Systematic identification of microalgal species for lipid production and genome based molecular characterization of the oleaginous microalga Monoraphidium neglectum

Bogen C. Systematic identification of microalgal species for lipid production and genome based molecular characterization of the oleaginous microalga Monoraphidium neglectum. Bielefeld: Universität Bielefeld; 2013.In the light of the depletion of fossil fuel reserves worldwide, the search for sustainable and more environmental friendly alternatives becomes decisive. The generation of liquid fuels as bioethanol or biodiesel from biomass are already considered as economically viable options. However, conflicts of interest arise when the generation of food or animal feedstock competes with biomass production for conversion to biofuels. The use of microalgae could offer a possible solution to several of these problems; however a more wide-spread use is hampered by the requirement of suitable strains for bulk chemical generation. Though a lot of effort has been spent in finding suitable strains in the past years, much of the potential that can be found in the biodiversity of algae remains untouched. In this work, microalgae that originated from established strain collections but have not been in the focus of biofuel-related research before were investigated on their potential for liquid biofuel production. This approach was complemented by the isolation of new strains from mainly local freshwater and marine water bodies, followed by a detailed characterization in terms of biomass and lipid productivity as well as of their fatty acid profiles. The genus Monoraphidium could be identified as highly interesting for these purposes, since many members show robust growth and considerably high lipid productivities. Two strains of interest, Monoraphidium contortum and Monoraphidium neglectum, were investigated in detail and compared to the model organism Chlamydomonas reinhardtii. Both Monoraphidium strains showed a pronounced increase of neutral lipids under nitrogen starvation which could be furthermore enhanced in lower culture densities, consequently resulting in better light availability for the cells. The accumulation of lipids was not only superior to that of C. reinhardtii but also resulted in a fatty acid profile with a dominance of C18:1 and C16:0 fatty acids, which is promising for liquid biofuel generation. In addition, cells of M. neglectum were found to increase their size at defined salt concentrations, thereby offering the possibility for facilitated down-stream processing. Key element for liquid biofuel production is the content of neutral lipids, namely triacylglycerol (TAG), in the biomass. The elucidation of pathways for TAG synthesis is currently subject to intense research efforts. Therefore the role of two distinct metabolic pathways was investigated in more detail in the model organism C. reinhardtii. To gain further insights into the lipid metabolism of Monoraphidium and to allow targeted improvement of these strains, the genome of M. neglectum was sequenced. The annotation of pathways of fatty acid synthesis as well as within the glycerolipid metabolism allowed not only detailed insights into the diversity of oleaginous organisms, but also leads to further promising targets to improve this strain. Within this work, the Selenastraceae could be identified as a highly interesting family with a number of interesting strains for biomass generation that also have a high potential for subsequent conversion to liquid biofuels. The sequencing of Monoraphidium neglectum was performed to establish this species as future model organism for the other members of this family and also opens the possibility for future targeted engineering approaches

Reconstruction of the lipid metabolism for the microalga Monoraphidium neglectum from its genome sequence reveals characteristics suitable for biofuel production

Bogen C, Al-Dilaimi A, Albersmeier A, et al. Reconstruction of the lipid metabolism for the microalga Monoraphidium neglectum from its genome sequence reveals characteristics suitable for biofuel production. BMC Genomics. 2013;14(1): 926.BACKGROUND: Microalgae are gaining importance as sustainable production hosts in the fields of biotechnology and bioenergy. A robust biomass accumulating strainof the genus Monoraphidium (SAG 48.87) was investigated in this work as apotential feedstock for biofuel production. The genome was sequenced, annotated, and key enzymes for triacylglycerol formation were elucidated. RESULTS: Monoraphidium neglectum was identified as an oleaginous species with favourable growth characteristics as well as a high potential for crude oil production, based on neutral lipid contents of approximately 21% (dry weight) under nitrogen starvation, composed of predominantly C18:1 and C16:0 fatty acids. Further characterization revealed growth in a relatively wide pH range and salt concentrations of up to 1.0% NaCl, in which the cells exhibited larger structures. This first full genome sequencing of a member of the Selenastraceae revealed a diploid, approximately 68 Mbp genome with a G + C content of 64.7%. The circular chloroplast genome was assembled to a 135,362 bp single contig, containing 67 protein-coding genes. The assembly of the mitochondrial genome resulted in two contigs with an approximate total size of 94 kb, the largest known mitochondrial genome within algae. 16,761 protein-coding genes were assigned to the nuclear genome. Comparison of gene sets with respect to functional categories revealed a higher gene number assigned to the category "carbohydrate metabolic process" and in "fatty acid biosynthetic process" in M. neglectum when compared to Chlamydomonas reinhardtii and Nannochloropsis gaditana, indicating a higher metabolic diversity for applications in carbohydrate conversions of biotechnological relevance. CONCLUSIONS: The genome of M. neglectum, as well as the metabolic reconstruction of crucial lipid pathways, provides new insights into the diversity of the lipid metabolism in microalgae. The results of this work provide a platform to encourage the development of this strain for biotechnological applications and production concepts

Remodelling of oxidative energy metabolism by galactose improves glucose handling and metabolic switching in human skeletal muscle cells

Cultured human myotubes have a low mitochondrial oxidative potential. This study aims to remodel energy metabolism in myotubes by replacing glucose with galactose during growth and differentiation to ultimately examine the consequences for fatty acid and glucose metabolism. Exposure to galactose showed an increased [14C]oleic acid oxidation, whereas cellular uptake of oleic acid uptake was unchanged. On the other hand, both cellular uptake and oxidation of [14C]glucose increased in myotubes exposed to galactose. In the presence of the mitochondrial uncoupler carbonylcyanide p-trifluormethoxy-phenylhydrazone (FCCP) the reserve capacity for glucose oxidation was increased in cells grown with galactose. Staining and live imaging of the cells showed that myotubes exposed to galactose had a significant increase in mitochondrial and neutral lipid content. Suppressibility of fatty acid oxidation by acute addition of glucose was increased compared to cells grown in presence of glucose. In summary, we show that cells grown in galactose were more oxidative, had increased oxidative capacity and higher mitochondrial content, and showed an increased glucose handling. Interestingly, cells exposed to galactose showed an increased suppressibility of fatty acid metabolism. Thus, galactose improved glucose metabolism and metabolic switching of myotubes, representing a cell model that may be valuable for metabolic studies related to insulin resistance and disorders involving mitochondrial impairments

Serum levels of bone sialoprotein correlate with portal pressure in patients with liver cirrhosis

Liver cirrhosis represents the common end-stage of chronic liver diseases regardless of its etiology. Patients with compensated disease are mostly asymptomatic, however, progression to a decompensated disease stage is common. The available stratification strategies are often unsuitable to identify patients with a higher risk for disease progression and a limited prognosis. SIBLINGs, soluble glycophosphoproteins, are secreted into the blood by immune-cells. While osteopontin, the most prominent member of the SIBLINGs family, has been repeatedly associated with liver cirrhosis, data on the diagnostic and/or prognostic value of bone sialoprotein (BSP) are scarce and partly inconclusive. In this study, we analyzed the diagnostic and prognostic potential of circulating BSP in comparison to other standard laboratory markers in a large cohort of patients with liver cirrhosis receiving transjugular intrahepatic portosystemic shunt (TIPS). Serum levels of BSP were similar in patients with different disease stages and were not indicative for prognosis. Interestingly, BSP serum levels did correlate inversely with portal pressure, as well as its surrogates such as platelet count, the portal vein cross-sectional area and correlated positively with the portal venous velocity. In summary, our data highlight that BSP might represent a previously unrecognized marker for portal hypertension in patients with liver cirrhosis

Tech Imaginations

Prof. Dr. Jens Schröter, Christoph Borbach, Max Kanderske und Prof. Dr. Benjamin Beil sind Herausgeber der Reihe. Die Herausgeber*innen der einzelnen Hefte sind renommierte Wissenschaftler*innen aus dem In- und Ausland.Technologies and especially media technologies are pervasive in modern societies. But even more omnipresent are the imaginaries of modern technologies – what technologies are thought to be capable of or what effects they are supposed to have. These imaginations reveal a lot of the political and ideological self-descriptions of societies, hence the (techno-)imaginary also functions as a kind of epistemic tool. Concepts of the imaginary therefore have experienced an increasing attention in cultural theory and the social sciences in recent years. In particular, work from political philosophy, but also approaches from science and technology studies (STS) or communication and media studies are worth mentioning here. The term "techno-imagination", coined by Vilém Flusser in the early 1990s, refers to the close interconnection of (digital) media and imaginations, whose coupling can not only be understood as a driver of future technology via fictional discourses (e.g. science fiction), but much more fundamentally also as a constitutive element of society and sociality itself, as Castoriadis has argued. In the first part of the issue several theoretical contributions add new aspects to the discussion of socio-technical imaginaries, while in the second part a workshop held in January 2022 at the CAIS in Bochum is documented, in which the case of the imaginaries of “Future Internets” was discussed

Järnring och nyhetsöken : En studie om rapporteringen under gisslandramat i Algeriet 2013

Detta är en studie om hur norska och svenska dagstidningar hanterade problem med källkritik, nyhetsvärdering och krisjournalistik i samband med gisslandramat på gasanläggningen In Amenas i Algeriet i januari 2013. Syftet med undersökningen är att se hur journalisterna arbetade i en situation där det fanns extremt lite information att tillgå, samtidigt som allmänheten krävde ständiga uppdateringar. Tidningarna som ingår i undersökningen är Verdens Gang, Aftenposten, Dagens Nyheter, Aftonbladet, Svenska Dagbladet och Expressen.  Vi har valt att genomföra undersökningen i två steg. Första steget var att göra en kvantitativ innehållsanalys för att ta reda på vilka källor journalisterna har använt sig av.  Till det har vi använt 93 artiklar författade under tidsperioden 16-30 januari 2013. Steg två var samtalsintervjuer med journalister som skrivit om händelsen.  Resultatet visar att tidningarna använde osäkra och tendensiösa källor i andra- och tredjehand i sin rapportering. Journalisterna ansåg att detta var rätt att göra i det svåra läge som rådde, dock under förutsättning att det framgick för läsarna att det var osäkra uppgifter och källor. Undersökningen visar också att tidningarna var beroende av nyhetsbyråer och andra medier för att klara rapporteringen

Estimating long term sediment yields from sediment core analysis

Abstract: Estimating long term sediment yields from sediment core analysis. Sediment cores from lakes and reservoirs can be used to estimate sediment yields. In proglacial lakes, the bed sediment typically accumulates as varves, refl ecting changes in seasonal and annual sedimentation. This report compares the results from two different methods of measuring suspended sediment transport in a Norwegian glacial river and lake. Sediment yields obtained from a study of sediment cores in the proglacial lake Nigardsvatn along with measurements of the delta topset were compared with a 25-year record of sediment transport based on automatic water sampling and water discharge measurements at a monitoring station at the infl owing river. During the period from 1980 to 2005, analyses of sediment cores taken from the lake bed along with measurements and grain size distribution analysis of the delta indicated that a volume of 175,670 to 202,697 m 3 was deposited in the lake Nigardsvatn and corresponding river delta. The year 1980 was selected as a convenient starting point because a large-magnitude fl ood with a 100-year recurrence interval occurred at the end of 1979, leaving an easily recognizable sediment layer and accurate reference point. Sediment cores were taken at a total of 24 locations throughout the lake and 25 locations in the delta. The densities of the sediment cores were found to vary between 1.3 and 1.5 g/cm 3 during the period examined in this study, giving a total suspended sediment load of between 175,670 and 202,697 tons. The measurements carried out at the sediment station in the glacier melt-water river gave a value of 294,800 tons during the same period. A fi nal value of 211,100 tons is calculated from the monitoring station results after deduction of the sediment fraction which passes through the lake without being deposited. This gives a discrepancy between the two methods of 8,403 to 35,430 tons (4-20%). This can be partially attributed to the diffi culties of measuring the water discharge in the unstable glacier meltwater river. In conclusion, sediment cores may be used to extrapolate or correct measurements from sediment monitoring stations over longer periods but caution should be made when considering single years

1 Abstract Service Level Management with Agent Technology

The essential aspect of the global evaluation of a service is the opinion of the users of the service. The result of this evaluation expresses the users ‘ degrees of satisfaction [ITU94]. This paper will outline a generic evaluation methodology for multimedia applications like e-mailbased services, the World Wide Web (WWW), and real-time applications. It concentrates on the application layer and the services aspects. Principles of software evaluation can be used for quality assessment and measurement for networked services and distributed applications. A specific method for measuring important service characteristics is therefore presented. The method and the measurement procedure allows to compare the actual characteristics of service quality with the required characteristics and thresholds. The approach can easily and efficiently be implemented in any organization with other applications too. The proof of concepts will be made by the implementation of quality measurement agents following the quality assessment and measurement methodology for different distributed applications outlined in this paper. Our approach of performing service level management with agent technology is distributed, slim, minimizable to the maximum, and independent in its methodology. Finally it offers comparable, objective results. This paper is not about [M.3010] or [X.711]. It is for end users and (competing) service providers trying to get comparable measurement results by applying common measurement methods and by concentrating on a well-defined subset of quality characteristics

Cost-effective approach to explore key impacts on the environment from agricultural tools to inform sustainability improvements: inversion tillage as a case study

Abstract The United Nations Food Systems Summit and the European Green Deal have prompted various policy and regulatory initiatives aiming to transition agricultural practices to become more sustainable. An array of agricultural systems (e.g., regenerative, conservation agriculture, integrated crop management) have been lauded as potential solutions to improve food production sustainability. These systems use combinations of agricultural tools (e.g., crop rotation) to modify the crop environment to reduce weeds, pests and disease, alongside chemical (e.g., plant protection products) tools. Each tool has the potential to impact both the abiotic and biotic environment, with different combinations of tools having different overall outcomes. To improve the sustainability of agricultural practices it is important to understand, and where possible, quantify the environmental costs and benefits of the various tools that are applied within diverse cropping systems, as well as their potential interactions. While extensive literature exists, practical approaches are needed to cost-effectively synthesise key impacts and interactions to support decision making. A cost-effective methodology, adapting a rapid evidence assessment, was developed to review evidence and enable identification of the key environmental impacts for commonly applied agricultural tool options. The approach was applied to each tool individually (e.g., inversion tillage, crop rotation) to, where possible, isolate their specific impacts on the environment. Focused categories were assessed, considering biotic (insect, earthworms, etc.) and abiotic (soil, water, air quality, climate) impacts. This paper considers inversion tillage (also known as ploughing) as a case study to illustrate findings using the approach. Evidence is presented for direct and indirect impacts on the environment, selectivity of impacts and data gaps. The approach quickly provided robust evidence summaries of the key environmental implications of inversion tillage, facilitating identification of opportunities and trade-offs that can inform practice. The evidence highlighted how inversion tillage can offer effective weed control to reduce herbicide use, but carries increased risk to soil health, with connected implications for water, air and climate. This time-efficient review methodology can facilitate development of clear guidance to inform farmers in their decision making to improve on-farm sustainability, while serving as a useful starting point for conducting evidence reviews for policy development