Bioproduct potential of outdoor cultures of tolypothrix sp.: effect of carbon dioxide and metal-rich wastewater

Rising CO2 levels, associated climatic instability, freshwater scarcity and diminishing arable land exacerbate the challenge to maintain food security for the fast growing human population. Although coal-fired power plants generate large amounts of CO2 emissions and wastewater, containing environmentally unsafe concentrations of metals, they ensure energy security. Nitrogen (N2)-fixation by cyanobacteria eliminate nitrogen fertilization costs, making them promising candidates for remediation of waste CO2 and metals from macronutrient-poor ash dam water and the biomass is suitable for phycocyanin and biofertilizer product development. Here, the effects of CO2 and metal mixtures on growth, bioproduct and metal removal potential were investigated for the self-flocculating, N2-fixing freshwater cyanobacterium Tolypothrix sp. Tolypothrix sp. was grown outdoors in simulated ash dam wastewater (SADW) in 500 L vertical bag suspension cultures and as biofilms in modified algal-turf scrubbers. The cultivation systems were aerated with air containing either 15% CO2 (v/v) or not. CO2-fertilization resulted in ∼1.25- and 1.45-fold higher biomass productivities and ∼40 and 27% increased phycocyanin and phycoerythrin contents for biofilm and suspension cultures, respectively. CO2 had no effect on removal of Al, As, Cu, Fe, Sr, and Zn, while Mo removal increased by 37% in both systems. In contrast, Ni removal was reduced in biofilm systems, while Se removal increased by 73% in suspension cultures. Based on biomass yields and biochemical data obtained, net present value (NPV) and sensitivities analyses used four bioproduct scenarios: (1) phycocyanin sole product, (2) biofertilizer sole product, (3) 50% phycocyanin and 50% biofertilizer, and (4) 100% phycocyanin and 100% biofertilizer (residual biomass) for power station co-located and not co-located 10 ha facilities over a 20-year period. Economic feasibility for the production of food-grade phycocyanin either as a sole product or with co-production of biofertilizer was demonstrated for CO2-enriched vertical and raceway suspension cultures raised without nitrogen-fertilization and co-location with power stations significantly increased profit marginsKH acknowledges grant funding by the AdvancedManufacturing Co-operative Research Centre (AMCRC), Melbourne, Australia, grant number 2.3.

Variability in the sxt Gene Clusters of PSP Toxin Producing Aphanizomenon gracile Strains from Norway, Spain, Germany and North America

Paralytic shellfish poisoning (PSP) toxin production has been detected worldwide in the cyanobacterial genera Anabaena, Lyngbya, Scytonema, Cuspidothrix and Aphanizomenon. In Europe Aphanizomenon gracile and Cuspidothrix issatschenkoi are the only known producers of PSP toxins and are found in Southwest and Central European freshwater bodies. In this study the PSP toxin producing Aphanizomenon sp. strain NIVA-CYA 851 was isolated from the Norwegian Lake Hillestadvannet. In a polyphasic approach NIVA-CYA 851 was morphologically and phylogenetically classified, and investigated for toxin production. The strain NIVA-CYA 851 was identified as A. gracile using 16S rRNA gene phylogeny and was confirmed to produce neosaxitoxin, saxitoxin and gonyautoxin 5 by LC-MS. The whole sxt gene clusters (circa 27.3 kb) of four A. gracile strains: NIVA-CYA 851 (Norway); NIVA-CYA 655 & NIVA-CYA 676 (Germany); and UAM 529 (Spain), all from latitudes between 40Ê and 59Ê North were sequenced and compared with the sxt gene cluster of reference strain A. gracile NH-5 from the USA. All five sxt gene clusters are highly conserved with similarities exceeding 99.4%, but they differ slightly in the number and presence of single nucleotide polymorphisms (SNPs) and insertions/deletions (In/Dels). Altogether 178 variable sites (44 SNPs and 4 In/Dels, comprising 134 nucleotides) were found in the sxt gene clusters of the Norwegian, German and Spanish strains compared to the reference strain. Thirty-nine SNPs were located in 16 of the 27 coding regions. The sxt gene clusters of NIVA-CYA 851, NIVACYA 655, NIVA-CYA 676 and UAM 529, were characterized by 15, 16, 19 and 23 SNPs respectively. Only the Norwegian strain NIVA-CYA 851 possessed an insertion of 126 base pairs (bp) in the noncoding area between the sxtA and sxtE genes and a deletion of 6 nucleotides in the sxtN gene. The sxtI gene showed the highest variability and is recommended as the best genetic marker for further phylogenetic studies of the sxt gene cluster of A. gracile. This study confirms for the first time the role of A. gracile as a PSP toxin producer in Norwegian waters, representing the northernmost occurrence of PSP toxin producing A. gracile in Europe known so far.publishedVersio

Drainage basins evolution during the Neogene-Quaternary. Ebro Basin eastern margin

The monocline layout of the sedimentary pile of the Ebro Basin in its Eastern margin determines the generation and emptying of the adjacent erosive basins. It controls the drainage changes in the original sedimentary basin. A model of emptying erosive basins corresponding to a drainage architecture and sediment production is proposed. The emptying of erosive basins is achieved by two vectors: A) A drainage basin area growth due to anaclinal streams eroding into the resistant layers of the monocline stratigraphic succession. These streams empty and link small depressions generated at the expense of the lateral extension on the less resistant lithologic member. B) The drainage basin outlet point base level controls the drainage network entrenchment facilitated by the gradients created by Neogene extensional faults from the Valencia Trough. A model of the growth and entrenchment of erosive basins as well as the generated landforms and sediment production is described and analyze

The dioritic-gabbroic intrusive complex of Susqueda (Montseny–Guilleries massif, Catalonia): lithological units and petrographic features

The intrusive complex of Susqueda constitutes the biggest association of plutonic mafic rocks of the Catalonian Coastal Ranges. It is located in the contact between the large calc-alkaline granitoid intrusions and the Paleozoic country rocks affected by Hercynian regional metamorphism. Intrusive relationships denote contemporaneity of basic magmas and, at least, an acid magma intrusion. A significant part of the outcrop consists of a heterogeneous mixing zone between the two magmas (mingling). The intrusion is made up of two oval-shaped outcrops about 3 km long, elongated in the N–S direction and separated by a NW–SE fault. In these units, the compositions of the plutonic rocks range from quartz diorites and tonalites (in the mixing zones) up to olivine hornblendites. Even though its distribution is quite heterogeneous, a preliminary cartography was made including the different petrographic types in three main groups: 1) hornblende gabbros and olivine hornblendites; 2) biotite-hornblende diorites; and 3) heterogeneous mixing zone between hornblende-biotite quartz diorite, granodiorite, and tonalite. The predominant mineral composition consists of plagioclase and amphibole, typical of dioritic rocks. Nevertheless, in a great part of the outcrop the plagioclase widely exceeds the 50% in An, typical of gabbroic rocksEl complejo intrusivo de Susqueda constituye la mayor asociación plutónica de rocas máficas del batolito de las Cordilleras Costeras Catalanas. Se halla situado en el contacto entre grandes intrusiones de granitoides calcoalcalinos y rocas encajantes paleozoicas afectadas por el metamorfismo regional herciniano. Las relaciones intrusivas indican una clara contemporaneidad entre los magmas básicos y, al menos, una intrusión ácida. Una parte significativa del afloramiento consiste en una zona de mezcla heterogénea entre los dos magmas (mingling). La intrusión está formada por dos afloramientos ovalados de unos 3 km de longitud, alargados en dirección N–S y separados por una falla NW–SE. En su interior se distinguen diversos tipos de rocas plutónicas con composiciones que varían desde cuarzodioritas y tonalitas (en las zonas de mezcla) hasta hornblenditas olivínicas. Aunque su distribución es bastante heterogénea se ha realizado una cartografía preliminar, incluyendo los distintos tipos petrográficos en tres grupos principales: 1) gabros hornbléndicos y hornblenditas olivínicas, 2) dioritas hornbléndico-biotíticas y 3) mezcla heterogénea entre cuarzodioritas biotítico-hornbléndicas, granodioritas y tonalitas. La mineralogía dominante consiste en plagioclasa y anfíbol que es típica de rocas dioríticas. No obstante, en gran parte del afloramiento la plagioclasa supera ampliamente el 50% de An, propia de rocas gabroica

Degradation of widespread cyanotoxins with high impact in drinking water (microcystins, cylindrospermopsin, anatoxin-a and saxitoxin) by CWPO

This Accepted Manuscript will be available for reuse under a CC BY-NC-ND license after 24 months of embargo periodThe occurrence of harmful cyanobacterial blooms has unabated increased over the last few decades, posing a significant risk for public health. In this work, we investigate the feasibility of catalytic wet peroxide oxidation (CWPO) promoted by modified natural magnetite (Fe3O4-R400/H2O2), as an inexpensive, simple-operation and environmentally-friendly process for the removal of the cyanotoxins that show the major impact on drinking water: microcystins (MC-LR and MC-RR), cylindrospermopsin (CYN), anatoxin-a (ATX) and saxitoxin (STX). The performance of the system was evaluated under ambient conditions and circumneutral pH (pH0 = 5) using relevant cyanotoxin concentrations (100–500 μg L−1). The nature of the cyanotoxins determined their reactivity towards CWPO, which decreased in the following order: MC-RR > CYN > MC-LR ≫ ATX > STX. In this sense, microcystins and CYN were completely removed in short reaction times (1–1.5 h) with a low catalyst concentration (0.2 g L−1) and the stoichiometric amount of H2O2 (2–2.6 mg L−1), while only 60–80% conversion was achieved with ATX and STX in 5 h. In these cases, an intensification of the operating conditions (1 g L−1 catalyst and up to 30 mg H2O2 L−1) was required to remove both toxins in 1 h. The impact of the main components of freshwaters i.e. natural organic matter (NOM) and several inorganic ions (HCO3−, HPO42-, SO42-) on the performance of the process was also investigated. Although the former led to a partial inhibition of the reaction due to HO· scavenging and catalyst coating, the latter did not show any remarkably effect, and the versatility of the process was finally confirmed in a real surface water. To further demonstrate the effectiveness of the catalytic system, the toxicity of both the initial cyanotoxins and the resulting CWPO effluents was measured with the brine shrimp Artemia salina. Remarkably, all CWPO effluents were non-toxic at the end of the treatment.This research has been supported by the Spanish MINECO through the project CTM-2016-76454-R and by the CM through the project P2018/EMT-4341. M. Munoz thanks the Spanish MINECO for the Ramón y Cajal postdoctoral contract (RYC-2016-20648). J. Nieto-Sandoval thanks the Spanish MINECO for the FPI predoctoral grant (BES-2017-081346

Effect of CO₂ and metal-rich waste water on bioproduct potential of the diazotrophic freshwater cyanobacterium, Tolypothrix sp.

Continued economic growth is reliant on stable, affordable energy, requiring at present fossil fuel-derived energy production. Coal-fired power stations produce metal-rich but macro-nutrient-poor waste waters and emit flue gas, containing ∼10% CO₂. Algae and cyanobacteria remediate metals and CO₂, but use of N₂-fixing (diazotrophic) cyanobacteria can reduce nitrogen-fertilization costs. The resulting biomass represents a promising source for biofuel and bio-product development. This study investigated the effect of CO₂- and trace metals on growth performance, biochemical profiles and metal content of the freshwater diazotrophic cyanobacterium Tolypothrix sp. to assess bioproduct potential. Aerated 2 L batch cultures were grown in simulated ash-dam water (SADW) and BG11 without nitrogen (BG11(-N) controls). Supplied air was supplemented with either 15% CO₂ or not (non-CO₂ controls). CO₂ supplementation resulted in 2.4 and 3.3-fold higher biomass productivities and 1.3 and 1.2-fold higher phycocyanin and phycoerythrin contents, whilst metals (media) had no effect. Al, Cu, Ni and V were more efficiently removed (50-90%) with CO₂-addition, while As, Mo, Se and Sr removal was higher (30-87%) for non-CO₂ controls. No significant effect on Zn and Fe removal was evident. Calculated biomass metal concentrations, at quantities required to meet N-requirements of wheat, suggests no metal toxicity when applied as a mineral-nitrogen biofertilizer. With a carbohydrate content of 50%, the biomass is also suitable for bioethanol production. In summary, Tolypothrix sp. raised in ash dam waste water supplemented with flue gas CO₂ could yield high-value phycobiliproteins, bioethanol or biogas, and mineral-rich nitrogen fertilizer which would offset remediation costs and improve agricultural productivity

Consecuencias de la migración lateral de una cuenca de drenaje (Homoclinal shifting) en la formación de la cuenca erosiva de la Plana de Vic. NE de la Cuenca del Ebro

Se analiza un proceso de migración lateral de una red de drenaje formada sobre materiales paleógenos de los macizos de Les Guilleries y Collsacabra en el NE de la Cuenca del Ebro. El proceso se inició por la reactivación de la Falla de Amer. Un curso anaclinal incidió sobre su escarpe de falla alcanzando las unidades menos resistentes de la serie. El resultado fue la formación de valles de dirección. El más importante, y con mayor migración lateral es la Plana de Vic. Se ha reconstruido el trazado remontante del curso anaclinal gracias a los restos de antiguos cursos de dirección que drenaban hacia el sumidero, y de sus tributarios cataclinales sobre la cuesta formada. Durante la migración lateral se produjeron tres incisiones en una gran estructura anticlinal por el N (Anticlinal de Bellmunt) y el macizo del Montseny por el S. La última de las incisiones al anticlinal alcanzó por erosión remontante una red de drenaje más antigua longitudinal al eje pirenaico con la cabecera en el Pirineo axial. El resultado final del proceso fue la captura de tramos de drenaje más antiguos y la formación de la actual cuenca de drenaje del río Ter

Ecotoxicity assessment of microcystins from freshwater samples using a bioluminescent cyanobacterial bioassay

The hepatotoxic cyanotoxins microcystins (MCs) are emerging contaminants naturally produced by cyanobacteria. Yet their ecological role remains unsolved, previous research suggests that MCs have allelopathic effects on competing photosynthetic microorganisms, even eliciting toxic effects on other freshwater cyanobacteria. In this context, the bioluminescent recombinant cyanobacterium Anabaena sp. PCC7120 CPB4337 (hereinafter Anabaena) was exposed to extracts of MCs. These were obtained from eight natural samples from freshwater reservoirs that contained MCs with a concentration range of 0.04–11.9 μg MCs L−1. MCs extracts included the three most common MCs variants (MC-LR, MC-RR, MC-YR) in different proportions (MC-LR: 100–0%; MC-RR: 100–0%; MC-YR: 14.2–0%). The Anabaena bioassay based on bioluminescence inhibition has been successfully used to test the toxicity of many emerging contaminants (e.g., pharmaceuticals) but never for cyanotoxins prior to this study. Exposure of Anabaena to MCs extracts induced a decrease in its bioluminescence with effective concentration decreasing bioluminescence by 50% ranging from 0.4 to 50.5 μg MC L−1 in the different samples. Bioluminescence responses suggested an interaction between MCs variants which was analyzed via the Additive Index method (AI), indicating an antagonistic effect (AI < 0) of MC-LR and MC-RR present in the samples. Additionally, MC extracts exposure triggered an increase of intracellular free Ca2+ in Anabaena. In short, this study supports the use of the Anabaena bioassay as a sensitive tool to assess the presence of MCs at environmentally relevant concentrations and opens interesting avenues regarding the interactions between MCs variants and the possible implication of Ca2+ in the mode of action of MCs towards cyanobacteri

White Paper: Addressing the challenges of global warming for polar freshwater resources

The polar regions are undergoing rapid transformations due to global warming, resulting in temperature increases far surpassing the global average and significantly impacting ecosystems, especially freshwater systems. Understanding the implications of climate change on Arctic and Antarctic freshwater systems is crucial, as vital ecosystem services essential for sustaining human and environmental well-being may be disrupted. Shifts in freshwater availability due to changes in precipitation patterns, ice melt, and permafrost thaw pose significant challenges for local communities, exacerbating their vulnerabilities. Additionally, climate warming can affect water quality, e. g. by releasing pollutants and potential hazardous microorganisms, further jeopardizing human and natural ecosystem health. Arctic communities face multiple challenges in adapting to these changes, including limited resources and infrastructure that may not be resilient to environmental change. Urgent action is needed to mitigate these impacts and safeguard freshwater resources through evidence-based approaches, scientific research, policy involvement, and community engagement to ensure a sustainable future in the polar regions. In the pursuit of understanding freshwater dynamics in the Arctic and Antarctic, international collaboration across disciplines stands as a cornerstone, essential for addressing the impacts of climate change on polar freshwater resources. Initiatives aiming to understand the dynamics of transboundary water resources underscore the pivotal role of collaboration across institutions and nations, allowing for collective efforts in providing effective solutions to advance the current knowledge of polar ecosystems. Such collaboration not only benefits the polar regions but also carries implications for the global community, aligning with the UN’s SDGs. Therefore, funding mechanisms to bridge the knowledge-to-action gap and support international cooperation should be set high in the research agenda. The scientific and funding roadmap presented here should be implemented urgently, to maximise, in a 10-year term, the benefits to be gained through synergies with the next International Polar Year (2032-33). It will leverage existing transnational initiatives and frameworks, including the Antarctic governance framework, to guide future research initiatives towards sustainable management of freshwater resources. Overall, a comprehensive approach integrating pole-to-pole collaboration, strategic funding, and adherence to governance frameworks is paramount, ensuring collective efforts contribute to the well-being of polar communities and the broader global understanding of climate change implications