The possibility of obtaining energy or nutritive streams and bioremediation as an add-on opens new perspectives for the massive culturing of microalgal biomass on waste waters generated by the ...agro-food sector. Ordinary revenue streams are fully preserved, or even boosted, if they are used in microalgal cultivation; however, the suitability of wastewaters depends on multiple nutritional and toxic factors. Here, the effect of modulating the Olive Mill Wastewater (OMW) and cattle digestate (CD) fraction in the formulation of a growth medium on biomass accumulation and productivity of selected biomass fractions and their relevance for biofuel and/or feed production were tested for the microalga Scenedesmus dimorphus and for the cyanobacterium Arthrospira platensis (Spirulina). Tests highlighted the strong S. dimorphus adaptability to digestate, as on OMW, compared to A. platensis, with the maximum lipid storage (48 %) when culture medium was composed by 50 % of cattle digestate.
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•S. dimorphus and A. platensis growth on OMW and CD diluted and/or fractionated.•S. dimorphus biomass showed characteristics in line for bio-oil/diesel production.•S. dimorphus protein storage opens feed applications.•Carbohydrate in A. platensis biomass could be applied for fermentative processes.
•Adapted C. vulgaris showed growth capacity on winery waste digestion effluent.•Batch growth test with 20% of digestate shows no inhibition effects.•C. vulgaris biomass concentration of ...1.36 ± 0.09 g l−1 was obtained.•Winery waste digestate promoted C. vulgaris lipid storage up to 28%.•Lipid characterization showed 65%w/w of oleic acid and 0.15%w/w of linolenic acid.
The recovery of high added value compound from waste stream is fundamental to keep biotechnological processes sustainable. In this study, anaerobic digestion of two highly produced organic waste was integrated with microalgae-based processes both to treat liquid digestate and recover high value compounds. Chlorella vulgaris growth was assessed for lipids accumulation and subsequent recovery, using two types of digestate: organic waste and sewage sludge digestate (DIG-OFMSW) and wine lees digestate (DIG-WL). Growth tests were carried out in batch mode and results showed a slightly higher final biomass concentration from DIG-WL (1.36 ± 0.09 g l−1) compared to DIG-OFMSW (1.05 ± 0.13 g l−1) and a clearly different lipids accumulation yield (28.86 ± 0.05% in DIG-WL compared to 6.1 ± 0.2% of DIG-OFMSW, on total solids). Lipid characterization showed a high oleic acid accumulation (69.52 ± 0.50%w/w in DIG-WL) that positively influence biodiesel properties and a low linolenic acids content (below 0.30%w/w) that comply with European law EN14214 for biodiesel (linolenic acid content lower than 12%w/w). In addition, due to the high concentration of palmitic and stearic acids detected at the end of test, this oil can be used as new substrate to produce stearin, normally produced from palm oil.
Native Americans derive from a small number of Asian founders who likely arrived to the Americas via Beringia. However, additional details about the initial colonization of the Americas remain ...unclear. To investigate the pioneering phase in the Americas we analyzed a total of 623 complete mtDNAs from the Americas and Asia, including 20 new complete mtDNAs from the Americas and seven from Asia. This sequence data was used to direct high-resolution genotyping from 20 American and 26 Asian populations. Here we describe more genetic diversity within the founder population than was previously reported. The newly resolved phylogenetic structure suggests that ancestors of Native Americans paused when they reached Beringia, during which time New World founder lineages differentiated from their Asian sister-clades. This pause in movement was followed by a swift migration southward that distributed the founder types all the way to South America. The data also suggest more recent bi-directional gene flow between Siberia and the North American Arctic.
Only a limited number of complete mitochondrial genome sequences belonging to Native American haplogroups were available until recently, which left America as the continent with the least amount of ...information about sequence variation of entire mitochondrial DNAs. In this study, a comprehensive overview of all available complete mitochondrial DNA (mtDNA) genomes of the four pan-American haplogroups A2, B2, C1, and D1 is provided by revising the information scattered throughout GenBank and the literature, and adding 14 novel mtDNA sequences. The phylogenies of haplogroups A2, B2, C1, and D1 reveal a large number of sub-haplogroups but suggest that the ancestral Beringian population(s) contributed only six (successful) founder haplotypes to these haplogroups. The derived clades are overall starlike with coalescence times ranging from 18,000 to 21,000 years (with one exception) using the conventional calibration. The average of about 19,000 years somewhat contrasts with the corresponding lower age of about 13,500 years that was recently proposed by employing a different calibration and estimation approach. Our estimate indicates a human entry and spread of the pan-American haplogroups into the Americas right after the peak of the Last Glacial Maximum and comfortably agrees with the undisputed ages of the earliest Paleoindians in South America. In addition, the phylogenetic approach also indicates that the pathogenic status proposed for various mtDNA mutations, which actually define branches of Native American haplogroups, was based on insufficient grounds.
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•S.obliquus and C.vulgaris growth on organic waste + sludge digestate was assessed.•C. vulgaris showed best growth performances in mixotrophic conditions.•Ammonia removal reached ...was greater than 96% after 8 days in all mixotrophic conditions.•Similar microalgae growth was observed on centrifugated and filtrated digestate.
In this research Scenedesmus obliquus and Chlorella vulgaris growth was tested on digestate sludge obtained from the anaerobic co-digestion treatment of the organic fraction of municipal solid waste (OFMSW) together with waste activated sludge (WAS). Digestate was diluted 1:10 and tested in three batch experimental conditions: with no pre-treatments (noPT), after centrifugation (AC) and after filtration (AUF), in order to evaluate microalgae limiting growth factors. The best growth was obtained by C. vulgaris on digestate AC compared to S. obliquus, reaching 479 ± 31 cell million ml−1 and 131 ± 12 cell million ml−1 respectively. Ammonia removal evaluated in C. vulgaris and S. obliquus cultures was 99.2% ± 0.3 and 98.146% ± 0.008 in AC condition, respectively. Considering that AUF showed similar microalgae growth values, the digestate pretreatment for microalgae growth, could be limited to centrifugation.
Olive milling produces huge amounts of wastewater (OMWW) characterized by an extremely high organic load. Its polyphenols content is a hindrance to conventional biological treatment and to using it ...as growing medium for common microbial biomasses. The practice to dump it on soil is in conflict with the latest EU directives about waste management.
OMWW can be effectively and efficiently treated by means of membrane technology to a fraction of the initial volume, but membrane processing concentrates still require treatment. Reversing the overall cost balance of membrane processing and subsequent treatment requires valorizing the concentrates through their reuse, as well as ensuring long-term service of the membrane system through effective wastewater pretreatment and sustainable, fouling-controlling, membrane operation conduite.
Aim of this work is to reuse and valorize the ultra- and nanofiltration membrane concentrates as media for biomass production of microalgae and cyanobacteria. Scenedesmus dimorphus and Arthrospira platensis, usable as a food, feed, nutraceutical component or feedstock for biofuels, were selected for this investigation. Microalgal growth was experimentally determined and related to the composition of the concentrate-based media and to the irradiance distribution within the photobioreactor volume to decouple light limitation and medium chemical composition effects.
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•Threshold fluxes and irreversible fouling of UF and NF membranes treating OMWW.•Effective fouling inhibition on membranes treating olive mill wastewater.•Light limitation and medium composition effects in microalgal biomass production.•Production of microalgal biomass in media obtained from agro-food wastewaters.
Wine production represents one of the most important agro-industrial sectors in Italy. Wine lees are the most significant waste in the winery industry and have high disposal and storage costs and few ...applications within the circular economy. In this study, anaerobic digestion and a microalgae coupled process was studied in order to treat wine lees and waste activated sludge produced within the same facility, with the aim of producing energy and valuable microalgae biomass that could be processed to recover biofuel or biostimulant. Chlorella vulgaris was cultivated on liquid digestate in a semi-continuous system without biomass recirculation. The best growth and phytoremediation performance were achieved applying a hydraulic retention time (HRT) of 20 days with a stable dry weight, lipid and protein storage of 1.85 ± 0.02 g l
, 33.48 ± 7.54 % and 57.85 ± 10.14 % respectively. Lipid characterization highlighted the potential use in high quality biodiesel production, according to EN14214 (<12 % v/v linolenic acid). The microalgae reactor's liquid output showed high removal of ammonia (95.72 ± 2.10 %), but low organic soluble matter reduction. Further semi-continuous process optimization was carried out by increasing the time between digestate feeding and biomass recovery at HRT 10. These operative changes avoided biomass wash-out and provided a stable phytoremediation of the digestate with 84.58 ± 4.02 % ammonia removal, 33.01 ± 1.44 % sCOD removal, 38.06 ± 2.65 % of polyphenols removal.
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•A daily amount of 360 kg of freeze-dried microalgae biomass is considered.•138.3 kg/day of Triolein, Tripalmitin, TriEPA and TriDHA mixture is produced.•A daily amount of 8.4 kg of ...carotenoids mixture is produced.•Estimated OPEX and CAPEX give an overview of the process’ feasibility.
This work shows how Omega-3 triglycerides and carotenoids can be produced industrially from the microalga Chlorella vulgaris by fractionating extraction employing supercritical CO2, also estimating the relevant costs. One key point is that the devised process separates triglycerides from carotenoids. The estimates have been carried out by modelling both triglycerides and carotenoids extraction and purification, by quantifying the overall process material and heat balance and required operating conditions with the aid of a process simulation spreadsheet. The results showed separate streams of 138.3 kg per day of triglycerides and 8.4 kg per day of carotenoids can be obtained from a daily feed of 360 kg of freeze-dried microalga. In addition, an estimation of Operating Expense (OPEX) and Capital Expenditure (CAPEX) was carried out obtaining, respectively, 1050 k€/y and 3699 k€. The developed integrated process shows, in terms of costs and product quality, a significant improvement respect to previous works, underlying its feasibility for industrial applications.
After several years of research, there is now a consensus that America was populated from Asia through Beringia, probably at the end of the Pleistocene. But many details such as the timing, route(s), ...and origin of the first settlers remain uncertain. In the last decade genetic evidence has taken on a major role in elucidating the peopling of the Americas. To study the early peopling of South America, we sequenced the control region of mitochondrial DNA from 300 individuals belonging to indigenous populations of Chile and Argentina, and also obtained seven complete mitochondrial DNA sequences. We identified two novel mtDNA monophyletic clades, preliminarily designated B2l and C1b13, which together with the recently described D1g sub-haplogroup have locally high frequencies and are basically restricted to populations from the extreme south of South America. The estimated ages of D1g and B2l, about ~15,000 years BP, together with their similar population dynamics and the high haplotype diversity shown by the networks, suggests that they probably appeared soon after the arrival of the first settlers and agrees with the dating of the earliest archaeological sites in South America (Monte Verde, Chile, 14,500 BP). One further sub-haplogroup, D4h3a5, appears to be restricted to Fuegian-Patagonian populations and reinforces our hypothesis of the continuity of the current Patagonian populations with the initial founders. Our results indicate that the extant native populations inhabiting South Chile and Argentina are a group which had a common origin, and suggest a population break between the extreme south of South America and the more northern part of the continent. Thus the early colonization process was not just an expansion from north to south, but also included movements across the Andes.
Population structure in Argentina Muzzio, Marina; Motti, Josefina M B; Paz Sepulveda, Paula B ...
PloS one,
05/2018, Letnik:
13, Številka:
5
Journal Article
Recenzirano
Odprti dostop
We analyzed 391 samples from 12 Argentinian populations from the Center-West, East and North-West regions with the Illumina Human Exome Beadchip v1.0 (HumanExome-12v1-A). We did Principal Components ...analysis to infer patterns of populational divergence and migrations. We identified proportions and patterns of European, African and Native American ancestry and found a correlation between distance to Buenos Aires and proportion of Native American ancestry, where the highest proportion corresponds to the Northernmost populations, which is also the furthest from the Argentinian capital. Most of the European sources are from a South European origin, matching historical records, and we see two different Native American components, one that spreads all over Argentina and another specifically Andean. The highest percentages of African ancestry were in the Center West of Argentina, where the old trade routes took the slaves from Buenos Aires to Chile and Peru. Subcontinentaly, sources of this African component are represented by both West Africa and groups influenced by the Bantu expansion, the second slightly higher than the first, unlike North America and the Caribbean, where the main source is West Africa. This is reasonable, considering that a large proportion of the ships arriving at the Southern Hemisphere came from Mozambique, Loango and Angola.
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