A cross-cultural study of domestic luminous environment in the United Kingdom and Japan

Abstract not available

A novel PCR-based method for high throughput prokaryotic expression of antimicrobial peptide genes

<p>Abstract</p> <p>Background</p> <p>To facilitate the screening of large quantities of new antimicrobial peptides (AMPs), we describe a cost-effective method for high throughput prokaryotic expression of AMPs. EDDIE, an autoproteolytic mutant of the N-terminal autoprotease, Npro, from classical swine fever virus, was selected as a fusion protein partner. The expression system was used for high-level expression of six antimicrobial peptides with different sizes: Bombinin-like peptide 7, Temporin G, hexapeptide, Combi-1, human Histatin 9, and human Histatin 6. These expressed AMPs were purified and evaluated for antimicrobial activity.</p> <p>Results</p> <p>Two or four primers were used to synthesize each AMP gene in a single step PCR. Each synthetic gene was then cloned into the pET30a/His-EDDIE-GFP vector via an <it>in vivo </it>recombination strategy. Each AMP was then expressed as an Npro fusion protein in <it>Escherichia coli</it>. The expressed fusion proteins existed as inclusion bodies in the cytoplasm and the expression levels of the six AMPs reached up to 40% of the total cell protein content. On <it>in vitro </it>refolding, the fusion AMPs was released from the C-terminal end of the autoprotease by self-cleavage, leaving AMPs with an authentic N terminus. The released fusion partner was easily purified by Ni-NTA chromatography. All recombinant AMPs displayed expected antimicrobial activity against <it>E. coli</it>, <it>Micrococcus </it>luteus and <it>S. cerevisia</it>.</p> <p>Conclusions</p> <p>The method described in this report allows the fast synthesis of genes that are optimized for over-expression in <it>E. coli </it>and for the production of sufficiently large amounts of peptides for functional and structural characterization. The Npro partner system, without the need for chemical or enzymatic removal of the fusion tag, is a low-cost, efficient way of producing AMPs for characterization. The cloning method, combined with bioinformatic analyses from genome and EST sequence data, will also be useful for screening new AMPs. Plasmid pET30a/His-EDDIE-GFP also provides green/white colony selection for high-throughput recombinant AMP cloning.</p

Sediment records of long chain alkyl diols in an upwelling area of the coastal northern South China Sea

Long chain alkyl diols in sediment cores were studied in the Yuedong Upwelling (YDU) area in the coastal northern South China Sea to investigate whether sea surface temperature (SST) and upwelling intensity over the last few decades can be traced by the diol-derived indices, i.e., the LDI (long chain diol index) as a proxy for SST and the DI-1 and DI-2 (diol index 1 and 2) as proxies for upwelling intensity. The influence of riverine long chain alkyl diols (e.g., 1,13- and 1,15-diols), which may affect LDI-reconstructed SSTs, was largely ruled out based on the comparison between diol distributions in suspended particulate materials in the Pearl River estuary and the core sediments. LDI-derived SSTs in downcore sediments matched well with local annual mean SSTs. The records of DI-2 changed in parallel with the local wind stress and inversely with SST at times of upwelling, suggesting that DI-2 is an effective proxy for upwelling intensity of YDU. The DI-1 showed a generally inverse variation pattern with DI-2, implying a major influence by SST, and it is thus not an applicable upwelling indicator for YDU. A negative relationship of DI-1 and a positive relationship of DI-2 with LDI-derived SST were observed. This occurrence might be attributed to El Nino-Southern Oscillation (ENSO), because the SST and upwelling intensity were largely modulated by ENSO, showing a warm annual mean SST during the years of enhanced El Nino and intensified summer upwelling. (C) 2018 Elsevier Ltd. All rights reserved

Molecular and stable carbon isotopic compositions of hopanoids in seep carbonates from the South China Sea continental slope

The lipid biomarkers of hopanoids in cold seep carbonates from the South China Sea continental slope were investigated by gas chromatography mass spectrometer (GC MS) and gas chromatography-isotope ratio-mass spectrometer (GC-ir-MS). The distribution of hopanes/hopenes shows a preference for the 'biological' 17 beta(H), 21 beta(H)-over the 'geological' 17 alpha(H), 21 beta(H)-configuration. This interpretation is in agreement with the strong odd even preference of long-chain n-alkanes in those samples, suggesting that the beta beta hopanes may be the early cliagenetic products of biohopanoids and the alpha beta, beta alpha configurations of hopanes were mainly derived from allochthonous sources contributing to the organic matter of the carbonates. In terms of hopanoid acids, the C-30 to C-33-17 beta(H), 21 beta(H)-hopanoid acids were detected with C-32 17 beta(H), 21 beta(H)-hopanoid acid being the most abundant. However, there is a significant difference in stable carbon isotopic compostions of the C-32 17 beta(H), 21 beta(H)-hopanoic acid among samples (-30.7 parts per thousand to -69.8 parts per thousand). The delta C-13 values match well with the carbon isotopic compositions of SRB-derived iso-lanteisoC(15:0) fatty acids in the samples, which strongly depend on the carbon utilization types by microbe. The most abundant compound of hopanols detected in the samples, C-30-17 beta(H), 21 beta(H)-hopanol, may be a good indicator of diagenetic product of type I methanotrophs. The molecular and carbon isotopic compositions of hopanoids demonstrate clearly that there is a combination contribution of both SRB and type I or type X methanotrophs to the source organism in the seep carbonates from the South China Sea continental slope. 2013 Elsevier Ltd. All rights reserved

Molecular distributions of phospholipid ester-linked fatty acids in a soil profile of the Dinghushan Biosphere Reserve

Phospholipid ester-linked fatty acids (PLFA) were used to investigate the microbial ecology and its association with carbon accumulation in one soil profile from the Dinghushan Biosphere Preserve in south China, in order to probe the mechanisms that control the carbon accumulation at the depth of 0 - 20 cm in the Dinghushan forest soil profile. The data show that sulfate reducing bacteria (SRB) occur in the top 10 cm, and methanotrophic bacteria and fungi are not present below 10 cm, and the gram-negative bacteria are reduced with gram-positive bacteria dominating at that depth; all of which indicated that the activities of some of the microorganisms were inhibited, from which we infer that the available carbon source and oxygen content of micro environment may be reduced below 10 cm of the profile. The shallow depth (top 10 cm) of the soil anaerobic zone at the Wukesong profile, compared to the normal soil anaerobic zone (top 20 - 30 cm), is considered to be mainly the result of the high precipitation of acidic rain. The physicochemical reactions caused by acid rain in the soil system result in a decreased soil porosity, and a correspondingly decreased porosity-dependent oxygen concentration, leading to the thriving of SRB in the shallow depth. Although the increase of soil organic carbon stock is attributed to numerous factors, the decreasing rate of litter decomposition in the topsoil layer, together with the rise of the depth of the anaerobic zone, may play key roles in the carbon accumulation in the depth of 0 - 20 cm in the soil profile from the Dinghushan Biosphere Preserve

Molecular and stable carbon isotopic compositions of saturated fatty acids within one sedimentary profile in the Shenhu, northern South China Sea: Source implications

This study examined the distributions and stable carbon isotopic compositions of saturated fatty acids (SaFAs) in one 300 cm long sedimentary profile, which was named as Site4B in Shenhu, northern South China Sea. The concentrations of total SaFAs in sediments ranged from 1.80 to 10.16 mu g/g (mu g FA/g dry sediment) and showed an even-over-odd predominance in the carbon chain of C-12 to C-32, mostly with n-C-16 and n-C-18 being the two major components. The short-chain fatty acids (ScFAs; n-C-12 to n-C-18) mainly from marine microorganisms had average delta C-13 values of -26.7 parts per thousand to -28.2 parts per thousand, whereas some terrigenous-sourced long-chain fatty acids (LcFAs; n-C-21 to n-C-32) had average delta C-13 values of -29.6 parts per thousand to -34.1 parts per thousand. The other LcFAs (n-C-24 & n-C-26 similar to n-C-28; average delta C-13 values are -26.1 parts per thousand to -28.0 parts per thousand) as well as n-C-19 and n-C-20 SaFAs (average delta C-13 values are -29.1 parts per thousand and -29.3 parts per thousand, respectively) showed a mixed signal of carbon isotope compositions