scholarly journals Autonomously replicating linear plasmids facilitate the analysis of replication origin function inCandida albicans

2019 ◽  
Author(s):  
Swati Bijlani ◽  
Mathuravani A. Thevandavakkam ◽  
Hung-Ji Tsai ◽  
Judith Berman
Keyword(s):  
Candida Albicans ◽  
Colony Size ◽  
Transformation Efficiency ◽  
Plasmid Stability ◽  
Kluyveromyces Lactis ◽  
Baker’S Yeast ◽  
Dependent Manner ◽  
Baker's Yeast ◽  
Linear Plasmids ◽  
Bona Fide

AbstractThe ability to generate autonomously replicating plasmids has been elusive inCandida albicans, a prevalent human fungal commensal and pathogen. Instead, plasmids generally integrate into the genome. Here, we assessed plasmid and transformant properties, including plasmid geometry, transformant colony size, four selectable markers, and potential origins of replication for their ability to drive autonomous plasmid maintenance. Importantly, linear plasmids with terminal telomere repeats yielded many more autonomous transformants than circular plasmids with the identical sequences.Furthermore, we could distinguish by colony size, transient, autonomously replicating and chromosomally integrated transformants (tiny, medium and large, respectively).Candida albicans URA3and a heterologous marker,ARG4,yielded many transient transformants indicative of weak origin activity; replication of plasmid carrying heterologousLEU2marker was highly dependent upon the addition of abona fideorigin sequence. Severalbona fidechromosomal origins, with an origin fragment of ~100 bp as well as a heterologous origin,panARS, fromKluyveromyces lactisdrove autonomous replication, yielding moderate transformation efficiency and plasmid stability. Thus,C. albicansmaintains linear plasmids that yield high transformation efficiency and are maintained autonomously in an origin-dependent manner.ImportanceCircular plasmids are important tools for molecular manipulation in model fungi such as baker’s yeast, yet, inCandida albicans, an important yeast pathogen of humans, prior studies were not able to generate circular plasmids that were autonomous (duplicated without inserting themselves into the chromosome). Here, we found that linearizing circular plasmids with sequences from telomeres, the chromosome ends, allows the plasmids to duplicate and segregate inC. albicans.We used this system to identify chromosomal sequences that facilitate the initiation of plasmid replication (origins) and to show that a ~100 bp fragment of aC. albicansorigin, as well as an origin sequence from a distantly related yeast, can both function as origins inC. albicans.Thus, the requirements for plasmid geometry, but not necessarily for origin sequences, differ betweenC. albicansand baker’s yeast.

scholarly journals Autonomously Replicating Linear Plasmids That Facilitate the Analysis of Replication Origin Function inCandida albicans

mSphere ◽  
2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Swati Bijlani ◽  
Mathuravani A. Thevandavakkam ◽  
Hung-Ji Tsai ◽  
Judith Berman
Keyword(s):  
Candida Albicans ◽  
Colony Size ◽  
Transformation Efficiency ◽  
Kluyveromyces Lactis ◽  
Baker’S Yeast ◽  
Dependent Manner ◽  
Baker's Yeast ◽  
Linear Plasmids ◽  
Content Type ◽  
Bona Fide

ABSTRACTThe ability to generate autonomously replicating plasmids has been elusive inCandida albicans, a prevalent human fungal commensal and pathogen. Instead, plasmids generally integrate into the genome. Here, we assessed plasmid and transformant properties, including plasmid geometry, transformant colony size, four selectable markers, and potential origins of replication, for their ability to drive autonomous plasmid maintenance. Importantly, linear plasmids with terminal telomere repeats yielded many more autonomous transformants than circular plasmids with the identical sequences. Furthermore, we could distinguish (by colony size) transient, autonomously replicating, and chromosomally integrated transformants (tiny, medium, and large, respectively).Candida albicansURA3and a heterologous marker,ARG4,yielded many transient transformants indicative of weak origin activity; the replication of the plasmid carrying the heterologousLEU2marker was highly dependent upon the addition of abona fideorigin sequence. Severalbona fidechromosomal origins, with an origin fragment of ∼100 bp as well as a heterologous origin,panARS, fromKluyveromyces lactis, drove autonomous replication, yielding moderate transformation efficiency and plasmid stability. Thus,C. albicansmaintains linear plasmids that yield high transformation efficiency and are maintained autonomously in an origin-dependent manner.IMPORTANCECircular plasmids are important tools for molecular manipulation in model fungi such as baker’s yeast, yet, inCandida albicans, an important yeast pathogen of humans, prior studies were not able to generate circular plasmids that were autonomous (duplicated without inserting themselves into the chromosome). Here, we found that linearizing circular plasmids with sequences from telomeres, the chromosome ends, allows the plasmids to duplicate and segregate inC. albicans. We used this system to identify chromosomal sequences that facilitate the initiation of plasmid replication (origins) and to show that an ∼100-bp fragment of aC. albicansorigin and an origin sequence from a distantly related yeast can both function as origins inC. albicans. Thus, the requirements for plasmid geometry, but not necessarily for origin sequences, differ betweenC. albicansand baker’s yeast.

scholarly journals Effect of the Leavening Agent on the Compositional and Sensorial Characteristics of Bread Fortified with Flaxseed Cake

2020 ◽  
Vol 10 (15) ◽  
pp. 5235 ◽  
Author(s):  
Isabella Taglieri ◽  
Chiara Sanmartin ◽  
Francesca Venturi ◽  
Monica Macaluso ◽  
Angela Zinnai ◽  
...  
Keyword(s):  
Value Added ◽  
Well Being ◽  
Baker’S Yeast ◽  
Dependent Manner ◽  
Baker's Yeast ◽  
Total Phenols ◽  
Sensory Profiles ◽  
Dose Dependent ◽  
Health And Well Being ◽  
By Products

Health and well-being improvement is currently driving innovation in bread, using a wide variety of value-added compounds as extra ingredients, including food industry by-products in a circular economy concept. In this context, this research aimed at evaluating the effect of the fortification of bread with different percentages of flaxseed cake, comparing two leavening agents: sourdough and baker’s yeast. Sensorial, physicochemical, and nutritional properties, including pH, the main fermentative metabolites, fatty acids, total phenols, antioxidant capacity, and volatile organic compounds were determined for fortified bread. The results showed a significant improvement of nutraceutical profile of the bread fortified with flaxseed cake in a dose-dependent manner. Regardless of the leavening agent, the fortification determined a decrease of n-6:n-3 ratio, reaching the recommended value (<3) already at the 7.5% level. Furthermore, under the same fortification level, sourdough breads showed a higher level of total phenols and antiradical activity than baker’s yeast breads. Sensory profiles were instead deeply influenced by both the fortification percentage and the leavening agents. In conclusion, considering both nutritional and sensory results, the best formulation as a function of leavening agent utilized was defined as 5% and 7.5% when sourdough and baker’s yeast were used, respectively.

scholarly journals Survival of Genetically Modified and Self-Cloned Strains of Commercial Baker's Yeast in Simulated Natural Environments: Environmental Risk Assessment

2005 ◽  
Vol 71 (11) ◽  
pp. 7075-7082 ◽  
Author(s):  
Akira Ando ◽  
Chise Suzuki ◽  
Jun Shima
Keyword(s):  
Genetic Engineering ◽  
Freeze Tolerance ◽  
Scientific Data ◽  
Baker’S Yeast ◽  
Natural Environments ◽  
Dependent Manner ◽  
Baker's Yeast ◽  
Viable Cells ◽  
Acid Trehalase ◽  
Pcr Method

ABSTRACT Although genetic engineering techniques for baker's yeast might improve the yeast's fermentation characteristics, the lack of scientific data on the survival of such strains in natural environments as well as the effects on human health prevent their commercial use. Disruption of acid trehalase gene (ATH1) improves freeze tolerance, which is a crucial characteristic in frozen-dough baking. In this study, ATH1 disruptants constructed by genetic modification (GM) and self-cloning (SC) techniques were used as models to study such effects because these strains have higher freeze tolerance and are expected to be used commercially. Behavior of the strains in simulated natural environments, namely, in soil and water, was studied by measuring the change in the number of viable cells and in the concentration of DNA that contains ATH1 loci. Measurements were made using a real-time PCR method during 40 days of cultivation. Results showed that the number of viable cells of GM and SC strains decreased in a time-dependent manner and that the decrease rate was nearly equal to or higher than that for wild-type (WT) yeast. For all three strains (SC, GM, and WT) in the two simulated natural environments (water and soil), the DNA remained longer than did viable cells but the decrease patterns of either the DNA or the viable cells of SC and GM strains had tendencies similar to those of the WT strain. In conclusion, disruption of ATH1 by genetic engineering apparently does not promote the survival of viable cells and DNA in natural environments.

scholarly journals Role of Elm1, Tos3, and Sak1 Protein Kinases in the Maltose Metabolism of Baker’s Yeast

2021 ◽  
Vol 12 ◽  
Author(s):  
Xu Yang ◽  
Lu Meng ◽  
Xue Lin ◽  
Huan-Yuan Jiang ◽  
Xiao-Ping Hu ◽  
...  
Keyword(s):  
Carbon Source ◽  
Glucose Repression ◽  
Regulatory System ◽  
Baker’S Yeast ◽  
Yeast Cells ◽  
Dependent Manner ◽  
Baker's Yeast ◽  
Maltose Metabolism ◽  
New Perspective

Glucose repression is a key regulatory system controlling the metabolism of non-glucose carbon source in yeast. Glucose represses the utilization of maltose, the most abundant fermentable sugar in lean dough and wort, thereby negatively affecting the fermentation efficiency and product quality of pasta products and beer. In this study, the focus was on the role of three kinases, Elm1, Tos3, and Sak1, in the maltose metabolism of baker’s yeast in lean dough. The results suggested that the three kinases played different roles in the regulation of the maltose metabolism of baker’s yeast with differential regulations on MAL genes. Elm1 was necessary for the maltose metabolism of baker’s yeast in maltose and maltose-glucose, and the overexpression of ELM1 could enhance the maltose metabolism and lean dough fermentation ability by upregulating the transcription of MALx1 (x is the locus) in maltose and maltose-glucose and MALx2 in maltose. The native level of TOS3 and SAK1 was essential for yeast cells to adapt glucose repression, but the overexpression of TOS3 and SAK1 alone repressed the expression of MALx1 in maltose-glucose and MALx2 in maltose. Moreover, the three kinases might regulate the maltose metabolism via the Snf1-parallel pathways with a carbon source-dependent manner. These results, for the first time, suggested that Elm1, rather than Tos3 and Sak1, might be the dominant regulator in the maltose metabolism of baker’s yeast. These findings provided knowledge about the glucose repression of maltose and gave a new perspective for breeding industrial yeasts with rapid maltose metabolism.

COD REDUCTION OF BAKER'S YEAST WASTEWATER USING BATCH ELECTROCOAGULATION

2014 ◽  
Vol 13 (12) ◽  
pp. 3153-3160 ◽  
Author(s):  
Zakaria Al-Qodah ◽  
Mohammad Al-Shannag ◽  
Kholoud Alananbeh ◽  
Nahla Bouqellah ◽  
Eman Assirey ◽  
...  
Keyword(s):  
Baker’S Yeast ◽  
Baker's Yeast ◽  
Cod Reduction ◽  
Yeast Wastewater

The use of β-glucan extracted from baker’s yeast (Saccharomyces cerevisiae) to increase non-specific immune system and resistence of tilapia (Oreochromis niloticus) to Aeromonas hydrophila

2013 ◽  
pp. 92
Author(s):  
Ida N Jamal ◽  
Reiny A Tumbol ◽  
Remy E.P Mangindaan
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Immune System ◽  
Aeromonas Hydrophila ◽  
Phagocytic Activity ◽  
Baker’S Yeast ◽  
Baker's Yeast ◽  
Yeast Saccharomyces Cerevisiae ◽  
Randomized Design ◽  
The Difference ◽  
Motile Aeromonas Septicaemia

Motile Aeromonas Septicaemia disease (MAS) attacking tilapia has increased in recent years as a consequence of intensive aquaculture activities, which led to losses in aquaculture industry. The agent causing MAS disease is Aeromonas hydrophila. The disease can be controlled with the β-glucan. As immunostimulants, β-glucans can also increase resistance in farmed tilapia. Studies on the use of β-glucan extracted from baker's yeast Saccharomyces cerevisiae was intended to evaluate the non-specific immune system of tilapia that were challenged with Aeromonas hydrophila. The method used was an experimental method with a completely randomized design consisting of four treatments with three replicats. The dose of β-glucan used as treatments were 0 mg.kg-1 fish (Control), 5 mg.kg-1 fish (B), 10 mg.kg-1 fish (C) and 20 mg.kg-1 fish (D), each treatment as injected three times at intervals of 3 days, the injection volume of 0.5 ml/fish for nine days and resistance surveillance for seven days. The results showed that the difference in the amount of β-glucan and the frequency of the injected real influence on total leukocytes, phagocytic activity and resistance. Total leukocytes, phagocytic activity and resistance to treatment was best achieved by the administration of C a dose of  10 mg.kg-1 of the fish© Penyakit Motil Aeromonas Septicaemia (MAS) yang menyerang ikan nila mengalami peningkatan selama beberapa tahun terakhir sebagai konsekuensi dari kegiatan akuakultur intensif, yang menyebabkan kerugian dalam industri budidaya. Agen utama penyebab penyakit MAS adalah Aeromonas hydrophila. Untuk mengendalikan penyakit tersebut dapat dilakukan dengan pemberian β-glukan. Sebagai imunostimulan, β-glukan juga dapat  meningkatkan resistensi pada ikan nila yang dibudidayakan. Pengkajian mengenai pemanfaatan β-glukan yang diekstrak dari ragi roti Saccharomyces cerevisiae dimaksudkan untuk menguji sistem imun non spesifik ikan nila yang diuji tantang dengan bakteri Aeromonas hydrophila. Metode yang digunakan yaitu metode eksperimen dengan rancangan acak lengkap yang terdiri dari empat perlakuan dan tiga ulangan. Dosis β-glukan  yang digunakan sebagai perlakuan sebesar 0 mg.kg-1 ikan (Kontrol), 5 mg.kg-1 ikan (B), 10 mg.kg-1 ikan (C) dan 20 mg.kg-1 ikan (D), masing-masing perlakuan diinjeksi sebanyak 3 kali dengan interval waktu 3 hari selama 9 hari, volume injeksi 0,5 mL/ekor ikan dan pengamatan resistensi selama tujuh hari. Hasil penelitian menunjukkan perbedaan jumlah β-glukan dan frekuensi pemberian yang diinjeksikan memberikan pengaruh nyata terhadap total leukosit, aktivitas fagositosis dan resistensi. Total leukosit, aktivitas fagositosis dan resistensi terbaik dicapai pada perlakuan C dengan dosis 10 mg.kg-1 ikan©

Efficacy of Novel Schiff base Derivatives as Antifungal Compounds in Combination with Approved Drugs Against Candida Albicans

2019 ◽  
Vol 15 (6) ◽  
pp. 648-658 ◽  
Author(s):  
Manzoor Ahmad Malik ◽  
Shabir Ahmad Lone ◽  
Parveez Gull ◽  
Ovas Ahmad Dar ◽  
Mohmmad Younus Wani ◽  
...  
Keyword(s):  
Schiff Base ◽  
Candida Albicans ◽  
Antifungal Activity ◽  
Fungal Infections ◽  
Total Sterol ◽  
Antifungal Drugs ◽  
New Drugs ◽  
Ergosterol Biosynthesis ◽  
Dependent Manner ◽  
Schiff Base Derivatives

Background: The increasing incidence of fungal infections, especially caused by Candida albicans, and their increasing drug resistance has drastically increased in recent years. Therefore, not only new drugs but also alternative treatment strategies are promptly required. Methods: We previously reported on the synergistic interaction of some azole and non-azole compounds with fluconazole for combination antifungal therapy. In this study, we synthesized some non-azole Schiff-base derivatives and evaluated their antifungal activity profile alone and in combination with the most commonly used antifungal drugs- fluconazole (FLC) and amphotericin B (AmB) against four drug susceptible, three FLC resistant and three AmB resistant clinically isolated Candida albicans strains. To further analyze the mechanism of antifungal action of these compounds, we quantified total sterol contents in FLC-susceptible and resistant C. albicans isolates. Results: A pyrimidine ring-containing derivative SB5 showed the most potent antifungal activity against all the tested strains. After combining these compounds with FLC and AmB, 76% combinations were either synergistic or additive while as the rest of the combinations were indifferent. Interestingly, none of the combinations was antagonistic, either with FLC or AmB. Results interpreted from fractional inhibitory concentration index (FICI) and isobolograms revealed 4-10-fold reduction in MIC values for synergistic combinations. These compounds also inhibit ergosterol biosynthesis in a concentration-dependent manner, supported by the results from docking studies. Conclusion: The results of the studies conducted advocate the potential of these compounds as new antifungal drugs. However, further studies are required to understand the other mechanisms and in vivo efficacy and toxicity of these compounds.

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