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Composts are often highly contaminated with microplastic (MP) of different polymer types and shapes. Being used for various (agricultural) applications, composts are an entry pathway of MP in terrestrial ecosystems. Microplastic particles found in composts are coated with a biofilm due to previous exposure and treatment in biowaste plants. It has been shown that pristine microplastics impact terrestrial organisms on a sublethal level. Until now it remains unexplored how composted polymers affect organisms especially in contrast to pristine MP. Both the compost worm Eisenia fetida and the woodlouse Porcellio scaber encounter those composted MP during food uptake. As they differ in behaviour and diet the effect of MP can differ between organisms. Therefore, we studied the effect of composted and pristine MP in an environmentally relevant concentration on the life-history and oxidative stress levels of E. fetida and P. scaber. We tested three different polymer types (PS, PE and PLA) as fragments and fibres. To understand possible mechanisms behind the observed effects we also characterized the formatted MP biofilm composition via 16SrRNA (bacteria) and ITS (fungi) amplicon sequencing. Interestingly, we found contrasting effects on the organisms. Exposure to composted MP fragments induced a higher weight gain and reproductive output in E. fetida. Oxidative stress was higher for worms incubated in pristine MP while we found no effect for worms in the composted treatments. In contrast P. scaber gained less weight and had higher oxidative stress ingesting food with composted MPs while no effect was found for pristine MP. Also see: https://micro2022.sciencesconf.org/428085/document, In MICRO 2022, Online Atlas Edition: Plastic Pollution from MACRO to nano

Background and novelty Due to its worldwide spread, microplastic (size range: 1 µm – 5 mm) has become a major concern in the past decade. It is proven, that microplastic particles (MP) accumulate in the food chain and most probably enter the human body via this path as well. After absorption (i.e., through the gastro-intestinal or pulmonary pathway), MP might be transferred more deeply into tissues increasing the potential of hazardous effects, e.g. local inflammation as well as cellular uptake associated with disturbance of the cellular homeostasis. Numerous studies in the recent years analysed the effect of commercial MP in vitro using model cell lines. Surprisingly, the results showed different and often even contradictory outcomes even when same polymers or size ranges were used. In our work, we aimed to correlate cellular uptake and induced biological responses with well-characterized physico-chemical properties of MPs (e.g., surface chemistry and size range) Results and discussion Uptake as well as noxiousness of particles were hereby highly dependent on their physico-chemical properties and also cell type-related. While epithelial cells showed only little PCI, macrophages engulfed a high number of particles. This interaction process is proved to be size-dependent and related to the respective surface charge. Interestingly, not only surface charge but also the surface charge density plays a crucial role for PCI. Subsequently, the number of engulfed MPs critically influenced the intensity of induced biological responses. While there was little to non-noxiousness effects of the particles to epithelial cells, macrophages showed a PCI-dependent noxiousness in various biological effects. Furthermore, besides surface chemistry, MP morphology and weathering status seemed to play an important role in inducing noxious effects at a wide level of biological effects. Also see: https://micro2022.sciencesconf.org/427172/document, In MICRO 2022, Online Atlas Edition: Plastic Pollution from MACRO to nano

Additional file 1: Figure S1. SMFC performance profile at different electrode spacings, substrate feeding intervals and electrode materials. (a) OCV from first block, the arrow shows point of first substrate feeding; (b) OCV from second block; (c) maximum power trends of the two blocks combined. The trends shown with dotted lines represent CF electrodes. Please refer to Table 1 of the main document for details of the different levels of the variables. Figure S2. Nyquist plots and the fits of SEC–MFCs at different electrode spacing: 2 h, 4 h and 8 h are SEC–MFCs at electrode spacing (ES) of 2, 4 and 8 cm, respectively. Figure S3. Nyquist plots of CF–MFCs at ES of 2, 4 and 8 cm, respectively (N:B Graphs were copied directly from EC-lab V11.32, where the fitting was performed). Figure S4. Taxonomic distribution of the 16S rDNA microbial community profile at the Phylum level. Table S1. Analysis of variance table for the model design. Table S2. Solutions for 2 combinations of categoric factor level. Table S3. Pairwise permanova results based on beta-group-significance (α = 0.05).

Additional file 3: Figure S3. Comparison between promoter motives of TSS located within (inMAI) and outside (exMAI) of the magnetosome island, cultivated under anoxic (0% dO2) and oxic (95% dO2) conditions. The motif logos were created with Weblogo [58].

Background One of the most complex prokaryotic organelles are magnetosomes, which are formed by magnetotactic bacteria as sensors for navigation in the Earth’s magnetic field. In the alphaproteobacterium Magnetospirillum gryphiswaldense magnetosomes consist of chains of magnetite crystals (Fe3O4) that under microoxic to anoxic conditions are biomineralized within membrane vesicles. To form such an intricate structure, the transcription of > 30 specific structural genes clustered within the genomic magnetosome island (MAI) has to be coordinated with the expression of an as-yet unknown number of auxiliary genes encoding several generic metabolic functions. However, their global regulation and transcriptional organization in response to anoxic conditions most favorable for magnetite biomineralization are still unclear. Results Here, we compared transcriptional profiles of anaerobically grown magnetosome forming cells with those in which magnetosome biosynthesis has been suppressed by aerobic condition. Using whole transcriptome shotgun sequencing, we found that transcription of about 300 of the > 4300 genes was significantly enhanced during magnetosome formation. About 40 of the top upregulated genes are directly or indirectly linked to aerobic and anaerobic respiration (denitrification) or unknown functions. The mam and mms gene clusters, specifically controlling magnetosome biosynthesis, were highly transcribed, but constitutively expressed irrespective of the growth condition. By Cappable-sequencing, we show that the transcriptional complexity of both the MAI and the entire genome decreased under anaerobic conditions optimal for magnetosome formation. In addition, predominant promoter structures were highly similar to sigma factor σ70 dependent promoters in other Alphaproteobacteria. Conclusions Our transcriptome-wide analysis revealed that magnetite biomineralization relies on a complex interplay between generic metabolic processes such as aerobic and anaerobic respiration, cellular redox control, and the biosynthesis of specific magnetosome structures. In addition, we provide insights into global regulatory features that have remained uncharacterized in the widely studied model organism M. gryphiswaldense, including a comprehensive dataset of newly annotated transcription start sites and genome-wide operon detection as a community resource (GEO Series accession number GSE197098).

Additional file 1: Figure S1. Cell growth and magnetic response (Cmag) under A) anoxic (dO2 0%, 10 mM nitrate), B) oxic (dO2 95%, 4 mM ammonium), C) microoxic (dO2 1%, 4 mM nitrate), D) oxic with nitrate (dO2 95%, 4 mM nitrate) conditions. (Scale bar 1 μm). Growth (black and grey lines) and Cmag (colored lines) were depicted for each replicate (circles, diamonds and triangles). The black arrow indicates the sampling timepoint for the RNA-seq experiments.

Additional file 4: Figure S2. Distribution of classified transcription start sites (TSS) under anoxic (0% dO2) and oxic (95% dO2) conditions in the whole genome (pTSS, primary TSS; asTSS, antisense TSS; iTSS, intragenic TSS; oTSS; other TSS).

Supplemental material, sj-docx-1-jbc-110.1177_08839115211053925 for Development of poly(ethyleneimine) grafted amphiphilic copolymers: Evaluation of their cytotoxicity and ability to complex DNA by Ivonne L Diaz, Val��rie J��r��me, Ruth Freitag and Le��n D Perez in Journal of Bioactive and Compatible Polymers

Additional file 1. Details of the Qiime2 scripts.

Additional file 1. Complete sequencing data at genus level.

A synthetic antibody phage library, (ETH-2) was screened against the MUC-1 peptide. Two standard methods were used, namely screening on immunotubes coated with the peptide antigen and on streptavidin-coated paramagnetic particles together with a biotinylated MUC-1 peptide. The results were compared with those obtained using a novel approach based on a stimuli-responsive bioconjugate of avidin and poly-(N-isopropylacrylamide), also in combination with the biotinylated peptide. The poly-(N-isopropylacrylamide)-based bioconjugate is soluble below a temperature of 30 degrees C in the aqueous solutions pertinent to this study, but precipitates rapidly once this temperature is surpassed. The process is reversible, and the bioconjugate redissolves once the temperature is lowered again. The stimuli-responsive bioconjugate was used to isolate specific phage from the library in several rounds of panning, consisting of repeated thermoprecipitation/redissolution cycles in a procedure known as "affinity precipitation." As Jar as we know, this is the first time a compound as big as a viral particle has been specifically captured by a stimuli-responsive bioconjugate. Compared to the two other investigated screening techniques, affinity precipitation of the phage led to a greater variety of genetically, different specific phage, while the process was easy to handle and required no dedicated equipment safe for a centrifuge and a thermostated water bath.

A linear water-soluble quaternary ammonium polymer having a homopolymeric chain of repeating unit of general formula (I):where each of R1 and R2 independently represents a member selected from the group consisting of linear or branched alkyl, hydroxyalkyl, alkoxyalkyl groups having from 1 to 6 carbon atoms, X- represents an anion and n is an integer comprised between 30 and 220 has been prepared. Furthermore, the polymer has a molar mass distribution of less than or equal to 1.5. The polymer is used as a displacer in a displacement mode of chromatography.

Affinity macroligands (AML) comprising a reversibly water soluble poly-N-alkylacrylamide linked to a ligand, and their use in the separation of a target substance from a mixture comprising the target substance and other materials are disclosed. Preferred AMLs have number average molar masses of less than 7,000 g/mol (chain length n typically about 25), mass distributions of less than 1.2 and narrow precipitation-solubility temperature (NPST) interval, typically in the range of 1-2° C.

A review discusses the principle of displacement chromatog., a chromatog. mode which has many advantages over conventional preparative elution chromatog., but which is handicapped by the lack of suitable displacers and stationary phases. [on SciFinder (R)]

Affinity precipitation was compared to affinity chromatography and batch adsorption as the final purification step in a protocol for the isolation of haemoglobin from human blood. Haptoglobin was the affinity ligand. The first steps on the process were realized by traditional methods (lyses of red blood cells followed by ammonium sulphate precipitation). For affinity chromatography (and batch adsorption) the ligand was linked to Sepharose, for affinity precipitation to a thermoresponsive polymer, namely poly(N-isopropylacrylamide). Five haptoglobin-poly(N-isopropylacrylamide) bioconjugates (affinity macroligands) were constructed with different polymer: haptoglobin-coupling ratios. Conjugation of haptoglobin to the soluble poly(N-isopropylacrylamide) apparently does not change the interaction thermodynamics with haemoglobin, as the haemoglobin binding constants calculated by a Scatchard analysis for the affinity macroligand were of the same order of magnitude as those described in the literature for the haemoglobin-haptoglobin complex in solution. Two elution protocols were used for haemoglobin release from the various affinity materials, one at pH 2, the other with 5 M urea at pH 11. Both affinity chromatography and affinity precipitation yielded a pure haemoglobin of high quality. Compared to the affinity chromatography, affinity precipitation showed a significantly higher ligand efficiency (ratio of the experimental capacity to the theoretical one). The method thus makes better use of the expensive affinity ligands. As affinity precipitation only requires small temperature changes to bring about precipitation/redissolution of the affinity complexes and a centrifugation step for recovery of the precipitate, the method in addition has advantages in term of scalability and simplicity. (C) 2008 Elsevier B.V. All rights reserved.

A review with 24 refs. The use of synthetic polyelectrolytes as displacers in displacement chromatog. is reported. Column liq. chromatog. is one of the main techniques of protein purifn. The majority of the present chromatog. biosepns. are performed in elution modes which have various disadvantages aside from economy. An attractive method to overcome the limitations of the elution mode is operation in the displacement mode. However, in order to exploit the full potential of displacement chromatog., suitable displacer/stationary phase systems must become available. The use of polyelectrolytes as displacers is believed to occupy an outstanding place. [on SciFinder (R)]