Converting highly productive arable cropland in Europe to grassland: - A poor candidate for carbon sequestration

© 2017 The Author(s). Sequestration of atmospheric CO 2 as organic carbon by agricultural soils (SOC) is promoted as a climate change mitigation option. IPCC provides guidelines for determining carbon stocks and sequestration potential, incentivising policy changes towards management of farmland for carbon sequestration. However, the basis of the assumption that agricultural soils can sequester significant atmospheric CO 2 has been questioned. We sought to determine the potential for conversion of arable cropland to grassland to sequester carbon in the short to medium term and potential limiting factors. There were no differences in SOC stocks in the top 30 cm between grassland up to 17 years old and arable cropland at 14 sites across the UK. However, SOC showed different distribution patterns, being concentrated in the top 10 cm under grassland. Soil microbial communities were significantly different between arable and grassland, with higher biomass and lesser dominance by bacteria in grassland soils. A land use conversion experiment showed these changes occurred within one year of land use change. Failure of grassland soils to accumulate SOC was attributed to reduced available soil nitrogen, resulting in low productivity. The implications of these results for carbon sequestration in soils as a climate change mitigation strategy are discussed

Reproducibility of Bacterial Cellulose Nanofibers Over Sub-Cultured Generations for the Development of Novel Textiles

The textile industry is in crisis and under pressure to minimize the environmental impact on its practices. Bacterial cellulose (BC), a naturally occurring form of cellulose, displays properties superior to those of its cotton plant counterpart, such as enhanced purity, crystallinity, tensile strength, and water retention and is thus suitable for an array of textile applications. It is synthesized from a variety of microorganisms but is produced in most abundance by Komagataeibacter xylinus. K. xylinus is available as a type strain culture and exists in the microbial consortium commonly known as Kombucha. Whilst existing literature studies have described the effectiveness of both K. xylinus isolates and Kombucha in the production of BC, this study investigated the change in microbial communities across several generations of sub-culturing and the impact of these communities on BC yield. Using Kombucha and the single isolate strain K. xylinus as inocula in Hestrin and Schramm liquid growth media, BC pellicles were propagated. The resulting pellicles and residual liquid media were used to further inoculate fresh liquid media, and this process was repeated over three generations. For each generation, the thickness of the pellicles and their appearance under SEM were recorded. 16S rRNA sequencing was conducted on both pellicles and liquid media samples to assess changes in communities. The results indicated that the genus Komagataeibacter was the most abundant species in all samples. Cultures seeded with Kombucha yielded thicker cellulose pellicles than those seeded with K. xylinus, but all the pellicles had similar nanofibrillar structures, with a mix of liquid and pellicle inocula producing the best yield of BC after three generations of sub-culturing. Therefore, Kombucha starter cultures produce BC pellicles which are more reproducible across generations than those created from pure isolates of K. xylinus and could provide a reproducible sustainable model for generating textile materials

Acquisition and Development of the Extremely Preterm Infant Microbiota Across Multiple Anatomical Sites

Microbial communities influencing health and disease are being increasingly studied in preterm neonates. There exists little data, however, detailing longitudinal microbial acquisition, especially in the most extremely preterm (<26 weeks' gestation). This study aims to characterize the development of the microbiota in this previously under-represented cohort.Methods:Seven extremely preterm infant-mother dyads (mean gestation 23.6 weeks) were recruited from a single neonatal intensive care unit. Oral and endotracheal secretions, stool, and breast milk (n = 157 total), were collected over the first 60 days of life. Targeted 16S rRNA gene sequencing identified bacterial communities present.Results:Microbiota of all body sites were most similar immediately following birth and diverged longitudinally. Throughout the sampling period Escherichia, Enterococcus, Staphylococcus, and an Enterobacteriaceae were dominant and well dispersed across all sites. Temporal divergence of the stool from other microbiota was driven by decreasing diversity and significantly greater proportional abundance of Bifidobacteriaceae compared to other sites.Conclusions:Four taxa dominated all anatomical sampling sites. Rare taxa promoted dissimilarity. Cross-seeding between upstream communities and the stool was demonstrated, possibly relating to buccal colostrum/breast milk exposure and indwelling tubes. Given the importance of dysbiosis in health and disease of extremely preterm infants, better understanding of microbial acquisition within this context may be of clinical benefit

Siblings Of Crohn’s Disease Patients Exhibit A Biologically Relevant Dysbiosis In The Mucosal Microbial Community: A 16s Rrna Gene Pyrosequencing Study

Introduction Reduced mucosal Faecalibacterium prausnitzii predicts disease recurrence in Crohn’s disease (CD) patients. Siblings (SIBS) of CD patients have elevated risk of developing CD and share aspects of CD phenotype including faecal dysbiosis. [1] No study has compared mucosal microbiota in CD SIBS to unrelated healthy controls (HC). Methods Phenol/chloroform DNA extraction from rectal biopsies of 21 patients with quiescent CD, 17 of their healthy SIBS and 19 unrelated HC, and PCR amplification of the V1-V3 region of the bacterial 16S ribosomal RNA gene were performed. Microbiota composition was resolved by 454 pyrosequencing. Results For each group, mucosal microbiota were classified into common/abundant (core) vs. infrequent/rare.2 In terms of both microbial diversity (Shannon-Wiener and Simpson’s indexes of diversity) and species richness, core microbiota of both SIBS and CD patients were significantly less diverse than HC. The rare microbiota diversity was lower in CD compared with HC, but was not different between SIBS and HC. Metacommunity profiling (Bray-Curtis (SBC) index of similarity with unweighted pair group averages) showed core microbial metacommunity of SIBS to be more similar to CD (SBC=0.70) than to HC, whereas the rare microbial metacommunity of SIBS was more similar to HC (SBC=0.42). As in CD patients, the species that contributed most to the dissimilarity of healthy SIBS vs. HC was F. prausnitzii, Table 1. Conclusion This is the first in depth case-control study of the mucosal microbiota of SIBS of CD patients. Dysbiosis in SIBS was characterised by reduced diversity of core microbiota and lower abundance of F. prausnitzii. This dysbiosis in otherwise healthy, but at-risk people implicates microbiological processes in CD pathogenesis and risk

Siblings of Crohn's Disease Patients Exhibit a Pathologically Relevant Dysbiosis: Examination of Mucosal Microbiota Communities Using 16S rRNA Gene Pyrosequencing

Background Reduced mucosal concentrations of Faecalibacterium prausnitzii predict disease recurrence in patients with Crohn's disease (CD). Siblings of CD patients have elevated risk of developing CD and share aspects of disease phenotype compared with healthy controls (HC), including dysbiosis in the faecal microbiota.[1] No study has compared the mucosal microbiota of CD siblings with unrelated healthy controls. Aim: to determine whether dysbiosis is present in the mucosal microbiota of siblings of CD patients with reference to HC, and to apply 16S rRNA gene pyrosequencing in order to accomplish a more comprehensive characterisation of that dysbiosis. Methods Rectal biopsies were taken from 21 patients with quiescent CD, 17 of their healthy siblings and 19 unrelated HC. Total DNA was extracted using phenol/chloroform based method. The V1 to V3 region of the bacterial 16S ribosomal RNA gene was amplified using PCR, and microbiota composition resolved by 454 pyrosequencing. Sequence processing and analyses were performed using the open source Mothur software package (www.mothur.org). Results For each group the resulting species in the microbiota were classified into core (common and abundant among similar subjects) versus infrequent and rare.[2] In terms of both microbial diversity (measured by both the ShannonWiener and Simpson's indexes of diversity) and species richness, the core mucosal microbiota of both siblings and CD patients were significantly less diverse than HC. Although the diversity of the rare microbiota was lower in CD compared with HC, there was no difference in diversity of rare microbiota between siblings and HC. Metacommunity profiling using the Bray-Curtis (SBC) index of similarity with unweighted pair group averages showed that the core microbial metacommunity of siblings was more similar to CD (SBC=0.70) than to HC, whereas the rare microbial metacommunity of siblings was more similar to HC (SBC= 0.42). As in CD patients, the species that contributed most to the dissimilarity between healthy siblings and HC was F. prausnitzii, Table 1. Conclusions This is the first in depth case-control study of the mucosal microbiota in the siblings of CD patients. We report a dysbiosis characterised by reduced diversity of core microbiota and lower abundance of F. prausnitzii. Given that siblings of CD patients have elevated risk of developing CD, this dysbiosis in otherwise healthy people implicates microbiological processes in CD pathogenesis and risk

Back to the basics of ovarian aging: A population-based study on longitudinal anti-Müllerian hormone decline

Background: Anti-Müllerian hormone (AMH) is currently used as an ovarian reserve marker for individualized fertility counseling, but very little is known of individual AMH decline in women. This study assessed whether the decline trajectory of AMH is uniform for all women, and whether baseline age-specific AMH levels remain consistently high or low during this trajectory. Methods: A total of 3326 female participants from the population-based Doetinchem Cohort Study were followed with five visits over a 20-year period. Baseline age was 40±10years with a range of 20-59 years. AMH was measured in 12,929 stored plasma samples using the picoAMH assay (AnshLabs). Decline trajectories of AMH were studied with both chronological age and reproductive age, i.e., time to menopause. Multivariable linear mixed effects models characterized the individual AMH decline trajectories. Results: The overall rate of AMH decline accelerated after 40years of age. Mixed models with varying age-specific AMH levels and decline rates provided the significantly best fit to the data, indicating that the fall in AMH levels over time does not follow a fixed pattern for individual women. AMH levels remained consistent along individual trajectories of age, with an intraclass correlation coefficient (ICC) of 0.87. The ICC of 0.32 for AMH trajectories with time to menopause expressed the large variation in AMH levels at a given time before the menopause. The differences between low and high age-specific AMH levels remained distinguishable, but became increasingly smaller with increasing chronological and reproductive age. Conclusions: This is the first study to characterize individual AMH decline over a long time period and broad age range. The varying AMH decline rates do not support the premise of a uniform AMH decline trajectory. Although age-specific AMH levels remain consistently high or low with increasing age, the converging trajectories and variance of AMH levels at a given time before menopause shed doubt on the added value of AMH to represent individualized reproductive age

Response: Commentary: Reducing Viability Bias in Analysis of Gut Microbiota in Preterm Infants at Risk of NEC and Sepsis

A Commentary on Commentary: Reducing Viability Bias in Analysis of Gut Microbiota in Preterm Infants at Risk of NEC and Sepsis by Agustí, G., and Codony, F. (2018). Front. Cell. Infect. Microbiol. 8:212. doi: 10.3389/fcimb.2018.0021

Differences in trauma history and psychopathology between PTSD patients with and without co-occurring dissociative disorders

Wabnitz P, Gast U, Catani C. Differences in trauma history and psychopathology between PTSD patients with and without co-occurring dissociative disorders. European Journal of Psychotraumatology. 2013;2013(4): 21452.Background: The interplay between different types of potentially traumatizing events, posttraumatic symptoms, and the pathogenesis of PTSD or major dissociative disorders (DD) has been extensively studied during the last decade. However, the phenomenology and nosological classification of posttraumatic disorders is currently under debate. The current study was conducted to investigate differences between PTSD patients with and without co-occurring major DD with regard to general psychopathology, trauma history, and trauma-specific symptoms. Methods: Twenty-four inpatients were administered the Clinician-Administered PTSD Scale for DSM-IV (CAPS) and the Mini-Structured Clinical Interview for DSM-IV Dissociative Disorders (MINI-SKID-D) to assess DD and PTSD. Additionally, participants completed questionnaires to assess general psychopathology and health status. Results: Symptom profiles and axis I comorbidity were similar in all patients. Traumatic experiences did not differ between the two groups, with both reporting high levels of childhood trauma. Only trauma-specific avoidance behavior and dissociative symptoms differed between groups. Conclusion: Results support the view that PTSD and DD are affiliated disorders that could be classified within the same diagnostic category. Our results accord with a typological model of dissociation in which profound forms of dissociation are specific to DD and are accompanied with higher levels of trauma-specific avoidance in DD patients