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Biomass and phycobiliprotein production of Galdieria sulphuraria, immobilized on a twin-layer porous substrate photobioreactor
No full textThe extremophile red alga Galdieria sulphuraria was successfully grown immobilized in a twin-layer porous substrate bioreactor (TL-PSBR). A maximal biomass growth rate of 10 g dry weight m−2 day−1 was measured at a photon fluence rate of 200 μmol photons m−2 s−1 with addition of 1% CO2 and a temperature of 34 °C. Under these conditions, a maximal biomass value of 232 g m−2 was attained after 33 days of growth. Phycobilin productivity, however, was highest at a lower photon fluence rate of 100 μmol photons m−2 s−1 and reached a phycobilin value of 14 g m−2, a phycobilin content in the biomass of 63 mg g−1 and a phycobilin growth rate of 0.28 g m−2 day−1 for phycocyanin and 0.23 g m−2 day−1 for allophycocyanin. Addition of CO2 was essential to enhance growth and phycobilin production in G. sulphuraria and further optimization of the cultivation process in the TL-PSBR appears possible using a multi-phase approach, higher growth temperatures and optimization of nutrient supply. It is concluded that autotrophic cultivation of G. sulphuraria in a TL-PSBR is an attractive alternative to suspension cultivation for phycobilin production and applications in bioremediation.</p
An automated modular microsystem for enzymatic digestion with gut-on-a-chip applications
No full textGut-on-a-chip models have gained attention as replacements for other cell-based assays or animal studies in drug development or toxicological studies. These models aim to provide a more accurate representation of the in vivo situation in form and function; however, no digestive processes have been included in these systems so far. This work describes a miniaturized digestive system based on artificial digestive juices that digest liquid samples in a series of three microreactors. After optimization of the pH value of juices and mixtures, samples leading to fluorescent products were digested to demonstrate enzyme functionality and to determine kinetic parameters.</p
Effects of exogenous compound sprays on cherry cracking: skin properties and gene expression
No full textBACKGROUND Cherry fruit cracking is a costly problem for cherry growers. The effect of repeated sprayings (gibberellic acid – GA3; abscisic acid – ABA; salicylic acid – SA; glycine betaine – GB, and Ascophyllum nodosum – AN) combined with CaCl2, on ‘Sweetheart’ cherry fruit‐cracking characteristics was investigated. Cracking was quantified in terms of cracking incidence, crack morphology, confocal scanning laser microscopy, cuticular wax content, cell‐wall modification, and cuticular wax gene expression.RESULTS All spray treatments reduced cracking compared with an untreated control (H2O), with fewer cheek cracks. The least cracking incidence was observed for ABA + CaCl2‐ and GB + CaCl2‐treated fruits, indicating an added benefit compared to spraying with CaCl2 alone. In addition, GB + CaCl2‐treated fruits showed higher fruit diameter. ABA + CaCl2 and GB + CaCl2 sprays showed higher wax content and higher cuticle and epidermal thickness compared with the control, including increased expression of wax synthase (ABA + CaCl2) and expansin 1 (GB + CaCl2). CONCLUSION In general, factors that improve the cuticle thickness appear to be important at the fruit‐coloring stage. At the fruit‐ripening stage, larger cell sizes of the epidermis, hypodermis, and parenchyma cells lower cracking incidence, indicating the importance of flexibility and elasticity of the epidermis. © 2020 Society of Chemical Industr
A review on the genetic resources, domestication and breeding history of spinach (Spinacia oleracea L.)
Get PDFThis paper addresses the genetic resources, domestication and breeding history of spinach as a comprehensive review of these crop aspects is currently unavailable. It is shown that the availability of genetic resources of wild relatives belonging to the primary gene pool is currently very limited, which hampers breeding and research activities. Therefore, new collecting expeditions are clearly warranted. The domestication of spinach is discussed on the basis of its presumed migration routes and the traits that were probably involved in the domestication syndrome. Spinach is thought to have domesticated in former Persia. Migration then occurred eastwards to China and westwards to Europe, but additional genetic data are needed to reveal the most likely migration routes. Morphological changes in pistillate flowers and loss of dormancy are identified as the main traits involved in the domestication syndrome of spinach. To a large extent we could re-construct the relationships between spinach cultivars that were developed until the 1950s, but this appeared difficult for the more recent cultivars due to intellectual property protection by breeding companies. Resistance against downy mildew has been the main breeding target in spinach. The introgression of NBS-LRR resistance genes from wild relatives is the major strategy to develop downy mildew resistant cultivars. However, the use of loss-of-function alleles of susceptibility genes may provide a more durable strategy to develop resistant cultivars. So far, abiotic resistance and quality traits have received minor attention in spinach research and breeding. This is expected to change considering the potential effects of climate change on these traits
“Candidatus Galacturonibacter soehngenii” Shows Acetogenic Catabolism of Galacturonic Acid but Lacks a Canonical Carbon Monoxide Dehydrogenase/Acetyl-CoA Synthase Complex
Get PDFAcetogens have the ability to fixate carbon during fermentation by employing the Wood-Ljungdahl pathway (WLP), which is highly conserved across Bacteria and Archaea. In a previous study, product stoichometries in galacturonate-limited, anaerobic enrichment cultures of “Candidatus Galacturonibacter soehngenii,” from a novel genus within the Lachnospiraceae, suggested the simultaneous operation of a modified Entner-Doudoroff pathway for galacturonate fermentation and a WLP for acetogenesis. However, a draft metagenome-assembled genome (MAG) based on short reads did not reveal homologs of genes encoding a canonical WLP carbon-monoxide-dehydrogenase/acetyl-Coenzyme A synthase (CODH/ACS) complex. In this study, NaH13CO3 fed to chemostat-grown, galacturonate-limited enrichment cultures of “Ca. G. soehngenii” was shown to be incorporated into acetate. Preferential labeling of the carboxyl group of acetate was consistent with acetogenesis via a WLP in which the methyl group of acetate was predominately derived from formate. This interpretation was further supported by high transcript levels of a putative pyruvate-formate lyase gene and very low transcript levels of a candidate gene for formate dehydrogenase. Reassembly of the “Ca. G. soehngenii” MAG with support from long-read nanopore sequencing data produced a single-scaffold MAG, which confirmed the absence of canonical CODH/ACS-complex genes homologs. However, high CO-dehydrogenase activities were measured in cell extracts of “Ca. G. soehngenii” enrichment cultures, contradicting the absence of corresponding homologs in the MAG. Based on the highly conserved amino-acid motif associated with anaerobic Ni-CO dehydrogenase proteins, a novel candidate was identified which could be responsible for the observed activities. These results demonstrate operation of an acetogenic pathway, most probably as a yet unresolved variant of the Wood-Ljungdahl pathway, in anaerobic, galacturonate-limited cultures of “Ca. G. soehngenii.”</p
Rethinking “development” : Land dispossession for the Rampal power plant in Bangladesh
Get PDFIn this article, we critically review the developmental claims made for the construction of the Rampal power plant in southwestern Bangladesh, in the light of evidence about transformations of land control related to this construction project. Land has become a heavily contested resource in the salinity-intruded southwestern coastal area of Bangladesh. Changes in land control for the construction of the Rampal power plant and similar projects have intensified decades of struggles over rights and access to land. The Rampal project is labelled as “development” and claims to contribute to the elimination of poverty. However, we find that, in reality, this project leads to a reorganization of land control, rights and access in ways that perpetuate and intensify waves of eviction and exclusion of small landholders and landless laborers, thus threatening agriculture-based rural livelihoods. We analyze how four actor groups involved in land control are differently affected by the project interventions, embedded in the context of historical land tenure developments. We find that the benefits of this “development”, primarily favoring rich and powerful social groups and investors, necessitates a critical rethinking of Bangladesh's development and its claims of poverty elimination in the light of related land control practices.</p
Environmental Software Systems. Data Science in Action : 13th IFIP WG 5.11 International Symposium, ISESS 2020, Wageningen, The Netherlands, February 5–7, 2020, Proceedings
No full textThis book constitutes the refereed proceedings of the 13th IFIP WG 5.11 International Symposium on Environmental Software Systems, ISESS 2020, held in Wageningen, The Netherlands, in February 2020. The 22 full papers and 3 short papers were carefully reviewed and selected from 29 submissions. The papers cover a wide range of topics on environmental informatics, including data mining, artificial intelligence, high performance and cloud computing, visualization and smart sensing for environmental, earth, agricultural and food applications
Assessment of Dickeya and Pectobacterium spp. on vegetables and ornamentals (Soft rot)
No full textDickeya and Pectobacterium belonging to the group of soft rot Pectobacteriaceae (SRP) are causing emerging problems in a wide range of vegetable and ornamental crops in Europe, including potato, carrot, cabbage, Chinese cabbage, celery, leek, pepper, parsley, Zantedeschia, hyacinth, Dahlia, Chrysanthemum, Philodendron, Freesia, Saintpaulia, Iris, Aglaonema, Crocus, Campanula and Phalaenopsis. The phytopathogens in both genera are genetically and phenotypically highly diverse. Disease problems in the different hosts are associated with the introduction of new variants or by spread of groups already present in Europe. Within this Euphresco project we aimed to identify and assess the risks of these new variants, and to develop management strategies, including reliable diagnostic methods to prevent introductions and further spread of SRP. To reach our goals, meetings were organized and collaborations were established with specialists worldwide. All information on meetings, protocols and activities of the Euphresco group are published on the Dickeya/Pectobacterium website, conveyed by the James Hutton Institute in Invergowrie (Scotland) (https://engage.hutton.ac.uk, contact person Dr I. Toth/Dr J. Fairly).During the project, 1.5 days meetings were held in 2015 in Gdansk (Poland), in 2016 in Helsinki (Finland), in 2017 in Edinburgh (Scotland) and in 2018 in Emmeloord (The Netherlands). Meetings were attended by an average of 30 participants from organizations in EU member states, North- and Latin America, Africa, Asia and Australia.One project’s objective was to develop methods for the detection and identification of Pectobacterium and Dickeya species in different matrices. For this, a panel of reference strains has been compiled for Dickeya and Pectobacterium species. Most strains have been deposited in international collections. For most strains also whole genome sequence data are available. During the course of this project, several diagnostic tests were developed and evaluated, often based on the TaqMan technology.In several countries, surveys in potato and ornamental crops were conducted, but also in other matrices of the potato ecosystem, including water used for irrigation. In addition, new taxonomic groups that have been identified, are now new species including: P. versatile, P. aquaticum, P. fontis and P. polonicum. In potato, P. brasiliense became dominant as blackleg causing organism and has largely outcompeted D. solani in the last five years. In surface water in Europe, D. zeae was found to be the dominant SRP. In other continents, serious outbreaks of potato blackleg with other SRP has been reported, such as D. dianthicola in the USA and Australia. Various new SRP have been described, namely P. punjabense, P. peruviense, P. polaris, D. lacustris and D. zantedeschia. For the first time, D. fangzhongdai was described in Phalaenopsis. Not all species can cause potato blackleg.Studies on various virulence factors were conducted for SRP, such as on chemoreceptors, small phenolic plant compounds interacting with signal molecules of Pectobacterium involved in the quorum sensing mechanism of the pathogen. A Tn-seq approach was developed and used to identify new virulence factors.Information was exchanged on disease management strategies which include cultivation practices, resistance breeding, hygiene and the use of (bio-) control agents. A strict hygiene and an intensive monitoring of seed lots was found to be associated with a significant reduction of infections with blackleg causing SRP. A phage therapy has been developed to protect (seed) potato tubers against soft rot during storage. Various bacteriophages and bacterial antagonists were characterized and some evaluated for control of potato soft rot and/or blackleg. Steam treatments for seed tubers were found to decrease the blackleg incidence. Cold plasma treatment was found to kill SRP grown in vitro. Similarly, stabilized silver nanostructures killed SRP. It was found that seed potato lots can differ in suppressiveness against D. solani. Indications were found that the microbiome in tuber tissue plays a role in this.<br/
Analyzing the Synoptic‐, Meso‐ and Local‐ Scale Involved in Sea Breeze Formation and Frontal Characteristics
No full textSea breeze (SB) frontal passages, the relevant factors influencing their formation and their interaction with local turbulence, are analyzed. To proceed, numerical simulations from the Weather Research and Forecasting (WRF) model are compared with a comprehensive observational database from the Cabauw Experimental Site for Atmospheric Research site, spanning a 10‐year period (January 2001 to December 2010). The fine horizontal resolution of 2 km and the replication of the observational vertical levels allow for a more precise comparison. An algorithm based on objective and strict criteria was applied to both observations and simulations to select the SB events. By carrying out a filter‐by‐filter comparison, we find that the simulated large‐scale conditions show a good rate of coincidence with the reanalysis (69%). Small biases in the large‐scale wind direction, however, induce important deviations in the surface‐wind evolution. Regarding mesoscale forcings, the land‐sea temperature gradient is overestimated in average up to 4 K, producing stronger SB fronts in WRF. The analysis of the SB characteristics and impacts is carried out by classifying the events into three boundary‐layer regimes (convective, transition, and stable) based on the value of the sensible‐heat flux at the SB onset. The stronger SB in the model leads to enhanced turbulence particularly in the convective and transition regimes: The friction velocity, for instance, is overstated by around 50% at the SB onset. In addition, the arrival of the SB front enhances the stable stratification and gives rise to faster afternoon and evening transitions compared with situations solely driven by local atmospheric turbulenc
One-carbon metabolites, B-vitamins and associations with systemic inflammation and angiogenesis biomarkers among colorectal cancer patients: Results from the ColoCare Study
No full textB-vitamins involved in one-carbon metabolism have been implicated in the development of inflammation- A nd angiogenesis-related chronic diseases, such as colorectal cancer. Yet, the role of one-carbon metabolism in inflammation and angiogenesis among colorectal cancer patients remains unclear.The objective of this study was to investigate associations of components of one-carbon metabolism with inflammation and angiogenesis biomarkers among newly diagnosed colorectal cancer patients (n=238) in the prospective ColoCare Study, Heidelberg.We cross-sectionally analyzed associations between 12 B-vitamins and one-carbon metabolites and 10 inflammation and angiogenesis biomarkers from pre-surgery serum samples using multivariable linear regression models. We further explored associations among novel biomarkers in these pathways with Spearman partial correlation analyses. We hypothesized that pyridoxal-5'-phosphate (PLP) is inversely associated with inflammatory biomarkers.We observed that PLP was inversely associated with CRP (r=-0.33, plinearlinear=0.003), IL-6 (r=-0.39, plinear linear=0.02) and TNFα (r=-0.12, plinear=0.045). Similar findings were observed for 5-methyl-tetrahydrofolate and CRP (r=-0.14), SAA (r=-0.14) and TNFα (r=-0.15) among colorectal cancer patients. Folate catabolite apABG was positively correlated with IL-6 (r= 0.27, plinearlinear<0.0001), indicating higher folate utilization during inflammation.Our data support the hypothesis of inverse associations between PLP and inflammatory biomarkers among colorectal cancer patients. A better understanding of the role and inter-relation of PLP and other one-carbon metabolites with inflammatory processes among colorectal carcinogenesis and prognosis could identify targets for future dietary guidance for colorectal cancer patients.</p