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1.
J Colloid Interface Sci ; 576: 1-9, 2020 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-32408158

RESUMO

Pathogen capture and removal from whole blood is a new strategy for extracorporeal blood purification, especially in initial treatment of sepsis before pathogen identification. Herein, hemocompatible magnetic particles with broad-spectrum bacteria capture capability were proposed for pathogen removal from whole blood, omitting the necessity of pathogen identification. Firstly, we designed and synthesized a new kind of imidazolium-based ionic liquid with good antibacterial activity, and polydopamine coating was utilized as a hemocompatible platform to immobilize ionic liquids on Fe3O4 nanoparticles, forming the hemocompatible magnetic particles (Fe3O4@PDA-IL). The magnetic particles exhibited good hemocompatibility and performed well in the removal of various species of clinically significant pathogens from human whole blood, including S. aureus, E. coli, and the hard-to-treat bacteria of P. aeruginosa and Methicillin-resistant S. aureus, which are the most common pathogens in bloodstream infections. Besides, the Fe3O4@PDA-IL particles were also capable to remove bacterial endotoxins from blood, inhibiting further aggravation of sepsis. Overall, we demonstrated the application of hemocompatible magnetic particles in the removal of pathogens and bacterial endotoxins from whole blood via electrostatic and hydrophobic interactions, without significant effects on blood cells or the activation of coagulation and complement, addressing the feasibility of using imidazolium-based ionic liquids for bacteria capture and removal from whole blood. It would contribute to the development of magnetic separation-based approaches to remove bacteria and bacterial endotoxin for extracorporeal blood purification, especially in initial sepsis therapy before pathogen identification.

2.
Int J Oral Sci ; 12(1): 15, 2020 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-32385260

RESUMO

The oral microbial community is widely regarded as a latent reservoir of antibiotic resistance genes. This study assessed the molecular epidemiology, susceptibility profile, and resistance mechanisms of 35 methicillin-resistant Staphylococcus epidermidis (MRSE) strains isolated from the dental plaque of a healthy human population. Broth microdilution minimum inhibitory concentrations (MICs) revealed that all the isolates were nonsusceptible to oxacillin and penicillin G. Most of them were also resistant to trimethoprim (65.7%) and erythromycin (54.3%). The resistance to multiple antibiotics was found to be largely due to the acquisition of plasmid-borne genes. The mecA and dfrA genes were found in all the isolates, mostly dfrG (80%), aacA-aphD (20%), aadD (28.6%), aphA3 (22.9%), msrA (5.7%), and the ermC gene (14.3%). Classical mutational mechanisms found in these isolates were mainly efflux pumps such as qacA (31.4%), qacC (25.7%), tetK (17.1%), and norA (8.6%). Multilocus sequence type analysis revealed that sequence type 59 (ST59) strains comprised 71.43% of the typed isolates, and the eBURST algorithm clustered STs into the clonal complex 2-II(CC2-II). The staphyloccoccal cassette chromosome mec (SCCmec) type results showed that 25 (71.43%) were assigned to type IV. Moreover, 88.66% of the isolates were found to harbor six or more biofilm-associated genes. The aap, atlE, embp, sdrF, and IS256 genes were detected in all 35 isolates. This research demonstrates that biofilm-positive multiple-antibiotic-resistant ST59-SCCmec IV S. epidermidis strains exist in the dental plaque of healthy people and may be a potential risk for the transmission of antibiotic resistance.

3.
Chemphyschem ; 2020 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-32291897

RESUMO

The crossed molecular beam reactions of the methylidyne radical (CH; X2 Π) with 1,3-butadiene (CH2 CHCHCH2 ; X1 Ag ) along with their (partially) deuterated counterparts were performed at collision energies of 20.8 kJ mol-1 under single collision conditions. Combining our laboratory data with ab initio calculations, we reveal that the methylidyne radical may add barrierlessly to the terminal carbon atom and/or carbon-carbon double bond of 1,3-butadiene, leading to doublet C5 H7 intermediates with life times longer than the rotation periods. These collision complexes undergo non-statistical unimolecular decomposition through hydrogen atom emission yielding the cyclic cis- and trans-3-vinyl-cyclopropene products with reaction exoergicities of 119±42 kJ mol-1 . Since this reaction is barrierless, exoergic, and all transition states are located below the energy of the separated reactants, these cyclic C5 H6 products are predicted to be accessed even in low-temperature environments, such as in hydrocarbon-rich atmospheres of planets and cold molecular clouds such as TMC-1.

4.
Technol Cancer Res Treat ; 19: 1533033820909911, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32281480

RESUMO

OBJECTIVE: Nasopharyngeal carcinoma is highly endemic in Southeast China. Circulating tumor cell is an important biomarker in the prognosis of variety kinds of cancers. Overexpression of fibronectin 1 was observed in variety kinds of malignancies and may contribute to progress and metastasis of the cancers. The current study was aimed to investigate phenotypes of circulating tumor cell in nasopharyngeal carcinoma blood and fibronectin 1 expression in the circulating tumor cell, and their clinical application in predicting nasopharyngeal carcinoma prognosis. METHODS: Blood samples were obtained from nasopharyngeal carcinoma patients before and after treatment. CanPatrol circulating tumor cell enrichment and RNA in situ hybridization were applied to identify circulating tumor cell and its phenotypes. Fibronectin 1 messenger RNA expression in the cells of circulating tumors was examined by messenger RNA-in situ hybridization. RESULTS: Circulating tumor cell was not associated with tumor characteristics or lymph node metastasis. Patients with >9 circulating tumor cells or >5 mesenchymal phenotype circulating tumor cell per 5-mL blood had poorer progression-free survival (P < .05). Multivariable analysis demonstrated that 2 or more mesenchymal phenotype circulating tumor cells with high fibronectin 1 messenger RNA expression predicted shorter progression-free survival (P < .05). CONCLUSIONS: Circulating tumor cells with high-level fibronectin 1 expression was associated with poor survival in patients with nasopharyngeal carcinoma and could be an independent prognostic factor for nasopharyngeal carcinoma.

5.
J Phys Chem Lett ; : 3882-3888, 2020 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-32338921

RESUMO

A significant, fundamental challenge in the field of valleytronics is how to generate and regulate valley-polarized currents in practical ways. Here, we discover a new mechanism for producing valley polarization in a monolayer transition metal dichalcogenide superlattice, in which valley-resolved gaps are formed at the supercell Brillouin zone boundaries and centers due to intervalley scattering. When the incident energy of the electron lies in the gaps, the available states are valley polarized, thus providing a valley-polarized current from the superlattice. We show that the direction and strength of the valley polarization may be further tuned by varying the potential applied to the superlattice. The transmission can have a net valley polarization of 55% for a four-period heterostructure. Moreover, two such valley filters in series may function as an electrostatically controlled giant valleyresistance device, representing a zero-magnetic field counterpart to the familiar giant magnetoresistance device.

6.
Int J Biochem Cell Biol ; 123: 105751, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32330554

RESUMO

This report aims to explore how LINC00691 regulates the proliferation and invasion of gastric cancer (GC). Clinical tissue and serum samples, as well as specimens in the Cancer Genome Atlas (TCGA) database, were used to analyse the expression of LINC00691 in GC. Our data indicated that the expression of LINC00691 in GC was significantly higher than that in healthy controls and was associated with clinicopathological features and survival time. In the GC cell lines MKN-45 and HGC-27, the knockdown of LINC00691 suppressed proliferation, colony formation, migration, and invasion. Bioinformatics analysis and luciferase reporter gene experiments showed that LINC00691 activated Lin28 transcription. Western blot analysis indicated that the knockdown of LINC00691 contributed to the decreased expression of p-JAK2 and p-STAT3 in GC cells. The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signalling pathway inhibitor ruxolitinib effectively suppressed the effects of LINC00691. In addition, both LINC00691 and Lin28 promoted the expression of epidermal growth factor (EGF). Therefore, our study clarified that LINC00691 is highly expressed in GC and is a potential biomarker for GC diagnosis and prognosis. LINC00691 promotes the proliferation and invasion of GC cells by activating Lin28 transcription and facilitating EGF expression through the JAK/STAT signalling pathway, which provides new ideas for targeted therapy of GC.

7.
J Hazard Mater ; 395: 122684, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32330782

RESUMO

Hydrogen and methane commonly co-exist in aquifer. Either hydrogen or methane has been individually utilized as electron donor for bio-reducing chromate. However, little is known whether microbial chromate reduction would be suppressed or promoted when both hydrogen and methane are simultaneously supplied as joint electron donors. This study for the first time demonstrated microbial chromate reduction rate could be accelerated by both hydrogen and methane donating electrons. The maximum chromate reduction rate (4.70 ±â€¯0.03 mg/L·d) with a volume ratio of hydrogen to methane at 1:1 was significantly higher than that with pure hydrogen (2.53 ±â€¯0.02 mg/L·d) or pure methane (2.01 ±â€¯0.02 mg/L·d) as the sole electron donor (p < 0.01). High-throughput 16S rRNA gene amplicon sequencing detected potential chromate reducers (e.g., Spirochaetaceae, Delftia and Azonexus) and hydrogenotrophic bacteria (e.g., Acetoanaerobium) and methane-metabolizing microorganisms (e.g., Methanobacterium), indicating that these microorganisms might play important roles on microbial chromate reduction using both hydrogen and methane as electron donors. Abundant hupL and mcrA genes responsible for hydrogen oxidation and methane conversion were harbored, together with chrA gene for chromate reduction. More abundant extracellular cytochrome c and intracellular NADH were detected with joint electron donors, suggesting more active electron transfers.

8.
Chirality ; 2020 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-32342529

RESUMO

In this paper, a novel l-glutamate based immobilized chiral ionic liquid (SBA-IL (Glu)) was prepared by chemical bonding method and applied as a solid sorbent for chiral separation of amlodipine. The performance of SBA-IL (Glu) was investigated for the absorption of (S)-amlodipine and separation of amlodipine enantiomer. The static experiment showed that equilibrium adsorption was achieved within 80 minutes, and the saturation adsorptions capacity was 12 mg/g. The complex was then packed in a glass chromatographic column for the separation of amlodipine and the enantiomeric excess (%ee) of (S)-amlodipine reached 24.67%. The immobilized ionic liquids exhibit good reusability, and the separation efficiency remains 18.24% after reused five times, which allows potential scale-up for the chiral separation of amlodipine.

9.
Rapid Commun Mass Spectrom ; : e8818, 2020 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-32342561

RESUMO

RATIONALE: Acquisition quality in analytical science is key to obtaining optimal data from a sample. In very high-resolution mass spectrometry, quality is driven by the optimization of multiple parameters, including the use of scans and micro-scans (or transients) for performing a Fourier transformation. METHODS: 39 mass spectra of a single synthesized complex sample were acquired using various numbers of scan and micro-scan determined through a simple experimental design. An electrospray ion source coupled with an LTQ-Orbitrap-XL mass spectrometer was used and acquisition was performed using a single mass range. All the resulting spectra were treated in the same way to enable comparisons of assigned stoichiometric formulae between acquisitions. RESULTS: Converting the number of scans into micro-scans enhances signal quality by lowering noise and reducing artifacts. This modification also increases the number of attributed stoichiometric formulae for an equivalent acquisition time, giving access to a larger molecular diversity for the analyzed complex sample. CONCLUSION: For complex samples, the use of long acquisition times leads to optimal data quality, and the use of micro-scans instead of scans-only maximizes the number of attributed stoichiometric formulae.

10.
Oncol Rep ; 2020 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-32319669

RESUMO

RAD18 is an E3 ubiquitin­protein ligase that has a role in carcinogenesis and tumor progression owing to its involvement in error­prone replication. Despite its significance, the function of RAD18 has not been fully examined in colorectal cancer (CRC). In the present research, by collecting clinical samples and conducting immunohistochemical staining, we found that RAD18 expression was significantly increased in the CRC tissue compared with that noted in the adjacent non­cancerous normal tissues and that high expression of RAD18 was associated with lymph node metastasis and poor prognosis in CRC patients. In vitro, as determined by cell transfection, scratch, and Transwell experiments, it was also demonstrated that RAD18 increased the invasiveness and migration capacity of CRC cells (HCT116, DLD­1, SW480). The signaling pathway was analyzed by western blotting and the clinical data were analyzed by immunohistochemical staining and RT­PCR, indicating that the process of epithelial­mesenchymal transition (EMT) may be involved in RAD18­mediated migration and invasion of CRC cells. All of the above data indicate that RAD18 is a novel prognostic biomarker that may become a potential therapeutic target for CRC in the future.

11.
Sheng Wu Gong Cheng Xue Bao ; 36(3): 436-449, 2020 Mar 25.
Artigo em Chinês | MEDLINE | ID: mdl-32237538

RESUMO

Phytomining technology cultivates hyperaccumulator plants on heavy metal contaminated soils, followed by biomass harvesting and incineration to recover valuable metals, offering an opportunity for resource recycling and soil remediation. Large areas of ultramafic soils, naturally rich in nickel (Ni), are present in numerous places around the world. As an environmentally friendly and cost-effective soil remediation technology, phytomining has a broad application prospect in such areas and thus has attracted great attention from global researchers. The key processes of phytomining include: (1) high-selectivity response of hyperaccumulator plants to Ni the underlying mechanisms involved in the rhizosphere; (2) underlying mechanisms of high-efficiency uptake and translocation of Ni in hyperaccumulators; and (3) resource recycling of high-added value Ni products from the Ni-rich bio-ore of hyperaccumulators. In recent 30 years, phytomining practices have successfully carried out in United States, Albania and Malaysia. However, the research and application of this technology in China are still in the fledging stage. This paper reviews the key processes and research progress of phytomining, and points out the bottleneck, to provide theoretical basis and technical guidance for phytomining.


Assuntos
Biodegradação Ambiental , Níquel , Poluentes do Solo , China , Níquel/metabolismo , Solo , Poluentes do Solo/metabolismo
12.
Phys Chem Chem Phys ; 2020 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-32270851

RESUMO

Inorganic ferroelectric perovskite oxides are more stable than hybrid perovskites. However, their solar energy harvesting efficiency is not so good. Here, by constructing a series of BiFeO3-based devices (solar cells), we investigated three factors that influence the photovoltaic performance, namely, spontaneous polarization, terminated ion species in the interface between BiFeO3 and the electrode, and polarized light irradiation. This work was carried out under the framework of the density functional theory combined with the non-equilibrium Green's function theory under a built-in electric field or finite bias. The results showed that (1) the photocurrent is larger only under a suitable electronic band gap rather than larger spontaneous polarization; (2) the photocurrent reaches the largest value in the Bi3+ ion-terminated interface than in the case of Fe3+ or O2- with the SrTiO3 electrode; (3) the photocurrent can be largely enhanced if the polarized direction of the monochromatic light is perpendicular to the spontaneous polarization direction. These results would deepen the understanding of some experimental results of BiFeO3-based solar cells.

13.
Biochem Biophys Res Commun ; 525(2): 498-504, 2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-32111353

RESUMO

BACKGROUND: Many studies had identified that MicroRNAs (miRNAs) could affect bone metabolism by regulating the expression of various proteins. This study explored the effect and mechanism of miR-532-3p on osteogenic differentiation. METHODS: We analyzed the content of miR-532-3p in osteoporosis patients, osteoporosis rats, and osteogenic induced MC3T3-E1 cells. MiR-532-3p mimic or inhibitor utilized to alter intracellular miR-532-3p content. MTT method executed to detect the effect of miR-532-3p on osteoblast proliferation. Real-time qPCR, Western blot, alkaline phosphatase staining, and alizarin red staining utilized to ascertain the influence of miR-532-3p on osteogenic differentiation. Then, databases and a dual-luciferase reporter gene assay used to verify the target of miR-532-3p. Furthermore, the lentiviral vector was utilized to overexpress interesting target gene expression and checked whether the target gene was involved in the regulation of osteogenic differentiation by miR-532-3p. RESULTS: MiR-532-3p expression boosted in low bone mineral density (BMD) patients and rats. In MC3T3-E1 cells, miR-532-3p expression gradually decreased as osteogenic induction matures. MiR-532-3p mimic negatively regulated succinate dehydrogenase (SDH) activity, alkaline phosphatase (ALP) activity, mineralization ability, the osteogenic-associated gene (Col1A1, Runx2, ALP, OPN, and OCN) and E-26 transformation specific-1 (ETS1) expression of MC3T3-E1 cells. Things are the opposite of the miR-532-3p inhibitor. ETS1 identified as the miR-532-3p target gene, and miR-532-3p could inhibit its expression. Besides, improved ETS1 expression could rescue the suppressive effect of miR-532-3p mimic on osteogenic differentiation. CONCLUSION: miR-532-3p can suppress osteogenic differentiation by downregulating ETS1 expression.

14.
FEMS Microbiol Ecol ; 96(4)2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32149339

RESUMO

Interactions between plants and microbes are involved in biodiversity maintenance, community stability and ecosystem functioning. However, differences in the community and network structures between phyllosphere epiphytic and endophytic bacteria have rarely been investigated. Here, we examined phyllosphere epiphytic and endophytic bacterial communities of six mangrove species using Illumina MiSeq sequencing of the 16S rRNA gene. The results revealed that the community structure of epiphytic and endophytic bacteria was different. Plant identity significantly affected the diversity and community structure of both epiphytic and endophytic bacteria, with a greater effect on the community structure of the former than the latter. Network analysis showed that both plant-epiphytic and plant-endophytic bacterial network structures were characterized by significantly highly specialized and modular but lowly connected and anti-nested properties. Furthermore, the epiphytic bacterial network was more highly specialized and modular but less connected and more strongly anti-nested than the endophytic bacterial network. This study reveals that the phyllosphere epiphytic and endophytic bacterial community structures differ and plant identity has a greater effect on the epiphytic than on the endophytic bacteria, which may provide a comprehensive insight into the role of plant identity in driving the phyllosphere epiphytic and endophytic microbial community structures in mangrove ecosystems.

15.
ACS Appl Mater Interfaces ; 12(12): 13698-13708, 2020 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-32129070

RESUMO

Recent emerged metal-organic frameworks (MOFs), as superior drug carriers, provide novel strategies to combat pathogenic bacterial infections. Although various antibacterial metal ions can be easily introduced in MOFs for chemical bacterial ablation, such a single-model bactericidal method suffers from high-dose use, limited antibacterial efficiency, and slow sterilization rate. Hence, developing a dual bactericidal system is urgently required. Herein, we report an MOF/Ag-derived nanocomposite with efficient metal-ion-releasing capability and robust photo-to-thermal conversion effect for synergistic sterilization. The MOF-derived nanocarbon consisting of metallic zinc and a graphitic-like carbon framework is first synthesized, and then Ag nanoparticles (AgNPs) are evenly introduced via the displacement reaction between Zn and Ag+. Upon near-infrared irradiation, the fabricated nanoagents can generate massive heat to destroy bacterial membranes. Meanwhile, abundant Zn2+ and Ag+ ions are released to make chemical damage to bacterial intracellular substances. Systematic antibacterial experiments reveal that such dual-antibacterial effort can endow the nanoagents with nearly 100% bactericidal ratio for highly concentrated bacteria at a very low dosage (0.16 mg/mL). Furthermore, the nanoagents exhibit less cytotoxicity, which provides potential possibilities for the applications in the biological field. In vivo assessment indicates that the nanocomposites can realize rapid and safe wound sterilization and are expected to be an alternative to antibiotics. Overall, we present an easily fabricated structure-engineered nanocomposite with chemical and photothermal effects for broad-spectrum bacterial sterilization.

16.
Bioresour Technol ; 305: 122900, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32146048

RESUMO

Starch agricultural leftover is a potential substrate for photosynthetic bacteria to produce hydrogen. In this work, the effect of initial pH on photo-fermentation biohydrogen production process and electron balance were investigated. The modified Gompertz model was adopted, and hydrogen yield, sugar consumption and metabolite evolution were monitored with initial pH varying from 5 to 9. Results showed that hydrogen was produced mainly through acetic acid and butyric acid metabolism pathways when starch taken as carbon source. It was found that the maximum hydrogen yield (642 ± 22 mL) and highest hydrogen production rate (77.78 mL/(L·h)) were obtained at initial pH of 7. 37.65% substrates electrons diverted towards hydrogen. Lower hydrogen yield, hydrogen production rate and lower electrons diversion were obtained at other initial pH levels. Also, the lag phase time was 0.04 h when pH was 7, which was significantly lower than other levels.


Assuntos
Elétrons , Amido , Fermentação , Hidrogênio , Concentração de Íons de Hidrogênio
17.
Bioengineered ; 11(1): 397-407, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32175806

RESUMO

The fur is hard to decompose during the fermentation process of diseased swine carcasses. In order to enhance the enzymolysis of pigskin, the ultrasonic was proposed to use during the process of the enzymatic hydrolysis. The response surface optimization experiments were carried out with the DH (degree of hydrolysis) as the response value and the optimum conditions for enzymatic hydrolysis were determined. Based the optimum conditions, orthogonal experiments were carried out with ultrasonic frequency, power and time as variables, and optimal ultrasonic parameters were obtained. Without the assistance of ultrasonic, the descending order of influence factors on DH was, temperature>SC(Substrate concentration)>RES(The ratio of enzyme to substrate)>pH. Moreover, the DH value is of 10.42% under the following optimal conditions: RES is of 16,006 U/g, the temperature is of 48.92°C, the SC is of 59.76 g/L and pH is of 10.43. Frequency has the greatest effect on DH, followed by power, and finally time. The optimum hydrolysis time is of 5 h, and the DH is of 22.94% were obtained under the following optimum ultrasonic pretreatment conditions: frequency combination is of (20,40,40), power is of 600 W and time is of 25 min. Comparing with the group without ultrasonic pretreatment, the DH for the ultrasonic assistance increased by 4%, the hydrolysis time was shorten by 3 h, and the total amino acids increased by 15.98%.

18.
Bioengineered ; 11(1): 251-260, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32125259

RESUMO

In order to explore the effect of pretreatment on corn straw degradation and biogas production, corn straw was pretreated with mixed microbes and composting at 30°C for 14 days. The characteristics of material were measured and analyzed in the pretreatment process. Then, the pretreated and untreated corn straw was digested by anaerobic fermentation. Gas production and methane content of corn straw were analyzed. The results showed that the biological pretreatment process with mixed microbes could accelerate the degradation rate of straw and increase the degradation efficiency of lignin. The pH value of material was more stable, and the content of organic matter in the material was higher in the pretreatment process of corn straw with mixed microbes. The Scanning Electron Microscope (SEM) images showed that the structure of the lignocellulose was changed by mixed microbes, increasing the exposed area of cellulose and hemicellulose, which was beneficial to improve the utilization efficiency of straw. The degradation rates of hemicellulose, cellulose and lignin were 44.4%, 34.9% and 39.2%, respectively, after the pretreatment process with mixed microbes. Pretreatment was more helpful to increase the methane content in the anaerobic fermentation process of corn straw pretreated with mixed microbes, and could also shorten the fermentation period.

19.
Bioengineered ; 11(1): 428-438, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32183587

RESUMO

Corn stovers are rich in carbohydrates and can be used by anaerobic bacteria to produce hydrogen by fermentation. In the present study, using hydrogen production as the main experimental index, the effect of different influential factors on hydrogen production from corn stover saccharification and fermentation was studied, using the response surface method BBD model. The significance of interactions between different influential factors on hydrogen production by simultaneous saccharification and fermentation of corn stover material were investigated and optimized. Results showed that there were several factors affecting simultaneous saccharification fermentative hydrogen production from corn stover, including substrate concentration, inoculation amount, pH value and enzyme concentration. In linear terms, substrate concentration had the greatest influence on hydrogen production by anaerobic simultaneous saccharification and fermentation. In terms of multi-factor interactions, the interaction between pH and enzyme concentration was the most significant. The optimal hydrogen production conditions established from the BBD model were as follows: substrate concentration of 25 mg/mL, inoculation amount proportion of 32.62%, initial pH value of 6.50 and enzyme concentration of 172.08 mg/g, resulting in the maximum hydrogen production of 55.29 mL/g TS. The actual maximum hydrogen production reached 56.66 mL/g TS, with these experimental results consistent with the predicted value established from equation fitting. This study provides a reference for hydrogen production by anaerobic synchronous saccharification fermentation using corn stover as substrate and lays a foundation and provides technical support for the industrialization of biological hydrogen production using corn stover as substrate.

20.
Mol Ecol Resour ; 2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-32220045

RESUMO

The greenhouse whitefly, Trialeurodes vaporariorum Westwood, is an agricultural pest of global importance. Here we report a 787-Mb high-quality draft genome sequence of T. vaporariorum assembled from PacBio long reads and Hi-C chromatin interaction maps, which has scaffold and contig N50 lengths of 70 Mb and 500 kb, respectively, and contains 18,275 protein-coding genes. About 98.8% of the assembled contigs were placed onto the 11 T. vaporariorum chromosomes. Comparative genomic analysis reveals significantly expanded gene families such as aspartyl proteases in T. vaporariorum compared to Bemisia tabaci Mediterranean (MED) and Middle East-Asia Minor 1 (MEAM1). Furthermore, the cytochrome CYP6 subfamily shows significant expansion in T. vaporariorum and several genes in this subfamily display developmental stage-specific expression patterns. The high-quality T. vaporariorum genome provides a valuable resource for research in a broad range of areas such as fundamental molecular ecology, insect-plant/insect-microorganism or virus interactions and pest resistance management.

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