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The 4th edition of this catalogue contains information on the cultivation and composition characteristics of 50 microalgae. Each entry includes relevant links to Atlantic Area stakeholders known to have a relevant connection with each of the species listed, be it in the form of culture collections, research expertise, technology developers, or biomass producers. We invite the readers to visit and/or join the EnhanceMicroAlgae Stakeholder database: an easily accessible, visual and open access database that brings together all the European Atlantic Area players working in the microalgae sector., This publication is part of the deliverables of the Interreg-funded international project EnhanceMicroAlgae. The authors gratefully acknowledge the European Regional Development Fund (ERDF) Interreg Atlantic Area programme which funded the EnhanceMicroAlgae project: EAPA_338/2016, "High added-value industrial opportunities for microalgae in the Atlantic Area".

Arbuscular mycorrhizal fungi were recovered from soil samples from the naturally radioactive soil at the long-abandoned South Terras uranium mine in Cornwall, UK. Species of Rhizophagus, Claroideoglomus, Paraglomus, Septoglomus, and Ambispora were recovered, and pot cultures from all except Ambispora were established. Cultures were identified to species level using morphological observation and rRNA gene sequencing combined with phylogenetic analysis. These cultures were used in pot experiments designed with a compartmentalised system to assess the contribution of fungal hyphae to the accumulation of essential elements, such as copper and zinc, and non-essential elements, such as lead, arsenic, thorium, and uranium into root and shoot tissues of Plantago lanceolata. The results indicated that none of the treatments had any positive or negative impact on shoot and root biomass. However, Rhizophagus irregularis treatments showed higher accumulation of copper and zinc in shoots, while R. irregularis and Septoglomus constrictum enhanced arsenic accumulation in roots. Moreover, R. irregularis increased uranium concentration in roots and shoots of the P. lanceolata plant. This study provides useful insight into fungal-plant interactions that determine metal and radionuclide transfer from soil into the biosphere at contaminated sites such as mine workings.

Identification of goals is a key social-cognitive process that guides whether adolescents engage in aggressive or nonviolent behavior during social conflicts. This study investigated early adolescents’ goals in response to hypothetical social conflict situations involving close friends and peers. Participants ( n = 160; Mage = 12.7, 53% female) were 7th graders from two urban and one rural middle school. On average, participants identified 2.5 goals for each situation. Qualitative analysis using a grounded theory approach identified nine themes representing the goals generated by participants: instrumental-control, relationship maintenance, maintain image and reputation/self-defense, conflict avoidance, seek more information, revenge, tension reduction, moral, and stay out of trouble. Quantitative analysis indicated that female participants identified more goals than male participants, but there were few differences in their types of goals. There were few differences across school sites. The findings highlight the variety of social goals specific to the developmental period of early adolescence.

This study examined beliefs about aggression and self-efficacy for nonviolent responses as mediators of longitudinal relations between exposure to violence and physical aggression. Participants were a predominantly African American (79%) sample of 2705 early adolescents from three middle schools within urban neighborhoods with high rates of violence. Participants completed measures across four waves (fall, winter, spring, and summer) within a school year. Beliefs supporting proactive aggression, beliefs against fighting, and self-efficacy for nonviolence partially mediated relations between witnessing violence and physical aggression. Indirect effects for beliefs supporting proactive aggression and self-efficacy were maintained after controlling for victimization and negative life events. Beliefs supporting proactive aggression mediated the effects of violent victimization on physical aggression, but these effects were not significant after controlling for witnessing violence and negative life events. The findings underscore the importance of examining the unique pathways from witnessing community violence versus violent victimization to physical aggression.

Although life satisfaction has been associated with maladjustment and adverse experiences among adolescents, few validated measures of life satisfaction have been evaluated for use with diverse populations. The Brief Multidimensional Students’ Life Satisfaction Scale (BMSLSS) is a promising measure that has been validated in samples of White and Black adolescents. This study used an item response theory approach to evaluate its psychometric properties in a diverse rural sample of early adolescents and its concurrent associations with other measures of youth adjustment. Support was found for partial invariance across sex and racial and ethnic identities. Scores on the BMSLSS were also correlated with measures of youth adjustment. However, the strength of these correlations differed for adolescents of different racial and ethnic identities. Findings suggest that the BMSLSS is a psychometrically sound measure for assessing life satisfaction in diverse samples of adolescents and highlights the importance of assessing invariance across racial and ethnic groups.

Industrial activity has left a legacy of pollution by radionuclides and heavy metals. The exposure of terrestrial environments to increased levels of ionising radiation and toxic elements is of concern, not only because of the immediate effects to biota but also because of the potential risk of mobilisation into higher levels of a food chain. Here, we present a study that extends our knowledge of how arbuscular mycorrhizal fungi contribute to the mobilisation of non-essential elements in environments such as former mine sites, and provides a perspective that will be of interest for the management and remediation of such sites. Summary Accumulation and transfer of long-lived radionuclides and toxic metals in terrestrial environments is of major concern because of potential mobilisation into food chains. In this study, we aimed to compare the role of four different arbuscular mycorrhizal fungal (AMF) cultures on the transfer of non-essential elements into Plantago lanceolata from a naturally contaminated soil source. Soil from an abandoned uranium ( 238U) mine was collected as a natural source of 238U, thorium ( 232Th), arsenic (As) and lead (Pb). P. lanceolata was inoculated with four AMF cultures (Rhizophagus irregularis DAOM181602, Acaulospora longula BEG8, Scutellospora calospora BEG245 and Funneliformis mosseae BEG12) to compare the uptake and transfer from root to shoot. Inductively coupled plasma (ICP) mass spectroscopy and ICP-absorption emission spectroscopy analyses provided quantification of total elemental concentrations in soil and plant tissues. Two of the AMF cultures, A. longula and F. mosseae, had contrasting roles in toxic element partitioning in plant tissue of P. lanceolata. F. mosseae increased the accumulation of 238U, 232Th, Pb, As and Cu in shoots whereas A. longula induced increased partitioning of 232Th, Ca, Fe and Zn in roots. The inoculation treatments and the differential accumulation of these elements had no significant effect on plant biomass. The use of different AMF cultures in enhancing phytoremediation of contaminated environments requires a wider understanding of the contribution of different AMF cultures to non-essential element acquisition as well as to plant nutrition.

Dominant missense mutations in DNAJB6, an HSP40 co-chaperone, cause limb girdle muscular dystrophy (LGMD) D1. No treatments are currently available. Two isoforms exist, DNAJB6a and DNAJB6b, each with distinct localizations in muscle. Mutations reside in both isoforms, yet evidence suggests only DNAJB6b is responsible for disease pathogenesis. Mechanistic data supports either a toxic gain of function, a dominant negative mechanism, or a combination of both. Knockdown treatment strategies involving both isoforms carry risk as DNAJB6 knockout is embryonic lethal. We therefore developed an isoform specific knockdown approach using morpholinos. Selective reduction of each isoform was achievedin-vitroin primary mouse myotubes and human myoblasts, as well asin-vivoin mouse skeletal muscle. To assess isoform specific knockdown in LGMDD1, we created primary myotube cultures from aknock-inLGMDD1 mouse model. Using mass spectrometry, we identified an LGMDD1 protein signature related to protein homeostasis and myofibril structure. Selective reduction of DNAJB6b levels in LGMDD1 myotubes corrected much of the proteomic disease signature towards wild type levels. While additionalin-vivofunctional data is required, these findings suggest selective reduction of DNAJB6b may be a viable therapeutic target for LGMDD1.

DnaJ homolog, subfamily B, member 4, a member of the heat shock protein 40 chaperones encoded by DNAJB4, is highly expressed in myofibers. We identified a heterozygous c.270 T>A (p.F90L) variant in DNAJB4 in a family with a dominantly inherited distal myopathy, in which affected members have specific features on muscle pathology represented by the presence of cytoplasmic inclusions and the accumulation of desmin, p62, HSP70 and DNAJB4 predominantly in type 1 fibers. Both Dnajb4- F90L knock-in and knockout mice developed muscle weakness and recapitulated the patient muscle pathology in the soleus muscle, where DNAJB4 has the highest expression. These data indicate that the identified variant is causative resulting in defective chaperone function and selective muscle degeneration in specific muscle fibers. This study demonstrates the importance of DNAJB4 in skeletal muscle proteostasis by identifying the associated chaperonopathy.

Sugar-Will-Eventually-be-Exported-Transporters (SWEETs) are an important family of sugar transporters that appear to be ubiquitous in all organisms. Recent research has determined the structure of SWEETs in higher plants, identified specific residues required for monosaccharide or disaccharide transport, and begun to understand the specific functions of individual plant SWEET proteins. However, in green algae (Chlorophyta) these transporters are poorly characterised. This study identified SWEET proteins from across representative Chlorophyta with the aim to characterise their phylogenetic relationships and perform protein structure modelling in order to inform functional prediction. The algal genomes analysed encoded between one and six SWEET proteins, which is much less than a typical higher plant. Phylogenetic analysis identified distinct clusters of over 70 SWEET protein sequences, taken from almost 30 algal genomes. These clusters remain separate from representative higher or non-vascular plant SWEETs, but are close to fungi SWEETs. Subcellular localisation predictions and analysis of conserved amino acid residues revealed variation between SWEET proteins of different clusters, suggesting different functionality. These findings also showed conservation of key residues at the substrate-binding site, indicating a similar mechanism of substrate selectivity and transport to previously characterised higher plant monosaccharide-transporting SWEET proteins. Future work is now required to confirm the predicted sugar transport specificity and determine the functional role of these algal SWEET proteins.

Metabolism of metals in microalgae and adaptation to metal excess are of significant environmental importance. We report a three-step mechanism that the green microalga Chlorella sorokiniana activates during the acquisition of and adaptation to manganese (Mn), which is both an essential trace metal and a pollutant of waters. In the early stage, Mn2+ was mainly bound to membrane phospholipids and phosphates in released mucilage. The outer cell wall was reorganized and lipids were accumulated, with a relative increase in lipid saturation. Intracellular redox settings were rapidly altered in the presence of Mn excess, with increased production of reactive oxygen species that resulted in lipid peroxidation and a decrease in the concentration of thiols. In the later stage, Mn2+ was chelated by polyphosphates and accumulated in the cells. The structure of the inner cell wall was modified and the redox milieu established a new balance. Polyphosphates serve as a transient Mn2+ storage ligand, as proposed previously. In the final stage, Mn was stored in multivalent Mn clusters that resemble the structure of the tetramanganese–calcium core of the oxygen-evolving complex. The present findings elucidate the bioinorganic chemistry and metabolism of Mn in microalgae, and may shed new light on water-splitting Mn clusters.

Giant juvenile fibroadenomas are usually seen as rare variants of fibroadenomas in adolescents as unilateral solitary masses that may be managed by surgical excision with conservation of normal breast tissue. We report a case of a premenarchal 13-year-old female presenting with bilateral multifocal giant juvenile fibroadenomas requiring essentially bilateral subtotal nipple sparing mastectomies. Surgical evaluation revealed replacement of normal breast tissue on the right side. She then had development of two additional right-sided fibroadenomas requiring excision.

Pseudanabaena dominates cyanobacterial blooms in the First-Generation Magnox Storage Pond (FGMSP) at a UK nuclear site. The fission product Cs is a radiologically significant radionuclide in the pond, and understanding the interactions between Cs and Pseudanabaena spp. is therefore important for determining facility management strategies, as well as improving understanding of microbiological responses to this non-essential chemical analogue of K. This study evaluated the fate of Cs following interactions with Pseudanabaena catenata, a laboratory strain most closely related to that dominating FGMSP blooms. Experiments showed that Cs (1 mM) exposure did not affect the growth of P. catenata, while a high concentration of K (5 mM) caused a significant reduction in cell yield. Scanning transmission X-ray microscopy elemental mapping identified Cs accumulation to discrete cytoplasmic locations within P. catenata cells, indicating a potential bioremediation option for Cs. Proteins related to stress responses and nutrient limitation (K, P) were stimulated by Cs treatment. Furthermore, selected K+ transport proteins were mis-regulated by Cs dosing, which indicates the importance of the K+ transport system for Cs accumulation. These findings enhance understanding of Cs fate and biological responses within Pseudanabaena blooms, and indicate that K exposure might provide a microbial bloom control strategy.

Although considerable research has examined factors that influence social-cognitive processes related to aggression, few studies have examined the factors that influence adolescents’ appraisal of the effectiveness of responses, particularly nonviolent alternatives to aggression. This study addressed that gap by examining patterns of adolescents’ perceived effectiveness of nonviolent and aggressive responses to hypothetical problem situations and their relations with aggression, victimization, and individual and contextual risk factors. The participants were a predominantly African American (90%) sample of 1469 students (55% female; mean age = 12.7 years; age range = 11–16) from three middle schools who completed measures of perceived effectiveness, self-efficacy, aggression and victimization, and contextual factors. Ratings of adolescents’ physical, relational, and verbal aggression and victimization, nonviolent and prosocial behavior were also obtained from their teachers. Latent class analysis identified four subgroups of adolescents including distinguishes effective, mixed support, everything works, and nothing works. Subgroups differed on measures of aggression, victimization, prosocial and nonviolent behavior, self-efficacy for nonviolence, witnessing community violence, and parents’ and peers’ support for nonviolence and aggression. The findings underscore the importance of designing violence prevention programs to target the unique needs of subgroups of adolescents.

TP53 mutations are implicated in the progression of mucinous borderline tumors (MBOT) to mucinous ovarian carcinomas (MOC). Optimized immunohistochemistry (IHC) for TP53 has been established as a proxy for the TP53 mutation status in other ovarian tumor types. We aimed to confirm the ability of TP53 IHC to predict TP53 mutation status in ovarian mucinous tumors and to evaluate the association of TP53 mutation status with survival among patients with MBOT and MOC. Tumor tissue from an initial cohort of 113 women with MBOT/MOC was stained with optimized IHC for TP53 using tissue microarrays (75.2%) or full sections (24.8%) and interpreted using established criteria as normal or abnormal (overexpression, complete absence, or cytoplasmic). Cases were considered concordant if abnormal IHC staining predicted deleterious TP53 mutations. Discordant tissue microarray cases were re-evaluated on full sections and interpretational criteria were refined. The initial cohort was expanded to a total of 165 MBOT and 424 MOC for the examination of the association of survival with TP53 mutation status, assessed either by TP53 IHC and/or sequencing. Initially, 82/113 (72.6%) cases were concordant using the established criteria. Refined criteria for overexpression to account for intratumoral heterogeneity and terminal differentiation improved concordance to 93.8% (106/113). In the expanded cohort, 19.4% (32/165) of MBOT showed evidence for TP53 mutation and this was associated with a higher risk of recurrence, disease-specific death, and all-cause mortality (overall survival: HR = 4.6, 95% CI 1.5-14.3, p = 0.0087). Within MOC, 61.1% (259/424) harbored a TP53 mutation, but this was not associated with survival (overall survival, p = 0.77). TP53 IHC is an accurate proxy for TP53 mutation status with refined interpretation criteria accounting for intratumoral heterogeneity and terminal differentiation in ovarian mucinous tumors. TP53 mutation status is an important biomarker to identify MBOT with a higher risk of mortality.

Human–animal interaction research is growing in popularity and methodological rigor; however, there remains a need for psychometrically validated measures and inclusion of broader populations. This study addressed these gaps by reporting on the psychometric properties of the Comfort from Companion Animals Scale (CCAS) in a sample of sexual and gender minority emerging adults. Participants included 138 emerging adults between the ages of 18–21 years (M = 19.33 years, SD = 1.11; 38.4% racial/ethnic minority) who identified as a gender (48.6%) and/or sexual minority (98.6%) and who reported living with a companion animal in the past year. We utilized the following analytic methods: (a) confirmatory factor analyses to compare the unidimensional structure of the CCAS with the two alternative models, (b) multiple group analyses to test measurement invariance across demographic groups, and (c) structural equation models to evaluate construct validity. Preliminary analysis found that the majority of participants did not endorse the two lowest response options. To conduct invariance testing, we eliminated items 3, 5, and 8 from the CCAS and collapsed the lowest response options. The results of the confirmatory factor analysis supported the use of this revised unidimensional model. We found evidence of measurement invariance across gender identity, sexual orientation, and race/ethnicity groups. Construct validity was supported by comparing the CCAS with factors on the Pet Attachment and Life Impact Scale; the positive association between the CCAS and anxiety are discussed in the context of prior research. Overall, our findings highlight the importance of validating human–animal interaction measures across samples from diverse backgrounds. We recommend that future studies continue to test the CCAS and other measures of human–animal attachment among diverse samples to delineate which aspects of human–animal interaction may be most beneficial in promoting mental health in vulnerable populations.

SUMMARY The pathogenic mechanism by which dominant mutations in VCP cause multisystem proteinopathy (MSP), a rare neurodegenerative disease that presents as fronto-temporal lobar degeneration with TDP-43 inclusions (FTLD-TDP), remains unclear. To explore this, we inactivate VCP in murine postnatal forebrain neurons (VCP conditional knockout [cKO]). VCP cKO mice have cortical brain atrophy, neuronal loss, autophago-lysosomal dysfunction, and TDP-43 inclusions resembling FTLD-TDP pathology. Conditional expression of a single disease-associated mutation, VCP-R155C, in a VCP null background similarly recapitulates features of VCP inactivation and FTLD-TDP, suggesting that this MSP mutation is hypomorphic. Comparison of transcriptomic and proteomic datasets from genetically defined patients with FTLD-TDP reveal that progranulin deficiency and VCP insufficiency result in similar profiles. These data identify a loss of VCP-dependent functions as a mediator of FTLD-TDP and reveal an unexpected biochemical similarity with progranulin deficiency., Graphical abstract, In brief Wani et al. demonstrate that loss of neuronal VCP recapitulates FTLD-TDP pathology in mice. Conditional expression of a VCP-R155C mutation, associated with MSP1, also recapitulates FTLD-TDP consistent with its hypomorphic function. A transcriptomic and proteomic signature of VCP inactivation resembles a transcriptomic signature in brains of patients with GRN insufficiency.

Background: Neuronal uptake and subsequent spread of proteopathic seeds, such as αS (alpha-synuclein), tau, and TDP-43, contribute to neurodegeneration and disease progression. The cellular machinery necessary for this process is poorly understood. Methods: Cas9 expressing αS FRET biosensors were transduced with a whole-genome guide RNA (gRNA) library, seeded with αS fibrils, and flow-sorted. Candidate genes protective against αS seeding were identified following gRNA sequencing of FRET+ and FRET- cell populations. Secondary validation of the high probability candidate suppressor VCP, utilized VCP inhibitors or gene knockdown in αS biosensors and primary neurons. In vivo validation was performed in VCP disease mutation mice following intrastriatal injection of αS seeds. TDP-43 seeding was performed in primary neurons from control or VCP mutant mice.Results: We devised a genome-wide CRISPR-Cas9 screen to identify suppressors of αS seeding. This approach identified Valosin Containing Protein (VCP) as a suppressor of αS seeding. Dominant mutations in VCP cause multisystem proteinopathy (MSP) a phenotypically and pathologically variable neurodegeneraive disease characterized by myopathy, motor neuron disease and dementia with TDP-43, αS and tau inclusions. VCP inhibition or MSP disease mutations increased αS seeding in cells and primary cultured neurons. This was similar to treatment with the lysosomal damaging agent, LLoMe or knockdown of the endolysosomal damage response associated VCP cofactor, UBXD1. Intrastriatal injection of αS seeds into VCP disease mice demonstrated enhanced seeding efficiency as compared with controls. Finally, this phenomenon was not specific to αS since VCP disease mutant expression increased TDP-43 seeding in neurons.Conclusion: VCP surveillance of permeabilized late endosomes protects neurons against the proteopathic spread of pathogenic protein aggregates. The spread of distinct aggregate species may dictate the pleiotropic phenotypes and pathologies in VCP associated MSP.

The 3rdedition of this catalogue contains information on the cultivation and composition characteristics of 37 microalgae. Each entry includes relevant links to Atlantic Area stakeholders known to have a relevant connection with each of the species listed, be it in the form of culture collections, research expertise, technology developers, or biomass producers. We invite the readers to visit and/or join the EnhanceMicroAlgaeStakeholder database: an easily accessible, visual and open access database that brings together all the European Atlantic Area players working in the microalgae sector.&nbsp

BACKGROUND Cybervictimization among adolescents is associated with multiple negative mental health consequences. Although pediatricians often screen for cyberbullying, validated and acceptable programs to reduce the frequency and impact of adolescent cybervictimization are lacking. OBJECTIVE This study uses agile qualitative methods to refine and evaluate the acceptability of a mixed-modality intervention, initiated within the context of usual pediatric care, for adolescents with a history of cyberharassment and cyberbullying victimization. METHODS Three groups of adolescents were successively recruited from an urban primary care clinic to participate in three consecutive iterations (1, 2, and 3) of the program, which consisted of a brief in-clinic intervention followed by 8 weeks of daily, automated SMS text messaging. After 2 weeks of messaging, iteration 1 (I1) participants completed semistructured interviews regarding intervention experiences. Participant feedback was evaluated via framework matrix analysis to guide changes to the program for iteration 2 (I2). Feedback from 2-week interviews of I2 participants was similarly used to improve the program before initiating iteration 3 (I3). Participants in all 3 iterations completed the interviews after completing the program (8 weeks). Daily response rates assessed participant engagement, and satisfaction questionnaires assessed acceptability. RESULTS A total of 19 adolescents (aged 13-17 years) reporting past-year cybervictimization were enrolled: 7 in I1, 4 in I2, and 8 in I3. Demographic variables included the following: a mean age of 15 (SD 1.5) years; 58% (11/19) female, 42% (8/19) male, 63% (12/19) Hispanic, 37% (7/19) non-Hispanic, 79% (15/19) people of color, and 21% (4/19) White. A total of 73% (14/19) self-identified as having a low socioeconomic status, and 37% (7/19) self-identified as lesbian, gay, or bisexual. The average past 12-month cybervictimization score at baseline was 8.2 (SD 6.58; range 2-26). Participant feedback was used to iteratively refine intervention content and design. For example, participants in I1 recommended that the scope of the intervention be expanded to include web-based conflicts and drama, rather than narrowly focusing on cyberbullying prevention. On the basis of this feedback, the I2 content was shifted toward more general de-escalation skills and bystander empowerment. Overall, 88.34% (940/1064) of the daily queries sent to participants across all 3 iterations received a reply. Participant satisfaction improved considerably with each iteration; 0% (0/7) of I1 participants rated the overall quality of Intervention to Prevent Adolescent Cybervictimization with Text message as excellent, compared to 50% (2/4) of I2 participants and 86% (6/7) of I3 participants. Engagement also improved between the first and third iterations, with participants replying to 59.9% (235/392) of messages in I1, compared to 79.9% (358/488) of messages in I3. CONCLUSIONS This study shows the value of structured participant feedback gathered in an agile intervention refinement methodology for the development of a technology-based intervention targeting adolescents.

Although considerable research has examined factors that influence social-cognitive processes related to aggression, few studies have examined the factors that influence adolescents' appraisal of the effectiveness of responses, particularly nonviolent alternatives to aggression. This study addressed that gap by examining patterns of adolescents' perceived effectiveness of nonviolent and aggressive responses to hypothetical problem situations and their relations with aggression, victimization, and individual and contextual risk factors. The participants were a predominantly African American (90%) sample of 1469 students (55% female; mean age = 12.7 years; age range = 11-16) from three middle schools who completed measures of perceived effectiveness, self-efficacy, aggression and victimization, and contextual factors. Ratings of adolescents' physical, relational, and verbal aggression and victimization, nonviolent and prosocial behavior were also obtained from their teachers. Latent class analysis identified four subgroups of adolescents including distinguishes effective, mixed support, everything works, and nothing works. Subgroups differed on measures of aggression, victimization, prosocial and nonviolent behavior, self-efficacy for nonviolence, witnessing community violence, and parents' and peers' support for nonviolence and aggression. The findings underscore the importance of designing violence prevention programs to target the unique needs of subgroups of adolescents.

A non-axenic culture of Pseudanabaena catenata, a close relative of the bloom-forming cyanobacterium found in the high pH First Generation Magnox Storage Pond at the Sellafield Nuclear Facility, was supplemented with 1 mM of SrCl 2, to determine its effect on the fate of Sr. The addition of 1 mM Sr to the P. catenata culture resulted in ∼16% reduction in the overall growth of the culture (OD 600nm) and a 21% reduction in the concentration of chlorophyll-a (Chl-a) compared to those without Sr. The fate of Sr was assessed using a multi-technique approach. Inductively coupled plasma atomic emission spectroscopy showed that virtually all of the Sr was removed from solution, while extracellular biomineral precipitates were analyzed using transmission electron microscopy analysis, and were shown to contain Sr, Ca, and S using energy-dispersive X-ray spectroscopy analysis. In addition, intracellular P-containing electron-dense features, likely to be polyphosphate bodies, were associated with the P. catenata cells and contained Sr. Bulk analysis of the cultures by X-ray diffraction showed the presence of Ca-containing strontianite whilst Extended X-ray Absorption Fine Structure analysis showed the presence of strontium phosphate minerals. The presence of Sr associated with intracellular polyphosphate was unexpected, and contrasts with other model photosynthetic systems in the literature that have highlighted carbonate biominerals as the dominant sink for Sr. Understanding the fate of Sr with microorganisms associated with the Spent Nuclear Fuel Ponds (SNFPs) is crucial to understanding the fate of radioactive 90Sr in such extreme environments, and could also suggest a potential remediation strategy for treatment of 90Sr contaminated waters from Spent Nuclear Fuel Ponds SNFPs and in contaminated aquatic systems.

Microalgae have evolved mechanisms to respond to changes in copper ion availability, which are very important for normal cellular function, to tolerate metal pollution of aquatic ecosystems, and for modulation of copper bioavailability and toxicity to other organisms. Knowledge and application of these mechanisms will benefit the use of microalgae in wastewater processing and biomass production, and the use of copper compounds in the suppression of harmful algal blooms. Here, using electron microscopy, synchrotron radiation-based Fourier transform infrared spectroscopy, electron paramagnetic resonance spectroscopy, and X-ray absorption fine structure spectroscopy, we show that the microalga Chlorella sorokiniana responds promptly to Cu2+ at high non-toxic concentration, by mucilage release, alterations in the architecture of the outer cell wall layer and lipid structures, and polyphosphate accumulation within mucilage matrix. The main route of copper detoxification is by Cu2+ coordination to polyphosphates in penta-coordinated geometry. The sequestrated Cu2+ was accessible and could be released by extracellular chelating agents. Finally, the reduction in Cu2+ to Cu1+ appears also to take place. These findings reveal the biochemical basis of the capacity of microalgae to adapt to high external copper concentrations and to serve as both, sinks and pools of environmental copper.

Understanding the long-term fate, stability, and bioavailability of uranium (U) in the environment is important for the management of nuclear legacy sites and radioactive wastes. Analysis of U behavior at natural analogue sites permits evaluation of U biogeochemistry under conditions more representative of long-term equilibrium. Here, we have used bulk geochemical and microbial community analysis of soils, coupled with X-ray absorption spectroscopy and mu-focus X-ray fluorescence mapping, to gain a mechanistic understanding of the fate of U transported into an organic-rich soil from a pitchblende vein at the UK Needle's Eye Natural Analogue site. U is highly enriched in the Needle's Eye soils (similar to 1600 mg kg(-1)). We show that this enrichment is largely controlled by U(VI) complexation with soil organic matter and not U(VI) bioreduction. Instead, organic-associated U(VI) seems to remain stable under microbially-mediated Fe(III)-reducing conditions. U(IV) (as non-crystalline U(IV)) was only observed at greater depths at the site (>25 cm); the soil here was comparatively mineral-rich, organic-poor, and sulfate-reducing/methanogenic. Furthermore, nanocrystalline UO2, an alternative product of U(VI) reduction in soils, was not observed at the site, and U did not appear to be associated with Fe-bearing minerals. Organicrich soils appear to have the potential to impede U groundwater transport, irrespective of ambient redox conditions. (C) 2020 The Authors. Published by Elsevier Ltd.

Recently a species of Pseudanabaena was identified as the dominant photosynthetic organism during a bloom event in a high pH (pH ∼11.4), radioactive spent nuclear fuel pond (SNFP) at the Sellafield Ltd., United Kingdom facility. The metabolic response of a laboratory culture containing the cyanobacterium Pseudanabaena catenata, a relative of the major photosynthetic microorganism found in the SNFP, to X-ray irradiation was studied to identify potential survival strategies used to support colonization of radioactive environments. Growth was monitored and the metabolic fingerprints of the cultures, during irradiation and throughout the post-irradiation recovery period, were determined using Fourier transform infrared (FT-IR) spectroscopy. A dose of 95 Gy delivered over 5 days did not significantly affect growth of P. catenata, as determined by turbidity measurements and cell counts. Multivariate statistical analysis of the FT-IR spectral data revealed metabolic variation during the post-irradiation recovery period, with increased polysaccharide and decreased amide spectral intensities. Increases in polysaccharides were confirmed by complementary analytical methods including total carbohydrate assays and calcofluor white staining. This observed increased production of polysaccharides is of significance, since this could have an impact on the fate of the radionuclide inventory in the pond via biosorption of cationic radionuclides, and may also impact on downstream processes through biofilm formation and biofouling.

Metal transport processes are relatively poorly understood in algae in comparison to higher plants and other eukaryotes. A screen of genomes from 33 taxonomically diverse algal species was conducted to identify members of the Cation Diffusion Facilitator (CDF) family of metal ion transporter. All algal genomes contained at least one CDF gene with four species having >10 CDF genes (median of 5 genes per genome), further confirming that this is a ubiquitous gene family. Phylogenetic analysis suggested a CDF gene organisation of five groups, which includes Zn-CDF, Fe/Zn-CDF and Mn-CDF groups, consistent with previous phylogenetic analyses, and two functionally undefined groups. One of these undefined groups was algal specific although excluded chlorophyte and rhodophyte sequences. The majority of sequences (22 out of 26 sequences) from this group had a putative ion binding site motif within transmembrane domain 2 and 5 that was distinct from other CDF proteins, such that alanine or serine replaced the conserved histidine residue. The phylogenetic grouping was supported by sequence cluster analysis. Yeast heterologous expression of CDF proteins from Chlamydomonas reinhardtii indicated Zn2+ and Co2+ transport function by CrMTP1, and Mn2+ transport function by CrMTP2, CrMTP3 and CrMTP4, which validated the phylogenetic prediction. However, the Mn-CDF protein CrMTP3 was also able to provide zinc and cobalt tolerance to the Zn- and Co-sensitive zrc1cot1 yeast strain. There is wide diversity of CDF transporters within the algae lineage, and some of these genes may be attractive targets for future applications of metal content engineering in plants or microorganisms.

Microalgae are considered a promising feedstock for biorefineries given that their chemical composition - rich in carbohydrate and lipid - can be directed towards the co-production of various value-added fuels and chemicals. Production of microalgal biomass for biorefinery purposes requires the identification and establishment of optimal cultivation systems, a crucial yet complicated task due to the numerous factors (e.g. media composition, light, temperature) that simultaneously regulate biomass growth and intracellular composition. Modelling these biological processes, taking into account a single or multiple growth-limiting factors, offers a valuable tool to simulate, design and optimise the dynamics of microalgae cultivation. This review provides an overview of existing models developed to describe microalgal growth processes at the macroscopic scale (also termed black-box models) and discusses their formulation in detail. The black-box kinetic modelling frameworks are compiled into single-factor (6 formulations) and multiple-factor (32 formulations - further divided into non-interactive, additive, and interactive) growth kinetic models, as reported in more than 80 studies, for the prediction of biomass growth as a function of major operational factors such as media composition (e.g. nutrient concentration) and environmental factors (e.g. transient light and temperature). In addition, the review focuses on those models that further account for the production dynamics of two microalgal intracellular products with renowned potential as biorefinery substrates: carbohydrate and lipid molecules. Models of microalgal cultivation dynamics offer a robust engineering tool to understand the natural yet complex responses of microalgae to their growing environment and can help - if used appropriately - to optimise microalgae cultivation and increase the economic viability and sustainability of microalgal systems.

The use of microalgal biomass for metal pollutant bioremediation might be improved by genetic engineering to modify the selectivity or capacity of metal biosorption. A plant cadmium (Cd) and zinc (Zn) transporter (AtHMA4) was used as a transgene to increase the ability of Chlamydomonas reinhardtii to tolerate 0.2 mM Cd and 0.3 mM Zn exposure. The transgenic cells showed increased accumulation and internalisation of both metals compared to wild type. AtHMA4 was expressed either as the full-length protein or just the C-terminal tail, which is known to have metal binding sites. Similar Cd and Zn tolerance and accumulation was observed with expression of either the full-length protein or C-terminal domain, suggesting that enhanced metal tolerance was mainly due to increased metal binding rather than metal transport. The effectiveness of the transgenic cells was further examined by immobilisation in calcium alginate to generate microalgal beads that could be added to a metal contaminated solution. Immobilisation maintained metal tolerance, while AtHMA4-expressing cells in alginate showed a concentration-dependent increase in metal biosorption that was significantly greater than alginate beads composed of wild type cells. This demonstrates that expressing AtHMA4 full-length or C-terminus has great potential as a strategy for bioremediation using microalgal biomass.

Dominant mutations in the HSP70 co-chaperone DNAJB6 cause a late onset muscle disease termed limb girdle muscular dystrophy type 1D (LGMD1D), which is characterized by protein aggregation and vacuolar myopathology. Disease mutations reside within the G/F domain of DNAJB6, but the molecular mechanisms underlying dysfunction are not well understood. Using yeast, cell culture, and mouse models of LGMD1D, we find that the toxicity associated with disease-associated DNAJB6 requires its interaction with HSP70, and that abrogating this interaction genetically or with small molecules is protective. In skeletal muscle, DNAJB6 localizes to the Z-disc with HSP70. Whereas HSP70 normally diffuses rapidly between the Z-disc and sarcoplasm, the rate of HSP70’s diffusion in LGMD1D mouse muscle is diminished likely because it has an unusual affinity for the Z-disc and mutant DNAJB6. Treating LGMD1D mice with a small molecule inhibitor of the DNAJ-HSP70 complex re-mobilizes HSP70, improves strength and corrects myopathology. These data support a model in which LGMD1D mutations in DNAJB6 are a gain-of-function disease that is, counter-intuitively, mediated via HSP70 binding. Thus, therapeutic approaches targeting HSP70:DNAJB6 may be effective in treating this inherited muscular dystrophy.