Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.573
Filtrar
Mais filtros

Assunto principal
Tipo de estudo
Idioma
Intervalo de ano de publicação
1.
Bioresour Technol ; 295: 122250, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31629281

##### RESUMO

Increasing nitrogenous contaminants have caused immense challenges to the environment and human health. As compared to physical and chemical methods, biological denitrification is considered to be an effective solution due to its environmental friendliness, high efficiency, and low cost. In the present work, a novel fungal strain identified as Fusarium solani (RADF-77) was isolated from cellulose material-supported denitrification reactor; this strain is capable of removing nitrogen under aerobic conditions. The average NO3--N removal rate for RADF-77 were 4.43â¯mg/(L·h) and 4.50â¯mg/(L·d), when using glucose and tea residue as carbon source, respectively. The nitrogen balance revealed that 53.66% of N vanished via gaseous products. Transcriptional results revealed that respiratory and assimilative nitrate reductases may work together for nitrate removal. Our results indicate that RADF-77 could be used as a potential means of enhancing nitrate-removal performance, as well as recycling tea residue, which is the main byproduct of the manufacture of tea extracts.

##### Assuntos
Desnitrificação , Fusarium , Aerobiose , Nitratos , Nitrificação , Nitrogênio
2.
J Proteome Res ; 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31789040

##### RESUMO

Ubiquitin ligases (E3s) serves as a key regulator for ubiquitylation-mediated pathway. The identification of the corresponding relationship between E3 and its substrates is challenging but required for understanding the regulatory network of ubiquitylation. The low abundance of ubiquitinated conjugates and high redundancy of E3s-substrates regulation made screening pretty hard. Herein, we combined SILAC-based quantitative proteomics with two contrary genetic methods (overexpression and knockout) in theory for E3 (Hrt3, F-box subunit of SCF complex) substrates screening. The knockout method could not overcome the constraint mentioned above, while the overexpression approach turned on the access to the potential substrates of E3. Subsequently, we obtained 77 candidates which involved in many critical biological processes and needed to be verified one by one in the future. Within these candidates, we confirmed the relationship between one of the candidates Nce103 and Hrt3, and linked the Hrt3 with oxygen sensitivity and oxidative stress response which Nce103 took part in as well. This research was also beneficial for our understanding the impact of oxygen supply on regulation of yeast growth through the ubiquitination of Nce103.

3.
Artigo em Inglês | MEDLINE | ID: mdl-31754859

##### RESUMO

As the composition of animal cell culture medium becomes more complex, the identification of key variables is important for simplifying and guiding the subsequent medium optimization. However, the traditional experimental design methods are impractical and limited in their ability to explore such large feature spaces. Therefore, in this work, we developed a NRGK (nonparametric regression with Gaussian kernel) method, which aimed to identify the critical components that affect product titres during the development of cell culture media. With this nonparametric model, we successfully identified the important components that were neglected by the conventional PLS (partial least squares regression) method. The superiority of the NRGK method was further verified by ANOVA (analysis of variance). Additionally, it was proven that the selection accuracy was increased with the NRGK method because of its ability to model both the nonlinear and linear relationships between the medium components and titres. The application of this NRGK method provides new perspectives for the more precise identification of the critical components that further enable the optimization of media in a shorter timeframe.

4.
Opt Express ; 27(20): 28866-28878, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31684631

##### RESUMO

We propose and analyze an evanescent-wave coupling phase-matching method for ultrawidely tunable frequency conversion in coupled χ (3)-waveguides which will boost the nonlinear optical properties of photonic chips. Taking a silicon-waveguide as an example, we design a two-coupled-waveguide system which provides an efficient coupling coefficient for the compensation of phase-mismatch in spontaneous four-wave mixing, achieving widely tunable entangled photon pairs which are usually not accessible in χ (3)-waveguides. A tuning range of 1170-2300n m for TE-mode or 1400-1730n m for TM-mode entangled photons is realized when the inter-waveguide gap varies within the range of 400-900n m. The bandwidth of evanescent-wave coupling phase-matching is also characterized. This unique phase-matching strategy is in principle applicable to any χ (2)- and χ (3)-waveguide chip, qualifying them as broadband frequency converters which will have wide applications in nonlinear optics and quantum optics.

5.
Acta Ophthalmol ; 2019 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-31736238

##### RESUMO

PURPOSE: To explore an early, rapid and precise diagnosis of Stickler syndrome type I (STL1) and to enrich the spectrum of COL2A1 mutations in the Chinese population, which is poorly studied at present. METHODS: In the current study, we analysed 115 patients with high myopia by next-generation sequencing and identified five STL1 patients from four unrelated Chinese families. The clinical features of all patients were reviewed in detail. RESULTS: Four variants of COL2A1 were identified, including two novel variants (c.1435delG and c.184delG) and two previously reported variants (c.1221+1G>A and c.1030C>T). Three variants caused premature termination codons which were common in STL1. In addition, we proposed a new diagnostic tactic to improve early diagnostics of STL1 in patients. CONCLUSION: In this study, our findings expanded the spectrum of COL2A1 mutations with two novel variants and provided a new diagnostic tactic for reference, which was of great significance. Precise diagnosis on the basis of clinical manifestations and genetic testing will become the gold standard to diagnose inherited ocular disorders or syndromes in the future.

6.
Artigo em Inglês | MEDLINE | ID: mdl-31758814

##### RESUMO

OBJECTIVE: To determine whether surgery for adnexal masses in the first trimester of pregnancy affects subsequent pregnancy outcomes compared to surgery in the second trimester. METHODS: Data were retrospectively reviewed from women who underwent adnexal mass surgery before 26 weeks of gestation at a university hospital between July 2008 and June 2018. Women who underwent surgery in the first trimester were classified as group 1 (n=78) and those in the second trimester were classified as group 2 (n=48). Information on clinical characteristics and pregnancy outcomes was from medical records and follow-up interviews and was compared between two groups. RESULTS: There were no differences in age, parity, mass size, laparoscopy, and operation time between two groups. A total of 98 cases were confirmed as ovarian torsion, including 72 cases in group 1 and 26 cases in group 2. Accordingly, adnexectomy was performed more often in group 1 (P=0.002). No significant differences concerning the rate of abortion, preterm birth, or cesarean delivery were found. CONCLUSION: Surgery for adnexal masses performed in the first trimester is almost as safe as that in the second trimester. Surgery should be performed for women with a complex adnexal mass in the first trimester to avoid unfavorable complications.

7.
Chem Commun (Camb) ; 55(97): 14649-14652, 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31746861

##### RESUMO

Here we demonstrate the synthesis of uniform Ru-doped NiFe2O4 nanosheets with robust hydrogen evolution reaction (HER) activity in alkaline solution, with an extremely low overpotential of 18 mV versus a reversible hydrogen electrode (RHE) at a current density of 10 mA cm-2 and a Tafel slope of 27 mV dec-1.

8.
Food Res Int ; 126: 108604, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31732021

##### RESUMO

This work aimed to develop a novel colorimetric indicator film for monitoring of food freshness based on gelatin/polyvinyl alcohol matrix incorporated with anthocyanin extracts from mulberry. The color of anthocyanin extracts solutions obviously changed from bright red to dark green in the pH range of 2.0-11.0. FTIR spectra and isothermal titration calorimetry showed that the anthocyanin extracts were successfully combined with gelatin/polyvinyl alcohol matrix by hydrogen binding and electrostatic interaction, which enhanced the stability of anthocyanin. The scanning electric microscopy showed that the compatibility between polyvinyl alcohol and gelatin were improved owing to the addition of anthocyanin extracts. With the anthocyanin extracts addition from 0 to 45â¯mg/100â¯mL mixed solution, the tensile strength decreased from 30.80 to 21.01â¯MPa and the elongation at break increased from 589.22% to 905.86%. The color response of film in buffer solution of different pH were in accordance with anthocyanin extracts solutions, and its color changes were clearly visible with naked eye. Finally, the film was evaluated by a test on monitoring fish spoilage, which presented visible color changes due to volatile nitrogenous compounds formed over time. These results showed that this developed film could be used as an effective method for the monitoring of food freshness.

9.
J Hazard Mater ; : 121578, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31732343

##### RESUMO

During the bloom seasons, the dissolved inorganic nitrogen declines, which results in the occurrence of nitrogen limitation. It is unclear where the nitrogen goes. Our enclosure experiments and batch tests suggested that Microcystis blooms could significantly reduce the nitrogen in water bodies and the key mechanisms for the nitrogen reduction in different layers were different. The assimilation was the main pathway for nitrogen reduction in the surface layer, while denitrification played an important role both at the sediment-water interface and in the overlying water. Stable nitrogen isotope experiments showed that the nitrate reduction efficiency at sediment-water interface was enhanced by Microcystis, reaching to 76.5â¼84.7 %. Dissimilation accounted for 63.8â¼67.3 % of the nitrate reduction, and the denitrification rate was 7.4â¼8.5 times of DNRA rate. In the water column, the Microcystis bloom facilitated the formation of dark/anoxic condition, which favored the denitrification. The Microcystis aggregates collected from the field showed a great potential in removing nitrogen, and the TN in the overly water was reduced by 3.76â¼6.03â¯mgâ¯L-1 within two days. This study provided field evidences and deeper insights into the relationship between Microcystis blooms and nitrogen reduction in the whole water column and gave more details about the enhancing effects of Microcystis on nitrogen reduction.

10.
Opt Lett ; 44(22): 5598-5601, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31730116

##### RESUMO

We present an experimental realization of a compact and reliable way to build a nondegenerate polarization-entangled photon-pair source based on a dual-periodically-poled ${\rm Ti}:{{\rm LiNbO}_3}$Ti:LiNbO3 waveguide, which is in the telecommunication window and compatible with the fiber quantum networks. The dual-periodic structure allows two inherently concurrent quasiphase-matching spontaneous parametric down-conversion processes pumped by a single laser beam, hence enabling our source to be compact and stable. We show that our source has a high brightness of $B = 1.22{\rm } \times {\rm }{10^7}\;{\rm pairs}/(\rm s \times mW \times nm)$B=1.22×107pairs/(s×mW×nm). With quantum state tomography, we estimate an entanglement fidelity of $0.945 \pm 0.003$0.945±0.003. A violation of Clauser-Horne-Shimony-Holt inequality with $S = 2.75 \pm 0.03$S=2.75±0.03 is also demonstrated.

11.
J Hazard Mater ; : 121465, 2019 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-31704114

##### RESUMO

Microwave-assisted selective degradation successfully converts thermosetting unsaturated polyester resins into a low-swelling (below 10â¯g g-1) gel material (GM) with a high yield (58-65%) in water at 100°C for only 1â¯h. The obtained GM possesses rough and porous structure while the content of carboxylate group obtained by cleavage of partial ester groups is more than 10%, varying with the concentration of the catalyst. It is suitable for use as packing of adsorption column to rapidly purify sewage. Super high filtering rates of 18582-27002â¯Lâ¯h-1â¯m-3 without external pressure and high removal efficiency of more than 99.8% were achieved, promoting practical application for rapid removal of organic pollutants.

12.
Sci Rep ; 9(1): 15651, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31666570

##### RESUMO

Lateral organ boundaries domain (LBD) proteins are plant-specific transcription factors that play a crucial role in growth and development, as well as metabolic processes. However, knowledge of the function of LBD proteins in Camellia sinensis is limited, and no systematic investigations of the LBD family have been reported. In this study, we identified 54 LBD genes in Camellia sinensis. The expression patterns of CsLBDs in different tissues and their transcription responses to exogenous hormones and abiotic stress were determined by RNA-seq, which showed that CsLBDs may have diverse functions. Analysis of the structural gene promoters revealed that the promoters of CsC4H, CsDFR and CsUGT84A, the structural genes involved in flavonoid biosynthesis, contained LBD recognition binding sites. The integrative analysis of CsLBD expression levels and metabolite accumulation also suggested that CsLBDs are involved in the regulation of flavonoid synthesis. Among them, CsLOB_3, CsLBD36_2 and CsLBD41_2, localized in the nucleus, were selected for functional characterization. Yeast two-hybrid assays revealed that CsLBD36_2 and CsLBD41_2 have self-activation activities, and CsLOB_3 and CsLBD36_2 can directly bind to the cis-element and significantly increase the activity of the CsC4H, CsDFR and CsUGT84A promoter. Our results present a comprehensive characterization of the 54 CsLBDs in Camellia sinensis and provide new insight into the important role that CsLBDs play in abiotic and flavonoid biosynthesis.

13.
Endokrynol Pol ; 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31681976

##### RESUMO

INTRODUCTION: We investigated the impact of long-term levothyroxine (LT4) treatment on bone mineral density (BMD) and bone turnover markers (BTMs) in premenopausal women with differentiated thyroid cancer (DTC) after thyroidectomy. MATERIAL AND METHODS: 65 premenopausal women who received LT4 therapy at least 1 year after thyroidectomy for DTC and 50 premenopausal women without thyroid diseases were enrolled in this study. We measured the T-scores of lumbar and hip BMD, Serum free triiodothyronine (FT3), free thyroxine (FT4), thyroid stimulating hormone (TSH), intact parathyroid hormone (iPTH), N-terminal propeptide of type 1 N procollagen (P1NP), C-terminal telopeptide of type 1 collagen (CTX-1), calcium (Ca), phosphorus (P) and alkaline phosphatase (ALP) in all participants. RESULTS: In DTC subjects, serum TSH levels was lower, serum FT4, P1NP, CTX-1 and ALP levels were higher compared with controls. The prevalence of osteopenia was higher in DTC subjects than in controls. Multivariate logistic regression analysis showed that serum TSH levels were negatively associated with CTX-1 and ALP. CONCLUSIONS: We found high prevalence of osteopenia among premenopausal women who received long-term LT4 therapy for DTC after thyroidectomy. Long-term TSH suppression therapy was an significant risk factor for decreased bone strength mainly by increasing bone turnover.

14.
Anal Chem ; 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31774262

##### RESUMO

Mass spectrometry (MS)-based identification of ubiquitinated sites requires trypsin digestion prior to MS analysis, and a signature peptide was produced with a diglycine residue attached to the ubiquitinated lysine (K-Îµ-GG peptide). However, the missed cleavage of modified lysines by trypsin results in modified peptides with increased length and charge, whose detection by MS analysis is suppressed by the vast majority of internally unmodified peptides. LysargiNase, the mirrored trypsin, is reported to cleave before lysine and arginine residues and to be favorable for the identification of methylation and phosphorylation, but its digestive characteristics related to ubiquitination are unclear. Herein, we tested the capacity of the in-house developed acetylated LysargiNase (Ac-LysargiNase) with high activity and stability, for cleaving ubiquitinated sites in both the seven types of ubiquitin chains and their corresponding K-Îµ-GG peptides. Interestingly, Ac-LysargiNase could efficiently cleave the K63-linked chain but had little effect on the other types of chains. Additionally, Ac-LysargiNase had higher exopeptidase activity than trypsin. Utilizing these features of the paired mirror proteases, a workflow of trypsin and Ac-LysargiNase tandem digestion was developed for the identification of ubiquitinated proteins. Through this method, the charge states and ionization capacity of the unmodified peptides were efficiently reduced, and the identification of modified sites was consequently increased by 30% to 50%. Strikingly, approximately 15% of the modified sites were cleaved by Ac-LysargiNase, resulting in shorter K-Îµ-GG peptides for better identification. The enzyme Ac-LysargiNase is expected to serve as an option for increasing the efficiency of modified site identification in ubiquitome research.

15.
Phys Rev Lett ; 123(19): 190501, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31765197

##### RESUMO

Recent advances on quantum computing hardware have pushed quantum computing to the verge of quantum supremacy. Here, we bring together many-body quantum physics and quantum computing by using a method for strongly interacting two-dimensional systems, the projected entangled-pair states, to realize an effective general-purpose simulator of quantum algorithms. The classical computing complexity of this simulator is directly related to the entanglement generation of the underlying quantum circuit rather than the number of qubits or gate operations. We apply our method to study random quantum circuits, which allows us to quantify precisely the memory usage and the time requirements of random quantum circuits. We demonstrate our method by computing one amplitude for a 7×7 lattice of qubits with depth (1+40+1) on the Tianhe-2 supercomputer.

16.
World Neurosurg ; 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31568902

##### RESUMO

OBJECTIVE: To investigate the ultrasonographic characteristics in hourglasslike constriction of peripheral nerve in the upper extremity and to evaluate the value of ultrasonography in the diagnosis. METHODS: Nineteen patients with hourglasslike constriction of peripheral nerve in the upper extremity underwent ultrasonography and the results were compared with surgery. The ultrasonographic characteristics, the accurate rate, and the relation between the ultrasonography and surgery were analyzed. RESULTS: There were 22 affected nerves involved in 19 patients, including 17 radial neuropathies, 4 median neuropathies, and 1 musculocutaneous neuropathy. The accuracy rate of ultrasonography in diagnosing hourglasslike constriction of upper limb nerve was 87.93%. Ultrasonography showed that the constriction sites were completely consistent with the operation. The ultrasonography characteristics of hourglasslike constriction of upper limb nerves were hourglasslike nerve incompleteness or complete constriction, and the nerves at both ends were thickened, and no compression structure was seen around. All lesions with complete constriction diagnosed by ultrasonography were treated with resection of the lesion with or without graft. In addition, 71.43% with incomplete constriction were treated with neurolysis, and 28.57% with resection of the lesion with direct repair. CONCLUSIONS: Ultrasonography could be used as a routine noninvasive examination for hourglasslike constriction of upper limb nerves. Ultrasonography suggests that resection of the lesion rather than neurolysis should be considered in the treatment of complete constriction. For patients with clinical symptoms, ultrasonography showed local nerve enlargement but no constriction; clinicians should be prompted to explore carefully during operation to avoid missing nerve hourglasslike constriction.

17.
J Proteome Res ; 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31657219

##### RESUMO

In recent years, high-throughput technologies have contributed to the development of a more precise picture of the human proteome. However, 2129 proteins remain listed as missing proteins (MPs) in the newest neXtProt release (2019-02). The main reasons for MPs are a low abundance, a low molecular weight, unexpected modifications, membrane characteristics, and so on. Moreover, >50% of the MS/MS data have not been successfully identified in shotgun proteomics. Open-pFind, an efficient open search engine, recently released by the pFind group in China, might provide an opportunity to identify these buried MPs in complex samples. In this study, proteins and potential MPs were identified using Open-pFind and three other search engines to compare their performance and efficiency with three large-scale data sets digested by three enzymes (Glu-C, Lys-C, and trypsin) with specificity on different amino acid (AA) residues. Our results demonstrated that Open-pFind identified 44.7-93.1% more peptide-spectrum matches and 21.3-61.6% more peptide sequences than the second-best search engine. As a result, Open-pFind detected 53.1% more MP candidates than MaxQuant and 8.8% more candidate MPs than Proteome Discoverer. In total, 5 (PE2) of the 124 MP candidates identified by Open-pFind were verified with 2 or 3 unique peptides containing more than 9 AAs by using a spectrum theoretical prediction with pDeep and synthesized peptide matching with pBuild after spectrum quality analysis, isobaric post-translational modification, and single amino acid variant filtering. These five verified MPs can be saved as PE1 proteins. In addition, three other MP candidates were verified with two unique peptides (one peptide containing more than 9 AAs and the other containing only 8 AAs), which was slightly lower than the criteria listed by C-HPP and required additional verification information. More importantly, unexpected modifications were detected in these MPs. All MS data sets have been deposited into ProteomeXchange with the identifier PXD015759.

18.
Genes (Basel) ; 10(10)2019 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-31575043

##### RESUMO

In field conditions, crops are adversely affected by a wide range of abiotic stresses including drought, cold, salt, and heat, as well as biotic stresses including pests and pathogens. These stresses can have a marked effect on crop yield. The present and future effects of climate change necessitate the improvement of crop stress tolerance. Plants have evolved sophisticated stress response strategies, and genes that encode transcription factors (TFs) that are master regulators of stress-responsive genes are excellent candidates for crop improvement. Related examples in recent studies include TF gene modulation and overexpression approaches in crop species to enhance stress tolerance. However, much remains to be discovered about the diverse plant TFs. Of the >80 TF families, only a few, such as NAC, MYB, WRKY, bZIP, and ERF/DREB, with vital roles in abiotic and biotic stress responses have been intensively studied. Moreover, although significant progress has been made in deciphering the roles of TFs in important cereal crops, fewer TF genes have been elucidated in sorghum. As a model drought-tolerant crop, sorghum research warrants further focus. This review summarizes recent progress on major TF families associated with abiotic and biotic stress tolerance and their potential for crop improvement, particularly in sorghum. Other TF families and non-coding RNAs that regulate gene expression are discussed briefly. Despite the emphasis on sorghum, numerous examples from wheat, rice, maize, and barley are included. Collectively, the aim of this review is to illustrate the potential application of TF genes for stress tolerance improvement and the engineering of resistant crops, with an emphasis on sorghum.

19.
Nat Cell Biol ; 21(10): 1261-1272, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31570835

##### RESUMO

The repression of transposons by the Piwi-interacting RNA (piRNA) pathway is essential to protect animal germ cells. In Drosophila, Panoramix enforces transcriptional silencing by binding to the target-engaged Piwi-piRNA complex, although the precise mechanisms by which this occurs remain elusive. Here, we show that Panoramix functions together with a germline-specific paralogue of a nuclear export factor, dNxf2, and its cofactor dNxt1 (p15), to suppress transposon expression. The transposon RNA-binding protein dNxf2 is required for animal fertility and Panoramix-mediated silencing. Transient tethering of dNxf2 to nascent transcripts leads to their nuclear retention. The NTF2 domain of dNxf2 competes dNxf1 (TAP) off nucleoporins, a process required for proper RNA export. Thus, dNxf2 functions in a Panoramix-dNxf2-dependent TAP/p15 silencing (Pandas) complex that counteracts the canonical RNA exporting machinery and restricts transposons to the nuclear peripheries. Our findings may have broader implications for understanding how RNA metabolism modulates heterochromatin formation.

20.
Microb Cell Fact ; 18(1): 184, 2019 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-31655591

##### RESUMO

BACKGROUND: As an attracted compatible solute, 1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid (ectoine) showed great potentials in various field. However, lower productivity and high saline medium seriously hinder its wide applications. RESULTS: The entire ectoine metabolism, including pathways for ectoine synthesis and catabolism, was identified in the genome of an ectoine-excreting strain Halomonas hydrothermalis Y2. By in-frame deletion of genes encoding ectoine hydroxylase (EctD) and (or) ectoine hydrolase (DoeA) that responsible for ectoine catabolism, the pathways for ectoine utilization were disrupted and resulted in an obviously enhanced productivity. Using an optimized medium containing 100 g L-1 NaCl in a 500-mL flask, the double mutant of Y2/ΔectD/ΔdoeA synthesized 3.13 g L-1 ectoine after 30 h cultivation. This is much higher than that of the wild type strain (1.91 g L-1), and also exceeds the production of Y2/ΔectD (2.21 g L-1). The remarkably enhanced accumulation of ectoine by Y2/ΔectD/ΔdoeA implied a critical function of Doe pathway in the ectoine catabolism. Furthermore, to reduce the salinity of fermentation medium and overcome the wastewater treatment difficulty, mutants that lacking key Na+/H+ antiporter, Mrp and (or) NhaD2, were constructed based on strain Y2/ΔectD/ΔdoeA. As a result, the Mrp-deficient strain could synthesize equal amount of ectoine (around 7 g L-1 or 500 mg (g DCW) -1) in the medium containing lower concentration of NaCl. During a fed-batch fermentation process with 60 g L-1 NaCl stress, a maximum 10.5 g L-1 ectoine was accumulated by the Mrp-deficient strain, with a specific production of 765 mg (g DCW)-1 and a yield of 0.21 g g-1 monosodium glutamate. CONCLUSION: The remarkably enhanced production of ectoine by Y2/ΔectD/ΔdoeA implied the critical function of Doe pathway in the ectoine catabolism. Moreover, the reduced salinity requirement of Mrp-deficient strain implied a feasible protocol for many compatible solute biosynthesis, i.e., by silencing some Na+/H+ antiporters in their halophilic producers and thus lowering the medium salinity.