https://scholar.dgist.ac.kr/handle/20.500.11750/890 2026-04-04T13:36:45Z https://scholar.dgist.ac.kr/handle/20.500.11750/59989 Title: Hydrogen Evolution via Oxygen Tolerant [NiFe]-Hydrogenase Immobilized on TiO2 Nanotubes Author(s): Kim, Hwapyong; Kim, Ki Nam; Lee, Sang-Hyeon; Nam, Chang-Hoon; Lee, Young-Sam; In, Su-Il Abstract: [FeFe]-hydrogenase has been of great interest due to its high enzymatic activity for hydrogen evolution reactions (HERs). However, the big challenge of [FeFe]-hydrogenase is a significant performance degradation in aerobic conditions. On the other hand, [NiFe]-hydrogenase of E. coli has an oxygen tolerant property. Therefore, using [NiFe]-hydrogenase is an effective solution to avoid performance degradation in aerobic conditions. Herein, we extracted [NiFe]-hydrogenases from E. coli and immobilized them on the TiO2 nanotube (TNT) electrode prepared by pyrrole-based electropolymerization for application in aerobic conditions. As a result, we can confirm that [NiFe]-hydrogenases coated TNT electrode demonstrates the increased HER activity underaerobic condition than control samples in in-vitro activity test using methylene viologen and linear sweep voltammetry. 2025-12-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/57310 Title: Brief guide to senescence assays using cultured mammalian cells Author(s): Kang, Eunseok; Kang, Chanhee; Lee, Young-Sam; Lee, Seung-Jae V. Abstract: Cellular senescence is a crucial biological process associated with organismal aging and many chronic diseases. Here, we present a brief guide to mammalian senescence assays, including the measurement of cell cycle arrest, change in cellular morphology, senescence-associated β-galactosidase (SA-β-gal) staining, and the expression of senescence-associated secretory phenotype (SASP). This work will be useful for biologists with minimum expertise in cellular senescence assays. © 2024 The Author(s) 2024-08-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/57090 Title: The ICL1 and MLS1 Genes, Integral to the Glyoxylate Cycle, are Essential and Specific for Caloric Restriction-Mediated Extension of Lifespan in Budding Yeast Author(s): Kwon, Young-Yon; Lee, Han-Jun; Lee, Myung-Jin; Lee, Young-Sam; Lee, Cheol-Koo Abstract: The regulation of complex energy metabolism is intricately linked to cellular energy demands. Caloric restriction (CR) plays a pivotal role in modulating the expression of genes associated with key metabolic pathways, including glycolysis, the tricarboxylic acid (TCA) cycle, and the glyoxylate cycle. In this study, the chronological lifespan (CLS) of 35 viable single-gene deletion mutants under both non-restricted and CR conditions, focusing on genes related to these metabolic pathways is evaluated. CR is found to increase CLS predominantly in mutants associated with the glycolysis and TCA cycle. However, this beneficial effect of CR is not observed in mutants of the glyoxylate cycle, particularly those lacking genes for critical enzymes like isocitrate lyase 1 (icl1Δ) and malate synthase 1 (mls1Δ). This analysis revealed an increase in isocitrate lyase activity, a key enzyme of the glyoxylate cycle, under CR, unlike the activity of isocitrate dehydrogenase, which remains unchanged and is specific to the TCA cycle. Interestingly, rapamycin, a compound known for extending lifespan, does not increase the activity of the glyoxylate cycle enzyme. This suggests that CR affects lifespan through a distinct metabolic mechanism. © 2024 The Authors. Advanced Biology published by Wiley-VCH GmbH. 2024-08-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/56995 Title: Animal-free scaffold from brown algae provides a three-dimensional cell growth and differentiation environment for steak-like cultivated meat Author(s): Lee, Heejae; Kima, Dasom; Choi, Kyeong Hun; Lee, Sangmin; Jo, Minguk; Chun, Song-Yi; Son, Yebin; Lee, Jong Ha; Kima, Kwanhyeong; Lee, TaeByung; Keum, Joonho; Yoon, Min; Cha, Hyung Joon; Rho, Sangchul; Cho, Sung Chun; Lee, Young Sam Abstract: Scaffolds for the production of cultivated meat, a promising sustainable meat alternative, should exhibit physical and chemical properties that enable three-dimensional animal cell culture, along with biological characteristics that support cell attachment, proliferation, and differentiation. Additionally, the scaffold should be crafted from edible materials and offer textural similarities to meat and have minimal influence on flavor and taste. Herein, an edible alginate-based alginate-cellulose hydrogel (ACe-gel) scaffold derived from the brown alga Undaria pinnatifida is developed. In terms of physical characteristics, the scaffold had porosity (119.5 ± 37.2 μm) and moisture-holding capacity (73.03 ± 3.82, 68.66 ± 9.54, and 84.17 ± 9.94 at 25 °C, 37 °C, and 60 °C, respectively) suitable for three-dimensional culture and differentiation of bovine muscle stem cells (bMuSCs). Accordingly, the scaffold was superior to a commercial alginate scaffold in terms of the attachment and proliferation of bMuSCs (5.5-fold over 72 h), and its performance was comparable with that of a lyophilized collagen scaffold (7.8-fold over 72 h, compared with the pure alginate). The bMuSCs cultured on the ACe-gel scaffold were capable of differentiating into muscle fibers, as verified by gene expression profile analysis. Furthermore, the scaffold exhibited minimal heavy metal contents and distinct seaweed odorants, while the stress-strain characteristics of the scaffold cultured with bMuSC (Young's modulus of raw ACe-gel: 285.19 ± 83.37 kPa, cooked ACe-gel meat: 880.60 ± 485.60 kPa) closely resembled that of meat (raw beef: 267.76 ± 156.42 kPa, cooked beef: 1331.94 ± 762.43 kPa). These findings highlight that the seaweed-derived and animal-free ACe-gel scaffold has strong potential for utilization as a food technology for cultured meat production in the future. © 2024 The Authors 2024-06-30T15:00:00Z