scholarly journals High Foam Phenotypic Diversity and Variability in Flocculant Gene Observed for Various Yeast Cell Surfaces Present as Industrial Contaminants

Fermentation ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 127
Author(s):  
Catarina M. de Figueiredo ◽  
Daniella H. Hock ◽  
Débora Trichez ◽  
Maria de Lourdes B. Magalhães ◽  
Mario L. Lopes ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Yeast Strain ◽  
Phenotypic Diversity ◽  
Strain Engineering ◽  
Fuel Ethanol ◽  
Invasive Growth ◽  
Foam Formation ◽  
Yeast Strains ◽  
Length Polymorphisms ◽  
Contaminant Yeast

Many contaminant yeast strains that survive inside fuel ethanol industrial vats show detrimental cell surface phenotypes. These harmful effects may include filamentation, invasive growth, flocculation, biofilm formation, and excessive foam production. Previous studies have linked some of these phenotypes to the expression of FLO genes, and the presence of gene length polymorphisms causing the expansion of FLO gene size appears to result in stronger flocculation and biofilm formation phenotypes. We performed here a molecular analysis of FLO1 and FLO11 gene polymorphisms present in contaminant strains of Saccharomyces cerevisiae from Brazilian fuel ethanol distilleries showing vigorous foaming phenotypes during fermentation. The size variability of these genes was correlated with cellular hydrophobicity, flocculation, and highly foaming phenotypes in these yeast strains. Our results also showed that deleting the primary activator of FLO genes (the FLO8 gene) from the genome of a contaminant and highly foaming industrial strain avoids complex foam formation, flocculation, invasive growth, and biofilm production by the engineered (flo8∆::BleR/flo8Δ::kanMX) yeast strain. Thus, the characterization of highly foaming yeasts and the influence of FLO8 in this phenotype open new perspectives for yeast strain engineering and optimization in the sugarcane fuel-ethanol industry.

scholarly journals Cell Surface Phenotypic Diversity and Flocculation Gene Variability in Contaminant Industrial Fuel-Ethanol Yeast Strains Exhibiting Highly Foaming Phenotypes

2021 ◽  
Author(s):  
Catarina M. de Figueiredo ◽  
Daniella H. Hock ◽  
Debora Trichez ◽  
Maria de Lurdes B. Magalhães ◽  
Mario L. Lopes ◽  
...  
Keyword(s):  
Cell Surface ◽  
Biofilm Formation ◽  
Yeast Strain ◽  
Phenotypic Diversity ◽  
Strain Engineering ◽  
Fuel Ethanol ◽  
Invasive Growth ◽  
Foam Formation ◽  
Yeast Strains ◽  
Gene Variability

Many contaminant yeast strains able to survive inside fuel ethanol industrial vats show detrimental cell surface phenotypes, such as filamentation, invasive growth, flocculation, biofilm formation and excessive foam production. Previous studies have linked some of these phenotypes to the expression of FLO genes, and the presence of gene length polymorphisms causing the expansion of FLO gene size appears to result in stronger flocculation and biofilm formation phenotypes. We have performed here a molecular analysis of FLO1 and FLO11 gene polymorphisms present in contaminant strains of S. cerevisae from Brazilian fuel ethanol distilleries showing strong foaming phenotypes during fermentation. The size variability of these genes was correlated with cellular hydrophobicity, flocculation and highly foaming phenotypes in these yeast strains. Our results also show that deleting the major activator of FLO genes (the FLO8 gene) from the genome of a contaminant and highly foaming industrial strain avoids problematic foam formation, flocculation, invasive growth and biofilm production by the engineered (flo8∆::BleR / flo8Δ::kanMX) yeast strain. Thus, the characterization of highly foaming yeasts and the influence of FLO8 in this phenotype opens new perspectives for yeast strain engineering and optimization in the sugarcane fuel-ethanol industry.

Mutation in genes coding for glucose-induced degradation-deficient protein contribute to high malate production in yeast strains No. 28 and No. 77 used for industrial brewing of sake

2021 ◽  
Author(s):  
Hiroaki Negoro ◽  
Atsushi Kotaka ◽  
Hiroki Ishida
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Organic Acids ◽  
Nonsense Mutation ◽  
Yeast Strain ◽  
Homozygous Mutation ◽  
Alcohol Fermentation ◽  
Protein Coding ◽  
Protein Coding Genes ◽  
Yeast Strains

ABSTRACT Saccharomyces cerevisiae produces organic acids including malate during alcohol fermentation. Since malate contributes to the pleasant flavor of sake, high-malate-producing yeast strain No. 28 and No. 77 have been developed by the Brewing Society of Japan. In this study, the genes responsible for the high malate phenotype in these strains were investigated. We had found previously that the deletion of components of the glucose induced degradation-deficient (GID) complex led to high malate production in yeast. Upon examining GID protein-coding genes in yeast strain No. 28 and No. 77, a nonsense homozygous mutation of GID4 in strain No. 28, and of GID2 in strain No. 77, were identified as the cause of high malate production. Furthermore, complementary tests of these mutations indicated that the heterozygous nonsense mutation in GID2 was recessive. In contrast, the heterozygous nonsense mutation in GID4 was considered semi-dominant.

Genotypic and phenotypic diversity of Rhizobium isolated from chickpea (Cicer arietinum L.)

1994 ◽  
Vol 40 (5) ◽  
pp. 345-354 ◽  
Author(s):  
Sarah M. Nour ◽  
Jean-Claude Cleyet-Marel ◽  
Douglas Beck ◽  
Aline Effosse ◽  
Maria P. Fernandez
Keyword(s):  
Cicer Arietinum ◽  
Restriction Fragment ◽  
Fragment Length ◽  
Phenotypic Diversity ◽  
Restriction Fragment Length Polymorphisms ◽  
Enzyme Electrophoresis ◽  
Cicer Arietinum L ◽  
Multilocus Enzyme Electrophoresis ◽  
Length Polymorphisms ◽  
Restriction Fragment Length

The diversity of 16 strains of chickpea-infective rhizobia from various geographical origins was analysed using genotypic and phenotypic approaches. Multilocus enzyme electrophoresis was performed, and restriction fragment length polymorphisms of the amplified 16S+IGS (intergenic spacer) rRNA gene, assimilation of 147 carbon sources, antibiotic resistance, and tolerance to NaCl and extreme pH values and temperatures were tested. These approaches had different discriminating powers. Esterase polymorphisms gave a unique pattern for each strain, allowing this method to be used for strain fingerprinting. Genetic distances between strains were estimated. The three approaches used in this study yielded consistent results. They evidenced high heterogeneity among the strains, and made it possible to classify the strains into two clusters. Isozyme patterns for superoxide dismutase were particularly interesting, since they delineated the same two groups. The phenotypic tests clearly confirmed the existence of two genetic groups on the basis of 11 phenotypic characters. Owing to the large phylogenetic distance between the two groups of strains, the taxonomic status of chickpea-infective strains is discussed.Key words: Rhizobium sp. (Cicer arietinum L.), genetic diversity, multilocus enzyme electrophoresis, restriction fragment length polymorphisms, phenotypic diversity.

Yeast Strain Selection for Fuel Ethanol Production

2020 ◽  
pp. 225-243
Author(s):  
Chandra J. Panchal ◽  
Flavio Cesar Almeida Tavares
Keyword(s):  
Ethanol Production ◽  
Yeast Strain ◽  
Fuel Ethanol ◽  
Strain Selection ◽  
Selection For

scholarly journals Mechanism of Aniline Degradation by Yeast Strain Candida methanosorbosa BP-6

2010 ◽  
Vol 59 (4) ◽  
pp. 311-315 ◽  
Author(s):  
KATARZYNA MUCHA ◽  
EWA KWAPISZ ◽  
URSZULA KUCHARSKA ◽  
ANDRZEJ OKRUSZEK
Keyword(s):  
Succinic Acid ◽  
Filamentous Fungi ◽  
Strong Evidence ◽  
Yeast Strain ◽  
Good Separation ◽  
Muconic Acid ◽  
Enrichment Technique ◽  
Yeast Strains ◽  
Microbiological Methods ◽  
Identification And Quantification

The ability of some bacteria and filamentous fungi to degrade aniline and its derivatives was reported earlier in the literature. However, there was no information about the biodegradation of aniline by yeast strains. The present work is focused on yeast strain Candida methanosorbosa BP-6 which was isolated from the wastewater pool of the old dye factory "Boruta" in Zgierz by enrichment technique and identified by standard microbiological methods. We have found that strain C. methanosorbosa BP-6 readily grows in the presence of aniline and can degrade this substrate. Relatively good separation of peaks corresponding to aniline and its biodegradation intermediates allowed us their identification and quantification by HPLC methodology. We have found that major intermediates of this degradation are: catechol, cis,cis-muconic acid, muconolactone, 3-oxoadipate enol-lactone, 3-oxoadipic acid and succinic acid. Our results provide strong evidence that biodegradation of aniline by the yeast strain C. methanosorbosa BP-6 proceeds according to the intradiolic pathway.

scholarly journals New Lager Brewery Strains Obtained by Crossing Techniques Using Cachaça (Brazilian Spirit) Yeasts

2017 ◽  
Vol 83 (20) ◽  
Author(s):  
Bruna Inez Carvalho Figueiredo ◽  
Margarete Alice Fontes Saraiva ◽  
Paloma Patrick de Souza Pimenta ◽  
Miriam Conceição de Souza Testasicca ◽  
Geraldo Magela Santos Sampaio ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Low Temperature ◽  
Yeast Strain ◽  
Genetically Modified ◽  
Acetate Esters ◽  
Content Type ◽  
Yeast Strains ◽  
Lager Beer ◽  
New Yeast ◽  
Beer Production

ABSTRACT The development of hybrids has been an effective approach to generate novel yeast strains with optimal technological profile for use in beer production. This study describes the generation of a new yeast strain for lager beer production by direct mating between two Saccharomyces cerevisiae strains isolated from cachaça distilleries: one that was strongly flocculent, and the other with higher production of acetate esters. The first step in this procedure was to analyze the sporulation ability and reproductive cycle of strains belonging to a specific collection of yeasts isolated from cachaça fermentation vats. Most strains showed high rates of sporulation, spore viability, and homothallic behavior. In order to obtain new yeast strains with desirable properties useful for lager beer production, we compare haploid-to-haploid and diploid-to-diploid mating procedures. Moreover, an assessment of parental phenotype traits showed that the segregant diploid C2-1d generated from a diploid-to-diploid mating experiment showed good fermentation performance at low temperature, high flocculation capacity, and desirable production of acetate esters that was significantly better than that of one type lager strain. Therefore, strain C2-1d might be an important candidate for the production of lager beer, with distinct fruit traces and originating using a non-genetically modified organism (GMO) approach. IMPORTANCE Recent work has suggested the utilization of hybridization techniques for the generation of novel non-genetically modified brewing yeast strains with combined properties not commonly found in a unique yeast strain. We have observed remarkable traits, especially low temperature tolerance, maltotriose utilization, flocculation ability, and production of volatile aroma compounds, among a collection of Saccharomyces cerevisiae strains isolated from cachaça distilleries, which allow their utilization in the production of beer. The significance of our research is in the use of breeding/hybridization techniques to generate yeast strains that would be appropriate for producing new lager beers by exploring the capacity of cachaça yeast strains to flocculate and to ferment maltose at low temperature, with the concomitant production of flavoring compounds.

scholarly journals Use of Pseudocereals Preferment Made with Aromatic Yeast Strains for Enhancing Wheat Bread Quality

Foods ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 443 ◽  
Author(s):  
Păucean ◽  
Man ◽  
Chiş ◽  
Mureşan ◽  
Pop ◽  
...  
Keyword(s):  
Yeast Strain ◽  
Wine Yeast ◽  
Wheat Bread ◽  
Bakery Products ◽  
Total Polyphenols ◽  
White Wheat ◽  
Yeast Strains ◽  
Wine Yeast Strain ◽  
Nutritional Qualities ◽  
Beer Yeast

Usually, aromatic yeasts are designed to ferment wheat substrates for baking purposes but identification of new substrates for these strains and consequently new formulations for dough could lead to diversified bakery products with improved nutritional qualities and specific sensorial properties. The purpose of our study was to optimize the fermentation of quinoa and amaranth flours with non-conventional yeast strains in order to obtain a preferment with high potential in enhancing nutritional, textural and sensorial features of white wheat bread. Two biotypes of Saccharomyces cerevisiae yeast—a wine yeast strain and a beer yeast strain—commercialized for their aromatic properties were used. Both aromatic yeast strains revealed good performance on fermenting pseudocereal substrates. Utilization of the obtained preferment in white wheat breadmaking led to bread with higher protein, fibres, mineral, total polyphenols content, with specific texture and aroma profile and high consumers’ acceptability.

scholarly journals Differential Proteome Analysis of a Flor Yeast Strain under Biofilm Formation

2017 ◽  
Vol 18 (4) ◽  
pp. 720 ◽  
Author(s):  
Jaime Moreno-García ◽  
Juan Mauricio ◽  
Juan Moreno ◽  
Teresa García-Martínez
Keyword(s):  
Biofilm Formation ◽  
Yeast Strain ◽  
Proteome Analysis ◽  
Flor Yeast

scholarly journals Genomic and phenotypic diversity of Enterococcus faecalis isolated from endophthalmitis

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250084
Author(s):  
Gayatri Shankar Chilambi ◽  
Hayley R. Nordstrom ◽  
Daniel R. Evans ◽  
Regis P. Kowalski ◽  
Deepinder K. Dhaliwal ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Biofilm Formation ◽  
Phenotypic Diversity ◽  
Medical Center ◽  
Phenotypic Variability ◽  
Spontaneous Mutation ◽  
Comparative Genomic ◽  
Mismatch Repair Gene ◽  
Ocular Infection ◽  
Repair Gene

Enterococcus faecalis are hospital-associated opportunistic pathogens and also causative agents of post-operative endophthalmitis. Patients with enterococcal endophthalmitis often have poor visual outcomes, despite appropriate antibiotic therapy. Here we investigated the genomic and phenotypic characteristics of E. faecalis isolates collected from 13 patients treated at the University of Pittsburgh Medical Center Eye Center over 19 years. Comparative genomic analysis indicated that patients were infected with E. faecalis belonging to diverse multi-locus sequence types (STs) and resembled E. faecalis sampled from clinical, commensal, and environmental sources. We identified known E. faecalis virulence factors and antibiotic resistance genes in each genome, including genes conferring resistance to aminoglycosides, erythromycin, and tetracyclines. We assessed all isolates for their cytolysin production, biofilm formation, and antibiotic susceptibility, and observed phenotypic differences between isolates. Fluoroquinolone and cephalosporin susceptibilities were particularly variable between isolates, as were biofilm formation and cytolysin production. In addition, we found evidence of E. faecalis adaptation during recurrent endophthalmitis by identifying genetic variants that arose in sequential isolates sampled over eight months from the same patient. We identified a mutation in the DNA mismatch repair gene mutS that was associated with an increased rate of spontaneous mutation in the final isolate from the patient. Overall this study documents the genomic and phenotypic variability among E. faecalis causing endophthalmitis, as well as possible adaptive mechanisms underlying bacterial persistence during recurrent ocular infection.

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