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

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.

2020 ◽  
Vol 72 (4) ◽  
pp. 183-194
Author(s):  
Viktoria Kapcsandi ◽  
Erika Lakatos Hanczne ◽  
Agnes Nagy ◽  
Rita Szekelyhidi

The aim of this study was to determine the effect of two yeast strains (Saccharomyces cerevisiae and S. bayanus) on the fermentation with or without additional pectinase. The organic acids products (tartaric, malic, and succinic acid), carbohydrates (glucose, fructose, and sucrose) utilized, and ethanol produced were examined by HPLC. The efficiency of fermentation was affected by several parameters such as the preparation procedure of the fruits, like temperature (18�C), yeast strain applied, pH adjustment (3.2), the dosage of yeast nutrient and application of pectinase. We have found that pectinase pre-treatment and S. cerevisiae could significantly alter the amount of the examined components, which changed the quality of the end product. We have also experienced significant (p≤0.05) differences in the sugar utilisation of yeast strains as well as organic acid contents in the different stages of fermentation, where the samples fermented with spontaneous and identified yeast strains.


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 ◽  
...  

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.


Author(s):  
Hiroaki Negoro ◽  
Atsushi Kotaka ◽  
Hiroki Ishida

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.


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 ◽  
...  

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.


Foods ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 443 ◽  
Author(s):  
Păucean ◽  
Man ◽  
Chiş ◽  
Mureşan ◽  
Pop ◽  
...  

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.


2014 ◽  
Vol 6 (19) ◽  
pp. 7891-7897 ◽  
Author(s):  
R. Wahlstrom ◽  
C. Styles ◽  
G. Hägglund

An UHPLC-MS/MS method has been developed and validated for the identification and quantification of three diethylphenethylamines in pre-workout sports supplements containing extracts from orchids of the Dendrobium genus. The method shows good separation and sensitivity.


2019 ◽  
Vol 12 ◽  
pp. 02021 ◽  
Author(s):  
M. Schmitt ◽  
S. Broschart ◽  
C.-D. Patz ◽  
D. Rauhut ◽  
M. Friedel ◽  
...  

Two commercial yeast strains with reduced alcohol production in comparison with a commercial yeast strain with common alcohol yield were assed for their suitability in sparkling wine production according to the traditional bottle fermentation. The different yeast strains were applied for the first fermentation. As expected the base wine differed in terms alcohol. Furthermore the yeast with lower alcohol content showed higher values of glycerol, higher arginine content and in the same time reduced levels of proline after fermentation. However those samples showed increased volatile acidity values, compared to the control wines. The later bottle fermentation with a uniform yeast strain showed similar fermentation kinetics for all four lots. Sensory evaluation showed no clear differences between the sparkling wines that were stored 9 months on the lees. The base wines nevertheless clearly differed from each other. Besides the increased production of volatile acidity, the tested yeast strains with lower alcohol production appear very promising for the sparkling wine industry to face the generally rising alcohol contents worldwide.


1994 ◽  
Vol 89 (8) ◽  
pp. 647-651 ◽  
Author(s):  
Kiyoshi YOSHIDA ◽  
Masaaki INAHASHI ◽  
Kin-ichi NAKAMURA ◽  
Hiroichi AKIYAMA ◽  
Kikuo NOJIRO

2001 ◽  
Vol 67 (9) ◽  
pp. 4346-4348 ◽  
Author(s):  
Vincent J. Higgins ◽  
Philip J. L. Bell ◽  
Ian W. Dawes ◽  
Paul V. Attfield

ABSTRACT A yeast strain capable of leavening both unsugared and sweet bread dough efficiently would reduce the necessity of carrying out the expensive procedure of producing multiple baker's yeast strains. But issues involving the use of genetically modified foods have rendered the use of recombinant techniques for developing yeast strains controversial. Therefore, we used strong selection and screening systems in conjunction with traditional mass mating techniques to develop a strain of Saccharomyces cerevisiaethat efficiently leavens both types of dough.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4519
Author(s):  
Brandon Whitmore ◽  
Stephanie McCann ◽  
Matthew Noestheden ◽  
Eric Dennis ◽  
Sarah Lyons ◽  
...  

When wine grapes are exposed to smoke, there is a risk that the resulting wines may possess smoky, ashy, or burnt aromas, a wine flaw known as smoke taint. Smoke taint occurs when the volatile phenols (VPs) largely responsible for the aroma of smoke are transformed in grape into a range of glycosides that are imperceptible by smell. The majority of VP-glycosides described to date are disaccharides possessing a reducing β-d-glucopyranosyl moiety. Here, a two-part experiment was performed to (1) assess the stability of 11 synthesized VP-glycosides towards general acid-catalyzed hydrolysis during aging, and (2) to examine whether yeast strains differed in their capacity to produce free VPs both from these model glycosides as well as from grapes that had been deliberately exposed to smoke. When fortified into both model and real wine matrices at 200 ng/g, all VP-disaccharides were stable over 12 weeks, while (42–50 ng/g) increases in free 4-ethylphenol and p-cresol were detected when these were added to wine as their monoglucosides. Guaiacol and phenol were the most abundantly produced VPs during fermentation, whether originating from natural VP-precursors in smoked-exposed Pinot Noir must, or due to fortification with synthetic VP-glycosides. Significant yeast strain-specific differences in glycolytic activities were observed for phenyl-β-d-glycopyranoside, with two strains (RC212 and BM45) being unable to hydrolyze this model VP, albeit both were active on the guaiacyl analogue. Thus, differences in Saccharomyces cerevisiae β-glucosidase activity appear to be influenced by the VP moiety.


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