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Glycogen is a highly branched polyglucan utilized as a carbohydrate reserve in major living systems. Industrially, it is used as a prebiotic and in the nanoencapsulation of drugs and nutraceuticals. In this study, optimal fermentation conditions enabling the highest glycogen accumulation in Saccharomyces cerevisiae were experimentally evaluated for possible mass production. Production efficiency was assessed by comparing specific growth rates, specific glycogen production rates, and glycogen yields under each condition. The results demonstrated that fermentation at 30 °C with an aeration rate of 3 vvm using a medium containing 120 g/L glucose without ethanol was optimal for robust cell growth and maximum glycogen yield. Additionally, a rich medium outperformed a minimally defined medium, and a single sugar carbon source, as opposed to mixed sugars, resulted in significantly higher cell growth and glycogen yields (p < 0.05). The optimized fermentation parameters enabled a glycogen production rate of up to 0.232 ± 0.012 g-glycogen/g-cell/h and a glycogen yield of 0.603 ± 0.006 g-glycogen/g-glucose. These results provide meaningful information for future studies and/or large-scale glycogen production using S. cerevisiae. [ABSTRACT FROM AUTHOR]

Meiosis is a process through which diploid cells divide into haploid cells, thus promoting genetic diversity. This diversity arises from the formation of genetic crossovers (COs) that repair DNA double-strand breaks (DSBs), through homologous recombination (HR). Deficiencies in HR can lead to chromosomal abnormality resulting from chromosomal nondisjunction, and genetic disorders. Therefore, investigating the mechanisms underlying effective HR is crucial for reducing genome instability. Budding yeast serves as an ideal model for studying HR mechanisms due to its amenability to gene modifications and the ease of inducing synchronized meiosis to yield four spores. During meiosis, at the DNA level, programmed DSBs are repaired as COs or non-crossovers (NCOs) through structural alterations in the nascent D-loop, involving single-end invasions (SEIs) and double-Holliday junctions (dHJs). This repair occurs using homologous templates rather than sister templates. This protocol, using Southern blotting, allows for the analysis and monitoring of changes in DNA structures in the recombination process. One-dimensional (1D) gel electrophoresis is employed to detect DSBs, COs, and NCOs, while two-dimensional (2D) gel electrophoresis is utilized to identify joint molecules (JMs). Therefore, physical analysis is considered the most effective method for investigating the HR mechanism. Our protocol provides more comprehensive information than previous reports by introducing conditions for obtaining a greater number of cells from synchronized yeast and a method that can analyze not only meiotic/mitotic recombination but also mitotic replication. [ABSTRACT FROM AUTHOR]

Buah merah oil and red palm oil are red colored and unrefined edible oils. Because of this color characteristic, measuring acid value by titration method can be uncertain and subjective, so more accurate and objective methods are needed. Gas chromatography-flame ionization detector (GC-FID) and high-performance liquid chromatography-evaporative light scattering detector (HPLC-ELSD) methods were developed to determine acid value in 3 buah merah oils and 1 red palm oil by measuring free fatty acid contents. The acid value was high in the order of titration > GC-FID > HPLC-ELSD in all samples. GC-FID method showed accurate and reliable results, whereas HPLC-ELSD showed rough data partly due to the non-linear standard curve and high limit of detection. Difference in acid value between titration method and GC-FID might be due to unrefined components that reacted with KOH titration solution. GC-FID can be used measuring free fatty acid contents in red colored oils. [ABSTRACT FROM AUTHOR]

Summary: Radio wave treatment (approximately 50 kHz frequency) on the oxidative stability was evaluated in corn oil at 180 °C and chicken frying oil for 150 cycles. Radio wave treatment decreased moisture content and critical micelle concentration of lecithin in corn oil. Moisture content in frying oil remained higher when radio wave was treated for the first 30 frying cycles. Radio wave treatment prevented lipid oxidation significantly in corn oil heated at 180 °C when moisture was not added (P < 0.05). p‐Anisidine value and total polar material in chicken frying oils treated with radio waves were significantly lower than those of frying oils without radio wave treatment (P < 0.05). Radio wave treatment enhanced the stability of tocopherols in corn oil heated at 180 °C in the absence of moisture, while the reverse result was observed with moisture addition. Overall, radio wave treatment can be a useful tool to enhance the oxidative stability of frying oils by modifying their moisture content and tocopherol stability. [ABSTRACT FROM AUTHOR]

Summary: Chitosan was modified using H2O2 and ascorbic acid with different incubation temperatures (4–40 °C). The properties of modified chitosan, including its oil entrapment ability, water solubility and the lipase‐resistant activities, using in vitro intestine model system were determined. Nuclear magnetic resonance analysis showed that ascorbic acid was bound to modified chitosan. All of the modified chitosan from 4 to 40 °C demonstrated improved water solubility (even in pH 7) compared to non‐modified chitosan, which was only soluble at pH 4. Modified chitosan from 4 °C exhibited 27.40% of oil entrapment ability which was approximately four times higher than 6.87% of non‐modified chitosan. Modified chitosan from 4 and 40 °C had increased resistance against lipase activity compared to other biopolymers, including beeswax, carnauba wax and non‐modified chitosan. Modified chitosan could be used as a new food ingredient due to their high water solubility, oil‐entrapping ability and resisting lipase activity. [ABSTRACT FROM AUTHOR]

The effects of polar and non‐polar compounds recovered from oxidized corn oils on oxidative stability in bulk oils are evaluated in the presence or absence of an antioxidant, tert‐butylhydroquinone (TBHQ). The balance of antioxidant and prooxidant compounds in oils is confirmed using the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) spectroscopic method. Polar compounds accelerated the depletion of headspace oxygen content and increased the conjugated dienoic acid value and p‐anisidine value in oils with or without 200 ppm TBHQ, which implies that polar compounds from oxidized lipids are prooxidants. However, added non‐polar compounds showed no prooxidative properties in oils, irrespective of the presence of TBHQ. The antioxidant‐prooxidant balance (APB) value, which is calculated as the ratio of the loss of DPPH in isooctane to that in methanol, may reflect the content balance between antioxidant and prooxidative oxidized lipid products in oils. Low APB values indicate that oils are in a highly oxidized state. Practical Applications: Polar compounds from oxidized oils act as prooxidants. Therefore, it is necessary to determine the polar content in frying oils accurately. Using modified DPPH methods, not only the content of antioxidants but also prooxidative polar compounds in oils can be determined simultaneously. Modified DPPH methods can predict the oxidative stability of frying oil and help to extend the shelf‐life of fried foods in the food industry. Polar compounds from oxidized oils function as prooxidants. Non‐polar compounds do not act as prooxidants nor antioxidants. Modified 2,2‐diphenyl‐1‐picrylhydrazyl methods can predict the oxidative stability of frying oil. [ABSTRACT FROM AUTHOR]

Effects of deuteron (D) and electron donors on the oxidative stability in linoleic acid-water model systems were evaluated by analyzing headspace oxygen content and headspace volatiles. Acetic acid- d and tetrakis(dimethylamino)ethylene (TDAE) were selected as a deuteron and an electron donor, respectively. Samples containing acetic acid- d had significantly lower headspace oxygen content than controls while those containing TDAE had significantly higher headspace oxygen content ( p < 0.05). Combination of acetic acid- d and TDAE accelerated the consumption of headspace oxygen. Volatiles including t-2-heptenal, 2-octenal, or 2,4-octadienal had higher mass to charge ratio ( m/ z) of (molecular weight +1)/molecular weight in samples with deuterium oxide than in samples with deuterium free water. However, no significant difference was observed in the m/ z ratio of (molecular weight +1)/molecular weight of those volatiles among samples with or without deuteron or electron donors. Also, lipid hydroperoxides with deuterium, were not found in samples containing deuterium oxide and acetic acid- d. Therefore, added acetic acid- d may not be involved on the formation of lipid hydroperoxides and volatiles directly. [ABSTRACT FROM AUTHOR]

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As optical lithography goes deep into the ultraviolet (UV) range for higher resolution, high-energy photons cause many problems that are associated with the photomask (PM). Upon repeated deep-UV exposure, unwanted crystals or layers can form on the PM surface following the photoreaction of surrounding contaminants. Moreover, the pellicle that is a part of the PM can react with deep UV, although it is designed to show high transparency and radiation durability. Our pellicle showed an initial reduction in thickness and then an increase in absorption after extended exposure to the 193 nm line of an ArF excimer laser. Both phenomena were responsible for the transmission loss of a pellicle. Particularly, the transmission loss caused by the thickness reduction was related to the interference effect. Lithography simulation showed that the reduced transmission by the pellicle led to the critical dimension variation. Moreover, a non-uniform reduction of thickness near the edge of the exposed area suggested that the apodization effect might occur near the edge of patterns. [ABSTRACT FROM AUTHOR]