Metabolic, organoleptic and transcriptomic impact of saccharomyces cerevisiae genes involved in the biosynthesis of linear and substituted esters

Esters constitute a broad family of volatile compounds impacting the organoleptic properties of many beverages, including wine and beer. They can be classified according to their chemical structure. Higher alcohol acetates differ from fatty acid ethyl esters, whereas a third group, substituted ethyl esters, contributes to the fruitiness of red wines. Derived from yeast metabolism, the biosynthesis of higher alcohol acetates and fatty acid ethyl esters has been widely investigated at the enzymatic and genetic levels. As previously reported, two pairs of esterases, respectively encoded by the paralogue genes ATF1 and ATF2, and EEB1 and EHT1, are mostly involved in the biosynthesis of higher alcohol acetates and fatty acid ethyl esters. These esterases have a moderate effect on the biosynthesis of substituted ethyl esters, which depend on mono-acyl lipases encoded by MGL2 and YJU3. The functional characterization of such genes helps to improve our understanding of substituted ester metabolism in the context of wine alcohol fermentation. In order to evaluate the overall sensorial impact of esters, we attempted to produce young red wines without esters by generating a multiple esterase-free strain (Δatf1, Δatf2, Δeeb1, and Δeht1). Surprisingly, it was not possible to obtain the deletion of MGL2 in the Δatf1/Δatf2/Δeeb1/Δeht1 background, highlighting unsuspected genetic incompatibilities between ATF1 and MGL2. A preliminary RNA-seq analysis depicted the overall effect of the Δatf1/Δatf2/Δeeb1/Δeht1 genotype that triggers the expression shift of 1124 genes involved in nitrogen and lipid metabolism, but also chromatin organization and histone acetylation. These findings reveal unsuspected regulatory roles of ester metabolism in genome expression for the first time

Evidence for the control of mutation in lysine catabolism by the mating type in Yarrowia lipolytica

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Improvement of ferulic acid bioconversion into vanillin by use of high-density cultures of Pycnoporus cinnabarinus

International audienceHigh-density cultures of Pycnoporus cinnabarinus were tested with a view to optimisation of ferulic acid bioconversion into vanillin. The dry weight was increased fourfold by using glucose, fructose or a mixture of glucose and phospholipids as carbon source instead of maltose, the carbon source previously used. 5 mmol l−1 vanillin, i.e. 760 mg l−1, was produced over 15 days with glucose-phospholipid medium. In contrast, formation of vanillin was lower using glucose or fructose compared to the maltose control. A bioreactor (2 l) with a glucose-phospholipid medium gave a molar yield of vanillin of 61% (4 mmol l−1). An alternative strategy was to grow the fungus on a glucose or fructose medium for 3 days, then switch to maltose during the bioconversion phase: this method allowed 3.3 mmol l−1 vanillin to be obtained in 10 days. Many by-products such as methoxyhydroquinone and vanillyl alcohol were also produced

An attempt to channel the transformation of vanillic acid into vanillin by controlling methoxyhydroquinone formation in Pycnoporus cinnabarinus with cellobiose

International audienceThe effects of adding cellobiose on the transformation of vanillic acid to vanillin by two strains of Pycnoporus cinnabarinus MUCL39532 and MUCL38467 were studied. When maltose was used as the carbon source in the culture medium, very high levels of methoxyhydroquinone were formed from vanillic acid. When cellobiose was used as the carbon source and/or added to the culture medium of P. cinnabarinus strains on day 3 just before vanillic acid was added, it channelled the vanillic acid metabolism via the reductive route leading to vanillin. Adding 3.5 g l−1 cellobiose to 3-day-old maltose cultures of P. cinnabarinus MUCL39532 and 2.5 g l−1 cellobiose to 3-day-old cellobiose cultures of P. cinnabarinus MUCL38467, yielded 510 mg l−1 and 560 mg l−1 vanillin with a molar yield of 50.2 % and 51.7 % respectively. Cellobiose may either have acted as an easily metabolizable carbon source, required for the reductive pathway to occur, or as an inducer of cellobiose:quinone oxidoreductase, which is known to inhibit vanillic acid decarboxylation

By-passing of unwanted vanillyl alcohol formation using selective adsorbents to improve vanillin production with Phanerochaete chrysosporium

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Design of a fungal bioprocess for vanillin production from vanillic acid at scalable level by Pycnoporus cinnabarinus

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A two-step bioconversion process for vanillin production from ferulic acid combining Aspergillus niger and Pycnoporus cinnabarinus

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Factors affecting trust in a remote leader – employee relationship

Background Globalization and technological progress have enabled working in a remote context. This is a common feature among actors providing Knowledge-Intense Business Services (KIBS) to companies and organizations, such as consultancy firms. Working in a remote context brings several leadership challenges, and trust is one of the most important ones to tackle.  Aim The aim for this research is to investigate which factors affect the sense of trust a remote leader – employee relationship. As well as look at how they affect that sense.  Methods The author chose a qualitative approach for this thesis with interviews as the source of information. Six people, whom all have a managerial position in Swedish consultant firms, were chosen for semi-structures interviews to open up for discussion and through this get a deeper understanding of the area. Results The factors affect the levels of trust in the relationship. They can also have impact on the type of trust that is perceived in the relationship. Conclusions The analysis of the interview show that all of the factors have an impact on, both each other, as well as trust. Which can lead to an increased or decreased sense of trust. In the case of decrease, or complete lack, of trust, the relationship between leader and employee can not go on.Bakgrund Globalisering och tekniska framsteg har möjliggjort arbete på distans. Detta är ett vanligt arbetssätt hos företag som arbetar med att tillhandahålla Kostnads-intensiva företagstjänster till andra företag och organisationer, exempelvis konsultfirmor. Detta arbetssätt för med sig flera utmaningar när det kommer till ledarskap, där tillit är en av de viktigaste att kunna hantera. Syfte Syftet med den här studien är att undersöka vilka faktorer som påverkar känslan av tillit i förhållandet chef – medarbetare. Samt att titta på hur dessa påverkar tilliten. Metod Författaren valde en kvalitativ ansats för studien med intervjuer som källa till information. Sex personer, som alla besitter chefspositioner på svenska konsultbolag, fick genomgå semistrukturerade intervjuer för att öppna upp till diskussion och på så sätt få en djupare förståelse kring ämnet. Resultat Faktorerna påverkar nivåerna av tillit i förhållandet. De kan också påverka vilken typ av tillit som framträder i förhållandet. Slutsatser Analysen visar att samtliga faktorer har inverkan, dels på varandra, och dels på tilliten. Vilket kan leda till en ökad eller minskad känsla av tillit. Vid minskad, eller helt saknad, tillit kan inte förhållandet mellan ledare och medarbetare fungera

A two-step bioconversion process for vanillin production from ferulic acid combining Aspergillus niger and Pycnoporus cinnabarinus

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By-passing of unwanted vanillyl alcohol formation using selective adsorbents to improve vanillin production with Phanerochaete chrysosporium

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