scholarly journals Association with an Ammonium-Excreting Bacterium Allows Diazotrophic Culture of Oil-Rich Eukaryotic Microalgae

2012 ◽  
Vol 78 (7) ◽  
pp. 2345-2352 ◽  
Author(s):  
Juan Cesar Federico Ortiz-Marquez ◽  
Mauro Do Nascimento ◽  
Maria de los Angeles Dublan ◽  
Leonardo Curatti

ABSTRACTConcerns regarding the depletion of the world's reserves of oil and global climate change have promoted an intensification of research and development toward the production of biofuels and other alternative sources of energy during the last years. There is currently much interest in developing the technology for third-generation biofuels from microalgal biomass mainly because of its potential for high yields and reduced land use changes in comparison with biofuels derived from plant feedstocks. Regardless of the nature of the feedstock, the use of fertilizers, especially nitrogen, entails a potential economic and environmental drawback for the sustainability of biofuel production. In this work, we have studied the possibility of nitrogen biofertilization by diazotrophic bacteria applied to cultured microalgae as a promising feedstock for next-generation biofuels. We have obtained anAzotobacter vinelandiimutant strain that accumulates several times more ammonium in culture medium than wild-type cells. The ammonium excreted by the mutant cells is bioavailable to promote the growth of nondiazotrophic microalgae. Moreover, this synthetic symbiosis was able to produce an oil-rich microalgal biomass using both carbon and nitrogen from the air. This work provides a proof of concept that artificial symbiosis may be considered an alternative strategy for the low-N-intensive cultivation of microalgae for the sustainable production of next-generation biofuels and other bioproducts.

2020 ◽  
Author(s):  
Lucielen Oliveira Santos ◽  
Pedro Garcia Pereira Silva ◽  
Sharlene Silva Costa ◽  
Taiele Blumberg Machado

Use of fuels from non-renewable sources has currently been considered unsustainable due to the exhaustion of supplies and environmental impacts caused by them. Climate change has concerned and triggered environmental policies that favor research on clean and renewable energy sources. Thus, production of third generation biofuels is a promising path in the biofuel industry. To yield this type of biofuels, microalgae should be highlighted because this raw material contains important biomolecules, such as carbohydrates and lipids. Technological approaches have been developed to improve microalgal cultivation under ecological conditions, such as light intensity, temperature, pH and concentrations of micro and macronutrients. Thus, magnetic field application to microalgal cultivation has become a viable alternative to obtain high yields of biomass concentration and accumulation of carbohydrates and lipids.


Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2663 ◽  
Author(s):  
Ziaur Rahman ◽  
Javed Nawab ◽  
Bong Hyun Sung ◽  
Sun Chang Kim

As global fossil reserves are abruptly diminishing, there is a great need for bioenergy. Renewable and sustainable bioenergy products such as biofuels could fulfill the global energy demand, while minimizing global warming. Next-generation biofuels produced by engineered microorganisms are economical and do not rely on edible resources. The ideal biofuels are alcohols and n-alkanes, as they mimic the molecules in fossil fuels and possess high energy densities. Alcohols and n-alkane hydrocarbons (C2 to C18) have been produced using engineered microorganisms. However, it is difficult to optimize the complex metabolic networks in engineered microorganisms to obtain these valuable bio-hydrocarbons in high yields. Metabolic engineering results in drastic and adverse cellular changes that minimize production yield in microbes. Here, we provide an overview of the progress in next-generation biofuel (alcohols and n-alkanes) production in various engineered microorganisms and discuss the latest tools for strain development that improve biofuel production.


2020 ◽  
Vol 37 (5) ◽  
pp. 579-590
Author(s):  
Jessica Keech ◽  
Maureen Morrin ◽  
Jeffrey Steven Podoshen

Purpose The increasing desire of consumers for socially responsible luxury products combined with fluctuating supplies in consumer markets are leading various industries to seek alternative sources to be able to meet the needs of its customers. One possible solution that may meet the demands of the future is lab-grown products. Because these products confer multiple benefits, this study aims to investigate the most effective ways to appeal to consumers by aligning the benefits of the products with their values as marketers seek to find effective promotion for these items. Design/methodology/approach We examine the effectiveness of an ethical positioning strategy for two types of luxury lab-grown (synthetic) products among high versus low materialism consumers in three experiments. Findings Findings suggest that a positioning strategy stressing product ethicality is more effective for low materialism consumers, whereas the strategy is less effective, and may even backfire, for high materialism consumers. The impact on social status consumers perceive from a lab-grown product explains why this effect occurs among low materialism consumers. Therefore, marketers should take caution and use specific appeals for different segments based on values such as consumers’ materialism levels. Originality/value If lab-grown products represent the wave of the future, it is important to understand how consumers will respond to this emerging technology and how promotion strategies may enhance their evaluation.


2008 ◽  
Vol 9 (12) ◽  
pp. 242 ◽  
Author(s):  
Blake A Simmons ◽  
Dominique Loque ◽  
Harvey W Blanch

2021 ◽  
Vol 118 (39) ◽  
pp. e2106576118
Author(s):  
Yulong Yin ◽  
Rongfang Zhao ◽  
Yi Yang ◽  
Qingfeng Meng ◽  
Hao Ying ◽  
...  

Hundreds of millions of smallholders in emerging countries substantially overuse nitrogen (N) fertilizers, driving local environmental pollution and global climate change. Despite local demonstration-scale successes, widespread mobilization of smallholders to adopt precise N management practices remains a challenge, largely due to associated high costs and complicated sampling and calculations. Here, we propose a long-term steady-state N balance (SSNB) approach without these complications that is suitable for sustainable smallholder farming. The hypothesis underpinning the concept of SSNB is that an intensively cultivated soil–crop system with excessive N inputs and high N losses can be transformed into a steady-state system with minimal losses while maintaining high yields. Based on SSNB, we estimate the optimized N application range across 3,824 crop counties for the three staple crops in China. We evaluated SSNB first in ca. 18,000 researcher-managed on-farm trials followed by testing in on-farm trials with 13,760 smallholders who applied SSNB-optimized N rates under the guidance of local extension staff. Results showed that SSNB could significantly reduce N fertilizer use by 21 to 28% while maintaining or increasing yields by 6 to 7%, compared to current smallholder practices. The SSNB approach could become an effective tool contributing to the global N sustainability of smallholder agriculture.


2017 ◽  
Vol 83 (22) ◽  
Author(s):  
Konstantia Gkarmiri ◽  
Shahid Mahmood ◽  
Alf Ekblad ◽  
Sadhna Alström ◽  
Nils Högberg ◽  
...  

ABSTRACT RNA stable isotope probing and high-throughput sequencing were used to characterize the active microbiomes of bacteria and fungi colonizing the roots and rhizosphere soil of oilseed rape to identify taxa assimilating plant-derived carbon following 13CO2 labeling. Root- and rhizosphere soil-associated communities of both bacteria and fungi differed from each other, and there were highly significant differences between their DNA- and RNA-based community profiles. Verrucomicrobia, Proteobacteria, Planctomycetes, Acidobacteria, Gemmatimonadetes, Actinobacteria, and Chloroflexi were the most active bacterial phyla in the rhizosphere soil. Bacteroidetes were more active in roots. The most abundant bacterial genera were well represented in both the 13C- and 12C-RNA fractions, while the fungal taxa were more differentiated. Streptomyces, Rhizobium, and Flavobacterium were dominant in roots, whereas Rhodoplanes and Sphingomonas (Kaistobacter) were dominant in rhizosphere soil. “Candidatus Nitrososphaera” was enriched in 13C in rhizosphere soil. Olpidium and Dendryphion were abundant in the 12C-RNA fraction of roots; Clonostachys was abundant in both roots and rhizosphere soil and heavily 13C enriched. Cryptococcus was dominant in rhizosphere soil and less abundant, but was 13C enriched in roots. The patterns of colonization and C acquisition revealed in this study assist in identifying microbial taxa that may be superior competitors for plant-derived carbon in the rhizosphere of Brassica napus. IMPORTANCE This microbiome study characterizes the active bacteria and fungi colonizing the roots and rhizosphere soil of Brassica napus using high-throughput sequencing and RNA-stable isotope probing. It identifies taxa assimilating plant-derived carbon following 13CO2 labeling and compares these with other less active groups not incorporating a plant assimilate. Brassica napus is an economically and globally important oilseed crop, cultivated for edible oil, biofuel production, and phytoextraction of heavy metals; however, it is susceptible to several diseases. The identification of the fungal and bacterial species successfully competing for plant-derived carbon, enabling them to colonize the roots and rhizosphere soil of this plant, should enable the identification of microorganisms that can be evaluated in more detailed functional studies and ultimately be used to improve plant health and productivity in sustainable agriculture.


2018 ◽  
Vol 70 (6) ◽  
pp. 691-707 ◽  
Author(s):  
Daniel Torres-Salinas ◽  
Juan Gorraiz ◽  
Nicolas Robinson-Garcia

Purpose The purpose of this paper is to analyze the capabilities, functionalities and appropriateness of Altmetric.com as a data source for the bibliometric analysis of books in comparison to PlumX. Design/methodology/approach The authors perform an exploratory analysis on the metrics the Altmetric Explorer for Institutions, platform offers for books. The authors use two distinct data sets of books. On the one hand, the authors analyze the Book Collection included in Altmetric.com. On the other hand, the authors use Clarivate’s Master Book List, to analyze Altmetric.com’s capabilities to download and merge data with external databases. Finally, the authors compare the findings with those obtained in a previous study performed in PlumX. Findings Altmetric.com combines and orderly tracks a set of data sources combined by DOI identifiers to retrieve metadata from books, being Google Books its main provider. It also retrieves information from commercial publishers and from some Open Access initiatives, including those led by university libraries, such as Harvard Library. We find issues with linkages between records and mentions or ISBN discrepancies. Furthermore, the authors find that automatic bots affect greatly Wikipedia mentions to books. The comparison with PlumX suggests that none of these tools provide a complete picture of the social attention generated by books and are rather complementary than comparable tools. Practical implications This study targets different audience which can benefit from the findings. First, bibliometricians and researchers who seek for alternative sources to develop bibliometric analyses of books, with a special focus on the Social Sciences and Humanities fields. Second, librarians and research managers who are the main clients to which these tools are directed. Third, Altmetric.com itself as well as other altmetric providers who might get a better understanding of the limitations users encounter and improve this promising tool. Originality/value This is the first study to analyze Altmetric.com’s functionalities and capabilities for providing metric data for books and to compare results from this platform, with those obtained via PlumX.


Author(s):  
Judita Koreivienė ◽  
Robertas Valčiukas ◽  
Jūratė Karosienė ◽  
Pranas Baltrėnas

Industry, transport and unsustainable agriculture result in the increased quantity of wastewater, release of nutrients and emission of carbon dioxide that promotes eutrophication of water bodies and global climate change. the application of microalgae for phycoremediation, their biomass use for human needs may increase sustainability and have a positive effect on the regional development. The experiments were carried out in order to establish the feasibility of treating the local municipal wastewater with microalgae consortia and their biomass potential for biofuel production. The results revealed that Chlorella/Scenedesmus consortium eliminated up to 99.7–99.9% of inorganic phosphorus and up to 88.6–96.4% of inorganic nitrogen from the wastewater within three weeks. The ammonium removal was more efficient than that of nitrate. Chlorella algae grew better in diluted, while Scenedesmus – in the concentrated wastewater. The consortium treated wastewater more efficiently than a single species. The maximum biomass (3.04 g/L) of algal consortium was estimated in concentrated wastewater. Algae accumulated 0.65–1.37 g of CO2/L per day in their biomass. Tus, Chlorella/Scenedesmus consortium is a promising tool for nutrients elimination from the local wastewater under the climatic conditions specific to Lithuania. However, none of the two species were able to accumulate lipids under the nitrogen starvation conditions.


2013 ◽  
Vol 31 (2) ◽  
pp. 236-253 ◽  
Author(s):  
Younghee Noh

PurposeThis study seeks to examine the concepts of context, context‐awareness, and context‐awareness technology needed for applying context‐awareness technology to the next‐generation of digital libraries, and proposed context‐aware services that can be applied to any situation by illustrating some library contexts.Design/methodology/approachThe paper investigated both theoretical research and case analysis studies before suggesting a service model for context‐awareness‐based libraries by examining the context, context‐awareness, and context‐awareness technology in depth.FindingsThis paper derived possible library services which could be provided if context‐awareness services are implemented by examining and analyzing case studies and systems constructed in other fields. A library‐applied context‐aware system could recognize users entering the library and provide optimal services tailored to each situation for both new and existing users. In addition, the context‐awareness‐based library could provide context‐awareness‐based reference services, context‐awareness‐based loan services, and cater to other user needs in the stacks, research space, and a variety of other information spaces. The context‐awareness‐based library could also recognize users in need of emergency assistance by detecting the user's behavior, movement path, and temperature, etc. Comfort or climate‐control services could provide the user with control of the temperature, humidity, illumination and other environmental elements to fit the circumstances of users, books, and instruments through context‐aware technology.Practical implicationsNext‐generation digital libraries apply new concepts such as semantic retrieval, real‐time web, cloud computing, mobile web, linked data, and context‐awareness. Context‐awareness‐based libraries can provide applied context‐awareness access service, reactive space according to the user's access, applied context‐awareness lobbies, applied context‐awareness reference services, and applied context‐awareness safety services, context‐awareness‐based comfort services and so on.Originality/valueReal instances of libraries applying context‐aware technology are few, according to the investigative results of this study. The study finds that the next‐generation digital library using context‐awareness technology can provide the best possible service for the convenience of its users.


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