| 1. |
- Modin, Oskar, 1980, et al.
(författare)
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Hill-based dissimilarity indices and null models for analysis of microbial community assembly
- 2020
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Ingår i: Microbiome. - : Springer Science and Business Media LLC. - 2049-2618. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundHigh-throughput amplicon sequencing of marker genes, such as the 16S rRNA gene in Bacteria and Archaea, provides a wealth of information about the composition of microbial communities. To quantify differences between samples and draw conclusions about factors affecting community assembly, dissimilarity indices are typically used. However, results are subject to several biases, and data interpretation can be challenging. The Jaccard and Bray-Curtis indices, which are often used to quantify taxonomic dissimilarity, are not necessarily the most logical choices. Instead, we argue that Hill-based indices, which make it possible to systematically investigate the impact of relative abundance on dissimilarity, should be used for robust analysis of data. In combination with a null model, mechanisms of microbial community assembly can be analyzed. Here, we also introduce a new software, qdiv, which enables rapid calculations of Hill-based dissimilarity indices in combination with null models.ResultsUsing amplicon sequencing data from two experimental systems, aerobic granular sludge (AGS) reactors and microbial fuel cells (MFC), we show that the choice of dissimilarity index can have considerable impact on results and conclusions. High dissimilarity between replicates because of random sampling effects make incidence-based indices less suited for identifying differences between groups of samples. Determining a consensus table based on count tables generated with different bioinformatic pipelines reduced the number of low-abundant, potentially spurious amplicon sequence variants (ASVs) in the data sets, which led to lower dissimilarity between replicates. Analysis with a combination of Hill-based indices and a null model allowed us to show that different ecological mechanisms acted on different fractions of the microbial communities in the experimental systems.ConclusionsHill-based indices provide a rational framework for analysis of dissimilarity between microbial community samples. In combination with a null model, the effects of deterministic and stochastic community assembly factors on taxa of different relative abundances can be systematically investigated. Calculations of Hill-based dissimilarity indices in combination with a null model can be done in qdiv, which is freely available as a Python package (https://github.com/omvatten/qdiv). In qdiv, a consensus table can also be determined from several count tables generated with different bioinformatic pipelines.
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| 2. |
- Pawar, Sudhanshu S., et al.
(författare)
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MultiBio: Environmental services from a multipurpose biorefinery
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- MultiBio project aimed to establish and demonstrate a novel multipurpose biorefinery cascade concept, producing three renewable biobased products: 1) biohydrogen, 2) biopolymers and 3) protein rich meal ingredients for fish farming. The cascade concept exploits the ability of a bacterium (Caldicellulosiruptor saccharolyticus) to transform nutrients present in low-value waste process waters of the pulp and paper industry, to high-value products hydrogen gas, organic acids and microbial biomass. The organic acid rich effluent will then be managed in an open culture microbial process used to achieve discharge water quality objectives and to produce polyhydroxyalkanoate (PHA) biopolymers. Moreover, since C. saccharolyticus protein content is more than 63% of cell dry weight, their potential in formulation of fish feed was evaluated. A fiber sludge containing, CTMP residual stream was found to be a possible feedstock for the MultiBio process concept. Due to safety risks the demo-scale experiments of biohydrogen gas technology were moved from Biorefinery demo plant (Örnsköldsvik) of 40 m3 capacity to ATEX classified pilot-scale facility with 0.4 m3 capacity. Hence, bacterial biomass enough for the large-scale fish feed ingredient could not be produced. Lab-scale experiments with Caldicellulosiruptor cells as fish feed ingredient showed promising results as a protein-rich, sustainable fish feed ingredient. In addition, PHA biopolymer also showed favourable results as fish food ingredient for experiments at Gårdsfisk AB. Lab-scale experimental tests showed that the surplus activated sludge from the mills wastewater treatment could currently accumulate PHA to about 20 % of its dry weight. Mass balance evaluations based on realistically achievable expectations indicated a PHA biopolymer production potential of 3 600 tons of PHA per year from available organic residuals and for the two evaluated mills combined. The MultiBio concept has a positive climate impact in comparison with current treatment and moves developments in a positive direction to achieve 7 of the 10 Swedish environmental goals. Through a detailed feasibility analysis, a natural progression in next steps in scenarios were suggested for PHA production. The MultiBio cascade process can be implemented with further necessary development with good business potential and a positive effect on climate change. However, biohydrogen technology needs further developments before this cascade process concept can be implemented. Alternatively, a scenario with only biopolymer technology shows already a significant business potential and even larger positive effect on climate change. A successful next step in demonstration of the PHA biopolymer production scenario may lead to it being implemented within the next few years. Furthermore, MultiBio has attracted a lot of attention regionally and nationally but also internationally with a total of 65 media listings. A licentiate thesis and three university degree projects linked to the project have been completed. Overall, the MultiBio project has successfully achieved its goals and objectives.
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| 3. |
- Burzio, Cecilia, 1991
(författare)
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Removal of Organic Micropollutants from Wastewater in Biofilm Systems
- 2020
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The presence of organic hazardous substances in the aquatic environment, such as pharmaceutically active compounds and personal care products, has become a worldwide issue of increasing environmental concern. Present at concentration of nano- to milligram per liter, they are defined as organic micropollutants (OMPs). Wastewater treatment plants (WWTPs) have been recognized as the main route of emission of OMPs into the environment and as hotspot for antibiotic resistance. Not being designed for the elimination of micropollutants, the removal is often incomplete, resulting in continuous discharge. Therefore, research currently focuses on the enhancement of conventional WWTPs via physical-chemical and biological treatment processes. Among biological processes, biofilm-based treatment technologies have been found more efficient in the biotransformation of OMPs than conventional activated sludge treatment processes. Aerobic granular sludge (AGS) is a form of free-floating biofilm technique for simultaneous removal of organic carbon, nitrogen, and phosphorus in a single process step. The longer solid retention time, the higher concentration and microbial diversity and the presence of micro-niches of different redox conditions are features of AGS that make this system very attractive for the removal of OMPs. An in-depth understanding of the fate of OMPs in such systems under different operational conditions is still required. The present work investigates the degradation mechanisms of OMPs in biomass from both full-scale treatment plants and laboratory reactors. Specifically, it focuses on the impact of different conformations of AGS on the sorption of selected pharmaceuticals and the potential of different biofilm systems at the full scale WWTP to eliminate OMPs.
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| 4. |
- Olsson, Joakim, 1988, et al.
(författare)
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Effects of geographical location on potentially valuable components in Ulva intestinalis sampled along the Swedish coast
- 2020
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Ingår i: Applied Phycology. - : Informa UK Limited. - 2638-8081. ; 1:1, s. 80-92
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Tidskriftsartikel (refereegranskat)abstract
- Macroalgal biomass has the potential to become an important source of chemicals and commodities in a future biorefinery. Currently, production of macroalgal biomass is expensive and the content of high-value compounds is often low. Therefore, in this study the biochemical composition of Ulva intestinalis along the Swedish west coast and the east coast up to Stockholm was assessed with the aim of determining how the content of potentially valuable compounds, such as rhamnose, iduronic acid and PUFAs, could be maximized by utilizing natural variation in the choice of marine cultivation site. Along the investigated coastline, the salinity dropped from 19.4‰ at high latitudes along the west coast to 5.4‰ at Stockholm. Nitrogen and phosphorus availability varied, while temperature was similar at all locations. The two major components of biomass, carbohydrates and ash, varied inversely with the highest content of ash in the west and carbohydrates in the east. In addition, total fatty acids were significantly higher in west coast samples at 3.2 g 100 g–1 dw, with a higher proportion of mono- and polyunsaturated fatty acids. Some health-beneficial fatty acids were found, including EPA and DPA, at 10–50 mg 100 g–1 dw, respectively. The metal content and elemental composition varied widely, probably due to the influence of specific local conditions. The P content was correlated with the phosphorus concentration in waters at the locations. In PCA analysis, the monosaccharides constituting the cell wall polysaccharide ulvan were found to vary by geographical location, with higher levels possibly associated with lower salinities. However, only glucuronic acid differed significantly between sites. These results show the considerable geographical variability in the composition of Swedish U. intestinalis and suggest that different salinities could be used to create a lipid- or carbohydrate-rich biomass.
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| 5. |
- Werker, Alan, et al.
(författare)
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The production of biopolymers for bioplastics using pulp and paper mill wastewater and residual fibre streams
- 2020
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Rapport (refereegranskat)abstract
- As part of the Multibio project, the potential for production of biobased and biodegradable polymers, from organic residuals in process effluent streams, was evaluated for Stora Enso Skoghalls and Rottneros pulp and paper mills in Värmland, Sweden. These biopolymers are thermoplastic polyesters made by naturally occurring bacteria and are from the family of polyhydroxyalkanoates (PHAs). They can be formulated as principal ingredients for plastics, functional chemicals, and composite materials of interest to a diversity of sectors including the pulp and paper industry. They can also be formulated into fish feed to impart pre/pro-biotic benefits in aquaculture. Commercial quantities and qualities of PHAs can be produced as a corollary benefit to biological wastewater treatment processes that are used to treat industrial and municipal wastewaters for environmental protection. The goal of the present study has been to determine the potential quantities of PHA that could be produced as an integral part of the mill residual organics and effluent management. The aim of this Multibio work package has also been to recommend steps forward.It was estimated that Skoghalls and Rottneros mills manage 70 and 15 tons per day of residual organic material on a chemical oxygen demand (COD) basis, and in relation to respective production levels of about 778,000 and 170,000 ton/yr paper and board. These numbers were calculated from mass balances using historical monitoring information provided by the mills and with measurements made in this study on samples from selected locations of the treatment processes. The residual COD is comprised of fibre and surplus activated sludge as well as soluble dissolved organic material. This organic material is a resource to produce a microbial biomass rich in PHA with remaining organic material being used for boiler heat production. Improved sludge dewatering is expected such that COD used for heat production today could be diverted to PHA without undue loss of heat production capacity in the balance.Two process scenarios are presented (Scenario 1 & 2) as a logical progression of risk and development. PHA production requires that some organic feedstock is first converted into volatile fatty acids (VFAs) through acidogenic fermentation. If all the residual organic mass is used to produce VFAs (Scenario 1), it was estimated that about 2 000 and 400 tons PHA per year could be produced at Skoghalls and Rottneros mills, respectively. Production amounts would be increased (Scenario 2) by about 50 % (3 000 and 600 tPHA/yr, respectively) if the residual mass flows of waste activated sludge biomass from the mill aerobic biological wastewater treatment processes could be exploited for a PHA storing potential rather than just being an organic feedstock to yield VFAs. A mill side-line of polymer production anchors in-house supply and experience with PHAs while casting a net for evolving and capturing future interesting materials and business. Future mill economies may foreseeably require standing on wider business footings including fibre as well as from other cellulose derived biobased revenue generating products and services. PHAs can naturally also be made using the prime input lumber starting with hemicellulose and cellulose. Opening a PHA specialty industry first is a way to open the door for discovery that may well motivate directing strategically separated mill upstream organic fractions to successful large commercial revenues from PHAs in the future.
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| 6. |
- Atasoy, Merve, PhD, 1990-, et al.
(författare)
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Butyric acid dominant volatile fatty acids production : Bio-Augmentation of mixed culture fermentation by Clostridium butyricum
- 2020
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Ingår i: Journal of Environmental Chemical Engineering. - : Elsevier Ltd. - 2213-3437. ; 8:6
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Tidskriftsartikel (refereegranskat)abstract
- The most sustainable and environmentally friendly butyric acid production method is fermentation; however, low production yield and high substrate cost limit the competition with petrol-based production. The study is aimed to enhance butyric acid production via bioaugmentated mixed culture by Clostridium butyricum. Anaerobic sequencing batch reactors (bioaugmented and control) were operated under alkali pH (pH 10) at 35 °C and fed by dairy industry wastewater as substrate. The performance of bioaugmentation was monitored in three stages: before the application, during the application (C. butyricum was injected as %10 of active reactor volume on a daily basis for seven days), after bioaugmentation. The VFA concentration and composition (by GC-FID) with the copy gene number of C. butyricum (by Q-PCR) were monitored in the bioaugmented reactor during the operation. The bioaugmentation of C. butyricum increased butyric acid production (mgCOD L-1) from 260 ± 36 to 2889 ± 180. The total VFA production (mgCOD L-1) was increased from 1434 ± 217 to 4642 ± 1778 in control and bioaugmented reactors, respectively. There was a positive correlation between the gene copies of C. butyricum with butyric, hexanoic, n-heptanoic, valeric acids production. Furthermore, the bioaugmented mixed culture had better performance than pure culture regarding butyric acid production. The cycle analysis showed that the similar butyric acid production efficiency would be obtained in the first 6 h in the bioaugmented reactor, in the first 14 h in the control reactor of the cycle. The study provides a fundamental solution to step forward to achieve next-generation biorefineries by using both monocultures modularity and mixed culture robustness and stability regarding.
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| 7. |
- Bajracharya, Suman, et al.
(författare)
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Prime Techniques for Pre- and Post-Treatments of Anaerobic Effluents and Solids
- 2020
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Ingår i: Environmental Microbiology and Biotechnology. - Singapore : Springer Nature. ; , s. 255-289
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Several pre-treatment approaches have been explored to enhance the anaerobic fermentation kinetics and efficiency, which include thermal-alkaline treatment, free ammonia, sequential ultrasound techniques as well as grinding, and sieving. Additionally, valorization of mineralized compounds and production of reusable water can also be achieved via post-treatments. The post-treatment concept allows preserving or recovery of value-added byproducts in the form of manures, soil conditioners, and renewable energy. In this chapter, we explain the recent advancement in the pre-treatment and post-treatment of anaerobic digestate to enhance the anaerobic process and for the removal of undesirable compounds, recovery of energy, nutrients, and waste stabilization before disposal.
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| 8. |
- Das, Oisik, et al.
(författare)
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Naturally-occurring bromophenol to develop fire retardant gluten biopolymers
- 2020
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Ingår i: Journal of Cleaner Production. - : Elsevier. - 0959-6526 .- 1879-1786. ; 243
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to impart fire retardancy in wheat gluten polymer through naturally-occurring additives such as lanosol. The fire properties of lanosol were compared with two other conventional brominated fire retardants (Tetrabromobisphenol A and Hexabromocyclododecane). Samples containing fire retardants and gluten were prepared through compression moulding process and then characterised for their fire and mechanical properties. All fire retardants enhanced the reaction-to-fire and thermal properties of gluten while generating V-0 (i.e. vertical position and self-extinguished) ratings in the UL-94 test. The presence of all the fire retardants increased the modulus of the gluten polymer but the fire retardant particles were detrimental for the tensile strength. Nevertheless, lanosol addition delayed ignition and lowered peak heat release rate of gluten by the maximum amount, thereby leading to relatively higher fire performance index (compared to the other fire retardants). Lanosol also allowed the gluten to create a dense char barrier layer during burning that impeded the transfer of heat and flammable volatiles. The fact that only 4 wt% lanosol was able to cause self-extinguishment under direct flame and reduce peak heat release rate by a significant 50% coupled with its inherent occurrence in nature, raises the question if lanosol can be a potential fire retardant in polymeric systems, although it is a bromophenol.
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| 9. |
- Holkenbrink, Carina, et al.
(författare)
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Production of moth sex pheromones for pest control by yeast fermentation
- 2020
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Ingår i: Metabolic Engineering. - : Elsevier BV. - 1096-7176. ; 62, s. 312-321
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Tidskriftsartikel (refereegranskat)abstract
- The use of insect sex pheromones is an alternative technology for pest control in agriculture and forestry, which, in contrast to insecticides, does not have adverse effects on human health or environment and is efficient also against insecticide-resistant insect populations. Due to the high cost of chemically synthesized pheromones, mating disruption applications are currently primarily targeting higher value crops, such as fruits. Here we demonstrate a biotechnological method for the production of (Z)-hexadec-11-en-1-ol and (Z)-tetradec-9-en-1-ol, using engineered yeast cell factories. These unsaturated fatty alcohols are pheromone components or the immediate precursors of pheromone components of several economically important moth pests. Biosynthetic pathways towards several pheromones or their precursors were reconstructed in the oleaginous yeast Yarrowia lipolytica, which was further metabolically engineered for improved pheromone biosynthesis by decreasing fatty alcohol degradation and downregulating storage lipid accumulation. The sex pheromone of the cotton bollworm Helicoverpa armigera was produced by oxidation of fermented fatty alcohols into corresponding aldehydes. The resulting yeast-derived pheromone was just as efficient and specific for trapping of H. armigera male moths in cotton fields in Greece as a conventionally produced synthetic pheromone mixture. We further demonstrated the production of (Z)-tetradec-9-en-1-yl acetate, the main pheromone component of the fall armyworm Spodoptera frugiperda. Taken together our work describes a biotech platform for the production of commercially relevant titres of moth pheromones for pest control via yeast fermentation.
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| 10. |
- Lalander, Cecilia, et al.
(författare)
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Using Hermetia illucens larvae to process biowaste from aquaculture production
- 2020
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Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 251
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Tidskriftsartikel (refereegranskat)abstract
- Aquaculture is a fast-growing activity that is generating increasing volumes of organic waste such as fish carcasses, which must be managed. In a study evaluating black soldier fly (BSF) larvae composting of this waste stream, we tested 21 combinations of reclaimed bread waste and aquaculture waste (with replacement increments of 5%). The best treatments were validated in a second experiment. Within 11-12 days of treatment, inclusion of 15% aquaculture waste increased larvae size by 35% and body protein content by 60% (45% DM ) compared with larvae fed only bread waste. Bioconversion of materials was favored by the addition of aquaculture waste, reaching 18%(DM). However, as revealed by a principal component analysis, 50.5% of the data variance was weighted by the addition of aquaculture waste in the treatments, negatively correlating to larvae survival, which declined as more of this waste stream was added. Nevertheless, the nitrogen content of the final compost increased as more aquaculture waste was added, while nitrogen volatilization varied slightly (max. 33% of total nitrogen). Overall, addition of small amounts (<15%) of aquaculture waste was demonstrated to be very beneficial for process performance in BSF larvae composting and for larval quality. (C) 2019 Elsevier Ltd. All rights reserved.
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