Algal bioproducts : investigating the effect of light quality on metabolite production by photosynthetic diatoms

University of Technology Sydney. Faculty of Science.In Australia, between 2016 and 2017, aquaculture products made up 44% of Australian seafood product in value, reaching over $1.35 billion in production value. One of the top five profitable Australian aquaculture products during this period were edible oysters which is worth more than$112 million in production value. Oysters are fed with live microalgae (including diatoms) during the larval, juvenile and adult stages of growth, as are other shellfish, some crustaceans, shrimps/prawns and fish. The rearing of oysters and other aquaculture products rely on the constant production of live diatoms as feed. Diatom production in Australian hatcheries are commonly recognised as the major bottleneck in oyster production, estimated to be on average, 30-40% of hatchery operational cost. In order to meet the increasing production demand diatom production must be improved, while making it economically feasible and environmentally sustainable. In this thesis, , a common feed for oysters, was studied for their responses to a variety of environmental growth conditions including light. To achieve this, laboratory scale photobioreactors were used to continuously monitor environmental factors to record biological responses of . to different environmental conditions including light wavelengths. A brief introduction to diatom physiology and its application to aquaculture will be provided in Chapter one. The second chapter assessed the two key environmental limitations in diatom cultivation in aquaculture facilities, light and CO₂. An empirical process model was developed to analyse the importance of light configuration to maximise light availability. High CO₂ availability coupled with high light availability significantly increased growth rates and maximum cell density. The third chapter then assessed the growth, metabolic content and cost efficiency of different colour LEDs (blue, green, red and white) based on the findings in Chapter 2. Blue light was found to be the most cost efficient in biomass and metabolite production, requiring less than half the Watt hours of other LEDs. In the fourth chapter, the wavelength of the growth light was shifted to assess its feasibility to modify metabolic content, as well as its effects on growth, photosynthesis and digestibility. The final chapter discussed the key findings of the thesis and the future research prospects. Several important avenues were identified to improve diatom production in aquaculture, such as improving light availability to increase the efficiency of CO₂ usage, blue LEDs to improve cost efficiency of biomass production and the utilization of wavelength shifting to manipulate diatom metabolite content

Biomass Gasification: A Review of Its Technology, Gas Cleaning Applications, and Total System Life Cycle Analysis

Gasification technology presents one option for energy-conversion technique from woody biomass contaminated by radionuclides released in March 2011 during the Fukushima Dai-ichi Nuclear Power Plant accident. The gasification process converts carbonaceous materials into combustible gases, carbon dioxide, and residues. Owing to their small-scale distributed configuration, woody biomass gasification plants are suitable for gasifying Japan’s biomass and have been installed increasingly in Japan recently. This chapter reviews current trends of gasification and life cycle assessment (LCA) of total systems, including gas cleaning

Key Interactions in Integrin Ectodomain Responsible for Global Conformational Change Detected by Elastic Network Normal-Mode Analysis

AbstractIntegrin, a membrane protein with a huge extracellular domain, participates in cell-cell and cell-extracellular-matrix interactions for metazoan. A group of integrins is known to perform a large-scale structural change when the protein is activated, but the activation mechanism and generality of the conformational change remain to be elucidated. We performed normal-mode analysis of the elastic network model on integrin αVβ3 ectodomain in the bent form and identified key residues that influenced molecular motions. Iterative normal-mode calculations demonstrated that the specific nonbonded interactions involving the key residues work as a snap to keep integrin in the bent form. The importance of the key residues for the conformational change was further verified by mutation experiments, in which integrin αIIbβ3 was used. The conservation pattern of amino acid residues among the integrin family showed that the characteristic pattern of residues seen around these key residues is found in the limited groups of integrin β-chains. This conservation pattern suggests that the molecular mechanism of the conformational change relying on the interactions found in integrin αVβ3 is unique to the limited types of integrins

Combined Omics Approaches Reveal the Roles of Non-canonical WNT7B Signaling and YY1 in the Proliferation of Human Pancreatic Progenitor Cells

ヒト膵臓細胞の増殖メカニズムを解明 --糖尿病治療に向けて前進--. 京都大学プレスリリース. 2020-10-30.The proliferation of human pancreatic progenitor cells (PPCs) is critical for developing cell therapies for diabetes. Here, using transcriptome analysis combined with small interfering RNA (siRNA) screening, we revealed that WNT7B is a downstream growth factor of AT7867, a compound known to promote the proliferation of PPCs generated from human pluripotent stem cells. Feeder cell lines stably expressing mouse Wnt7a or Wnt7b, but not other Wnts, enhanced PPC proliferation in the absence of AT7867. Importantly, Wnt7a/b ligands did not activate the canonical Wnt pathway, and PPC proliferation depended on the non-canonical Wnt/PKC pathway. A comparison of the phosphoproteome in response to AT7867 or a newly synthesized AT7867 derivative uncovered the function of YY1 as a transcriptional regulator of WNT7B. Overall, our data highlight unknown roles of non-canonical WNT7B/PKC signaling and YY1 in human PPC proliferation and will contribute to the stable supply of a cell source for pancreatic disease modeling and therapeutic applications

Der durch die Versicherung ersätzte Schiffbauschaden : bei construction pour compte und construction par économie

故池垣定太郎教授追悼特