclear whether, in ancient times, humans accidentally stumbled across fermented beverages like wine or beer, or was it a product intended as such. What is a fact is that since then, alcoholic beverages have been part of the diet and culture of many of the civilizations that have preceded us. The typical examples of beer and wine are an example of many other drinks resulting from the action of yeasts. In addition to these two beverages, various companies have developed other types of fermented foods and non-alcoholic beverages prepared in a traditional or commercial manner. The climatic conditions, the availability of raw material and the preferences of each region have conditioned and favored the maintenance of some of these products. In addition to the aforementioned traditional alcoholic beverages produced from fruits, berries, or grains, humans use yeast in the production of chemical precursors, global food processing such as coffee and chocolate, or even wastewater processing. Yeast fermentation is not only useful in food manufacturing. Its uses extend to other products of high interest such as the generation of fuel from vegetable sources.
Sergi Maicas. The Role of Yeasts in Fermentation Processes. Microorganisms 2020, 8, 1142 .
AMA StyleSergi Maicas. The Role of Yeasts in Fermentation Processes. Microorganisms. 2020; 8 (8):1142.
Chicago/Turabian StyleSergi Maicas. 2020. "The Role of Yeasts in Fermentation Processes." Microorganisms 8, no. 8: 1142.
There a lot of studies including the use of non-Saccharomyces yeasts in the process of wine fermentation. The attention is focused on the first steps of fermentation. However, the processes and changes that the non-Saccharomyces yeast populations may have suffered during the different stages of grape berry ripening, caused by several environmental factors, including antifungal treatments, have not been considered in depth. In our study, we have monitored the population dynamics of non-Saccharomyces yeasts during the ripening process, both with biochemical identification systems (API 20C AUX and API ID 32C), molecular techniques (RFLP-PCR) and enzymatic analyses. Some unusual non-Saccharomyces yeasts have been identified (Metschnikowia pulcherrima, Aureobasidium pullulans, Cryptococcus sp. and Rhodotorula mucilaginosa). These yeasts could be affected by antifungal treatments used in wineries, and this fact could explain the novelty involved in their isolation and identification. These yeasts can be a novel source for novel biotechnological uses to be explored in future work.
José Juan Mateo; Patricia Garcerà; Sergi Maicas. Unusual Non-Saccharomyces Yeasts Isolated from Unripened Grapes without Antifungal Treatments. Fermentation 2020, 6, 41 .
AMA StyleJosé Juan Mateo, Patricia Garcerà, Sergi Maicas. Unusual Non-Saccharomyces Yeasts Isolated from Unripened Grapes without Antifungal Treatments. Fermentation. 2020; 6 (2):41.
Chicago/Turabian StyleJosé Juan Mateo; Patricia Garcerà; Sergi Maicas. 2020. "Unusual Non-Saccharomyces Yeasts Isolated from Unripened Grapes without Antifungal Treatments." Fermentation 6, no. 2: 41.
Wine production is one of the most important agricultural activities around the world. The production of wine involves the use of a large number of valuable resources, such as water, fertilizers, and other organic products. Moreover, it produces a large amount of wastewater and organic waste that must be treated adequately to avoid contaminating the areas of production. The nature of the waste produced depends very closely on the specific vinification procedures, which also affect the physical–chemical properties of the residual material generated, whose characteristics determine its subsequent use and even condition the subsequent specific recovery circuit in which can be integrated.
Sergi Maicas; José Juan Mateo. Sustainability of Wine Production. Sustainability 2020, 12, 559 .
AMA StyleSergi Maicas, José Juan Mateo. Sustainability of Wine Production. Sustainability. 2020; 12 (2):559.
Chicago/Turabian StyleSergi Maicas; José Juan Mateo. 2020. "Sustainability of Wine Production." Sustainability 12, no. 2: 559.
The enterobacteria that produce β-lactamases are the main focus of infections in the healthcare environment. This is due to the difficulty they present in terms of treatment, their ease of transmission, and the impact they represent at the economic and personal level. The bacteria of greatest clinical relevance are those with resistance to third and fourth generation cephalosporins, extended spectrum β-lactamase and AmpC. Currently, carbapenemics are one of the few antimicrobials effective against multi-drug resistant organisms. However, the emergence of carbapenem-resistant enterobacteria has increased health concerns. These microorganisms include K. pneumoniae, a pan-resistant bacteria with high morbidity and mortality rates in public health facilities. In this work, we have carried out a review on the antimicrobial resistance genes found in its genome, as well as the resistance mechanisms involved. Finally, we will focus on the main outbreaks causing nosocomial infections during the last few years.
Celeste Moya; Sergi Maicas. Antimicrobial Resistance in Klebsiella pneumoniae Strains: Mechanisms and Outbreaks. Proceedings 2020, 66, 11 .
AMA StyleCeleste Moya, Sergi Maicas. Antimicrobial Resistance in Klebsiella pneumoniae Strains: Mechanisms and Outbreaks. Proceedings. 2020; 66 (1):11.
Chicago/Turabian StyleCeleste Moya; Sergi Maicas. 2020. "Antimicrobial Resistance in Klebsiella pneumoniae Strains: Mechanisms and Outbreaks." Proceedings 66, no. 1: 11.
Laura Cabello; Estefanía Gómez-Herreros; Jordan Fernández-Pereira; Sergi Maicas; María Concepción Martínez-Esparza; Piet W J De Groot; Eulogio Valentín. Deletion of GLX3 in Candida albicans affects temperature tolerance, biofilm formation and virulence. FEMS Yeast Research 2018, 19, 1 .
AMA StyleLaura Cabello, Estefanía Gómez-Herreros, Jordan Fernández-Pereira, Sergi Maicas, María Concepción Martínez-Esparza, Piet W J De Groot, Eulogio Valentín. Deletion of GLX3 in Candida albicans affects temperature tolerance, biofilm formation and virulence. FEMS Yeast Research. 2018; 19 (2):1.
Chicago/Turabian StyleLaura Cabello; Estefanía Gómez-Herreros; Jordan Fernández-Pereira; Sergi Maicas; María Concepción Martínez-Esparza; Piet W J De Groot; Eulogio Valentín. 2018. "Deletion of GLX3 in Candida albicans affects temperature tolerance, biofilm formation and virulence." FEMS Yeast Research 19, no. 2: 1.
A β-glucosidase-producing strain, Candida adriatica CECT13142, was isolated from olive oil wastes (alpeorujo) and identified by PCR/restriction fragment length polymorphism of the rDNA internal transcribed spacer and sequence analysis of the D1/D2 region of the 26S rRNA gene techniques. The enzyme was purified by sequential chromatography on DEAE-cellulose and Sephadex G-100. The relative molecular mass of the enzyme was estimated to be 50 kDa by SDS-PAGE. The hydrolytic activity of the β-glucosidase had an optimum pH of 8.2 and an optimum temperature of 40°C. The enzyme displayed high substrate specificity and high catalytic efficiency (Km 0.85 mM, Vmax 12.5 U/g of cells) for p-nitrophenyl-β-D-glucopyranoside. Although β-glucosidases have been purified and characterized from several other organisms, the C. adriatica β-glucosidase is able to have optimal activity at alkaline pH.
Sergi Maicas; Joaquín Lilao-Garzón; José Juan Mateo. Characterization of a β-glucosidase isolated from an alpeorujo strain of Candida adriatica. Food Biotechnology 2017, 31, 114 -127.
AMA StyleSergi Maicas, Joaquín Lilao-Garzón, José Juan Mateo. Characterization of a β-glucosidase isolated from an alpeorujo strain of Candida adriatica. Food Biotechnology. 2017; 31 (2):114-127.
Chicago/Turabian StyleSergi Maicas; Joaquín Lilao-Garzón; José Juan Mateo. 2017. "Characterization of a β-glucosidase isolated from an alpeorujo strain of Candida adriatica." Food Biotechnology 31, no. 2: 114-127.
Trehalose is a non-reducing disaccharide highly conserved throughout evolution. In yeasts, trehalose hydrolysis is confined to the enzyme trehalase, an α–glucosidase specific for trehalose as sole substrate. Two kinds of trehalase activity exist in yeasts: neutral and acid enzymes. This review makes a comparative survey of the main biochemical and genetic parameters, regulatory systems, tridimensional structure and catalytic mechanism of the two yeast trehalases. The yeast neutral and acid trehalases display sharp differences in biochemical features (optimum pH, Mr or amino acid sequence) physiological roles, subcellular location (cytosol vs vacuoles or cell wall) and regulatory control (phosphorylation vs catabolite repression). However, their identical specificity for trehalose is based on the presence of an (α/α)6 toroid folding structure in the active centre and a catalytic mechanism of anomeric inversion. This review expands our knowledge of the homology, functional features and catalytic mechanisms of α–glucosidases in yeasts. It provides a further analysis of the correlation between structures and predicted biological roles of macromolecules.
Sergi Maicas; José P. Guirao-Abad; Juan-Carlos Argüelles. Yeast trehalases: Two enzymes, one catalytic mission. Biochimica et Biophysica Acta (BBA) - General Subjects 2016, 1860, 2249 -2254.
AMA StyleSergi Maicas, José P. Guirao-Abad, Juan-Carlos Argüelles. Yeast trehalases: Two enzymes, one catalytic mission. Biochimica et Biophysica Acta (BBA) - General Subjects. 2016; 1860 (10):2249-2254.
Chicago/Turabian StyleSergi Maicas; José P. Guirao-Abad; Juan-Carlos Argüelles. 2016. "Yeast trehalases: Two enzymes, one catalytic mission." Biochimica et Biophysica Acta (BBA) - General Subjects 1860, no. 10: 2249-2254.
The sensorial characteristics of the wines produced with Muscat grapes are related to the level of terpene alcohols, so an improvement of such a level is expected as a result of hydrolytic processes conducted by Hanseniaspora. The aim of this work was to select and identify new strains for this purpose. In a second step, the strains were assayed to evaluate their oenological abilities. H. uvarum H107 and H. vineae G26 and P38 were proven to be good candidates to be used in commercial vinification processes to enhance wine properties. Wine inoculated with yeasts showed an increase in the level of aromatic compounds.
S. López; J.J. Mateo; Sergi Maicas. Characterisation of Hanseniaspora Isolates with Potential Aroma-enhancing Properties in Muscat Wines. South African Journal of Enology and Viticulture 2016, 35, 292 -303.
AMA StyleS. López, J.J. Mateo, Sergi Maicas. Characterisation of Hanseniaspora Isolates with Potential Aroma-enhancing Properties in Muscat Wines. South African Journal of Enology and Viticulture. 2016; 35 (2):292-303.
Chicago/Turabian StyleS. López; J.J. Mateo; Sergi Maicas. 2016. "Characterisation of Hanseniaspora Isolates with Potential Aroma-enhancing Properties in Muscat Wines." South African Journal of Enology and Viticulture 35, no. 2: 292-303.
Winemaking is a complex process involving the interaction of different microbes. The two main groups of microorganisms involved are yeasts and bacteria. The yeasts present in spontaneous fermentation may be divided into two groups: the Saccharomyces yeasts, particularly S. cerevisiae; and the non-Saccharomyces yeasts, which include members of the genera Rhodotorula, Pichia, Candida, Debaryomyces, Metschtnikowia, Hansenula, and Hanseniaspora. S. cerevisiae yeasts are able to convert sugar into ethanol and CO2 via fermentation. They have been used by humans for thousands of years for the production of fermented beverages and foods, including wine. Their enzymes provide interesting organoleptic characteristics in wine. Glycosidases with oenological implications have been widely reported in yeasts, bacteria, and fungi. β-Glucosidase activity is involved in the release of terpenes to wine, thus contributing to varietal aroma. α-Rhamnosidase, α-arabinosidase, or β-apiosidase activities have also been reported to contribute to the wine production process. Oenococcus oeni (a lactic acid bacteria present in wine) also has numerous glycosidases, and their activities contribute to the liberation of several aromatic compounds which contribute to floral and fruity wine characteristics.
Sergi Maicas; José Juan Mateo. Microbial Glycosidases for Wine Production. Beverages 2016, 2, 20 .
AMA StyleSergi Maicas, José Juan Mateo. Microbial Glycosidases for Wine Production. Beverages. 2016; 2 (3):20.
Chicago/Turabian StyleSergi Maicas; José Juan Mateo. 2016. "Microbial Glycosidases for Wine Production." Beverages 2, no. 3: 20.
Winemaking is a complex process involving the interaction of different microbes. The two main groups of microorganisms involved are yeasts and bacteria. Non-Saccharomyces yeasts are present on the grape surface and also on the cellar. Although these yeasts can produce spoilage, these microorganisms could also possess many interesting technological properties which could be exploited in food processing. It has been shown that some of the metabolites that these yeasts produce may be beneficial and contribute to the complexity of the wine and secrete enzymes providing interesting wine organoleptic characteristics. On the other hand, non-Saccharomyces yeasts are the key to obtain wines with reduced ethanol content. Among secreted enzymes, β-glucosidase activity is involved in the release of terpenes to wine, thus contributing to varietal aroma while β-xylosidase enzyme is also interesting in industry due to its involvement in the degradation of hemicellulose by hydrolyzing its main heteroglycan (xylan).
José Juan Mateo; Sergi Maicas. Application of Non-Saccharomyces Yeasts to Wine-Making Process. Fermentation 2016, 2, 14 .
AMA StyleJosé Juan Mateo, Sergi Maicas. Application of Non-Saccharomyces Yeasts to Wine-Making Process. Fermentation. 2016; 2 (4):14.
Chicago/Turabian StyleJosé Juan Mateo; Sergi Maicas. 2016. "Application of Non-Saccharomyces Yeasts to Wine-Making Process." Fermentation 2, no. 4: 14.
Candida albicans Gca1p is a putative glucoamylase enzyme which contains 946 amino acids, 11 putative sites for N-glycosylation and 9 for O-glycosylation. Gca1p was identified in β-mercaptoethanol extracts from isolated cell walls of strain C. albicans SC5314 and it is involved in carbohydrate metabolism. The significance and the role of this protein within the cell wall structure were studied in the corresponding mutants. The homozygous mutant showed that GCA1 was not an essential gene for cell viability. Subsequent phenotypic analysis performed in the mutants obtained did not show significant difference in the behavior of mutant when compared with the wild strain SC5314. Zymoliase, Calcofluor White, Congo red, SDS, caffeine or inorganic compounds did not affect the integrity of the cell wall. No differences were observed when hyphal formation assays were carried out. However, an enzyme assay in the presence of substrate p-nitrophenyl-α-D-glucopyranoside enabled us to detect a significant decrease in glycosidase activity in the mutants compared with the parental strain, revealing the function of Gca1.
Sergi Maicas; Antonio Caminero; José Pedro Martínez; Rafael Sentandreu; Eulogio Valentín. TheGCA1gene encodes a glycosidase-like protein in the cell wall ofCandida albicans. FEMS Yeast Research 2016, 16, 1 .
AMA StyleSergi Maicas, Antonio Caminero, José Pedro Martínez, Rafael Sentandreu, Eulogio Valentín. TheGCA1gene encodes a glycosidase-like protein in the cell wall ofCandida albicans. FEMS Yeast Research. 2016; 16 (4):1.
Chicago/Turabian StyleSergi Maicas; Antonio Caminero; José Pedro Martínez; Rafael Sentandreu; Eulogio Valentín. 2016. "TheGCA1gene encodes a glycosidase-like protein in the cell wall ofCandida albicans." FEMS Yeast Research 16, no. 4: 1.
Some non-Saccharomyces yeasts, including Hanseniaspora, participate in the first stages of wine fermentation. Besides their importance in the wine production process some of these yeasts have been described to be potential producers of hydrolytic enzymes to industrial level. In this work, we pretend to evaluate the technological abilities of the Hanseniaspora strains deposited in the Spanish Type Culture Collection (CECT). First of all, we considered verification of the correct identification of the strains using several miniaturized biochemical systems and molecular techniques (PCR, RFLP and sequencing of the ribosomal D1/D2 region). The results allowed us to verify the correct adscription of the 26 strains included in this study, which exhibited concordant profiles of restriction with one of the three species described in previous studies (H. occidentalis, H. osmophila and H. valbyensis). Some other strains assigned to the species (H. uvarum, H. vineae and H. guilliermondii) showed at least two different profiles. The other objective of this study was to perform an initial screening to characterize both at quantitative and qualitative levels, the ability of these yeasts to produce valuable enzymes for wine fermentation (increase of aroma) and other applications. The more important enzymatic activities detected were β-glucosidase, β-xylosidase, and protease. The HU7, HU8, HV1, HV3, HO2 and HOC1 strains showed high levels of β-glucosidase and β-xylosidase activity, whereas some strains (HG1, HG3, HVA1, HOC 3 and HOC4 were useful for protease production.
Sandra López; José Juan Mateo; Sergi Maicas. Screening of Hanseniaspora Strains for the Production of Enzymes with Potential Interest for Winemaking. Fermentation 2015, 2, 1 .
AMA StyleSandra López, José Juan Mateo, Sergi Maicas. Screening of Hanseniaspora Strains for the Production of Enzymes with Potential Interest for Winemaking. Fermentation. 2015; 2 (4):1.
Chicago/Turabian StyleSandra López; José Juan Mateo; Sergi Maicas. 2015. "Screening of Hanseniaspora Strains for the Production of Enzymes with Potential Interest for Winemaking." Fermentation 2, no. 4: 1.
A double homozygous atc1Δ/atc1Δ/ntc1Δ/ntc1Δ mutant (atc1Δ/ntc1Δ KO) was constructed in the pathogen opportunistic yeast Candida parapsilosis by disruption of the two chromosomal alleles coding for NTC1 gene (encoding a neutral trehalase) in a Cpatc1Δ/atc1Δ background (atc1Δ KO strain, deficient in acid trehalase). The Cpatc1Δ/ntc1Δ KO mutant failed to counteract the inability of Cpatc1Δ cells to metabolize exogenous trehalose and showed a similar growth pattern on several monosaccharides and disaccharides. However, upon prolonged incubation in either rich medium (YPD) or nutrient-starved medium the viability of Cpatc1Δ cells exhibited a sensitive phenotype, which was augmented by further CpNTC1/NTC1 disruption. Furthermore, Cpatc1Δ/ntc1Δ KO cells had difficulty in resuming active growth in fresh YPD. This homozygous mutant also lacked any in vitro measurable trehalase activity, whether acid or neutral, suggesting that a single gene codes for each enzyme. By contrast, in Cpatc1Δ/ntc1Δ KO strain the resistance to oxidative and heat stress displayed by atc1Δ mutant was suppressed. Cpatc1Δ/ntc1Δ KO cells showed a significant decrease in virulence as well as in the capacity to form biofilms. These results point to a major role for acid trehalase (Atc1p) in the pathobiology of C. parapsilosis, whereas the activity of neutral trehalase can only partially counteract Atc1p deficiency. They also support the use of ATC1 and NTC1 genes as interesting antifungal targets.
Ruth Sánchez-Fresneda; José P. Guirao-Abad; María Martínez-Esparza; Sergi Maicas; Eulogio Valentín; Juan-Carlos Argüelles. Homozygous deletion of ATC1 and NTC1 genes in Candida parapsilosis abolishes trehalase activity and affects cell growth, sugar metabolism, stress resistance, infectivity and biofilm formation. Fungal Genetics and Biology 2015, 85, 45 -57.
AMA StyleRuth Sánchez-Fresneda, José P. Guirao-Abad, María Martínez-Esparza, Sergi Maicas, Eulogio Valentín, Juan-Carlos Argüelles. Homozygous deletion of ATC1 and NTC1 genes in Candida parapsilosis abolishes trehalase activity and affects cell growth, sugar metabolism, stress resistance, infectivity and biofilm formation. Fungal Genetics and Biology. 2015; 85 ():45-57.
Chicago/Turabian StyleRuth Sánchez-Fresneda; José P. Guirao-Abad; María Martínez-Esparza; Sergi Maicas; Eulogio Valentín; Juan-Carlos Argüelles. 2015. "Homozygous deletion of ATC1 and NTC1 genes in Candida parapsilosis abolishes trehalase activity and affects cell growth, sugar metabolism, stress resistance, infectivity and biofilm formation." Fungal Genetics and Biology 85, no. : 45-57.
Sergi Maicas; Jose Juan Mateo. Enzyme Contribution of Non-Saccharomyces Yeasts to Wine Production. Universal Journal of Microbiology Research 2015, 3, 17 -25.
AMA StyleSergi Maicas, Jose Juan Mateo. Enzyme Contribution of Non-Saccharomyces Yeasts to Wine Production. Universal Journal of Microbiology Research. 2015; 3 (2):17-25.
Chicago/Turabian StyleSergi Maicas; Jose Juan Mateo. 2015. "Enzyme Contribution of Non-Saccharomyces Yeasts to Wine Production." Universal Journal of Microbiology Research 3, no. 2: 17-25.
José Juan Mateo; Sergi Maicas. Valorization of winery and oil mill wastes by microbial technologies. Food Research International 2015, 73, 13 -25.
AMA StyleJosé Juan Mateo, Sergi Maicas. Valorization of winery and oil mill wastes by microbial technologies. Food Research International. 2015; 73 ():13-25.
Chicago/Turabian StyleJosé Juan Mateo; Sergi Maicas. 2015. "Valorization of winery and oil mill wastes by microbial technologies." Food Research International 73, no. : 13-25.