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Hidradenitis suppurativa (HS) is a chronic condition that can overwhelm patients, and the effectiveness of supplementary dietary treatments remains uncertain. The primary aim of this review is to explore the connection between diet and HS progression. However, it is imperative to note that the evidence supporting a substantial role of the diet in HS remains weak. Dietary alterations alone should not be considered independent solutions for managing HS. Medical therapy continues to be indispensable for adequate treatment. Research indicates that the Mediterranean lifestyle and diet may provide cost‐effective and beneficial adjustments when combined with traditional therapies. Conversely, foods with a high glycemic index and dairy could worsen HS symptoms, conceivably through mechanisms linked to insulin resistance and inflammation. Zinc, known for its antioxidant properties, shows promise as an adjunct therapy. Moreover, evidence suggests a connection between vitamin D deficiency and HS severity, although the findings are inconclusive. Brewer's yeast‐free diet, B12 supplementation, intermittent fasting, and reducing the intake of refined sugar and dairy merit further investigation. In conclusion, this review highlights the need for additional research because of the lack of standardized reporting of clinical effects in the studies under scrutiny. A deeper exploration of the pathophysiology focusing on dietary modifications and their potential associations with HS severity is essential. Furthermore, it is crucial to recognize that patients' willingness to experiment with new diets makes them vulnerable to fraudulent interventions, highlighting the importance of evidence‐based dietary guidance. [ABSTRACT FROM AUTHOR]

Nutrition in early life has profound effects on an organism, altering processes such as organogenesis. However, little is known about how specific nutrients affect neuronal development. Dendrites of class IV dendritic arborization neurons in Drosophila larvae become more complex when the larvae are reared on a low-yeast diet compared to a high-yeast diet. Our systematic search for key nutrients revealed that the neurons increase their dendritic terminal densities in response to a combined deficiency in vitamins, metal ions, and cholesterol. The deficiency of these nutrients upregulates Wingless in a closely located tissue, body wall muscle. Muscle-derived Wingless activates Akt in the neurons through the receptor tyrosine kinase Ror, which promotes the dendrite branching. In larval muscles, the expression of wingless is regulated not only in this key nutrient-dependent manner, but also by the JAK/STAT signaling pathway. Additionally, the low-yeast diet blunts neuronal light responsiveness and light avoidance behavior, which may help larvae optimize their survival strategies under low-nutritional conditions. Together, our studies illustrate how the availability of specific nutrients affects neuronal development through inter-organ signaling. [ABSTRACT FROM AUTHOR]

Background: The adaptive significance of phenotypic changes elicited by environmental conditions experienced early in life has long attracted attention in evolutionary biology. In this study, we used Drosophila melanogaster to test whether the developmental diet produces phenotypes better adapted to cope with similar nutritional conditions later in life. To discriminate among competing hypotheses on the underlying nature of developmental plasticity, we employed a full factorial design with several developmental and adult diets. Specifically, we examined the effects of early- and late-life diets (by varying their yeast and sugar contents) on reproductive fitness and on the amount of energy reserves (fat and glycogen) in two wild-caught populations. Results: We found that individuals that had developed on either low-yeast or high-sugar diet showed decreased reproductive performance regardless of their adult nutritional environment. The lower reproductive fitness might be caused by smaller body size and reduced ovariole number. Overall, these results are consistent with the silver spoon concept, which posits that development in a suboptimal environment negatively affects fitness-associated traits. On the other hand, the higher amount of energy reserves (fat) in individuals that had developed in a suboptimal environment might represent either an adaptive response or a side-effect of compensatory feeding. Conclusion: Our findings suggest that the observed differences in the adult physiology induced by early-life diet likely result from inevitable and general effects of nutrition on the development of reproductive and metabolic organs, rather than from adaptive mechanisms. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Efficiency of engineered yeast to convert fructose to d -psicose was 26.6%. • 50 MT/h corn processing facility estimated to produce 29,835 MT/yr d -psicose. • Minimum selling price of d -psicose with an IRR of 15% was calculated as $1.29/kg. Abstract The objective of this study was to analyze the processing and technoeconomic feasibility of coproduction of d -psicose and ethanol in a modified dry grind ethanol process. The yeast strain was constructed by expressing d -psicose 3-epimerases (DPE) in Sachharomyces cerevisiae. The strain was capable of converting d -fructose to d -psicose at 55 °C with a conversion efficiency of 26.6%. A comprehensive process model for modified dry grind ethanol plant with 396,000 MT/yr corn processing capacity was developed using SuperPro Designer. Predicted ethanol and d -psicose yields were 390.4 L and 75.3 kg per MT of corn, with total annual production of 154.6 million L and 29,835 MT respectively. The capital investment for the plant was estimated as 150.3 million USD with total operating cost of 85.2 million USD/yr. The unit production cost and minimum selling price of d -psicose with an internal rate of return of 15% were calculated as $0.43/kg and $1.29/kg respectively. [ABSTRACT FROM AUTHOR]

Kaoliang is a refreshing fragranced type of Chinese spirits with slight apple fragrance that comes from ethyl acetate (EA). Special aromas are produced by esterification microorganisms, which affect the taste and quality of the wine. In this study, new yeast strains were isolated from yellow water, a by-product during fermentation process. Meanwhile, the optimal culture condition was determined for its growth and EA production. Three new strains, Kazachstaniaexigua, Candida humilis and Saccharomyces cerevisiae were identified from yellow water. Among these strains, S. cerevisiae S5 was the new and dominant strain. Results from response surface methodology showed that S. cerevisiae S5 produced 161.88 ppm of EA, in the medium with 4.91% yeast extract, 9.82% peptone, and 20.91% glucose after 96 hours of cultivation at 27.53°C. GC analysis showed that aroma compounds, such as EA, isoamyl acetate and 2-phenylethanol increased from the sample of optimal condition when compared to the one from initial fermentation condition. [ABSTRACT FROM AUTHOR]

This article reveals how nineteenth-century chemists and health reformers tried to eradicate the use of yeast in bread, claiming they had devised healthier and more sanitary ways to raise bread. It describes the alternative technological solutions to baking bread, investigating factors that influenced their development and adaptation in the marketplace. A lack of scientific and cultural consensus surrounding yeast, what it was and what it did, fermented during this period. The conflict over yeast helped create a heterogeneous industrialization of the baking industry, changing processes and ingredients and creating new forms of bakery products. By examining the claims of promoters of rival scientific beliefs and technologies, as well as those of users and social commentators, we can see that technology’s eventual adaptation and impact on society is not predictable at its outset. Exploring the relationship between differing scientific beliefs, cultural understandings and alternative technologies also shows how science and industry cannot be isolated from their social and cultural context. The examination of the nineteenth-century technological development of commonplace commodities such as bread, baking powder and yeast, also reveals and explores a story that has not been told before in the history of science and technology. Why it has not been told is as enlightening as the story itself, revealing as it does our own privileging of what is important in science and history. [ABSTRACT FROM AUTHOR]

A novel edible film and coating with antagonistic yeast in arabinoxylan (AX) matrix was prepared and its effects on preserving against fungus infection on limes were investigated. The effect of yeast cell incorporation of developed films was evaluated in terms of viability, biocontrol activity and barrier properties. Furthermore, the application of AX as bioactive coatings was investigated in order to evaluate their efficacy to preserve postharvest quality and prevent or cure infection by Penicillium italicum during storage. Results revealed AX as a matrix compatible with D. hansenii and able to maintain more than 97% viability of the initial inoculum at temperatures tested, films with antagonistic yeast are capable to inhibit the growth of P. italicum in vitro . Presence of yeast did not change water vapor permeability on films. Viability of yeasts was preserved on coated limes on 100%. Preventive application of treatments was more effective than curative applications in the control of blue mold decay. Yeast added coatings were effective at reducing weight loss and had no effect on limes color. This study demonstrates the potential application of bioactive AX coatings with D. hansenii as an alternative of postharvest disease management. [ABSTRACT FROM AUTHOR]

The effect of Maillard reaction products (MRPs), formed during the production of dark malts, on the synthesis of higher alcohols and esters in beer fermentations was investigated by headspace solid-phase microextraction GC–MS. Higher alcohol levels were significantly ( p < 0.05) higher in dark malt fermentations, while the synthesis of esters was inhibited, due to possible suppression of enzyme activity and/or gene expression linked to ester synthesis. Yeast strain also affected flavour synthesis with Saccharomyces cerevisiae strain A01 producing considerably lower levels of higher alcohols and esters than S288c and L04. S288c produced approximately double the higher alcohol levels and around twenty times more esters compared to L04. Further investigations into malt type-yeast strain interactions in relation to flavour development are required to gain better understanding of flavour synthesis that could assist in the development of new products and reduce R&D costs for the industry. [ABSTRACT FROM AUTHOR]

Red yeast rice product (RYP) has been used as a food supplement because of its lipid lowering, and in food additives as a natural colorant. Lovastatin of RYP is a hypolipidemic commercial drug. To enhance the beneficial effects of RYP, we performed a bioconversion with Bacillus subtilis . This B. subtilis- fermentation process of RYP increased the ratio of the active open-hydroxyl acid form and the prodrug lactone form of lovastatin, which is a potent cholesterol synthesis inhibitor. 3(2H)-benzofuranone was newly produced in the fermented red yeast rice product (FRYP) as analyzed by GC–MS. FRYP increased the free radical scavenging activity compared with RYP. FRYP blocked xanthine oxidase (XO)-induced oxidative cytotoxicity and inhibited the H 2 O 2 -induced intracellular ROS in cells. This is the first study to illustrate that B. subtilis- fermented FRYP is useful for facilitating the alteration in the physico-chemical property of lovastatin and enhancing antioxidant activity, which may have greater pharmacological activity. [ABSTRACT FROM AUTHOR]

The yeast Hsp26 protein, a conserved a-crystallin small heatshock chaperone, is assembled in to oligomeric complexes, microscopically visible as distinct cytoplasmic foci. We studied at single cell resolution the dynamics of Hsp26p foci assembly, the mode of their inheritance in to progeny cells and the physiological significance of Hsp26p function. We showed that Hsp26p foci are formed upon cells' entry in to stationary phase, but upon re-entry to proliferation they are asymmetrically retained in the mother cells and are absent from the newborn daughters. Despite the fact that Hsp26p assists re-solubilization of aggregation-prone proteins it does not extend chronological life span nor does it increase the tolerance of either mother or daughters against lethal stresses. Upon sequential HSP26 inductions, newly synthesized Hsp26p is readily incorporated in pre-existing foci, generating larger in size, but similar in appearance foci. At extreme heat-shock conditions, Hsp26p foci break apart into smaller granules dispersed in both mothers and growing buds, while recovery at normal temperature results in Hsp26p foci reassembly. These results suggested that such a complicated mechanism of dynamic Hsp26p assembly and disassembly, as well as asymmetric segregation may contribute to fine tuning regulation of protein aggregates' refolding, cell fitness and survival. [ABSTRACT FROM AUTHOR]

InSaccharomyces cerevisiae, a group of more than 200 co-regulated genes (Ribi genes) is involved in ribosome biogenesis. This regulon has recently been shown to rely on a small set of transcriptional regulators (mainly Abf1, but also Reb1, Tbf1 and Rap1) previously referred to as general regulatory factors (GRFs) because of their widespread binding and action at many promoters and other specialized genomic regions. Intriguingly, Abf1 binding to Ribi genes is differentially modulated in response to distinct nutrition signaling pathways. Such a dynamic promoter association has the potential to orchestrate both activation and repression of Ribi genes in synergy with neighboring regulatory sites and through the functional interplay of histone acetyltransferases and deacetylases. [ABSTRACT FROM AUTHOR]

Yeast ageing has been gaining much attention in gerontology research, yet the process itself is still not entirely clear. One of the constraints related to the use of the Saccharomyces cerevisiae yeast in studies is the ambiguity of the results concerning ageing determinants for different genetic backgrounds. In this paper, we compare reproductive potentials and lifespans of seven widely used haploid laboratory strains differing in daughter cells production capabilities and highlight the importance of choosing an appropriate genotype for the studies on ageing. Moreover, we show here links between post-reproductive lifespan and lipid metabolism, as well as between reproductive potential, reproductive lifespan and phylogenetic relationship. Using FTIR spectroscopy that generated a biochemical fingerprint of cells, coupled with chemometrics, we found that the band of carbonyl (C = O) stretching vibration discriminates the strains according to post-reproductive lifespan. The results indicated that prolonged post-reproductive lifespan was associated with relatively lower amount of fatty acids esterified to phospholipids compared to a free acid pool, thus implying phospholipid metabolism for the post-reproductive lifespan of yeast. In addition, phylogenetic analysis showed a correlation between nucleotide similarity and the reproductive potential or reproductive lifespan, but not to the longevity expressed in time units. [ABSTRACT FROM AUTHOR]

During cell division, aberrant DNA structures are detected by regulators called checkpoints that slow division to allow error correction. In addition to checkpoint-induced delay, it is widely assumed, though rarely shown, that merely slowing the cell cycle might allow more time for error detection and correction, thus resulting in a more stable genome. Fidelity by a slowed cell cycle might be independent of checkpoints. Here we tested the hypothesis that a slowed cell cycle stabilizes the genome, independent of checkpoints, in the budding yeast Saccharomyces cerevisiae. We were led to this hypothesis when we identified a gene (ERV14, an ER cargo membrane protein) that when mutated, unexpectedly stabilized the genome, as measured by three different chromosome assays. After extensive studies of pathways rendered dysfunctional in erv14 mutant cells, we are led to the inference that no particular pathway is involved in stabilization, but rather the slowed cell cycle induced by erv14 stabilized the genome. We then demonstrated that, in genetic mutations and chemical treatments unrelated to ERV14, a slowed cell cycle indeed correlates with a more stable genome, even in checkpoint-proficient cells. Data suggest a delay in G2/M may commonly stabilize the genome. We conclude that chromosome errors are more rarely made or are more readily corrected when the cell cycle is slowed (even ~15 min longer in an ~100-min cell cycle). And, some chromosome errors may not signal checkpoint-mediated responses, or do not sufficiently signal to allow correction, and their correction benefits from this "time checkpoint.". [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the effects of dietary yeast autolysate (Saccharomyces cerevisiae) supplementation on performance characteristics, some blood parameters and lysozyme activity in rainbow trouts. A total of 180 rainbow trouts (Oncorhynchus mykiss) weighing approximately 35 g were used in this experiment. They were divided into one control group and two treatment groups each containing 60 fish. Each group was divided into three subgroups each containing 20 fish. The diets of the first and second treatment groups were supplemented with 0.1% and 0.2% yeast autolysates, respectively. The experimental period lasted for eight weeks. Fish, fed diets with yeast autolysate exhibited higher body weights and specific growth rates than those fed with control diet after eight weeks of experimental period. Feed conversion ratio was improved by dietary yeast autolysate. There were no significant differences among the groups on length, condition factor, serum lysozyme activity, serum total protein and serum cholesterol at the end of the experiment. Serum triglyceride levels decreased with yeast autolysate. Liver lysozyme level was higher in fish fed with diets including yeast autolysate than that of fed with control diet (P<0.05). It was concluded that dietary yeast autolysate supplementation can be effective in rainbow trout feeding due to the improvement in performance, specific growth rate and liver lysozyme level. Yeast autolysate can be used at 0.1% because no differences between the doses of yeast autolysate were seen in the performance and other parameters in the feeding of rainbow trout. [ABSTRACT FROM AUTHOR]

To appropriately acclimate to environmental stresses, plants have to rapidly activate a specific transcriptional program. Yet, the identity and function of many of the transcriptional regulators that mediate early responses to abiotic stress stimuli is still unknown. In this work we employed the promoter of the multi-stress-responsive zinc-finger protein Zat12 in yeast one-hybrid ( Y1H) screens to identify early abiotic stress-responsive transcriptional regulators. Analysis of Zat12 promoter fragments fused to luciferase underlined an approximately 200 bp fragment responsive to NaCl and to reactive oxygen species ( ROS). Using these segments and others as baits against Y1H control or stress Arabidopsis prey libraries, we identified 15 potential Zat12 transcriptional regulators. Among the prominent proteins identified were known transcription factors including bZIP29 and ANAC91 as well as unknown function proteins such as a homolog of the human USB1, a U6 small nuclear RNA ( snRNA) processing protein, and dormancy/auxin-associated family protein 2 ( DRM2). Altered expression of Zat12 during high light stress in the knockout mutants further indicated the involvement of these proteins in the regulation of Zat12. Using a state of the art microfluidic approach we showed that AtUSB1 and DRM2 can specifically bind dsDNA and were able to identify the preferred DNA-binding motif of all four proteins. Overall, the proteins identified in this work provide an important start point for charting the earliest signaling network of Zat12 and of other genes required for acclimation to abiotic stresses. [ABSTRACT FROM AUTHOR]

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In our prior work by Hose et al., we performed a genome-sequencing survey and reported that aneuploidy was frequently observed in wild strains of S. cerevisiae. We also profiled transcriptome abundance in naturally aneuploid isolates compared to isogenic euploid controls and found that 10-30% of amplified genes, depending on the strain and affected chromosome, show lower-than-expected expression compared to gene copy number. In Hose et al., we argued that this gene group is enriched for genes subject to one or more modes of dosage compensation, where mRNA abundance is decreased in response to higher dosage of that gene. A recent manuscript by Torres et al. refutes our prior work. Here, we provide a response to Torres et al., along with additional analysis and controls to support our original conclusions. We maintain that aneuploidy is well tolerated in the wild strains of S. cerevisiae that we studied and that the group of genes enriched for those subject to dosage compensation show unique evolutionary signatures. [ABSTRACT FROM AUTHOR]

Background: Lymphatic filariasis is caused by the parasitic worms Wuchereria bancrofti, Brugia malayi or B. timori, which are transmitted via the bites from infected mosquitoes. Once in the human body, the parasites develop into adult worms in the lymphatic vessels, causing severe damage and swelling of the affected tissues. According to the World Health Organization, over 1.2 billion people in 58 countries are at risk of contracting lymphatic filariasis. Very few drugs are available to treat patients infected with these parasites, and these have low efficacy against the adult stages of the worms, which can live for 7–15 years in the human body. The requirement for annual treatment increases the risk of drug-resistant worms emerging, making it imperative to develop new drugs against these devastating diseases. Methodology/Principal Findings: We have developed a yeast-based, high-throughput screening system whereby essential yeast genes are replaced with their filarial or human counterparts. These strains are labeled with different fluorescent proteins to allow the simultaneous monitoring of strains with parasite or human genes in competition, and hence the identification of compounds that inhibit the parasite target without affecting its human ortholog. We constructed yeast strains expressing eight different Brugia malayi drug targets (as well as seven of their human counterparts), and performed medium-throughput drug screens for compounds that specifically inhibit the parasite enzymes. Using the Malaria Box collection (400 compounds), we identified nine filarial specific inhibitors and confirmed the antifilarial activity of five of these using in vitro assays against Brugia pahangi. Conclusions/Significance: We were able to functionally complement yeast deletions with eight different Brugia malayi enzymes that represent potential drug targets. We demonstrated that our yeast-based screening platform is efficient in identifying compounds that can discriminate between human and filarial enzymes. Hence, we are confident that we can extend our efforts to the construction of strains with further filarial targets (in particular for those species that cannot be cultivated in the laboratory), and perform high-throughput drug screens to identify specific inhibitors of the parasite enzymes. By establishing synergistic collaborations with researchers working directly on different parasitic worms, we aim to aid antihelmintic drug development for both human and veterinary infections. [ABSTRACT FROM AUTHOR]

To overcome endoplasmic reticulum (ER) stress, ER-localized stress sensors actuate distinct downstream organelle-nucleus signaling pathways to invoke a cytoprotective response, known as the unfolded protein response (UPR). Compared to yeast and metazoans, plant UPR studies are more recent but nevertheless fascinating. Here we discuss recent discoveries in plant UPR, highlight conserved and unique features of the plant UPR as well as critical yet-open questions whose answers will likely make significant contributions to the understanding plant ER stress management. [ABSTRACT FROM AUTHOR]

Background and Aims Proanthocyanidins ( PAs), the predominant phenolic substances in wine, are responsible for the astringency of wine. The present work aims to understand the effect of yeast on the concentration and composition of the subunits of PAs during fermentation. Methods and Results The concentration and cleavage products (subunits) of PAs were measured during fermentation. Early in fermentation (within about 4 days), the concentration of PAs decreased significantly by around 78% for strain BH8 and 67% for strain AWRI R2; in addition, the mean degree of polymerisation and composition of PAs underwent considerable change. At the later phase of fermentation, no significant change was recorded in the concentration and mean degree of polymerisation of PAs, whereas the composition of PAs evolved progressively. Conclusions Yeast can exert a significant influence on the concentration and structure of PAs during wine fermentation in a strain- and time-dependent manner. Significance of the Study The results will enable a better understanding of the effect of yeast on the evolution of PAs in winemaking, as well as increase knowledge of the interaction between yeasts and phenolic substances to improve wine composition. [ABSTRACT FROM AUTHOR]

The small Rho-family GTPase Cdc42 is critical for cell polarization and polarizes spontaneously in absence of upstream spatial cues. Spontaneous polarization is thought to require dynamic Cdc42 recycling through Guanine nucleotide Dissociation Inhibitor (GDI)-mediated membrane extraction and vesicle trafficking. Here, we describe a functional fluorescent Cdc42 allele in fission yeast, which demonstrates Cdc42 dynamics and polarization independent of these pathways. Furthermore, an engineered Cdc42 allele targeted to the membrane independently of these recycling pathways by an amphipathic helix is viable and polarizes spontaneously to multiple sites in fission and budding yeasts. We show that Cdc42 is highly mobile at the membrane and accumulates at sites of activity, where it displays slower mobility. By contrast, a near-immobile transmembrane domain-containing Cdc42 allele supports viability and polarized activity, but does not accumulate at sites of activity. We propose that Cdc42 activation, enhanced by positive feedback, leads to its local accumulation by capture of fast-diffusing inactive molecules. [ABSTRACT FROM AUTHOR]

The proteasome controls the concentrations of most proteins in eukaryotic cells. It recognizes its protein substrates through ubiquitin tags and initiates degradation at disordered regions within the substrate. Here we show that the proteasome has pronounced preferences for the amino acid sequence of the regions at which it initiates degradation. Specifically, proteins in which the initiation regions have biased amino acid compositions show longer half-lives in yeast than proteins with unbiased sequences in the regions. The relationship is also observed on a genomic scale in mouse cells. These preferences affect the degradation rates of proteins in vitro, can explain the unexpected stability of natural proteins in yeast and may affect the accumulation of toxic proteins in disease. We propose that the proteasome's sequence preferences provide a second component to the degradation code and may fine-tune protein half-life in cells. [ABSTRACT FROM AUTHOR]

This study was designed to investigate the growth promoting effects of supplementing different sources and concentrations of prebiotic yeast cell wall (YCW) products containing mannanoligosaccharides in starter broilers under an immune stress and Clostridium perfringens challenge. Through a series of 6 individual studies either 240 or 288 newly hatched chicks were randomly distributed to specific dietary treatments. All birds received a commercial infectious bursa disease vaccine at 10 or 15 d age followed by an orally administered Clostridium perfringens challenge on d 15, 16, and 17; or 18, 19, and 20. Weekly BW, feed consumption, and daily mortality were recorded per pen. Each study was terminated after 21 d. Pooled data analysis of all studies revealed no effect between different product sources of YCW. Products from both sources produced a significant improvement in growth rate compared to control birds fed no YCW. However, a blend of two YCW products showed an approximate 15% improvement in growth rate and a 10% reduction in FCR. The optimum dose of any YCW product among those tested was determined to be approximately 250 ppm. Prebiotic YCW additives increased BW and improved feed conversion and may be considered as alternative growth promoters for starting broilers. [ABSTRACT FROM AUTHOR]

Robus coreanus Miquel is a small berry fruit used for Korean black raspberry (KBR) wine-making. Twelve different yeast strains were investigated by laboratory-scale fermentation to develop a wine with a high flavour quality. Volatile aroma compounds from the wines were analysed using headspace-solid phase microextraction-gas chromatography-mass spectrometry and sensory evaluation was performed to evaluate the flavour characteristics. The volatile aroma compounds that mostly contributed to the flavour of KBR wines were those related to fruity (esters) and floral (terpenes) aromas. Fifteen out of the 67 identified volatile compounds showed higher odour activity values than other compounds in the wines, and these compounds were considered as important contributors to the final aromas of the wine. Additionally, the KBR wine fermented by the M1 yeast strain had the highest sensory preference because of higher fruity and floral aroma characters compared with other wines. In addition to the M1 strain, the other yeast strains that produced favourable sensory characteristics included Enoferm CSM, Uvaferm VRB, Lalvin ICV GRE, Lalvin ICV Opale and LevureSeche Active. Of these strains, the M1 strain produced a particularly excellent black raspberry wine, and thus could be applied for further large-scale production of black raspberry wines. It is also expected that this work will expedite research on the production of high-quality black raspberry wines with beneficial physicochemical properties, functionality and good sensory characteristics. Copyright © 2015 The Institute of Brewing & Distilling [ABSTRACT FROM AUTHOR]

The aroma of wine can be classified accordingly to its origin, in varietal aroma, pre-fermentative aroma, fermentative aroma and postfermentative aroma. Although a number of flavor components are found in the original grape, the dominant and major compounds contributing to white wines are formed during alcoholic fermentation, in concordance with the yeast strain used. In order to highlight the influence of the yeast strain to the aroma composition of wines, wine samples from 'Aligoté' grape variety made with 8 different yeast strains were subjected to stir bar sorptive extraction-gas chromatography-mass spectrometry (SBSE-GC-MS) analyses. Also, a sensorial analysis of the studied wines was performed by a tasting panel consisting of 15 tasters. 38 minor volatile compounds were quantified by SBSE-GC-MS technique. Different concentration of the same compound and different aroma compounds were identified and quantified in wines obtained with different yeast strains. A wine finger printing was obtained by multivariate data analyses of aroma compounds grouped by chemical families. The analytical and sensorial analysis of the wine samples confirms that there are differences in aroma composition of the wines made with different yeast strains. [ABSTRACT FROM AUTHOR]

Abstract: The inoculation of a Debaryomyces hansenii strain in dry fermented sausages with reduced fat and salt contents was evaluated in terms of chemical, microbial and consumer acceptability. The implantation of the inoculated yeast strain was confirmed by RAPDs of M13 minisatellite. A reduction of 17–20% salt and 10–16% fat content was achieved. These reductions affected the sausage quality by producing an increase in a w, hardness and chewiness values and a decrease of staphylococci growth. However, D. hansenii inoculation compensated these changes although it was not able to modify neither the hardness of reduced fat batches nor the staphylococci growth decrease. In terms of sensory acceptability, different preferences patterns of consumers were found. Yeast inoculation improved the aroma and taste quality when fat or salt reductions were carried out in dry fermented sausages. [Copyright &y& Elsevier]

The brewing process and strain employed can play key roles in controlling the level of total higher alcohols (THA) in plum wine. In this study, fermentations using Saccharomyces cerevisiae XN3 and plum must led to the production of 671 mg/L THA (including 1-propanol, isobutanol and isopentanol). A mutant of XN3, exhibiting a higher activity of lactic acid dehydrogenase, named XN3-3, produced lower levels of THA at 538 mg/L. Further optimization of the brewing process, including rapid nitrogen and sugar fed-batch additions, were conducted with XN3-3. Tests with the addition of 0.4 g/L (NH4)2HPO4 produced a lower level of THA (385 mg/L) than sucrose additions (to a 20°Brix level) using the fed-batch method (452 mg/L). These additions were effective in reducing the higher alcohols and could be combined in application. Copyright © 2014 The Institute of Brewing & Distilling [ABSTRACT FROM AUTHOR]

Background The regulatory mechanism of recombination is one of the most fundamental problems in genomics, with wide applications in genome wide association studies (GWAS), birth-defect diseases, molecular evolution, cancer research, etc. Recombination events cluster into short genomic regions called "recombination hotspots". Recently, a zinc finger protein PRDM9 was reported to regulate recombination hotspots in human and mouse genomes. In addition, a 13-mer motif contained in the binding sites of PRDM9 is found to be enriched in human hotspots. However, this 13-mer motif only covers a fraction of hotspots, indicating that PRDM9 is not the only regulator of recombination hotspots. Therefore, the challenge of discovering other regulators of recombination hotspots becomes significant. Furthermore, recombination is a complex process. Hence, multiple proteins acting as machinery, rather than individual proteins, are more likely to carry out this process in a precise and stable manner. Therefore, the extension of the prediction of individual trans-regulators to protein complexes is also highly desired. Results In this paper, we introduce a pipeline to identify genes and protein complexes associated with recombination hotspots. First, we prioritize proteins associated with hotspots based on their preference of binding to hotspots and coldspots. Second, using the above identified genes as seeds, we apply the Random Walk with Restart algorithm (RWR) to propagate their influences to other proteins in protein-protein interaction (PPI) networks. Hence, many proteins without DNA-binding information will also be assigned a score to implicate their roles in recombination hotspots. Third, we construct sub-PPI networks induced by top genes ranked by RWR for various species (e.g., yeast, human and mouse) and detect protein complexes in those sub-PPI networks. Conclusions The GO term analysis show that our prioritizing methods and the RWR algorithm are capable of identifying novel genes associated with recombination hotspots. The trans-regulators predicted by our pipeline are enriched with epigenetic functions (e.g., histone modifications), demonstrating the epigenetic regulatory mechanisms of recombination hotspots. The identified protein complexes also provide us with candidates to further investigate the molecular machineries for recombination hotspots. Moreover, the experimental data and results are available on our web site http://www.ntu.edu.sg/home/zhengjie/data/RecombinationHotspot/NetPipe/. [ABSTRACT FROM AUTHOR]

crtYB, encoding lycopene cyclase and phytoene synthase was cloned from Rhodosporidium diobovatum ATCC 2527 by rapid amplification of cDNA ends method. The full-length cDNA of crtYB is 2, 330 bp and contains eight introns. The gene products is a 594 amino acids, with a predicted molecular mass of 65.63 kDa and a pI of 6.73. The N-terminus of the protein contains six transmembrane regions, which has been characterized as a lycopene beta-cyclase. The C-terminal half has squalene and phytoene synthase signatures that identified as phytoene synthetase. By heterologous complementary detection of this gene in E. coli and HPLC analysis, the regions responsible for phytoene synthesis and lycopene cyclization were localized within the protein. [ABSTRACT FROM AUTHOR]

In this study, we present a nonhazardous biological method of producing chitosan beads using the budding yeast Saccharomyces cerevisiae. Yeast cells cultured under conditions of nutritional starvation cease vegetative growth and instead form spores. The spore wall has a multilaminar structure with the chitosan layer as the second outermost layer. Thus, removal of the outermost dityrosine layer by disruption of the DIT1 gene, which is required for dityrosine synthesis, leads to exposure of the chitosan layer at the spore surface. In this way, spores can be made to resemble chitosan beads. Chitosan has adsorptive features and can be used to remove heavy metals and negatively charged molecules from solution. Consistent with this practical application, we find that spores are capable of adsorbing heavy metals such as Cu2+, Cr3+, and Cd2+, and removal of the dityrosine layer further improves the adsorption. Removal of the chitosan layer decreases the adsorption, indicating that chitosan works as an adsorbent in the spores. Besides heavy metals, spores can also adsorb a negatively charged cholesterol derivative, taurocholic acid. Furthermore, chitosan is amenable to chemical modifications, and, consistent with this property, dit1▵ spores can serve as a carrier for immobilization of enzymes. Given that yeast spores are a natural product, our results demonstrate that they, and especially dit1▵ mutants, can be used as chitosan beads and used for multiple purposes. [ABSTRACT FROM AUTHOR]

Aims/Introduction Dysregulated inflammatory response is believed to be an important factor in the pathogenesis of several late complications of diabetes mellitus. β-Glucans are potent inducers of immune function. The present randomized, double blind, two-center, placebo-controlled study was undertaken to explore safety, tolerability and efficacy of soluble β-1,3/1,6-glucan ( SBG) as a local treatment of diabetic foot ulcers. Materials and Methods A total of 60 patients with type 1 or 2 diabetes and lower extremity ulcers (Wagner grade 1-2, Ankle/Brachial Index ≥0.7) received SBG or a comparator product (methylcellulose) locally three times weekly up to 12 weeks in addition to conventional management scheme. A total of 54 patients completed the study. Results A tendency for shorter median time to complete healing in the SBG group was observed (36 vs 63 days, P = 0.130). Weekly percentage reduction in ulcer size was significantly higher in the SBG group than in the methylcellulose group between weeks 1-2, 3-4 and 5-6 ( P < 0.05). The proportion of ulcers healed by week 12 was also in favor of SBG (59% vs 37%, P = 0.09), with a significantly higher healing incidence in the SBG group at week 8 (44% vs 17%, P = 0.03). SBG was safe and well tolerated. There was a clinically significant difference regarding the incidence of serious adverse events in favor of the SBG treatment. Conclusions Local treatment of diabetic lower extremity ulcers with β-1,3/1,6-polyglucose shows good safety results. This β-glucan preparation shows promising potential as a treatment accelerating cutaneous healing. Further studies are required to confirm this effect. This trial was registered with ClinicalTrials.gov (no. NCT00288392). [ABSTRACT FROM AUTHOR]

Vinegar is a traditional fermented condiment, and the microbial diversity of DaQu makes the quality of vinegar products. Recently, turbidity spoilage of vinegar sharply tampered with the quality of vinegar. In this study, the relation between the microbial diversity of DaQu and turbidity spoilage of vinegar was analyzed by plating technique, PCR-denaturing gradient gel electrophoresis (DGGE), and high-performance liquid chromatography (HPLC). The 16S rRNA sequencing and DGGE analysis indicated that Bacillus ( Bacillus subtilis, Bacillus amyloliquefaciens, and Bacillus thuringiensis) and Lactobacillus (including Lactobacillus acidipiscis and Lactobacillus pobuzihii) species were the dominant contaminants in vinegar products. Meanwhile, DGGE analysis showed that the dominant bacteria in DaQu belonged to genera Bacillus, Lactobacillus, Pseudomonas, Weissella, Saccharopolyspora, Enterobacter, and Pantoea. However, only two yeast species ( Pichia kudriavzevii and Saccharomycopsis fibuligera) and seven mold species including Aspergillus oryzae, Aspergillus niger, Aspergillus candidus, Rhizopus microspores, Eurotium herbariorum, Absidia corymbifera, and Eupenicillium javanicum were detected in the DaQu. The population level of fungi was below 5 log CFU/g in DaQu. The chemical and physical properties of vinegar and sediments were also determined. On the basis of a combined microbial diversity-chemical analysis, we demonstrated that turbidity spoilage of vinegar was a result of cooperation among the low population level and abundance of fungal species in DaQu, the suitable climate conditions, and the contaminants in vinegar. This is the first report to analyze the relation between the microbial diversity of DaQu and turbidity spoilage of vinegar. [ABSTRACT FROM AUTHOR]

Background Lignocellulosic materials are a diverse group of substrates that are generally scarce in nutrients, which compromises the tolerance and fermentation performance of the fermenting organism. The problem is exacerbated by harsh pre-treatment, which introduces sugars and substances inhibitory to yeast metabolism. This study compares the fermentation behaviours of two yeast strains using different types of lignocellulosic substrates; high gravity dilute acid spruce hydrolysate (SH) and spent sulphite liquor (SSL), in the absence and presence of yeast extract. To this end, the fermentation performance, energy status and fermentation capacity of the strains were measured under different growth conditions. Results Nutrient supplementation with yeast extract increased sugar uptake, cell growth and ethanol production in all tested fermentation conditions, but had little or no effect on the energy status, irrespective of media. Nutrient-supplemented medium enhanced the fermentation capacity of harvested cells, indicating that cell viability and reusability was increased by nutrient addition. Conclusions Although both substrates belong to the lignocellulosic spruce hydrolysates, their differences offer specific challenges and the overall yields and productivities largely depend on choice of fermenting strain. [ABSTRACT FROM AUTHOR]

Background Yeasts tolerant to toxic inhibitors from steam-pretreated lignocellulose with xylose cofermentation capability represent an appealing approach for 2nd generation ethanol production. Whereas rational engineering, mutagenesis and evolutionary engineering are established techniques for either improved xylose utilisation or enhancing yeast tolerance, this report focuses on the simultaneous enhancement of these attributes through mutagenesis and evolutionary engineering of Saccharomyces cerevisiae harbouring xylose isomerase in anoxic chemostat culture using non-detoxified pretreatment liquor from triticale straw. Results Following ethyl methanesulfonate (EMS) mutagenesis, Saccharomyces cerevisiae strain D5A+ (ATCC 200062 strain platform), harbouring the xylose isomerase (XI) gene for pentose co-fermentation was grown in anoxic chemostat culture for 100 generations at a dilution rate of 0.10 h-1 in a medium consisting of 60% (v/v) non-detoxified hydrolysate liquor from steam-pretreated triticale straw, supplemented with 20 g/L xylose as carbon source. In semiaerobic batch cultures in the same medium, the isolated strain D5A+H exhibited a slightly lower maximum specific growth rate (μmax = 0.12 ± 0.01 h-1) than strain TMB3400, with no ethanol production observed by the latter strain. Strain D5A+H also exhibited a shorter lag phase (4 h vs. 30 h) and complete removal of HMF, furfural and acetic acid from the fermentation broth within 24 h, reaching an ethanol concentration of 1.54 g/L at a yield (Yp/s) of 0.06 g/g xylose and a specific productivity of 2.08 g/gh. Evolutionary engineering profoundly affected the yeast metabolism, given that parental strain D5A+ exhibited an oxidative metabolism on xylose prior to strain development. Conclusions Physiological adaptations confirm improvements in the resistance to and conversion of inhibitors from pretreatment liquor with simultaneous enhancement of xylose to ethanol fermentation. These data support the sequential application of random mutagenesis followed by continuous culture under simultaneous selective pressure from inhibitors and xylose as primary carbon source. [ABSTRACT FROM AUTHOR]

Abstract: The Montepulciano d'Abruzzo “Colline Teramane” premium wine DOCG is produced in the Teramo province (Abruzzo, Italy). This region has a great tradition in winemaking and the wine is produced by a spontaneous fermentation so it could represent a reservoir of wine natural yeasts with important oenological features. The aim of this study was to characterize the yeast community of this wine grape growing region in order to create a Saccharomyces cerevisiae bank, providing data on oenological properties for potential industrial applications. A total of 430 yeasts were isolated at the end of spontaneous fermentation. PCR-RFLP was applied for the identification at the species level and underlined that 14 strains exhibited unusual and characteristic restriction patterns different from those typical of the species S. cerevisiae. This difference was due to the insertion of base C at a position 138 in the ITS1 region that determined an additional cleavage site for the enzyme HaeIII. This insertion could be associated to the fermentative performance and associated to the relationship existing between yeasts and a viticulture region or ‘terroir’. [Copyright &y& Elsevier]

Abstract: The effects of dietary supplementation with Saccharomyces cerevisiae boulardii (CNCM I-1079 strain, LSB) at 0, 300 and 600mg/kg on apparent digestibility, growth performance, caecal fermentation, carcass characteristics and meat quality of broiler rabbits were studied from 37 to 84 days of age. One hundred and fifty New Zealand White rabbits were single housed and randomly allotted into three groups. Animals were fed isocaloric and isonitrogenous basal diets ad libitum, supplemented with different levels of concentrated live yeast LSB (0, 3×106 and 6×106 colony forming unit (CFU)/g diet, respectively). Protected LSB was resistant to the pelleting process and to passage through the rabbit digestive tract as far as the caecum, where it showed an 86% survival rate in the 600mg/kg supplementation level group. Significant differences were found only for the fibrous fractions digestibility that were lowest (P=0.001) in the animals fed 300mg/kg supplemented diet, while yeast and mould populations in the caecum increased (P=0.001) in the animals fed 300 and 600mg/kg supplemented diets (4.16 and 4.76logCFU/g, respectively). Mortality did not differ amongst dietary treatments being 10%, 8% and 6% for groups fed LSB at 0, 300 and 600mg/kg, respectively. [Copyright &y& Elsevier]

Highlights: [•] Presequences can bind to PBD of Tim50 in a manner similar to Tom20. [•] PBD can bind to the core domain of Tim50 through the presequence binding region. [•] Core domain binding to PBD could promote efficient presequence transfer. [ABSTRACT FROM AUTHOR]

Abstract: Proteins from various biological sources previously identified in wine play important roles in the functioning and survival of their producers and may exhibit oenological properties. Yeasts contribute significantly to the protein pool during and after alcoholic fermentation. While the extracellular proteins of Saccharomyces cerevisiae, the main wine yeast species, have been characterised, those of non-Saccharomyces yeasts remain restricted to a few enzymes. A more comprehensive insight into all proteins released during fermentation could improve our understanding of how yeasts survive and interact in mixed culture fermentations. This study aimed to characterise the exo-proteome of Saccharomyces and selected non-Saccharomyces yeasts in pure and mixed cultures in a wine-like medium. While S. cerevisiae completed the fermentation rapidly, Metschnikowia pulcherrima hardly fermented and Lachancea thermotolerans fermented slowly but steadily. In sequential fermentations, the kinetics resembled those of the non-Saccharomyces yeasts for a period before switching to that of S. cerevisiae. Identification of the proteins present in wine at the end of fermentation using mass fingerprinting revealed the large diversity of proteins secreted and the influence of yeast interactions therein. The fermentation kinetics observed could partially be explained by the extent of the contribution of the different yeast to the protein content. [Copyright &y& Elsevier]

Ginsenosides are the primary bioactive components of ginseng, which is a popular medicinal plant that exhibits diverse pharmacological activities. Protopanaxadiol, protopanaxatriol and oleanolic acid are three basic aglycons of ginsenosides. Producing aglycons of ginsenosides in Saccharomyces cerevisiae was realized in this work and provides an alternative route compared to traditional extraction methods. Synthetic pathways of these three aglycons were constructed in S. cerevisiae by introducing β-amyrin synthase, oleanolic acid synthase, dammarenediol-II synthase, protopanaxadiol synthase, protopanaxatriol synthase and NADPH-cytochrome P450 reductase from different plants. In addition, a truncated 3-hydroxy-3-methylglutaryl-CoA reductase, squalene synthase and 2,3-oxidosqualene synthase genes were overexpressed to increase the precursor supply for improving aglycon production. Strain GY-1 was obtained, which produced 17.2 mg/L protopanaxadiol, 15.9 mg/L protopanaxatriol and 21.4 mg/L oleanolic acid. The yeast strains engineered in this work can serve as the basis for creating an alternative way for producing ginsenosides in place of extractions from plant sources. [ABSTRACT FROM AUTHOR]

The aim of the study was to use spent brewer's yeast biomass (SBY) as a nutrient adjunct of distillery type corn mashes to improve the process of ethanol fermentation by yeast Saccharomyces cerevisiae. There were prepared corn mashes with raw material loading at 20% ww. with SBY addition at solids loadings of 0 (control); 0.1; 0.5; 0.7; 1.0; 3.0 and 5.0% ww. The obtained mashes were inoculated with yeast and subjected to batch fermentation for 72 h. It was observed that supplementation of corn mashes with SBY improved the process of fermentation. The consumption of sugars and production of ethanol by yeast in supplemented mashes was accelerated and the overall ethanol yield was improved by 6.5 to 11% depending on the amount of added SBY. It was also observed that the fermentation could be shortened by 24 h in mashes enriched with SBY. [ABSTRACT FROM AUTHOR]

Highlights: [•] G1 control networks are highly similar in budding yeast and mammals. [•] Lack of protein sequence conservation suggests significant evolution of G1 control. [•] Accurate cellular decisions may be based on time-integrated signals. [•] Single-cell analysis has elucidated Start and should be used to study the restriction point. [Copyright &y& Elsevier]

Highlights: [•] Overexpression of gene HXT13 confers resistance to miltefosine (MI) in S. cerevisiae. [•] Overexpression of similar genes HXT15 and HXT17 does not confer MI resistance. [•] MI treated HXT13 overexpressed cells had greater viability compared to control. [•] Hxt13p functions as an ATP-independent MI specific efflux pump. [•] HXT13 overexpressed strain was not multidrug resistant. [Copyright &y& Elsevier]

Abstract: We demonstrated a novel yeast cell assay using a multiple depth surface plasmon resonance platform, which has three detection depths. In the study we first identified the minimal and maximum number of cells required for detection and then used the platform to conduct a drug potency study. The study showed that the rank order of potency for 3 drugs could be clearly determined and was the same regardless of the penetration depth used for the measurement. The rank order made sense based on their respective mechanism of action. However the data quality of the inhibition curve was best when measured at the 1500nm depth. The dose dependent response was noticeable even after only 15min treatment, which is much earlier than those from traditional methods. By comparing the response units obtained at 3 different penetration depths in various yeast cell assays, we have confirmed that simultaneously monitoring from multiple penetration depths likely offers advantages to better detect robust signals from yeast cells, which proves difficult with other optical sensors with a short penetration depth of <300nm. The assay could be broadly applicable to other rigid and spherical cell types for biology studies and for antibiotic discovery. [Copyright &y& Elsevier]

Background: Identifying modules from time series biological data helps us understand biological functionalities of a group of proteins/genes interacting together and how responses of these proteins/genes dynamically change with respect to time. With rapid acquisition of time series biological data from different laboratories or databases, new challenges are posed for the identification task and powerful methods which are able to detect modules with integrative analysis are urgently called for. To accomplish such integrative analysis, we assemble multiple time series biological data into a higher-order form, e.g., a gene × condition × time tensor. It is interesting and useful to develop methods to identify modules from this tensor. Results: In this paper, we present MultiFacTV, a new method to find modules from higher-order time series biological data. This method employs a tensor factorization objective function where a time-related total variation regularization term is incorporated. According to factorization results, MultiFacTV extracts modules that are composed of some genes, conditions and time-points. We have performed MultiFacTV on synthetic datasets and the results have shown that MultiFacTV outperforms existing methods EDISA and Metafac. Moreover, we have applied MultiFacTV to Arabidopsis thaliana root(shoot) tissue dataset represented as a gene×condition×time tensor of size 2395 × 9 × 6(3454 × 8 × 6), to Yeast dataset and Homo sapiens dataset represented as tensors of sizes 4425 × 6 × 6 and 2920×14×9 respectively. The results have shown that MultiFacTV indeed identifies some interesting modules in these datasets, which have been validated and explained by Gene Ontology analysis with DAVID or other analysis. Conclusion: Experimental results on both synthetic datasets and real datasets show that the proposed MultiFacTV is effective in identifying modules for higher-order time series biological data. It provides, compared to traditional non-integrative analysis methods, a more comprehensive and better view on biological process since modules composed of more than two types of biological variables could be identified and analyzed. [ABSTRACT FROM AUTHOR]

Fungal infections with multiple resistance to conventional antifungals are increasingly becoming a medical problem, and there is an urgent need for new antifungal compounds with novel mechanisms of action. Here, we show that aurein 2.5, a naturally occurring peptide antibiotic, displays activity against the fungal strains: Rhodotorula rubra and Schizosaccharomyces pombe ( MICs < 130 μM). The peptide adopted high levels of membrane-interactive α-helical structure (> 65%) in the presence of lipid membranes derived from these organisms and showed strong propensities to penetrate (π ≥ 13 mN m−1) and lyse them (> 70%). Based on these data, we suggest that aurein 2.5 kills yeasts via membranolytic mechanisms and may act as a template for the development of therapeutically useful antifungal agents. [ABSTRACT FROM AUTHOR]

Lead (Pb) and cadmium (Cd) in functional health foods (FHF) and Korean herbal medicines (KHM) were analysed by the standard addition method with inductively coupled plasma–mass spectrometry. A total of 672 samples were collected from 2347 people (1015 adults, 557 students and 775 infants and children) who lived in Korea. Pb and Cd concentrations were analysed in the samples (FHF,n = 535; KHM,n = 50). Method validation was carried out using standard reference material (SRM), recovery rate and limits of detection and quantification. Recovery rates for Pb and Cd using three SRMs were 94.9%–101.6% and 96.7%–115.2%, respectively. Mean Pb values in FHF and KHM were 0.146 and 0.349 mg kg−1, respectively. Mean Cd levels in FHF and KHM were 0.035 and 0.056 mg kg−1, respectively. Mean values inSpirulinaand yeast products were the highest in the FHF samples (0.940 mg kg−1for Pb inSpirulinaproducts and 0.115 mg kg−1for Cd in yeast products). [ABSTRACT FROM AUTHOR]

An efficient method for Pichia cell disruption that employs an aminopropyl magnesium phyllosilicate (AMP) clay-assisted glass beads mill is presented. AMP clay is functionalized nanocomposite resembling the talc parent structure SiMgO(OH) that has been proven to permeate the bacterial membrane and cause cell lysis. The recombinant capsid protein of cowpea chlorotic mottle virus (CCMV) expressed in Pichia pastoris GS115 was used as demonstration system for their ability of self-assembly into icosahedral virus-like particles (VLPs). The total protein concentration reached 4.24 mg/ml after 4 min treatment by glass beads mill combined with 0.2 % AMP clay, which was 11.2 % higher compared to glass beads mill only and the time was half shortened. The stability of purified CCMV VLPs illustrated AMP clay had no influence on virus assembly process. Considering the tiny amount added and simple approach of AMP clay, it could be a reliable method for yeast cell disruption. [ABSTRACT FROM AUTHOR]

In this work eighteen red yeasts were screened for carotenoids production on glycerol containing medium. Strain C2.5t1 of Rhodotorula glutinis, that showed the highest productivity, was UV mutagenized. Mutant 400A15, that exhibited a 280 % increase in β-carotene production in respect to the parental strain, was selected. A central composite design was applied to 400A15 to optimize carotenoids and biomass productions. Regression analyses of the quadratic polynomial equations obtained (R = 0.87 and 0.94, for carotenoids and biomass, respectively) suggest that the models are reliable and significant ( P < 0.0001) in the prediction of carotenoids and biomass productions on the basis of the concentrations of crude glycerol, yeast extract and peptone. Accordingly, total carotenoids production achieved (14.07 ± 1.45 mg l) under optimized growth conditions was not statistically different from the maximal predicted (14.64 ± 1.57 mg l) ( P < 0.05), and it was about 100 % higher than that obtained under un-optimized conditions. Therefore mutant 400A15 may represent a biocatalyst of choice for the bioconversion of crude glycerol into value-added metabolites, and a tool for the valorization of this by-product of the biodiesel industry. [ABSTRACT FROM AUTHOR]

Diphtheria toxin (DT) inhibits eukaryotic translation elongation factor 2 (eEF2) by ADP-ribosylation in a fashion that requires diphthamide, a modified histidine residue on eEF2. In budding yeast, diphthamide formation involves seven genes, DPH1-DPH7. In an effort to further study diphthamide synthesis and interrelation among the Dph proteins, we found, by expression in E. coli and co-immune precipitation in yeast, that Dph1 and Dph2 interact and that they form a complex with Dph3. Protein-protein interaction mapping shows that Dph1-Dph3 complex formation can be dissected by progressive DPH1 gene truncations. This identifies N- and C-terminal domains on Dph1 that are crucial for diphthamide synthesis, DT action and cytotoxicity of sordarin, another microbial eEF2 inhibitor. Intriguingly, dph1 truncation mutants are sensitive to overexpression of DPH5, the gene necessary to synthesize diphthine from the first diphthamide pathway intermediate produced by Dph1-Dph3. This is in stark contrast to dph6 mutants, which also lack the ability to form diphthamide but are resistant to growth inhibition by excess Dph5 levels. As judged from site-specific mutagenesis, the amidation reaction itself relies on a conserved ATP binding domain in Dph6 that, when altered, blocks diphthamide formation and confers resistance to eEF2 inhibition by sordarin. [ABSTRACT FROM AUTHOR]