Water quality indicator interval prediction in wastewater treatment process based on the improved BES-LSSVM algorithm

This paper proposes a novel interval prediction method for effluent water quality indicators (including biochemical oxygen demand (BOD) and ammonia nitrogen (NH3-N)), which are key performance indices in the water quality monitoring and control of a wastewater treatment plant. Firstly, the effluent data regarding BOD/NH3-N and their necessary auxiliary variables are collected. After some basic data pre-processing techniques, the key indicators with high correlation degrees of BOD and NH3-N are analyzed and selected based on a gray correlation analysis algorithm. Next, an improved IBES-LSSVM algorithm is designed to predict the BOD/NH3-N effluent data of a wastewater treatment plant. This algorithm relies on an improved bald eagle search (IBES) optimization algorithm that is used to find the optimal parameters of least squares support vector machine (LSSVM). Then, an interval estimation method is used to analyze the uncertainty of the optimized LSSVM model. Finally, the experimental results demonstrate that the proposed approach can obtain high prediction accuracy, with reduced computational time and an easy calculation process, in predicting effluent water quality parameters compared with other existing algorithms.Peer ReviewedPostprint (published version

Pathway and kinetics of cyhalothrin biodegradation by Bacillus thuringiensis strain ZS-19

10.1038/srep08784Scientific Reports

Differential Modulation of Burkholderia cenocepacia Virulence and Energy Metabolism by the Quorum-Sensing Signal BDSF and Its Synthase▿

Burkholderia cenocepacia produces the molecule cis-2-dodecenoic acid (BDSF), which was previously shown to play a role in antagonism against the fungal pathogen Candida albicans by interfering with its morphological transition. In this study, we show that production of BDSF is under stringent transcriptional control and the molecule accumulates in a cell density-dependent manner, typically found with quorum-sensing (QS) signals. B. cenocepacia mutant strain J2315 with a deleted Bcam0581 gene, which encodes an enzyme essential for BDSF production, exhibited a growth defect in minimal medium but not in rich medium, decreased virulence gene expression, and attenuated virulence in a zebrafish infection model. Exogenous addition of BDSF to the mutant rescues virulence gene expression but fails to restore its growth defect in minimal medium. We show that Bcam0581, but not BDSF, is associated with B. cenocepacia ATP biogenesis. We also provide evidence that some of the BDSF-regulated genes are also controlled by the acyl-homoserine-lactone-dependent QS system and are thus coregulated by two cell-to-cell signaling systems. These data demonstrate that in addition to the role in cross-kingdom signal interference, BDSF and its synthase are also important for the virulence and physiology of B. cenocepacia

Structural and Functional Characterization of Diffusible Signal Factor Family Quorum-Sensing Signals Produced by Members of the Burkholderia cepacia Complex▿

Previous work has shown that Burkholderia cenocepacia produces the diffusible signal factor (DSF) family signal cis-2-dodecenoic acid (C12:Δ2, also known as BDSF), which is involved in the regulation of virulence. In this study, we determined whether C12:Δ2 production is conserved in other members of the Burkholderia cepacia complex (Bcc) by using a combination of high-performance liquid chromatography, mass spectrometry, and bioassays. Our results show that five Bcc species are capable of producing C12:Δ2 as a sole DSF family signal, while four species produce not only C12:Δ2 but also a new DSF family signal, which was identified as cis,cis-11-methyldodeca-2,5-dienoic acid (11-Me-C12:Δ2,5). In addition, we demonstrate that the quorum-sensing signal cis-11-methyl-2-dodecenoic acid (11-Me-C12:Δ2), which was originally identified in Xanthomonas campestris supernatants, is produced by Burkholderia multivorans. It is shown that, similar to 11-Me-C12:Δ2 and C12:Δ2, the newly identified molecule 11-Me-C12:Δ2,5 is a potent signal in the regulation of biofilm formation, the production of virulence factors, and the morphological transition of Candida albicans. These data provide evidence that DSF family molecules are highly conserved bacterial cell-cell communication signals that play key roles in the ecology of the organisms that produce them

Response of broomcorn millet (Panicum miliaceum L.) genotypes from semiarid regions of China to salt stress

Salt tolerance of crops is becoming more and more important, owing to the constant increase of salinity in arid and semi-arid regions. Broomcorn millet (Panicum miliaceum L.), generally considered tolerant to salinity, can be an alternative crop for salt affected areas. To assess genotypic variation for vegetative-stage salinity tolerance, 195 broomcorn millet accessions from a core collection were evaluated for germination percentage, shoot length, and root length during germination in 8 mL of deionized water (control) or 8 mL of a 120 mmol L− 1 salt solution (treatment). Six genotypes with different levels of salt tolerance were selected based on the growth parameters and ion concentrations in plant at the seedling stage and used for confirmation of the initial salinity response. Substantial variation for salinity tolerance was found on the basis of salt damage index [(germination percentage under control − germination percentage under salinity) / germination percentage under control × 100, SDI] and 39 accessions exhibited strong salt tolerance with SDI lower than 20%. The salt tolerance performance of the genotypes was generally consistent across experiments. In the seedling growth study, seedling number, root length and belowground biomass were adversely affected (showing more than 70%, 50%, and 32% reduction, respectively) in sensitive genotypes compared to tolerant genotypes (35%, 31%, and 3% reduction, respectively) under 160 mmol L− 1 NaCl treatment. In general, whole-plant salinity tolerance was associated with increased Na+ concentration and Na+/K+ ratio, and salt-tolerant genotypes often had higher root and lower shoot Na+ concentration than sensitive ones. Na+ concentration in root was closely related to salt tolerance and may be considered as a selection criterion for screening salt tolerance of broomcorn millet at the seedling or vegetative stages

Modulation of Inter-kingdom Communication by PhcBSR Quorum Sensing System in Ralstonia solanacearum Phylotype I Strain GMI1000

Ralstonia solanacearum is a ubiquitous soil-borne plant pathogenic bacterium, which frequently encounters and interacts with other soil cohabitants in competition for environmental niches. Ralsolamycin, which is encoded by the rmy genes, has been characterized as a novel inter-kingdom interaction signal that induces chlamydospore development in fungi. In this study, we provide the first genetic evidence that the rmy gene expression is controlled by the PhcBSR quorum sensing (QS) system in strain GMI1000. Mutation of phcB could lead to significant reduction of the expression levels of the genes involved in ralsolamycin biosynthesis. In addition, both the phcB and rmy mutants were attenuated in induction of chlamydospore formation in Fusarium oxysporum f. cubense and diminished in the ability to compete with the sugarcane pathogen Sporisorium scitamineum. Agreeable with the pattern of QS regulation, transcriptional expression analysis showed that the transcripts of the rmy genes were increased along with the increment of the bacterial population density. Taken together, the above findings provide new insights into the regulatory mechanisms that the QS system involves in governing the ralsolamycin inter-kingdom signaling system

Genetic Diversity and Population Structure of Broomcorn Millet (Panicum miliaceum L.) Cultivars and Landraces in China Based on Microsatellite Markers

Broomcorn millet (Panicum miliaceum L.), one of the first domesticated crops, has been grown in Northern China for at least 10,000 years. The species is presently a minor crop, and evaluation of its genetic diversity has been very limited. In this study, we analyzed the genetic diversity of 88 accessions of broomcorn millet collected from various provinces of China. Amplification with 67 simple sequence repeat (SSR) primers revealed moderate levels of diversity in the investigated accessions. A total of 179 alleles were detected, with an average of 2.7 alleles per locus. Polymorphism information content and expected heterozygosity ranged from 0.043 to 0.729 (mean = 0.376) and 0.045 to 0.771 (mean = 0.445), respectively. Cluster analysis based on the unweighted pair group method of mathematical averages separated the 88 accessions into four groups at a genetic similarity level of 0.633. A genetic structure assay indicated a close correlation between geographical regions and genetic diversity. The uncovered information will be valuable for defining gene pools and developing breeding programs for broomcorn millet. Furthermore, the millet-specific SSR markers developed in this study should serve as useful tools for assessment of genetic diversity and elucidation of population structure in broomcorn millet

A Sfp-type phosphopantetheinyl transferase ZmsO is essential for zeamines production and the virulence of Dickeya zeae

10.1007/s10658-016-0971-1European Journal of Plant Pathology1464937-94

Regenerated silk fibroin based on small aperture scaffolds and marginal sealing hydrogel for osteochondral defect repair

Abstract Background Osteochondral defects pose an enormous challenge without satisfactory repair strategy to date. In particular, the lateral integration of neo-cartilage into the surrounding native cartilage is a difficult and inadequately addressed problem determining tissue repair’s success. Methods Regenerated silk fibroin (RSF) based on small aperture scaffolds was prepared with n-butanol innovatively. Then, the rabbit knee chondrocytes and bone mesenchymal stem cells (BMSCs) were cultured on RSF scaffolds, and after induction of chondrogenic differentiation, cell-scaffold complexes strengthened by a 14 wt% RSF solution were prepared for in vivo experiments. Results A porous scaffold and an RSF sealant exhibiting biocompatibility and excellent adhesive properties are developed and confirmed to promote chondrocyte migration and differentiation. Thus, osteochondral repair and superior horizontal integration are achieved in vivo with this composite. Conclusions Overall, the new approach of marginal sealing around the RSF scaffolds exhibits preeminent repair results, confirming the ability of this novel graft to facilitate simultaneous regeneration of cartilage–subchondral bone