east biomass is often used in the fermentation of bread dough. Dough fermentation can be maximized by adding a nitrogen source. This study used yeast isolates from salak pondoh (YIS-3, YIS-4, and ...YIS-7). The purpose of this study was to determine the effect of nitrogen addition on yeast growth and bread quality. This study used an experimental approach. The results of the growth study showed that all isolates treated with 0.05% urea produced higher biomass and cell counts than those treated with control. The highest biomass was produced by YIS-7, which was 3.81 g/300mL, while the highest number of cells was produced by YIS-3, which was 29.02x106 cells/mL. The percentage of proofing results showed that all yeast isolates treated with 0.05% urea needed a longer time to achieve the highest proofing. However, the volume of bread after baking showed better results than those treated with control. The largest volume of bread produced by YIS-3, was 972.14 cm3. The results of the organoleptic test showed that P<5%, which means that all treatments had a significant effect on the taste, aroma, color, and texture of the bread. Overall, the panelists gave good acceptance of the bread fermented by YIS-3 with 0.05% urea treatment. So it can be concluded that the addition of urea with a concentration of 0.05% in YIS-3 gave the best effect on the yeast growth and bread quality.
Ribosome and protein synthesis lie at the core of cell growth and are major consumers of the cellular budget. Here we review recent progress in the coupling of ribosome synthesis and translational ...capacity with cell growth in bacteria. We elaborate on the different strategies of bacteria to modulate the protein synthesis rate at fast and slow growth rates. In particular, bacterial cells maintain translational potential at very slow growth as a strategy to keep fitness in fluctuating environments. We further discuss the important role of ribosome synthesis in rapidly proliferating eukaryotic cells such as yeast cells and cancer cells. The tight relation between ribosome and cell growth provides a broad research avenue for researchers from various disciplines.
At fast growth rates, cellular ribosome synthesis is tightly coupled with cell growth by guanosine tetra- or pentaphosphate (p)ppGpp to attain optimal proteome resource allocation in bacterial cells.Under slow growth conditions, bacterial cells adopt an ingenious strategy to keep translational potential through maintaining both a basal inactive ribosome pool and a moderate translational elongation rate; such a design reflects an adaptive mechanism to fluctuating environments.Ribosome synthesis is also tightly coupled with growth rate in yeast cells, being similar to that in bacterial cells.Excessive ribosome synthesis is crucial for cancer cells to support rapid proliferation and a high protein synthesis rate, and upregulation of ribosome synthesis promotes cancer progression.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Dominant-negative mutations can help to investigate the biological mechanisms and to understand the selective pressures for multifunctional proteins. However, most studies have focused on recessive ...mutant effects that occur in the absence of a second functional gene copy, which overlooks the fact that most eukaryotic genomes contain more than one copy of many genes. We have identified dominant effects on yeast growth rate among all possible point mutations in ubiquitin expressed alongside a wild-type allele. Our results reveal more than 400 dominant-negative mutations, indicating that dominant-negative effects make a sizable contribution to selection acting on ubiquitin. Cellular and biochemical analyses of individual ubiquitin variants show that dominant-negative effects are explained by varied accumulation of polyubiquitinated cellular proteins and/or defects in conjugation of ubiquitin variants to ubiquitin ligases. Our approach to identify dominant-negative mutations is general and can be applied to other proteins of interest.
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•Overexpression of inducible variants alongside functional wild-type ubiquitin•Numerous dominant-negative mutations are enriched throughout the ubiquitin protein•Dominant mutations exert balancing selection on ubiquitin and polyubiquitin levels•Versatile method to identify dominant-negative mutations in protein of interest
Padhy et al. employed inducible variant overexpression alongside functional wild-type ubiquitin to investigate the dominant mutant effects underlying its functions. The results show widespread prevalence of dominant mutations associated with altered polyubiquitination, underscoring their critical role in cellular ubiquitination and limiting impacts on ubiquitin evolution.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this paper the effect of aflatoxin B
1
, ochratoxin A and zearalenon on morphology, growth parameters and metabolic activity of yeasts
Saccharomyces cerevisiae
,
Saccharomyces uvarum
,
Candida ...utilis
and
Kluyveromyces marxianus
was determined. The results showed that the three mycotoxins affected the morphology of all these yeasts, primarily the cell diameter, but not their final cell count. Fourier transform infrared spectroscopy showed that the yeast membranes bound the mycotoxins,
C. utilis
in particular. The cell membranes of most yeasts underwent denaturation, except
S. uvarum
exposed to ochratoxin A and zearalenone. In the early stage of fermentation, all mycotoxin-exposed yeasts had lower metabolic activity and biomass growth than controls, but fermentation products and biomass concentrations reached the control levels by the end of the fermentation, except for
C. utilis
exposed to 20 µg/mL of zearalenone. The adaptive response to mycotoxins suggests that certain yeasts could be used to control mycotoxin concentrations in the production of fermented food and beverages.
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•NtZIP11 is a plasma membrane protein mediating Zn uptake, but not Fe, Mn or Cd.•NtZIP11 is highly expressed in leaves and upregulated by high Zn concentrations.•NtZIP11 is the first ...known tobacco gene contributing to accumulation of Zn in leaves of tobacco plants at Zn excess.
Understanding the molecular mechanisms governing the uptake and accumulation of Zn in the leaves of tobacco plants exposed to high Zn concentrations is important from the perspective of phytoremediation of metal contaminated soil. This study identifies a new candidate gene, NtZIP11, which may contribute to Zn accumulation in tobacco leaves. NtZIP11 encodes a protein of 346 amino acids, with characteristic conserved sequences of the ZIP family of proteins. Phylogenetic analysis shows that NtZIP11 forms a distinct clade with other ZIP11 proteins. Transient expression of GFP-tagged ZIP11 in the abaxial epidermis of tobacco leaves demonstrates localization at the plasma membrane. Yeast complementation tests and growth assays indicate that NtZIP11 is involved in Zn but not Fe, Mn and Cd uptake. NtZIP11 complements the zrt1zrt2 mutant deficient in Zn uptake, but not the fet3fet4 mutant deficient in Fe uptake. Nor does it modify the sensitivity of wild-type yeast, DY1457, to increasing concentrations of Fe, Mn and Cd. NtZIP11 is expressed in both roots and leaves, with transcript abundance increasing with age. Noteworthy, the expression level of NtZIP11 is not modulated by Zn-deficiency but is highly upregulated especially in the older leaves by high Zn concentrations (50 and 200 μM). Our data indicate that the primary role for NtZIP11 is in the uptake of Zn by the cells of tobacco leaves specifically when experiencing high Zn concentrations. It also likely contributes to maintaining a basal supply of Zn to cells at the level of the whole plant. Thus the present study contributes to broadening our understanding of Zn homeostasis mechanisms in tobacco, and clarifying the role of ZIP11 genes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
► Carbohydrates from microalgae can be a promising feedstock for yeast culture to produce biofuels. ► Pretreatment of microalgae and carbohydrates extraction from algal cell were performed. ► Four ...factors of ultrasound assisted extraction were examined by fractional factorial design. ► Refined model was confirmed as a good fitting model via analysis of variance (ANOVA). ► Yeast biomass of the group with glucose from microalgae was much higher than that of control group.
Recently, carbohydrates biomass from microalgae is considered as a promising and inexpensive feedstock for biofeuls production by microorganism fermentation. The main obstacle of the process is microalgae pretreatment and carbohydrates extraction from algal cell. In this study, comparison of three pretreatment methods was performed and the results showed that ultrasonic assisted extraction (UAE) was very effective. The effects of four parameters (ultrasonic power, extraction time, flow rate and algal cell concentration, respectively) on extraction efficiency were also investigated. Additionally, in order to identify significant factors for glucose yield, combination of these four parameters was examined by using fractional factorial design (FFD) and the regression model was obtained. Meanwhile, the refined model was confirmed as a good fitting model via analysis of variance (ANOVA). After extraction, glucose obtained from microalgae was used as substrate for Rhodosporidium toruloides fermentation and yeast biomass was much higher than that of control culture.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
and
, the most frequently isolated candidiasis species in the world, have developed mechanisms of resistance to treatment with azoles. Among the clinically used antifungal drugs are statins and other ...compounds that inhibit 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), resulting in decreased growth and ergosterol levels in yeasts. Ergosterol is a key element for the formation of the yeast cell membrane. However, statins often cause DNA damage to yeast cells, facilitating mutation and drug resistance. The aim of the current contribution was to synthesize seven series of compounds as inhibitors of the HMGR enzyme of
ssp., and to evaluate their effect on cellular growth, ergosterol synthesis and generation of
mutants of
and
Compared to the reference drugs (fluconazole and simvastatin), some HMGR inhibitors caused lower growth and ergosterol synthesis in the yeast species and generated fewer
mutants. Moreover, heterologous expression was achieved in
, and compounds
,
,
and
inhibited the activity of recombinant CgHMGR and showed better binding energy values than for α-asarone and simvastatin. Thus, we believe these are good candidates for future antifungal drug development.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
This study was aimed to investigate the effect of earthworms after their decomposition on yeast growth. To achieve this objective, in vitro crude soluble extracts were prepared from two earthworms ...lots: freshly harvested from the field “FHE” and the other previously starved for one week “SE”. The dry residues of these two crude extracts were used at different concentrations as a solid media for the growth of two yeast species: one “Candida tropicalis” got from another laboratory and the other was isolated by our team from earthworms’ casts “Filobasidium uniguttulatum”, and their growth was evaluated by colonies counting. The results obtained, compared with the Sabouraud Dextrose Agar (SDA), showed that the growth of both yeast isolates was significantly higher on mediums prepared using exclusively earthworms’ crude extracts and agar. Optimal growth was obtained at a concentration corresponding to 0.375g/100 mL of earthworms’ soluble matter of the two types of earthworms’ lots. These results affirmed the richness and the diversification of those extracts, in nutrients and growth factors, that comes mainly from the intrinsic composition of earthworm’s body biomass. The efficiency of the FHE and SE extracts for cultivation of yeast shows their possible use as a culture media that may be applied to other soil microorganisms and even in vivo as soil amendments or biofertilizers.
Background and Aims
Microoxygenation (MOX) is widely used in winemaking. Its impact, however, on Pinot Noir wines has not been well documented. We investigated the influence of MOX on colour ...parameters and on the anthocyanin and polymeric pigment concentration of a young Pinot Noir wine. The relationship between MOX, yeast growth and acetaldehyde production was also explored.
Methods and Results
Microoxygenation was applied before or after malolactic fermentation (MLF), and at two oxygen doses 10.8 and 52.4 mg/(L ·month), for 30 days. The end result was reported after dissolved oxygen was depleted and 90 mg/L SO2 was added. Microoxygenation induced a higher yeast growth and acetaldehyde production, where the latter was associated with both yeast metabolism and chemical oxidation. A larger loss in total anthocyanins and malvidin‐3‐glucoside occurred under MOX but absorbance at 520 nm and colour intensity were higher. With the higher oxygen dose, MOX promoted the formation of large polymeric pigments.
Conclusions
Acetaldehyde formation was strongly induced by MOX, contributing to reactions between anthocyanins and acetaldehyde forming pigments in the red spectrum. Between MOX treatments, only slight variation was found for each parameter, indicating a less important effect of the timing and dosage of MOX on the young Pinot Noir wine than anticipated from prior work.
Significance of the Study
Microoxygenation caused a significant impact on the colour development of light‐coloured Pinot Noir wine, increasing the colour intensity.
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BFBNIB, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
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