Improved Short-Term Microbial Degradation in Circulating Water Reducing High Stagnant Atrazine Concentrations in Subsurface Sediments

The triazine herbicide atrazine easily leaches with water through soil layers into groundwater, where it is persistent. Its behavior during short-term transport is poorly understood, and there is no in situ remediation method for it. The aim of this study was to investigate whether water circulation, or circulation combined with bioaugmentation (Pseudomonas sp. ADP, or four isolates from atrazine-contaminated sediments) alone or with biostimulation (Na-citrate), could enhance atrazine dissipation in subsurface sediment–water systems. Atrazine concentrations (100 mg L−1) in the liquid phase of sediment slurries and in the circulating water of sediment columns were followed for 10 days. Atrazine was rapidly degraded to 53–64 mg L−1 in the slurries, and further to 10–18 mg L−1 in the circulating water, by the inherent microbes of sediments collected from 13.6 m in an atrazine-contaminated aquifer. Bioaugmentation without or with biostimulation had minor effects on atrazine degradation. The microbial number simultaneously increased in the slurries from 1.0 × 103 to 0.8–1.0 × 108 cfu mL−1, and in the circulating water from 0.1–1.0 × 102 to 0.24–8.8 × 104 cfu mL−1. In sediments without added atrazine, the cultivable microbial numbers remained low at 0.82–8.0 × 104 cfu mL−1 in the slurries, and at 0.1–2.8 × 103 cfu mL−1 in the circulating water. The cultivated microorganisms belonged to the nine genera Acinetobacter, Burkholderia, Methylobacterium, Pseudomonas, Rhodococcus, Sphingomonas, Streptomyces, Variovorax and Williamsia; i.e., biodiversity was low. Water flow through the sediments released adsorbed and complex-bound atrazine for microbial degradation, though the residual concentration of 10–64 mg L−1 was high and could contaminate large groundwater volumes from a point source, e.g., during heavy rain or flooding

Evaluation of the factors limiting biogas production in full-scale processes and increasing the biogas production efficiency

Biogas production from sewage sludge volatile solids (VS) by anaerobic digestion slows down towards the end of the process, among inhibitory factors being pH increase upon ammonia accumulation, poorly digestible biomaterials, and high fixed solid (FS) content. The possibility of concentrating the digested sludge VS (41.7-56.6% on a dry weight basis) by surface and bottom layer separation with biogas post-production was studied. Furthermore, the potential to recycle concentrated VS and digested sludge back to the process after adjusting pH 7.0 to optimal for biogas-producing microbes and after acid, alkali, thermal, and sonolytic treatments was examined. In general, pH 7.0 control alone improved biogas production from the recycled digested sludge the most. An equally good improvement in biogas production was achieved by recycling the digested sludge, which had been heated until ammonia had evaporated and the pH dropped to 7.0 (1-2 h, 75 degrees C), and at the same time, VS was degraded. The biogas production from the sonicated and recycled sludge was almost as good as from the pH-adjusted, or heat-treated recycled sludge. After the acid and base treatments of the digested sludge, the recycled sludge yielded often the lowest biogas volume, as the added chemicals increased the FS concentration, which proved to be a more important inhibitory factor than poorly degradable VS. The high FS content significantly reduced the benefits of the treatments. By separating the surface and bottom layers with biogas post-production, the surface layer of VS was concentrated to 51.6-61.8%, while different compositions of the layers affected the biogas production.Peer reviewe

Vascular adhesion protein-1 defines a unique subpopulation of human hematopoietic stem cells and regulates their proliferation

Although the development of hematopoietic stem cells (HSC) has been studied in great detail, their heterogeneity and relationships to different cell lineages remain incompletely understood. Moreover, the role of Vascular Adhesion Protein-1 in bone marrow hematopoiesis has remained unknown. Here we show that VAP-1, an adhesin and a primary amine oxidase producing hydrogen peroxide, is expressed on a subset of human HSC and bone marrow vasculature forming a hematogenic niche. Bulk and single-cell RNAseq analyses reveal that VAP-1+ HSC represent a transcriptionally unique small subset of differentiated and proliferating HSC, while VAP-1- HSC are the most primitive HSC. VAP-1 generated hydrogen peroxide acts via the p53 signaling pathway to regulate HSC proliferation. HSC expansion and differentiation into colony-forming units are enhanced by inhibition of VAP-1. Contribution of VAP-1 to HSC proliferation was confirmed with mice deficient of VAP-1, mice expressing mutated VAP-1 and using an enzyme inhibitor. In conclusion, VAP-1 expression allows the characterization and prospective isolation of a new subset of human HSC. Since VAP-1 serves as a check point-like inhibitor in HSC differentiation, the use of VAP-1 inhibitors enables the expansion of HSC

The Kolumbo submarine volcano of Santorini island is a large pool of bacterial strains with antimicrobial activity

Microbes in hydrothermal vents with their unique secondary metabolism may represent an untapped potential source of new natural products. In this study, samples were collected from the hydrothermal field of Kolumbo submarine volcano in the Aegean Sea, in order to isolate bacteria with antimicrobial activity. Eight hundred and thirty-two aerobic heterotrophic bacteria were isolated and then differentiated through BOX-PCR analysis at the strain level into 230 genomic fingerprints, which were screened against 13 different type strains (pathogenic and nonpathogenic) of Gram-positive, Gram-negative bacteria and fungi. Forty-two out of 176 bioactive-producing genotypes (76 %) exhibited antimicrobial activity against at least four different type strains and were selected for 16S rDNA sequencing and screening for nonribosomal peptide (NRPS) and polyketide (PKS) synthases genes. The isolates were assigned to genus Bacillus and Proteobacteria, and 20 strains harbored either NRPS, PKS type I or both genes. This is the first report on the diversity of culturable mesophilic bacteria associated with antimicrobial activity from Kolumbo area; the extremely high proportion of antimicrobial-producing strains suggested that this unique environment may represent a potential reservoir of novel bioactive compounds

Men, Mental Health and Elite Sport: a Narrative Review

Mental health in elite sport is receiving more publicity due to an increase in male athletes sharing their personal experiences. Sports injury is recognised as the major risk factor for psychological distress amongst male athletes, although anecdotally this may be that athletes are more likely to discuss their emotional wellbeing when related to the injury they are experiencing. Stress can be amplified within elite sport and the pressure they experience in relation to competition and performance can be exacerbated by adverse life events. This ongoing stress does not end when their sporting career does, it can follow them into retirement. The physical and psychological demands placed upon them by the sporting environment may predispose athletes to developing depression. As an athlete's symptoms of mental illness intensify, their performance can be negatively affected leaving them vulnerable and exposed to further symptoms of common mental disorders. The pressure of performance can also expose male athletes to overtraining syndrome which can be difficult to distinguish from depression. Male athletes are more vulnerable to eating disorders compared with males in the general population and they do have anxieties, particularly around their bodies, but find it difficult to disclose their concerns. In addition to this, male athletes are more likely to use substances, including opioids to improve both sport and non-sport performance.Despite the prevalence of common mental disorders in male athletes, stigma still exists, and although some athletes discuss their issues publicly after their career has ended, the majority of athletes prefer to remain silent. There remains a view that athletes who seek help for psychological problems may be seen as weak. Although there is an improvement in help-seeking attitudes within elite sport, further research and education is needed to encourage men to talk about their mental health, share their experiences and to enjoy a greater sense of emotional wellbeing

Allelic Imbalance of Recurrently Mutated Genes in Acute Myeloid Leukaemia

The patho-mechanism of somatic driver mutations in cancer usually involves transcription, but the proportion of mutations and wild-type alleles transcribed from DNA to RNA is largely unknown. We systematically compared the variant allele frequencies of recurrently mutated genes in DNA and RNA sequencing data of 246 acute myeloid leukaemia (AML) patients. We observed that 95% of all detected variants were transcribed while the rest were not detectable in RNA sequencing with a minimum read-depth cut-off (10x). Our analysis focusing on 11 genes harbouring recurring mutations demonstrated allelic imbalance (AI) in most patients. GATA2, RUNX1, TET2, SRSF2, IDH2, PTPN11, WT1, NPM1 and CEBPA showed significant AIs. While the effect size was small in general, GATA2 exhibited the largest allelic imbalance. By pooling heterogeneous data from three independent AML cohorts with paired DNA and RNA sequencing (N = 253), we could validate the preferential transcription of GATA2-mutated alleles. Differential expression analysis of the genes with significant AI showed no significant differential gene and isoform expression for the mutated genes, between mutated and wild-type patients. In conclusion, our analyses identified AI in nine out of eleven recurrently mutated genes. AI might be a common phenomenon in AML which potentially contributes to leukaemogenesis.Peer reviewe

Organic Matter Causes Chemical Pollutant Dissipation Along With Adsorption and Microbial Degradation

Views on the entry of organic pollutants into the organic matter (OM) decaying process are divergent, and in part poorly understood. To clarify these interactions, pesticide dissipation was monitored in organic and mineral soils not adapted to contaminants for 241 days; in groundwater sediment slurries adapted to pesticides for 399 days; and in their sterilized counterparts with and without peat (5%) or compost-peat-sand (CPS, 15%) mixture addition. The results showed that simazine, atrazine and terbuthylazine (not sediment slurries) were chemically dissipated in the organic soil, and peat or CPS-amended soils and sediment slurries, but not in the mineral soil or sediment slurries. Hexazinone was chemically dissipated best in the peat amended mineral soil and sediment slurries. In contrast, dichlobenil chemically dissipated in the mineral soil and sediment slurries. The dissipation product 2,6-dichlorobenzamide (BAM) concentrations were lowest in the mineral soil, while dissipation was generally poor regardless of plant-derived OM, only algal agar enhanced its chemical dissipation. Based on sterilized counterparts, only terbutryn appeared to be microbially degraded in the organic soil, i.e., chemical dissipation of pesticides would appear to be utmost important, and could be the first response in the natural cleansing capacity of the environment, during which microbial degradation evolves. Consistent with compound-specific dissipation in the mineral or organic environments, long-term concentrations of pentachloroaniline and hexachlorobenzene were lowest in the mineral-rich soils, while concentrations of dichlorodiphenyltrichloroethane (DTT) and metabolites were lowest in the organic soils of old market gardens. OM amendments changed pesticide dissipation in the mineral soil towards that observed in the organic soil; that is OM accelerated, slowed down or stopped dissipation.Peer reviewe

The Occurrence of potential and novel isolates of Oceanobacillus sp. JAS12 and Salinicoccus sp. JS20 recovered from West Coast of Arabian Sea, India

Many halophiles were considered to be extremophiles due to their inborn industrial potentials and tolerance to hostile environmental conditions. The isolated halophilic bacteria described in the present study are not only grown at environmentally adverse conditions, also they can be able to produce bioactive molecules. Among the isolated strains, Oceanobacillus iheyensis strain JAS12 and Salinicoccus roseus strain JS20 are known for the unique biotechnological applications. The isolate Oceanobacillus sp. grows well at 35-55 degrees C (optimum 45 degrees C) and pH 6 to 12 (maximum growth at pH 8), interestingly the strain could hydrolyze casein, starch and gelatin. The G+C content was 40.2 mol % and the major fatty acids are iso-15:0: 30.52%, primary-C15: 0 (29.29 %), iso-14:0 (16.15%) anteiso-C17: 0 (4.03%). Another isolate was Salinicoccus sp. JS20 The DNA G+C content was 50.4 mol % and the major fatty acids are anteiso-C15: 0 (26.23%), iso15:0, (17.62%)Y, 16:0 (11.5%), anteiso-C17: 0 (7.7 %), iso- C16: 0 (10.20 %), iso-17:0: (5.43%) and iso-C14: 0 (3.97 %). These isolates are also producers of many extracellular enzymes such as protease, amylase, inulinases, gelatinase and beta-fructofurinosidase above the optimal conditions. Oceanobacillus sp. JAS12 16S rRNA gene sequence similarity is 99% similar to the reported genera. Salinicoccus sp. JS20 indicated 96% 16S rRNA sequence similarity with near species Salinicoccus genus, thus, they were found to be novel concerning to their genetic makeup and biochemical features.Peer reviewe

The physicochemical conditions of isolation source determine the occurrence of Pseudomonas fluorescens group species

International audiencePseudomonas fluorescens group species are indigenous bacteria in many different environments. The physicochemical conditions related to their selection to different surface and subsurface environments are poorly understood. We isolated 35 P. fluorescens group strains under the pesticide stress from mesocosms of surface soils and groundwater-monitoring pipe deposit slurries, and from a few of their initially sterilized counterparts, which were colonized during 599-625 days of laboratory incubation. In addition, strains were isolated from mesocosms of drilling sediment slurries. Based on the 16S rDNA analysis, strains belonged to five species. The statistical analysis of relationships between the isolates and physicochemical conditions in their isolation mesocosms revealed the typical habitats of five species. Pseudomonas IC038 and Pseudomonas LAB-23-like strains were common in mesocosms of deposit/sediment slurries low in growth substrates. Pseudomonas marginalis-like isolates preferred surface soil mesocosms rich in nutrients. Pseudomonas veronii and Pseudomonas mandelii-like strains grew in mesocosms of surface soils and subsurface deposit/sediment slurries, which indicated that they either had a versatile metabolism to adapt to different environments, or differed in substrate specificities. The initially sterilized mesocosms were mainly colonized with the same species as their non-sterilized counterparts, while all P. fluorescens group species tolerated atrazine and/or terbutryn. Our results on habitats were in agreement with the isolation sources of strains with identical 16S rDNA sequences in databases. The observed differences in the distribution patterns of the P. fluorescens group species indicate that species selection should be carefully done for man-made ecosystem applications, such as stable bioremediation