Biodegradation of microplastic in freshwaters: A long-lasting process affected by the lake microbiome

Plastics have been produced for over a century, but definitive evidence of complete plastic biodegradation in different habitats, particularly freshwater ecosystems, is still missing. Using ¹³C-labelled polyethylene microplastics (PE-MP) and stable isotope analysis of produced gas and microbial membrane lipids, we determined the biodegradation rate and fate of carbon in PE-MP in different freshwater types. The biodegradation rate in the humic-lake waters was much higher (0.45% ± 0.21% per year) than in the clear-lake waters (0.07% ± 0.06% per year) or the artificial freshwater medium (0.02% ± 0.02% per year). Complete biodegradation of PE-MP was calculated to last 100–200 years in humic-lake waters, 300–4000 years in clear-lake waters, and 2000–20,000 years in the artificial freshwater medium. The concentration of 18:1ω7, characteristic phospholipid fatty acid in Alpha- and Gammaproteobacteria, was a predictor of faster biodegradation of PE. Uncultured Acetobacteraceae and Comamonadaceae among Alpha- and Gammaproteobacteria, respectively, were major bacteria related to the biodegradation of PE-MP. Overall, it appears that microorganisms in humic lakes with naturally occurring refractory polymers are more adept at decomposing PE than those in other waters.     

HDL Subspecies in Young Adult Twins: Heritability and Impact of Overweight

The association between abdominal obesity and atherogenic lipid profile emerges from complex interactions of genes and environment. We aimed to explore the heritability and effects of overweight on serum lipid profile (high‐density lipoprotein‐cholesterol (HDL‐C), HDL mean particle size, percentages of HDL_{2b, 2a, 3a, 3b, and 3c}, low‐density lipoprotein‐cholesterol (LDL‐C), LDL peak particle size and triglycerides (TGs)) in healthy, young adults. HDL‐C, LDL‐C, and TG were measured in 52 monozygotic (MZ) and 89 dizygotic (DZ) twin pairs, aged 23–32 years, chosen to represent a wide range of BMIs (17.6–42.9 kg/m²). Of them, 24 MZ and 26 DZ pairs were chosen at random for measurements of HDL mean and LDL peak particle sizes and percentages of HDL subspecies. The heritabilities of the lipid parameters adjusted for BMI were HDL‐C 73%, HDL mean particle size 56%, HDL subspecies 46–63%, LDL‐C 79%, LDL peak particle size 49%, and TG 64%. Genetic and environmental correlations between BMI and HDL‐C, LDL‐C, and TG were modest (0.3–0.4). Abdominal overweight (waist circumference ≥94 cm for males and ≥80 cm for females) associated with decreased HDL‐C, increased LDL‐C, and TG concentrations, smaller HDL mean particle size, lower HDL_2b, and higher HDL_3c percentages in both genders. Within MZ twins, controlling for genetic influences, within‐pair differences in HDL_3c percentage were associated with those in waist (r = 0.46, P = 0.032) and BMI (r = 0.51, P = 0.013). In conclusion, serum lipid parameters, including LDL peak and HDL mean particle sizes and HDL subspecies distribution are under strong genetic control. Overweight associated with significant lipid profile changes, particularly, small HDL_3c increased in overweight independent of genetic influences.     

Expression,purification, characterization and in silico analysis of newly isolated hydrocarbon degrading bleomycin resistance dioxygenase

Molecular Biology Reports - In the present investigation, we report cloning, expression, purification and characterization of a novel Bleomycin Resistance Dioxygenase (BRPD). His-tagged fusion...     

Post-bloom feeding of Calanus finmarchicus copepodites: Selection for autotrophic versus heterotrophic prey

Feeding and faecal pellet production of late copepodite stages of Calanus finmarchicus were measured in mixtures of cultured autotrophic and heterotrophic food, as well as in a natural post-bloom plankton assemblage, in order to evaluate food selection and its potential effect on sedimentation of organic matter. Calanus finmarchicus consistently selected for diatoms, both in mixtures with the heterotrophic dinoflagellate Oxyrrhis marina, and in natural seston containing dinoflagellates, ciliates and flagellates. Similarly, the filtration, ingestion and faecal pellet production rates were significantly higher feeding on diatoms than when feeding on other food species. Calanus finmarchicus selection appeared relatively inflexible, so that changes in seston composition induced large changes in diet quantity and composition. Our results support the traditional view of C. finmarchicus as a major grazer of diatoms, and suggest potentially high post-bloom faecal pellet production rates.     

Haplotype mining panel for genetic dissection and breeding in Eucalyptus

To improve our understanding of genetic mechanisms underlying complex traits in plants, a comprehensive analysis of gene variants is required. Eucalyptus is an important forest plantation genus that is highly outbred. Trait dissection and molecular breeding in eucalypts currently relies on biallelic single-nucleotide polymorphism (SNP) markers. These markers fail to capture the large amount of haplotype diversity in these species, and thus multi-allelic markers are required. We aimed to develop a gene-based haplotype mining panel for Eucalyptus species. We generated 17 999 oligonucleotide probe sets for targeted sequencing of selected regions of 6293 genes implicated in growth and wood properties, pest and disease resistance, and abiotic stress responses. We identified and phased 195 834 SNPs using a read-based phasing approach to reveal SNP-based haplotypes. A total of 8915 target regions (at 4637 gene loci) passed tests for Mendelian inheritance. We evaluated the haplotype panel in four Eucalyptus species (E. grandis, E. urophylla, E. dunnii and E. nitens) to determine its ability to capture diversity across eucalypt species. This revealed an average of 3.13–4.52 haplotypes per target region in each species, and 33.36% of the identified haplotypes were shared by at least two species. This haplotype mining panel will enable the analysis of haplotype diversity within and between species, and provide multi-allelic markers that can be used for genome-wide association studies and gene-based breeding approaches.     

EATB Donor Case Workshop 2007

The European Association of Tissue Banks (EATB) Donor Case Workshop is a forum held within the programme of the EATB annual Congress since 2003. This workshop has been used to discuss clinical donor cases with peer review of practice. It was agreed in advance that the experience of the 2007 workshop should be shared by publication as an example of participative learning which can be extended to other fields within tissue banking and which may be applicable in other disciplines. The EATB Congress in 2008 will extend the idea of participative open workshops with two additional workshops, one on Quality System cases and another on heart valve cases.     

Possible role of acrolein in oxazaphosphorine-induced enhancement of immunological reactivity

Summary The aim of the present study was to analyze further the immunopotentiating effects of low doses of oxazaphosphorines. We examined 4-hydroperoxycyclophosphamide (4-HC) and mafosfamide, which degrade spontaneously in water without requiring liver enzymes to become active. Both drugs, at concentrations ranging from 0.01 µM to 1 µM, enhanced mitogenic responses of human lymphocytes. Higher concentrations were toxic. Acrolein, which is one of the degradation products of oxazaphosphorines, had similar effects. Immunopotentiation was not monocyte-dependent. Attempts to inactivate released acrolein with human serum reduced toxicity but the immunostimulating property of the drugs remained Similar effects were noted when lymphocytes were exposed to acrolein dissolved in serum. 2-Mercaptoethanesulfonate (mesna), which is highly reactive with acrolein, reduced the toxicity of solutions of both oxazaphosphorines and acrolein. Immunopotentiation was not clearly demonstrable since mesna itself enhanced the responses. Pretreatment of lymphocytes with 4-HC or mafosfamide did not reduce the capacity of concanavalin A to induce suppressor cells. It is speculated that acrolein may play a role in oxazaphosphorine-induced enhancements of immune responses.