Nitrogen fixation and other biogeochemically important features of Atacama Desert giant horsetail plant microbiomes inferred from metagenomic contig analysis.

BACKGROUND AND AIMS: Canyon stream beds in the hyperarid Atacama Desert surprisingly harbour magnificent groves of endemic giant horsetail wetland plants, Equisetum xylochaetum. Our previous metagenomic study of eukaryotes closely associated with this plant indicated that the microbiome included prokaryotes that might likewise influence host success and environment. We explored this possibility by using the metagenomic sequence to characterize prokaryote taxa and functional genes present in the microbiome of E. xylochaetum sampled from remote sites differing in the degree of anthropogenic disturbance. We focused on biogeochemical functions known to be important in wetland ecosystems. METHODS: To ensure that analyses were conducted on microbes most closely associated with plants, we extracted DNA from well-washed plant organs whose microbial biofilms were revealed with scanning electron microscopy. To assess the benefits of longer sequences for taxonomic and gene classifications, results of analyses performed using contigs were compared with those obtained with unassembled reads. We employed methods widely used to estimate genomic coverage of single taxa for genomic analysis to infer relative abundances of taxa and functional genes. KEY RESULTS: Key functional bacterial genera (e.g. Hydrogenophaga, Sulfuritalea and Rhodoferax) inferred from taxonomic and functional gene analysis of contigs - but not unassembled reads - to occur on surfaces of (or within) plants at relatively high abundance (>50× genomic coverage) indicated roles in nitrogen, sulfur and other mineral cycling processes. Comparison between sites revealed impacts on biogeochemical functions, e.g. reduced levels of the nifH gene marker under disturbance. Vanadium nitrogenases were more important than molybdenum nitrogenases, indicated by both functional genes and taxa such as Rhodomicrobium and Phaeospirillum inferred from contigs but not unassembled reads. CONCLUSIONS: Our contig-based metagenomic analyses revealed that microbes performing key wetland biogeochemical functions occur as tightly adherent biofilms on the plant body, not just in water or sediments, and that disturbance reduces such functions, providing arguments for conservation efforts.

Preventing Health Care-Associated Infections Through Implementation of an Interprofessional Visual Management Safety Tracker.

BACKGROUND: The management of health care associated infections (HAIs) challenges acute care facilities due to variability in practices. The purpose of this quality improvement project was to decrease central line-associated bloodstream infection, catheter-associated urinary tract infection, and Clostridioides difficile infection in a high acuity care environment using a visual management (VM) tool to address practice variations. LOCAL PROBLEM: An acute care unit experienced increasing HAIs. METHODS: An interprofessional team used Lean methodology to implement a VM tool reflective of evidence-based HAI prevention practices that staff had frequently omitted. INTERVENTIONS: A VM tool called the Safety Tracker was created. RESULTS: In 12 months, HAIs decreased from 9 events to 1, with a corresponding reduction in indwelling urinary catheter utilization and central line utilization. More than $160 000 were avoided in health care costs. CONCLUSIONS: Creating an interprofessional VM Safety Tracker could significantly reduce HAIs.

Shotgun metagenomics and microscopy indicate diverse cyanophytes, other bacteria, and microeukaryotes in the epimicrobiota of a northern Chilean wetland Nostoc (Cyanobacteria).

Prokaryotic Nostoc, one of the world's most conspicuous and widespread algal genera (similar to eukaryotic algae, plants, and animals) is known to support a microbiome that influences host ecological roles. Past taxonomic characterizations of surface microbiota (epimicrobiota) of free-living Nostoc sampled from freshwater systems employed 16S rRNA genes, typically amplicons. We compared taxa identified from 16S, 18S, 23S, and 28S rRNA gene sequences filtered from shotgun metagenomic sequence and used microscopy to illuminate epimicrobiota diversity for Nostoc sampled from a wetland in the northern Chilean Altiplano. Phylogenetic analysis and rRNA gene sequence abundance estimates indicated that the host was related to Nostoc punctiforme PCC 73102. Epimicrobiota were inferred to include 18 epicyanobacterial genera or uncultured taxa, six epieukaryotic algal genera, and 66 anoxygenic bacterial genera, all having average genomic coverage ≥90X. The epicyanobacteria Geitlerinemia, Oscillatoria, Phormidium, and an uncultured taxon were detected only by 16S rRNA gene; Gloeobacter and Pseudanabaena were detected using 16S and 23S; and Phormididesmis, Neosynechococcus, Symphothece, Aphanizomenon, Nodularia, Spirulina, Nodosilinea, Synechococcus, Cyanobium, and Anabaena (the latter corroborated by microscopy), plus two uncultured cyanobacterial taxa (JSC12, O77) were detected only by 23S rRNA gene sequences. Three chlamydomonad and two heterotrophic stramenopiles genera were inferred from 18S; the streptophyte green alga Chaetosphaeridium globosum was detected by microscopy and 28S rRNA genes, but not 18S rRNA genes. Overall, >60% of epimicrobial taxa were detected by markers other than 16S rRNA genes. Some algal taxa observed microscopically were not detected from sequence data. Results indicate that multiple taxonomic markers derived from metagenomic sequence data and microscopy increase epimicrobiota detection.

Deconstruction of banana peel for carbohydrate fractionation.

The deconstruction of banana peel for carbohydrate recovery was performed by sequential treatment (acid, alkaline, and enzymatic). The pretreatment with citric acid promoted the extraction of pectin, resulting in a yield of 8%. In addition, xylose and XOS, 348.5 and 17.3 mg/g xylan, respectively, were also quantified in acidic liquor as a result of partial depolymerization of hemicellulose. The spent solid was pretreated with alkaline solution (NaOH or KOH) for delignification and release of residual carbohydrates from the hemicellulose. The yields of xylose and arabinose (225.2 and 174.0 mg/g hemicellulose) were approximately 40% higher in the pretreatment with KOH, while pretreatment with NaOH promoted higher delignification (67%), XOS yield (32.6 mg/g xylan), and preservation of cellulosic fraction. Finally, the spent alkaline solid, rich in cellulose (76%), was treated enzymatically to release glucose, reaching the final concentration of 28.2 g/L. The mass balance showed that through sequential treatment, 9.9 g of xylose, 0.5 g of XOS, and 8.2 g of glucose were obtained from 100 g of raw banana peels, representing 65.8% and 46.5% conversion of hemicellulose and cellulose, respectively. The study of the fractionation of carbohydrates in banana peel proved to be a useful tool for valorization, mainly of the hemicellulose fraction for the production of XOS and xylose with high value applications in the food industry.

Cello-oligosaccharides production from lignocellulosic biomass and their emerging prebiotic applications.

Cello-oligosaccharides (COS) are linear oligosaccharides composed of ß-1,4-linked glucopyranose units. They comprise a group of important new oligosaccharides of significant interest and potential applications in the pharmaceutical, food, chemical, and feed industries, currently emerging as potential prebiotic compounds. COS from lignocellulosic biomass, specifically the agro-industrial residues and by-products of the forestry industry, constitute a new attractive process that imposes the sustainable use of biomass resources. Two main strategies have been used for the production of COS: acid-based and enzyme-based cellulose hydrolysis. The latter has been considered more attractive due to the use of milder reaction conditions and less production of monomers. This review summarizes that although COS is emerging as a potential prebiotic with also other potential applications, there is a lack of information regarding the large-scale production, which could be associated with the recalcitrant nature of cellulose compared to other polysaccharides, which hinders the hydrolysis of its dense network.

Automated Text Messaging as an Adjunct to Cognitive Behavioral Therapy for Depression: A Clinical Trial.

BACKGROUND: Cognitive Behavioral Therapy (CBT) for depression is efficacious, but effectiveness is limited when implemented in low-income settings due to engagement difficulties including nonadherence with skill-building homework and early discontinuation of treatment. Automated messaging can be used in clinical settings to increase dosage of depression treatment and encourage sustained engagement with psychotherapy. OBJECTIVES: The aim of this study was to test whether a text messaging adjunct (mood monitoring text messages, treatment-related text messages, and a clinician dashboard to display patient data) increases engagement and improves clinical outcomes in a group CBT treatment for depression. Specifically, we aim to assess whether the text messaging adjunct led to an increase in group therapy sessions attended, an increase in duration of therapy attended, and reductions in Patient Health Questionnaire-9 item (PHQ-9) symptoms compared with the control condition of standard group CBT in a sample of low-income Spanish speaking Latino patients. METHODS: Patients in an outpatient behavioral health clinic were assigned to standard group CBT for depression (control condition; n=40) or the same treatment with the addition of a text messaging adjunct (n=45). The adjunct consisted of a daily mood monitoring message, a daily message reiterating the theme of that week's content, and medication and appointment reminders. Mood data and qualitative responses were sent to a Web-based platform (HealthySMS) for review by the therapist and displayed in session as a tool for teaching CBT skills. RESULTS: Intent-to-treat analyses on therapy attendance during 16 sessions of weekly therapy found that patients assigned to the text messaging adjunct stayed in therapy significantly longer (median of 13.5 weeks before dropping out) than patients assigned to the control condition (median of 3 weeks before dropping out; Wilcoxon-Mann-Whitney z=-2.21, P=.03). Patients assigned to the text messaging adjunct also generally attended more sessions (median=6 sessions) during this period than patients assigned to the control condition (median =2.5 sessions), but the effect was not significant (Wilcoxon-Mann-Whitney z=-1.65, P=.10). Both patients assigned to the text messaging adjunct (B=-.29, 95% CI -0.38 to -0.19, z=-5.80, P<.001) and patients assigned to the control conditions (B=-.20, 95% CI -0.32 to -0.07, z=-3.12, P=.002) experienced significant decreases in depressive symptom severity over the course of treatment; however, the conditions did not significantly differ in their degree of symptom reduction. CONCLUSIONS: This study provides support for automated text messaging as a tool to sustain engagement in CBT for depression over time. There were no differences in depression outcomes between conditions, but this may be influenced by low follow-up rates of patients who dropped out of treatment.

Randomized controlled trial protocol: balance training with rhythmical cues to improve and maintain balance control in Parkinson's disease.

BACKGROUND: Postural instability is a particularly incapacitating disorder, whose loss of motor independence by Parkinson´s Disease (PD) patients marks a significant stage of disease onset. Evidence suggests that deficits in automatic motor control, sensory integration and attention are associated with the lack of balance in PD. Physiotherapy together with medication play an important role in the treatment of this state, although no consensus has been reached on the best treatment modality. The aim of this randomized controlled trial protocol is to evaluate the effects of balance training with rhythmical (BRT), which is a motor program to improve balance associated with rhythmical auditory cues (RACs). This study is ongoing in the stage 1. METHODS AND DESIGN: A total of 150 PD patients at H&Y stages II-III and asymptomatic for depression and dementia are enrolled in a single-blind randomized study. Randomization is achieved via a computer-generated random-sequence table. All patients should also present a fall history. They will be assigned into one of three groups, and their balance and gait will be assessed before and after 10 training sessions, and after 4 and 30 weeks subsequent to the end of the training. The BRT group will receive a motor program to improve balance associated with RACs, the MT group will perform motor training with the same aims as those in the BRT group but without RACs, and the control group (CG) will be trained only in orientations. The exercise program specific to balance is of 5 weeks' duration with two sessions per week, 45 min each, and consists of general physiotherapy exercises. Each session will be divided into five warm-up minutes-30 min for the main part and 10 min for the cool down. The training progresses and intensifies each week depending on the individual's performance. The subjects should be able to execute 10 repetitions of the exercise sequences correctly to progress to the next movement. DISCUSSION: This randomized study protocol will evaluate the effects of a motor program designed to improve balance associated with RACs, and will also assess whether balance training leads to activation of balance reactions at the appropriate time. We hypothesize that if this motor program is maintained long-term, it will prevent falls. TRIAL REGISTRATION: Clinicaltrials.gov NCT02488265 ; Ethics Committee of the University of São Paulo Faculty of Medicine Clinics Hospital 1.102.464.

Lacustrine Nostoc (Nostocales) and associated microbiome generate a new type of modern clotted microbialite.

Microbialites are mineral formations formed by microbial communities that are often dominated by cyanobacteria. Carbonate microbialites, known from Proterozoic times through the present, are recognized for sequestering globally significant amounts of inorganic carbon. Recent ecological work has focused on microbial communities dominated by cyanobacteria that produce microbial mats and laminate microbialites (stromatolites). However, the taxonomic composition and functions of microbial communities that generate distinctive clotted microbialites (thrombolites) are less well understood. Here, microscopy and deep shotgun sequencing were used to characterize the microbiome (microbial taxa and their genomes) associated with a single cyanobacterial host linked by 16S sequences to Nostoc commune Vaucher ex Bornet & Flahault, which dominates abundant littoral clotted microbialites in shallow, subpolar, freshwater Laguna Larga in southern Chile. Microscopy and energy-dispersive X-ray spectroscopy suggested the hypothesis that adherent hollow carbonate spheres typical of the clotted microbialite begin development on the rigid curved outer surfaces of the Nostoc balls. A surface biofilm included >50 nonoxygenic bacterial genera (taxa other than Nostoc) that indicate diverse ecological functions. The Laguna Larga Nostoc microbiome included the sulfate reducers Desulfomicrobium and Sulfospirillum and genes encoding all known proteins specific to sulfate reduction, a process known to facilitate carbonate deposition by increasing pH. Sequences indicating presence of nostocalean and other types of nifH, nostocalean sulfide:ferredoxin oxidoreductase (indicating anoxygenic photosynthesis), and biosynthetic pathways for the secondary products scytonemin, mycosporine, and microviridin toxin were identified. These results allow comparisons with microbiota and microbiomes of other algae and illuminate biogeochemical roles of ancient microbialites.

Effect of ensiling treatment on secondary compounds and amino acid profile of tropical forage legumes, and implications for their pig feeding potential.

BACKGROUND: Smallholders in the tropics depend on local protein supplements to balance pig diets. Thus, various tropical forage legumes are a potential feeding option. Ensiling allows converting forages into a ready-to-feed-out choice, but the lactic acid fermentation may influence various (anti)nutritional components. The purpose of this study was to evaluate the effects of sucrose (SU) and a tropical Lactobacillus plantarum strain (LAB) as ensiling treatments (control, SU, LAB, LAB + SU) on the potential nutrient availability of 10 forage legume species. RESULTS: Ensiling commonly reduced antinutritional compounds such as tannins (by 49-84%) and trypsin inhibitory activity (by 74-78%), as well as oxalic acid (by 51-100%). An improved potential absorbability of protein and minerals for pigs is thus inferred. There was no major loss in total amino acids. In general, the species effect was stronger than the treatment effect. A clear effect of the treatments SU, LAB and LAB + SU over all 10 forage species was only observed for oxalic acid, single amino acids and trypsin inhibitory activity. CONCLUSION: Ensiling is a viable option to enhance nutrient utilization of tropical forages for pigs. Species-specific treatment of forage legumes is recommended.

Anonna crassiflora suppresses colonic carcinogenesis through its antioxidant effects, bioactive amines, and phenol content in rats.

Marolo (Annona crassiflora) is an underutilized Brazilian Cerrado fruit with few reports in the literature about its bioactive compounds and functional properties. In this context, the chemoprevention against the carcinogen 1,2-dimethylhydrazine (DMH)-induced pre-neoplastic lesions in Wistar rat colon was investigated and correlated with marolo's antioxidant activity and the contents of phenolic compounds and bioactive amines. Total phenolic compounds (TPC) and total flavonoids compounds (TFC) were determined in the marolo pulp extract by spectrophotometric and Ultra-Performance Liquid Chromatography and diode array detection (UPLC-DAD) analysis. Free bioactive amines were determined by High Performance Liquid Chromatography and fluorescence detection (HPLC-FLD) after post column derivatization with o-phthalaldehyde. In addition, the in vitro antioxidant activity was determined by DPPH, and ABTS. Wistar rats were treated orally with marolo pulp at 0.7, 1.4 and 2.8 g/kg body weight (bw)/day added to a standard ration. Four subcutaneous injections of DMH (40 mg/kg bw) were used to induce a pre-neoplastic lesion that was assessed by the aberrant crypt foci (ACF) assay. The marolo pulp (fresh weigh) showed high content of total phenolic compounds (9.16 mg GAE/g), with predominance of chlorogenic acid (1.86 µg/g) and epicatechin (0.99 µg/g), and total flavonoids (7.26 mg CE/g), ∼85 % of the TPC. The marolo pulp had significant contents of tyramine (31.97 mg/kg), putrescine (20.65 mg/kg), and spermidine (6.32 mg/kg). The marolo pulp inhibited (p < 0.05) pre-neoplastic lesions induced by DMH administration at the all concentrations tested. These findings indicate that marolo pulp has a colon carcinogenesis chemopreventive effect, which could be due to, at least in parts, its antioxidant action associated with its phenolics and flavonoids content as well of spermidine.

Influence of cocoa varieties on carbohydrate composition and enzymatic activity of cocoa pulp.

In Brazil, after the witch's broom disease incidence, diverse cocoa hybrids were developed, and variations were reported on their composition and characteristics. Based on this, the present study aimed to evaluate the pulp composition of several cocoa hybrids in order to better understand these variations. Results show that cocoa pulp is composed, on average, of 76 % sugar, and a wide variation (20 %) was observed in sugar content between hybrids. Regarding the sugar profile, a prevalence of reducing sugars was observed. Pod origin also plays an important role in pulp composition, with variations between hybrids from Espírito Santo and Bahia states. In relation to the degree of ripeness, ripe pods showed higher fructose and glucose content, while unripe pods presented mainly sucrose. Similar to sugars, the cello-oligossacharides profile was influenced by the degree of pod ripeness and origin and most ripe samples presented mainly cellobiose, cellotriose and cellotetrose. In addition, the prebiotic potential of cocoa pulp was highlighted by cello-oligossacharides digestion assay which exhibited low rates of degradation. Varying enzymatic activity was observed amongst different pulp hybrids, with polyphenol oxidase showing a higher variation when compared to invertase and polygalacturonase ranging. This study shows that the pod hybrid, origin and ripening degree may change the cocoa pulp composition. Therefore, it is very important to understand and evaluate these variations, in order to obtain better results in pulp utilization either in cocoa fermentation or as a coproduct.

Fractionation of functional oligosaccharides produced from sugarcane straw using serial nanofiltration membranes and their influence on prebiotic potential.

Functional oligosaccharides are non-digestible by human gut enzymes and provide health benefits as fibers and prebiotics. The cello-oligosaccharides (COS) and xylooligosaccharides (XOS) are functional oligosaccharides obtained from xylan and cellulose, respectively, and are present in lignocellulosic material. The serial NF membranes process was performed to investigate the impact of the fractionation process on the prebiotic activity of oligosaccharides from xylan and cellulose. The NP030 (weight cut-off of 500-600 Da) and DK (weight cut-off of 150-300 Da) NF polymeric membranes were employed using defined operational conditions. The diafiltration (DF) was also investigated and it was determined that only a 1-time DF for NP030 was a more suitable strategy and improved the performance indices for short DP oligosaccharides. The short DP fractions obtained favored cell density for probiotic strains, which presented an increase on the optical density of up to 25 % after the fractionating process; enabling the use of short purified fractions in the food and pharmaceutical industry as a prebiotic ingredient.

Metabolic engineering of Saccharomyces cerevisiae for second-generation ethanol production from xylo-oligosaccharides and acetate.

Simultaneous intracellular depolymerization of xylo-oligosaccharides (XOS) and acetate fermentation by engineered Saccharomyces cerevisiae offers significant potential for more cost-effective second-generation (2G) ethanol production. In the present work, the previously engineered S. cerevisiae strain, SR8A6S3, expressing enzymes for xylose assimilation along with an optimized route for acetate reduction, was used as the host for expressing two ß-xylosidases, GH43-2 and GH43-7, and a xylodextrin transporter, CDT-2, from Neurospora crassa, yielding the engineered SR8A6S3-CDT-2-GH34-2/7 strain. Both ß-xylosidases and the transporter were introduced by replacing two endogenous genes, GRE3 and SOR1, that encode aldose reductase and sorbitol (xylitol) dehydrogenase, respectively, and catalyse steps in xylitol production. The engineered strain, SR8A6S3-CDT-2-GH34-2/7 (sor1Δ gre3Δ), produced ethanol through simultaneous XOS, xylose, and acetate co-utilization. The mutant strain produced 60% more ethanol and 12% less xylitol than the control strain when a hemicellulosic hydrolysate was used as a mono- and oligosaccharide source. Similarly, the ethanol yield was 84% higher for the engineered strain using hydrolysed xylan, compared with the parental strain. Xylan, a common polysaccharide in lignocellulosic residues, enables recombinant strains to outcompete contaminants in fermentation tanks, as XOS transport and breakdown occur intracellularly. Furthermore, acetic acid is a ubiquitous toxic component in lignocellulosic hydrolysates, deriving from hemicellulose and lignin breakdown. Therefore, the consumption of XOS, xylose, and acetate expands the capabilities of S. cerevisiae for utilization of all of the carbohydrate in lignocellulose, potentially increasing the efficiency of 2G biofuel production.

Screening and Identification of Coastal Chilean Thraustochytrids for Arachidonic Acid Production: Biotechnological Potential of Ulkenia visurgensis Lng2-Strain.

Thraustochytrids are unicellular heterotrophic marine protists that have been described as producing a high content of polyunsaturated fatty acids (PUFAs). Among them, arachidonic acid (ARA) stands out as a precursor of several mediators of pivotal importance for the immune system. However, the biotechnological potential of thraustochytrids for ARA production has not been developed. The objective of this study is to isolate and identify native strains from different Chilean coastal environments and evaluate in vitro the effect of culture parameters such as C/N ratio (19 and 33) and temperature (15 °C and 23 °C) on biomass production and arachidonic acid content. A total of nine strains were identified and classified into four genera of the Thraustochitridae family. The Lng2 strain with 99% identity belongs to the species Ulkenia visurgenis and was the most prominent one for ARA production. Temperature had an effect on the PUFA profile but not on the ARA content nor on the biomass yield. Additionally, the C/N ratio has been identified as a key parameter. The ARA productivity increased by 92% (from 0.6 to 8.3 ARA mg/g-DW) and its total biomass by 62.7% (from 1.9 to 5.1 g/L) at a high C/N ratio (33) as compared to the control.

Aeroterrestrial Coleochaete (Streptophyta, Coleochaetales) models early plant adaptation to land.

PREMISE OF THE STUDY: The streptophyte water-to-land transition was a pivotal, but poorly understood event in Earth history. While some early-diverging modern streptophyte algae are aeroterrestrial (living in subaerial habitats), aeroterrestrial survival had not been tested for Coleochaete, widely regarded as obligately aquatic and one of the extant green algal genera most closely related to embryophytes. This relationship motivated a comparison of aeroterrestrial Coleochaete to lower Paleozoic microfossils whose relationships have been uncertain. METHODS: We tested the ability of two species of the experimentally tractable, complex streptophyte algal genus Coleochaete Bréb. to (1) grow and reproduce when cultivated under conditions that mimic humid subaerial habitats, (2) survive desiccation for some period of time, and (3) produce degradation-resistant remains comparable to enigmatic Cambrian microfossils. KEY RESULTS: When grown on mineral agar media or on quartz sand, both species displayed bodies structurally distinct from those expressed in aquatic habitats. Aeroterrestrial Coleochaete occurred as hairless, multistratose, hemispherical bodies having unistratose lobes or irregular clusters of cells with thick, layered, and chemically resistant walls that resemble certain enigmatic lower Paleozoic microfossils. Whether grown under humid conditions or air-dried for a week, then exposed to liquid water, aeroterrestrial Coleochaete produced typical asexual zoospores and germlings. Cells that had been air-dried for periods up to several months maintained their integrity and green pigmentation. CONCLUSIONS: Features of modern aeroterrestrial Coleochaete suggest that ancient complex streptophyte algae could grow and reproduce in moist subaerial habitats, persist through periods of desiccation, and leave behind distinctive microfossil remains.

Characterization of Rapana thomasiana as an indicator of environmental quality of the Black Sea coast of Bulgaria.

The aim of this investigation was to determine the contents of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), minerals, trace elements and bioactivity in the gastropod Rapana thomasiana, which can be used as an environmental bioindicator organism. The chemical differences between Rapana thomasiana from polluted (RapaPol) and non-polluted (RapaNPol) sites of the Black Sea coast in Bulgarian were investigated. Chromatography and high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) were used for evaluation of PAHs, PCBs, minerals and trace elements. Methanol extracts from RapaPol and RapaNPol (to a lesser degree) contained relatively high amounts of free phenolics (2.50 +/- 0.3 and 1.57 +/- 0.18 mg GAE/g DW, respectively) and exhibited the following respective levels of antioxidant activities determined by two radical-scavenging assays (microMTE/g DW): 1.8 +/- 0.2 and 0.98 +/- 0.08 by 1-diphenyl-2-picrylhydrazyl method (DPPH); 1.74 +/- 0.17 and 1.04 +/- 0.12 by cupric reducing antioxidant capacity (CUPRAC). The total amounts of elements, PAHs and PCBs were higher in RapaPol than in RapaNPol. The obtained indices of Rapana thomasiana can serve as a bioindicator of the environmental ecological quality.

Plastid Genome of Equisetum xylochaetum from the Atacama Desert, Chile and the Relationships of Equisetum Based on Frequently Used Plastid Genes and Network Analysis.

The modern pteridophyte genus Equisetum is the only survivor of Sphenopsida, an ancient clade known from the Devonian. This genus, of nearly worldwide distribution, comprises approximately 15 extant species. However, genomic information is limited. In this study, we assembled the complete chloroplast genome of the giant species Equisetum xylochaetum from a metagenomic sequence and compared the plastid genome structure and protein-coding regions with information available for two other Equisetum species using network analysis. Equisetum chloroplast genomes showed conserved traits of quadripartite structure, gene content, and gene order. Phylogenetic analysis based on plastome protein-coding regions corroborated previous reports that Equisetum is monophyletic, and that E. xylochaetum is more closely related to E. hyemale than to E. arvense. Single-gene phylogenetic estimation and haplotype analysis showed that E. xylochaetum belonged to the subgenus Hippochaete. Single-gene haplotype analysis revealed that E. arvense, E. hyemale, E. myriochaetum, and E. variegatum resolved more than one haplotype per species, suggesting the presence of a high diversity or a high mutation rate of the corresponding nucleotide sequence. Sequences from E. bogotense appeared as a distinct group of haplotypes representing the subgenus Paramochaete that diverged from Hippochaete and Equisetum. In addition, the taxa that were frequently located at the joint region of the map were E. scirpoides and E. pratense, suggesting the presence of some plastome characters among the Equiseum subgenera.

Arbuscular Mycorrhizal Fungi and Soil Quality Indicators in Eucalyptus genotypes With Different Drought Tolerance Levels.

Silviculture has great importance worldwide, and the use of Eucalyptus species, which account for 75% of the local planted forest in Brazil, is one of the factors that contributes to the success of this activity in the country. Despite its adaptability, the yield of Eucalyptus is often affected by climate change, particularly water deficiency. Plants have developed strategies to mitigate water stress, for example, through their association with mycorrhizal fungi. The genus Eucalyptus, particularly in the plant domain, establishes symbioses with arbuscular mycorrhizal fungi (AMF) and ectomycorrhizal fungi (ECMF). The influence of Eucalyptus species on AMF and soil quality indicators is not well understood. Our aim was to conduct a preliminary evaluation of the various responses of soil AMF communities and soil nutrient dynamics in the presence of Eucalyptus species with different degrees of drought tolerance. A field experiment was established containing six Eucalyptus species, E. brassiana, E. camaldulensis, E. citriodora, E. cloeziana, E. grandis, and E. urophylla, all of which were planted in large plots. Soil and root samples were taken when the plants were 1.7 and 2.2 years old. We found that Eucalyptus species with low (E. grandis and E. urophylla) and intermediate drought tolerance (E. citriodora and E. cloeziana) showed stronger correlations with the AMF community than Eucalyptus species with high drought tolerance (E. brassiana and E. camaldulensis). Differences were also found between Eucalyptus species for AMF spore numbers and root colonization percentages, which was most evident for E. urophylla. The microbiological attributes found to be most responsive to Eucalyptus species were soil enzyme activities, AMF spore numbers, root colonization percentages, and fungal abundance. Soil organic carbon, phosphorus, potassium, zinc, copper, and iron were the main chemical drivers related to the soil AMF community structure in the presence of E. brassiana.

Xylo-oligosaccharide microparticles with synbiotic potential obtained from enzymatic hydrolysis of sugarcane straw.

Synbiotic formulations and microencapsulation techniques have been explored in food industries to guarantee the viability of probiotic organisms; playing an important role in microbiota balance. Microparticles of alginate, gelatin and xylo-oligosaccharides (XOS) were produced by external gelation with the purpose of enhancing the survival rate of the probiotic L. acidophilus. XOS was obtained through enzymatic hydrolysis of xylan extracted from sugarcane straw, achieving more than 70% conversion and used for microparticle preparation. Microparticles containing 3% XOS provided greater cell protection during exposure to the gastrointestinal tract and during refrigerated storage; keeping 97.86 ± 0.44% of viability during 28 days of storage and enabling 87.50 ± 0.02% survival after digestive simulation. However, particles without XOS showed 84.49 ± 0.59% of viability after storage and 68.45 ± 0.03% after digestion assay. These results lead to promising applications in synbiotic and functional food formulations comprised of components requiring extended shelf-life, protection from gastrointestinal conditions and gradual bioactive delivery.

Hydrothermal treatment on depolymerization of hemicellulose of mango seed shell for the production of xylooligosaccharides.

Hydrothermal processing is an interesting biorefinery technology for converting lignocellulosic biomass into biofuels and biocompounds. This process is based on the selective solubilization and depolymerization of hemicellulose fraction (xylan) and may be considered beneficial, due to the possibility of obtaining xylooligosaccharides (XOS) with a degree of polymerization (DP) suitable for prebiotic applications. This study evaluated the effect of pressure (2.5 and 10 MPa) in a kinetic study (30 min) of hydrothermal treatment (180 °C) to optimize the extraction of XOS from mango seed shell. Total reducing sugars (TRS) values were close to the maximum in 15 min showing a slower rate for both pressures after this time, but at 10 MPa the value was 20 % lower than at 2.5 MPa. Based on these results, a new extraction was performed at 2.5 MPa and 15 min, and the extracted XOS were quantified, yielding 393.44 mg XOS/g xylan. XOS with a degree of polymerization between X2-X6 corresponded to 82.24 mg/g and XOS with X > 6 (or soluble xylan) corresponded to 311.20 mg/g. A low amount of xylose (8.81 mg/g xylan) was released, resulting in a hemicellulose conversion of 40.2 %. In general, approximately 8.1 kg of total XOS was produced from 100 kg of dried mango seed shell (X2-X6-1.7 kg and X > 6-6.4 kg).