Microbial tropicalization driven by a strengthening western ocean boundary current

Western boundary currents (WBCs) redistribute heat and oligotrophic seawater from the tropics to temperate latitudes, with several displaying substantial climate change‐driven intensification over the last century. Strengthening WBCs have been implicated in the poleward range expansion of marine macroflora and fauna, however, the impacts on the structure and function of temperate microbial communities are largely unknown. Here we show that the major subtropical WBC of the South Pacific Ocean, the East Australian Current (EAC), transports microbial assemblages that maintain tropical and oligotrophic (k‐strategist) signatures, to seasonally displace more copiotrophic (r‐strategist) temperate microbial populations within temperate latitudes of the Tasman Sea. We identified specific characteristics of EAC microbial assemblages compared with non‐EAC assemblages, including strain transitions within the SAR11 clade, enrichment of Prochlorococcus, predicted smaller genome sizes and shifts in the importance of several functional genes, including those associated with cyanobacterial photosynthesis, secondary metabolism and fatty acid and lipid transport. At a temperate time‐series site in the Tasman Sea, we observed significant reductions in standing stocks of total carbon and chlorophyll a, and a shift towards smaller phytoplankton and carnivorous copepods, associated with the seasonal impact of the EAC microbial assemblage. In light of the substantial shifts in microbial assemblage structure and function associated with the EAC, we conclude that climate‐driven expansions of WBCs will expand the range of tropical oligotrophic microbes, and potentially profoundly impact the trophic status of temperate waters.     

Chiral Separation of Uncharged Pomalidomide Enantiomers Using Carboxymethyl‐β‐Cyclodextrin: A Validated Capillary Electrophoretic Method

The racemic mixture of pomalidomide (POM), a second‐generation immunomodulatory uncharged drug, was separated into enantiomers by capillary zone electrophoresis for the first time. Seven different chargeable cyclodextrin (CD) derivatives were screened as complexing agents and chiral selectors, investigating the stability of the POM‐CD inclusion complexes and their enantiodiscriminating capacities. Based on preliminary experiments, carboxymethyl‐β‐CD (CM‐β‐CD) was found to be the most effective chiral selector. Factors influencing enantioseparation were systematically optimized, using an orthogonal experimental design. Optimal parameters (background electrolyte [BGE]: 50 mM Tris‐acetate buffer, pH 6.5, containing 15 mM CM‐β‐CD; capillary temperature: 20°C; voltage applied +15 kV) allowed baseline separation of POM enantiomers with a resolution as high as 4.87. The developed method was validated, in terms of sensitivity (limit of detection and limit of quantification), linearity, accuracy, repeatability, and intermediate precision. Chirality 28:199–203, 2016. © 2015 Wiley Periodicals, Inc.     

Biogeography of Southern Ocean prokaryotes: a comparison of the Indian and Pacific sectors

We investigated the Southern Ocean (SO) prokaryote community structure via zero-radius operational taxonomic unit (zOTU) libraries generated from 16S rRNA gene sequencing of 223 full water column profiles. Samples reveal the prokaryote diversity trend between discrete water masses across multiple depths and latitudes in Indian (71–99°E, summer) and Pacific (170–174°W, autumn-winter) sectors of the SO. At higher taxonomic levels (phylum-family) we observed water masses to harbour distinct communities across both sectors, but observed sectorial variations at lower taxonomic levels (genus-zOTU) and relative abundance shifts for key taxa such as Flavobacteria, SAR324/Marinimicrobia, Nitrosopumilus and Nitrosopelagicus at both epi- and bathy-abyssopelagic water masses. Common surface bacteria were abundant in several deep-water masses and vice-versa suggesting connectivity between surface and deep-water microbial assemblages. Bacteria from same-sector Antarctic Bottom Water samples showed patchy, high beta-diversity which did not correlate well with measured environmental parameters or geographical distance. Unconventional depth distribution patterns were observed for key archaeal groups: Crenarchaeota was found across all depths in the water column and persistent high relative abundances of common epipelagic archaeon Nitrosopelagicus was observed in deep-water masses. Our findings reveal substantial regional variability of SO prokaryote assemblages that we argue should be considered in wide-scale SO ecosystem microbial modelling.     

The alternative<Emphasis Type="SmallCaps"> d</Emphasis>-galactose degrading pathway of<Emphasis Type="Italic"> Aspergillus nidulans</Emphasis> proceeds via<Emphasis Type="SmallCaps"> l</Emphasis>-sorbose

The catabolism of d-galactose in yeast depends on the enzymes of the Leloir pathway. In contrast, Aspergillus nidulans mutants in galactokinase (galE) can still grow on d-galactose in the presence of ammonium—but not nitrate—ions as nitrogen source. A. nidulans galE mutants transiently accumulate high (400 mM) intracellular concentrations of galactitol, indicating that the alternative d-galactose degrading pathway may proceed via this intermediate. The enzyme degrading galactitol was identified as l-arabitol dehydrogenase, because an A. nidulans loss-of-function mutant in this enzyme (araA1) did not show NAD⁺-dependent galactitol dehydrogenase activity, still accumulated galactitol but was unable to catabolize it thereafter, and a double galE/araA1 mutant was unable to grow on d-galactose or galactitol. The product of galactitol oxidation was identified as l-sorbose, which is a substrate for hexokinase, as evidenced by a loss of l-sorbose phosphorylating activity in an A. nidulans hexokinase (frA1) mutant. l-Sorbose catabolism involves a hexokinase step, indicated by the inability of the frA1 mutant to grow on galactitol or l-sorbose, and by the fact that a galE/frA1 double mutant of A. nidulans was unable to grow on d-galactose. The results therefore provide evidence for an alternative pathway of d-galactose catabolism in A. nidulans that involves reduction of the d-galactose to galactitol and NAD⁺-dependent oxidation of galactitol by l-arabitol dehydrogenase to l-sorbose.     

Oligonucleotide microarrays in microbial diagnostics

Oligonucleotide microarrays offer a fast, high-throughput alternative for the parallel detection of microbes from virtually any sample. The application potential spreads across most sectors of life sciences, including environmental microbiology and microbial ecology; human, veterinary, food and plant diagnostics; water quality control; industrial microbiology, and so on. The past two years have witnessed a rapid increase of research in this field. Many alternative techniques were developed and validated as seen in 'proof-of-concept' articles. Publications reporting on the application of oligonucleotide microarray technology for microbial diagnostics in microbiology driven projects have just started to appear. Current and future technical and bioinformatics developments will inevitably improve the potential of this technology further.     

The Hypocrea jecorina gal10 (uridine 5'-diphosphate-glucose 4-epimerase-encoding) gene differs from yeast homologues in structure,genomic organization and expression

As part of a comprehensive study on lactose metabolism in Hypocrea jecorina (anamorph: Trichoderma reesei), a genomic clone of the gal10 gene encoding H. jecorina uridine 5'-diphosphate (UDP)-glucose 4-epimerase has been cloned and sequenced. It contains an open reading frame of 1548-base pair, interrupted by three introns, and encoding a 370-amino acids protein with similarity to pro- and eukaryotic UDP-glucose-4-epimerases. H. jecorina Gal10 does not contain the C-terminal mutarotase domain which is present in yeast Gal10 proteins but is able to functionally complement a corresponding Saccharomyces cerevisiae gal10 mutant. gal10 is not clustered with other H. jecorina gal genes (gal7, gene encoding galactose-1-phosphate uridylyltransferase and gal1, gene encoding galactokinase). The genomic location of H. jecorina gal10 and gal7 was syntenic with that in Neurospora crassa and colinear over an area of 6 and 3.5-kilobase. gal10 is constitutively expressed, and--unlike H. jecorina gal7--not further stimulated by D-galactose or L-arabinose or its corresponding polyols.     

<Emphasis Type="Italic">Aspergillus niger</Emphasis> citric acid accumulation: do we understand this well working black box?

This Mini-Review summarizes the current knowledge on the biochemical and physiological events leading to massive citric acid accumulation by Aspergillus niger under industrially comparable conditions, thereby particularly emphasizing the roles of glycolytic flux and its control, excretion of citric acid from the mitochondria and the cytosol, and the critical fermentation variables. The potential of novel techniques for metabolic analysis and genomic approaches in understanding this fermentation is also discussed.     

The role of high-dose-rate brachytherapy boost in breast-conserving therapy: Long-term results of the Hungarian National Institute of Oncology

AimTo report the long-term results of high-dose-rate (HDR) brachytherapy (BT) boost for breast cancer patients treated with conservative surgery and radiotherapy.Materials and methodsBetween 1995 and 2007, 100 early-stage breast cancer patients received an HDR BT boost after conservative surgery and whole breast irradiation. Ten patients (10%) received a single-fraction HDR boost of 8–10.35 Gy using rigid needles, while 90 (90%) were treated with a fractionated multi-catheter HDR BT boost. The latter consisted of 3 × 4 Gy (n = 19), 3 × 4.75 Gy (n = 70), and 2 × 6.4 Gy (n = 1). Breast cancer related events, cosmetic results and side effects were assessed.ResultsAt a median follow-up time of 94 months (range: 8–152) only 7 (7%) ipsilateral breast failures were observed for a 5- and 8-year actuarial rate of 4.5 and 7.0%, respectively. The 8-year disease-free, cancer-specific, and overall survival was 76.1, 82.8, and 80.4%, respectively. Cosmetic outcome was rated excellent in 17%, good in 39%, fair in 33%, and poor in 11%. Data on late radiation side effects were available for 91 patients (91%). Grade 3 fibrosis and grade 3 telangiectasia occurred in 6 (6.6%) and 2 (2.2%) patients, respectively. In univariate analysis only positive margin status had a significant negative effect on local control.ConclusionsHDR BT boost using multi-catheter implants produce excellent long-term local tumour control with acceptable cosmetic outcome and low rate of grade 3 late radiation side effects.     

Aspirin-triggered lipoxins override the apoptosis-delaying action of serum amyloid A in human neutrophils: a novel mechanism for resolution of inflammation

Elevated plasma levels of the acute-phase reactant serum amyloid A (SAA) have been used as a marker and predictor of inflammatory diseases. SAA regulates leukocyte activation; however, it is not known whether it also modulates neutrophil apoptosis, which is critical to the optimal expression and resolution of inflammation. Culture of human neutrophils with SAA (0.1-20 microg/ml) markedly prolonged neutrophil longevity by delaying constitutive apoptosis. SAA evoked concurrent activation of the ERK and PI3K/Akt signaling pathways, leading to phosphorylation of BAD at Ser(112) and Ser(136), respectively, and to prevention of collapse of mitochondrial transmembrane potential, cytochrome c release, and caspase-3 activation. These actions were abrogated by pharmacological inhibition of the formyl peptide receptor, ERK or PI3K. Furthermore, aspirin-triggered 15-epi-lipoxin A(4) (15-epi-LXA(4)) and its stable analog 15-epi-16-p-fluorophenoxy-LXA(4), which binds to the same receptor as SAA, effectively overrode the antiapoptosis signal from SAA even when neutrophils were treated with 15-epi-LXA(4) at either 1 or 4 h postculture with SAA. 15-Epi-LXA(4) itself did not affect neutrophil survival and apoptosis. Our results indicate that SAA at clinically relevant concentrations promotes neutrophil survival by suppressing the apoptotic machinery, an effect that can be opposed by 15-epi-LXA(4). The opposing actions of SAA and aspirin-triggered 15-epi-LXA(4) may contribute to the local regulation of exacerbation and resolution of inflammation, respectively.