Comparative Proteomic Analysis of saccharopolyspora spinosa SP06081 and PR2 strains reveals the differentially expressed proteins correlated with the increase of spinosad yield

<p>Abstract</p> <p>Background</p> <p><it>Saccharopolyspora spinosa </it>produces the environment-friendly biopesticide spinosad, a mixture of two polyketide-derived macrolide active ingredients called spinosyns A and D. Therefore considerable interest is in the improvement of spinosad production because of its low yield in wild-type <it>S. spinosa</it>. Recently, a spinosad-hyperproducing PR2 strain with stable heredity was obtained from protoplast regeneration of the wild-type <it>S. spinosa </it>SP06081 strain. A comparative proteomic analysis was performed on the two strains during the first rapid growth phase (RG1) in seed medium (SM) by using label-free quantitative proteomics to investigate the underlying mechanism leading to the enhancement of spinosad yield.</p> <p>Results</p> <p>In total, 224 proteins from the SP06081 strain and 204 proteins from the PR2 strain were unambiguously identified by liquid chromatography-tandem mass spectrometry analysis, sharing 140 proteins. A total of 12 proteins directly related to spinosad biosynthesis were identified from the two strains in RG1. Comparative analysis of the shared proteins revealed that approximately 31% of them changed their abundance significantly and fell in all of the functional groups, such as tricarboxylic acid cycles, glycolysis, biosynthetic processes, catabolic processes, transcription, translation, oxidation and reduction. Several key enzymes involved in the synthesis of primary metabolic intermediates used as precursors for spinosad production, energy supply, polyketide chain assembly, deoxysugar methylation, and antioxidative stress were differentially expressed in the same pattern of facilitating spinosad production by the PR2 strain. Real-time reverse transcriptase polymerase chain reaction analysis revealed that four of five selected genes showed a positive correlation between changes at the translational and transcriptional expression level, which further confirmed the proteomic analysis.</p> <p>Conclusions</p> <p>The present study is the first comprehensive and comparative proteome analysis of <it>S. spinosa </it>strains. Our results highlight the differentially expressed proteins between the two <it>S. spinosa </it>strains and provide some clues to understand the molecular and metabolic mechanisms that could lead to the increased spinosad production yield.</p

A Location Selection Policy of Live Virtual Machine Migration for Power Saving and Load Balancing

Green cloud data center has become a research hotspot of virtualized cloud computing architecture. And load balancing has also been one of the most important goals in cloud data centers. Since live virtual machine (VM) migration technology is widely used and studied in cloud computing, we have focused on location selection (migration policy) of live VM migration for power saving and load balancing. We propose a novel approach MOGA-LS, which is a heuristic and self-adaptive multiobjective optimization algorithm based on the improved genetic algorithm (GA). This paper has presented the specific design and implementation of MOGA-LS such as the design of the genetic operators, fitness values, and elitism. We have introduced the Pareto dominance theory and the simulated annealing (SA) idea into MOGA-LS and have presented the specific process to get the final solution, and thus, the whole approach achieves a long-term efficient optimization for power saving and load balancing. The experimental results demonstrate that MOGA-LS evidently reduces the total incremental power consumption and better protects the performance of VM migration and achieves the balancing of system load compared with the existing research. It makes the result of live VM migration more high-effective and meaningful

Induction of ROS Overload by Alantolactone Prompts Oxidative DNA Damage and Apoptosis in Colorectal Cancer Cells

Cancer cells typically display higher than normal levels of reactive oxygen species (ROS), which may promote cancer development and progression but may also render the cancer cells more vulnerable to further ROS insult. Indeed, many of the current anticancer therapeutics kill cancer cells via induction of oxidative stress, though they target both cancer and normal cells. Recently, alantolactone (ATL), a natural sesquiterpene lactone, has been shown to induce apoptosis by increasing ROS levels specifically in cancer cells; however, the molecular mechanisms linking ROS overproduction to apoptosis remain unclear. Here we show that the ATL-induced ROS overload in human SW480 and SW1116 colorectal cancer cells was followed by a prominent accumulation of cellular oxidized guanine (8-oxoG) and immediate increase in the number of DNA strand breaks, indicating that increased ROS resulted in extensive oxidative DNA damage. Consequently, the G1/S-CDK suppresser CDKN1B (p21) and pro-apoptotic proteins Bax and activated caspase-3 were upregulated, while anti-apoptotic Bcl-2 was downregulated, which were followed by cell cycle arrest at G1 and marked apoptosis in ATL-treated cancer but not non-cancer cells. These results suggest that the ATL-induced ROS overload triggers cell death through induction of massive oxidative DNA damage and subsequent activation of the intrinsic apoptosis pathway

Spatial and seasonal variations of organic carbon distributions in typical intertidal sediments of China

Intertidal zones are the main sites for land-ocean interaction and play an important role in transporting and accumulating organic carbon (OC). Understanding sources and preservation of sedimentary OC are vital to better evaluate the processes controlling the OC distribution in intertidal zones. In this study, we present bulk parameters of total organic carbon (TOC), delta C-13(org), grain size and biomarker contents in surface sediments of 14 typical intertidal zones along China's coastline during both the wet season (WS) and the dry season (DS). Statistical analysis of our data set showed that TOC and biomarker contents were generally high in small estuaries, intermediate but more variable in large estuaries and low in non-estuaries; and these distribution patterns broadly correlated with sedimentary clay contents. TOC and biomarker contents were generally higher in the WS than the DS reflecting both OC inputs and preservation. A binary mixing model based on delta C-13(org) and biomarker proxies revealed that large estuaries were characterized by higher terrestrial OC fractions (62-80%) except for the Yellow River Estuary (24%), while lower terrestrial OC fractions occurred in non-estuaries (13-15%). Variable OC contributions were found in small estuaries, with most sites characterized by low terrestrial OC contributions (3-35%), but high terrestrial OC contributions were found at the Qiantang River Estuary site (59%) and the Jiulong River Estuary site (67%). Carbon stocks in Chinese intertidal sediments are comparable with those in marine sediments from shelf areas and the Exclusive Economic Zone (EEZ). This study suggests that intertidal sediments are potentially an important carbon sink. (C) 2020 Elsevier Ltd. All rights reserved

Rapid diagnosis of Tobacco mosaic virus in tobacco using time-resolved fluorescence immunoassay

ABSTRACTTobacco mosaic virus (TMV) causes a significant yield loss in solanaceous crops. Accurate and rapid diagnosis of TMV is an essential pre-requisite for proactive and tailored disease management strategies, filling the gap between more rigorous laws regarding pesticide use and maintaining crop production. Herein, we developed a time-resolved fluorescence immunoassay (TRFIA) to quantitatively detect TMV in tobacco. TMV virions were used as immunogens to develop monoclonal antibodies, which were then conjugated to Eu3+ nanospheres. The detection limit of the TRFIA platform was 0.24 ng/mL, with recovery rates in the range of 90.71–108.11% in spiked tobacco. The specificity was confirmed using ten species of tobacco-infecting phytopathogens. In-field applicability was implemented by screening for TMV in 10,000 tobacco leaf samples collected from five fields in Kunming, China. Overall, the proposed TRFIA platform is rapid, accurate, and end-user friendly, demonstrating its application in TMV onsite testing in tobacco