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1.
Sci Rep ; 14(1): 11899, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38789536

RESUMO

The construction of underground cavern groups represents a particularly challenging task in current subsurface engineering due to a multitude of variable and often unknown factors, including diverse geological conditions. This study introduces a four-dimensional spatiotemporal model and formulates a dynamic safety information model for these underground systems. Developed using C# and Python, the model integrates the finite element analysis software ABAQUS and Microsoft SQL Server database. The framework allows for real-time visual management of monitoring data, dynamic coupling of construction phases with safety metrics, and continual updates correlating with construction progress. The theoretical findings offer valuable insights for enhancing the safety and efficiency of underground cavern group construction while also supplying methods for real-time safety feedback and control throughout the construction process.

2.
J Environ Qual ; 53(1): 57-65, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37830264

RESUMO

The urealytically active microorganism Sporosarcina luteola induces the precipitation of metals, which has attracted attention in biomineralization, bioremediation, and industrial waste recycling. Herein, we report a novel biosurfactant-producing strain of S. luteola ME44 isolated from Chinese Oilfield. The structure, composition, and surface activity of the biosurfactants produced by S. luteola ME44 were investigated by using a combination of the high-performance liquid chromatography, time-of-flight mass spectrometry, and surface tensiometer. The biosurfactant extracted by strain ME44 was identified as surfactin with five variants and the yield was 1010 ± 60 mg⋅L-1 . This is the first report on the structural composition and surface activity of biosurfactants isolated from the S. luteola. It extended our knowledge about the role of the species S. luteola in the ecosystem of extreme natural environments such as oil reservoir. In addition, S. luteola ME44 showed bioprecipitation properties for metal ions Cd(II), Cu(II), Zn(II), and Ag(I), which indicated the application potential of S. luteola in the field of bioremediation.


Assuntos
Campos de Petróleo e Gás , Sporosarcina , Ecossistema , Tensoativos/química , Biodegradação Ambiental
3.
Environ Technol ; : 1-7, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37647352

RESUMO

The genus Fictibacillus contains twelve species significant in the synthesis of cellulose-degrading enzymes and phenylalanine dehydrogenase, isolated mainly from marine sedimentary environments. Here, we report a new biosurfactant-producing strain, Fictibacillus nanhaiensis ME46, isolated from Daqing oil field in China. The biosurfactant extracted from Strain ME46 was determined as surfactin, one of the representative families of lipopeptide biosurfactants. The yield of the surfactin produced by strain ME46 was 0.62 g·L-1 as determined by high-performance liquid chromatography, and the critical micelle concentration (CMC) of the surfactin was estimated to be about 68 mg·L-1 and the surface tension at CMC was 35.1 mN·m-1. This study extended our knowledge about the role of the species Fictibacillus nanhaiensis in the ecosystem of natural environments such as the oil field.

4.
Biotechnol Appl Biochem ; 70(6): 1806-1816, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37278163

RESUMO

Rhamnolipid, as a low-toxic, biodegradable and environmentally friendly biosurfactant, has broad application prospects in many industries. However, the quantitative determination of rhamnolipid is still a challenging task. Here, a new sensitive method for the quantitative analysis of rhamnolipid based on a simple derivatization reaction was developed. In this study, 3-[3'-(l-rhamnopyranosyloxy) decanoyloxy] decanoic acid (Rha-C10-C10) and 3-[3'-(2'-O-α-l-rhamnopyranosyloxy) decanoyloxy] decanoic acid (Rha-Rha-C10-C10) were utilized as the representative rhamnolipids. Liquid chromatography-mass spectrometry and high-performance liquid chromatography-ultra violet results showed that these two compounds were successfully labeled with 1 N1-(4-nitrophenyl)-1,2-ethylenediamine. There was an excellent linear relationship between rhamnolipid concentration and peak area of labeled rhamnolipid. The detection limits of the Rha-C10-C10 and Rha-Rha-C10-C10 were 0.018 mg/L (36 nmol/L) and 0.014 mg/L (22 nmol/L), respectively. The established amidation method was suitable for the accurate analysis of rhamnolipids in the biotechnological process. The method had good reproducibility with the relative standard deviation of 0.96% and 0.79%, respectively, and sufficient accuracy with a recovery of 96%-100%. This method was applied to quantitative analysis of 10 rhamnolipid homologs metabolized by Pseudomonas aeruginosa LJ-8. The single labeling method was used for the quantitative analysis of multiple components, which provided an effective method for the quality evaluation of other glycolipids with carboxyl groups.


Assuntos
Biotecnologia , Glicolipídeos , Cromatografia Líquida de Alta Pressão , Reprodutibilidade dos Testes , Glicolipídeos/metabolismo , Pseudomonas aeruginosa , Tensoativos/química
5.
ACS Omega ; 8(24): 22150-22158, 2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-37360472

RESUMO

The genus Geobacillus is active in degradation of hydrocarbons in thermophilic and facultative environments since it was first reported in 1920. Here, we report a new strain, Geobacillus thermodenitrificans ME63, isolated from an oilfield with the ability of producing the biosurfactant. The composition, chemical structure, and surface activity of the biosurfactant produced by G. thermodenitrificans ME63 were investigated by using a combination of the high-performance liquid chromatography, time-of-flight ion mass spectrometry, and surface tensiometer. The biosurfactant produced by strain ME63 was identified as surfactin with six variants, which is one of the representative family of lipopeptide biosurfactants. The amino acid residue sequence in the peptide of this surfactin is N-Glu → Leu → Leu → Val → Leu → Asp → Leu-C. The critical micelle concentration (CMC) of the surfactin is 55 mg L-1, and the surface tension at CMC is 35.9 mN m-1, which is promising in bioremediation and oil recovery industries. The surface activity and emulsification properties of biosurfactants produced by G. thermodenitrificans ME63 showed excellent resistance to temperature changes, salinity changes, and pH changes.

6.
Front Med (Lausanne) ; 10: 1187186, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37250640

RESUMO

Acne vulgaris is a common skin condition that affects a large proportion of teenagers and young adults. Despite the availability of various treatment options, many patients experience inadequate relief or intolerable side effects. Photodynamic therapy (PDT) is a growing interest in the treatment of acne vulgaris, with 5-Aminolaevulinic acid (ALA) being one of the most commonly used photosensitizers. Adalimumab is a biologic medication used to treat inflammatory skin conditions such as Psoriasis and Hidradenitis suppurativa (HS), which targets TNF-α. Combining different therapies, such as ALA-PDT and adalimumab, can often provide more effective and longer-lasting results. This report presents the case of a patient with severe and refractory acne vulgaris who was treated with a combination of ALA-PDT and adalimumab, resulting in significant improvement in the condition. The literature review highlights the significant comorbidity associated with acne, emphasizing the need for potential of TNF-α inhibitors for its effective treatments that address physical symptoms and ALA-PDT is known to treat scar hyperplasia, and to prevent or minimize the formation of post-acne hypertrophic scars. The combination of TNF inhibitors and ALA-PDT or adalimumab has shown promising results in treating inflammatory skin conditions, including severe and refractory acne vulgaris, as per recent studies.

7.
J Phys Chem B ; 127(16): 3728-3736, 2023 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-37043396

RESUMO

Surfactin is a typical kind of biosurfactant with a large diversity of structure, and its molecular structure is expected to play a crucial role in its adsorption dynamics. Adsorption kinetics of surfactin homologues at the n-hexadecane/aqueous solution interface is studied using a droplet-based microfluidic method. Molecular dynamics simulations are performed to illustrate the dependence of adsorption energy on the surfactin structure. Rapid reduction of dynamic interfacial tensions is obtained. The best fit to experimental results reveals that surfactin with shorter aliphatic chains, C13-surfactin and C14-surfactin, has larger rate constants of adsorption and desorption. Interfacial tensions are rapidly reduced in the case of the oil/water interface which is freshly formed, and the equilibrium adsorption is rapidly established approximately in 100-350 ms at concentrations above the critical micelle concentration. C15-surfactin that has a longer aliphatic chain adsorbs and desorbs slower, and the equilibration time of adsorption is slightly longer. Moreover, C15-surfactin has a strong tendency for adsorbing at the interface, which is in accordance with the larger adsorption energy obtained by molecular dynamics simulation, and aggregating behavior in solution. The present study provides insights on the surfactin structure and the dynamics of adsorption at the liquid/liquid interface.

8.
Biotechnol Appl Biochem ; 70(1): 238-248, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35419893

RESUMO

Surfactin, which is composed of a ß-hydroxy fatty acid chain and a peptide ring, has drawn considerable attention due to its potential applications in the biomedicine, bioremediation, and petroleum industries. However, the low yield of surfactin from wild strains still restricts its industrial applications. In this study, eight genes relevant to the fatty acid biosynthesis pathway were targeted to enhance surfactin production, and high surfactin-yielding strains with potential industrial applications were obtained. When ldeHA and acc were co-overexpressed, the surfactin yield of recombinant strains TDS8 and TPS8 increased to 1.55- and 1.19-fold of their parental strains, respectively, again proving that the conversion of acetyl-coenzyme A (CoA) to malonyl-CoA is the rate-limiting step in fatty acid biosynthesis. Furthermore, changes in surfactin isoforms of recombinant strain TPS8 suggest that the fatty acid precursor synthesis pathway can be modified to improve the proportion of different isoforms. In addition, the deletion of lpdV, which is responsible for the conversion of α-ketoacyl-CoA precursors, resulted in a sharp decrease in surfactin production, further demonstrating the importance of branched-chain fatty acid biosynthesis in surfactin production. This work will facilitate the design and construction of more efficiently engineered strains for surfactin production and further extend industrial applications.


Assuntos
Bacillus subtilis , Ácidos Graxos , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Ácidos Graxos/metabolismo , Engenharia Genética , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Lipopeptídeos/genética , Lipopeptídeos/metabolismo , Peptídeos Cíclicos/genética , Peptídeos Cíclicos/metabolismo
9.
Sci Total Environ ; 858(Pt 3): 159861, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36397603

RESUMO

Microbial diversity and activities in petroleum reservoir systems can be altered by water-flooding operation, but the current understanding of the mechanism for such changes in microbial composition characteristics and community is inadequate. In this study, microbial communities especially functional groups in production water from five petroleum reservoirs in China were investigated by chemical and molecular biological analyses. The dominant and core phyla in the five oil reservoirs were Proteobacteria, Deferribacterota, Firmicutes, Desulfobacterota, Euryarchaeota and Thermoplasmatota. At the genus level, the dominant taxa in each petroleum reservoir were different, and not all of the dominant genera were the core members across the five oil reservoirs. The microbiologically influenced corrosion (MIC) were investigated for the functional groups in each production water. The corrosion rates in production water were higher than controls with a positive correlation to the abundances of sulfate-reducing prokaryotes (SRP). The SRP diversity based on the aprA and dsrA gene analysis showed that obvious differences were evident between onshore (JS, SL, DQ and XJ) and offshore (BS) oilfields. The core SRP taxa in onshore oilfields were Desulfomicrobium and Desulfovibrio, also with Desulfotomaculum in medium/low-temperature oil reservoirs (DQ and XJ), but in high-temperature petroleum reservoirs (JS, BS and SL), Archaeoglobus, Thermodesulfobacterium and Thermodesulfovibrio were the core groups. Statistical analysis indicated that temperature, electron acceptors and donors showed significant influence on the SRP community. This research reveals the characteristics of microbial and functional community as well as their interaction mechanism on corrosion in petroleum reservoir environments, and will improve industrial bio-control and management of MIC in oilfields.


Assuntos
Microbiota , Petróleo , Sulfatos , Água , China
10.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-1003606

RESUMO

Objective To investigate the prevalence of Echinococcus infections in wild carnivores in Serthar County, Sichuan Province, so as to provide insights into echinococcosis control in local areas. Methods Stool samples were collected from wild carnivores in Serthar County, Sichuan Province in May 2021, and the host sources of stool samples and Echinococcus infections were identified using PCR assays. The prevalence of E. multilocularis, E. granulosus and E. shiquicus infections was estimated in different hosts. Results A total of 583 stool samples were collected from wild carnivores, including 147 stool samples from fox, 154 from wolf, 227 from wild dogs and 11 from lynx. The overall prevalence of E. multilocularis, E. granulosus and E. shiquicus infections was 5.68%, 0.19% and 14.20% in canine stool samples, and no E. granulosus infection was detected in fox stool samples, while the prevalence of E. multilocularis and E. shiquicus infections was 0.68% and 47.62% in fox stool samples (χ2 = 88.41, P < 0.001). No E. granulosus or E. shiquicus infection was detected in wolf stool samples, and the prevalence of E. multilocularis infection was 10.39% in wolf stool samples. The prevalence of E. multilocularis, E. granulosus and E. shiquicus infections was 5.73%, 0.44% and 2.20% in canine stool samples (χ2 = 12.13, P < 0.01). In addition, the prevalence of E. multilocularis infections was significantly higher in wolf stool samples than in canine and fox stool samples (χ2 = 13.23, P < 0.01), and the prevalence of E. shiquicus infections was significantly higher in fox stool samples than in canine and wolf stool samples (χ2 = 187.01, P < 0.001). No Echinococcus infection was identified in 11 lynx stool samples. Conclusions The prevalence of Echinococcus infections is high in wild canines in Serthar County, Sichuan Province. Wolf, wild dog and fox all participate in the wild life cycle of E. multilocularis in Serthar County, and wolf and wild dogs may play a more important role.

11.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-1011419

RESUMO

Objective To evaluate the effectiveness of comprehensive echinococcosis control measures with emphasis on management of infectious source in Sichuan Province from 2010 to 2022, so as to provide insights into formulation of future control interventions. Methods Data pertaining to comprehensive echinococcosis control measures with emphasis on management of infectious source and echinococcosis surveillance in Sichuan Province from 2010 to 2022 were collected. The effectiveness of comprehensive echinococcosis control measures with emphasis on management of infectious source was evaluated with prevalence of human echinococcosis, detection of newly diagnosed echinococcosis patients, prevalence of Echinococcus infection in domestic dogs, prevalence of cystic echinococcosis in livestock, prevalence of alveolar echinococcosis in small mammals and awareness of echinococcosis control knowledge, and Spearman’s rank correlation analysis. Results The prevalence of human echinococcosis reduced from 1.08% in 2010 to 0.40% in 2022 in Sichuan Province (χ2 = 1 482.97, P < 0.05), with a reduction from 0.30% to 0.02% in the detection of newly diagnosed echinococcosis cases (χ2 = 2 776.41, P < 0.05), a reduction from 15.87% to 0.46% in the prevalence of Echinococcus infection in domestic dogs (χ2 = 20 823.96, P < 0.05), a reduction from 8.05% to 1.07% in the prevalence of cystic echinococcosis in livestock (χ2 = 1 296.02, P < 0.05), and the awareness of echinococcosis control knowledge increased from 50.65% to 95.24% (χ2 = 34 938.63, P < 0.05); in addition, there was a year-specific prevalence rate of alveolar echinococcosis in small mammals (χ2 = 164.07, P < 0.05). Spearman’s rank correlation analysis revealed that the detection of newly diagnosed echinococcosis cases correlated positively with the prevalence of Echinococcus infections in domestic dogs (rs = 0.823, P < 0.05) and the prevalence of cystic echinococcosis in livestock (rs = 0.795, P < 0.05), and correlated negatively with the awareness of echinococcosis control knowledge (rs = − 0.918, P < 0.05), and the prevalence of Echinococcus infection in domestic dogs correlated positively with the prevalence of cystic echinococcosis in livestock (rs = 0.753, P < 0.05) and negatively with the awareness of echinococcosis control knowledge (rs = −0.747, P < 0.05); however, there was no correlation between the prevalence of Echinococcus infections in domestic dogs and the prevalence of alveolar echinococcosis in small mammals (rs = −0.750, P > 0.05). Conclusions The comprehensive echinococcosis control measures with emphasis on management of infectious source had achieved remarkable effectiveness in Sichuan Province; however, the transmission chain of echinococcosis has not been interrupted. Reinforced comprehensive echinococcosis control measures with emphasis on management of infectious source and sustained tracking evaluation of the effectiveness are recommended in Sichuan Province.

12.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-985513

RESUMO

Objective: To establish reference values for carotid intima-media thickness (CIMT) of adult dwellers in Shenzhen City. Methods: The study was conducted based on the Shenzhen heart failure epidemiological survey from 2021 to 2022. In this survey, residents aged 18 years and above in Shenzhen were selected by using a multi-stage stratified random sampling method. General information, cardiovascular disease (CVD) related behavior and carotid ultrasound examination and etc. were collected from the participants. People with CVD factors, a history of atherosclerotic cardiovascular disease, carotid plaque or having no carotid ultrasound examination results were excluded. The parameter regression model based on fractional polynomial was used to establish the reference values of CIMT by age and sex. Results: A total of 2 163 healthy individuals were enrolled in the final analysis, including 576 males (26.6%) and 1 587 females (73.4%). The fractional polynomial regression of the CIMT mean and standard deviation was obtained. For men, the regression was meanCIMT=0.324 7+0.006 9×age and SDCIMT=0.076 9+0.001 2×age. For women, the regression was meanCIMT=0.354 9+0.005 4×age and SDCIMT=0.041 6+0.002 0×age. Conclusion: The age and sex reference values for CIMT of adult people in Shenzhen established in this study could provide the latest reference standards for early screening of subclinical CVD.


Assuntos
Masculino , Humanos , Adulto , Feminino , Espessura Intima-Media Carotídea , Doenças Cardiovasculares , Valores de Referência , Artérias Carótidas/diagnóstico por imagem , Ultrassonografia das Artérias Carótidas , Fatores de Risco , Doenças das Artérias Carótidas
13.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-953838

RESUMO

Objective To investigate the prevalence of Echinococcus infection in small mammals in Shiqu County, Sichuan Province from 2015 to 2020, so as to provide insights into echinococcosis control in Shiqu County. Methods One setting with frequent activity of small mammals was sampled as the survey site from each of 9 townships where human alveolar echinococcosis was hyperendemic, in Shiqu County, Sichuan Province from 2015 to 2020. Two quadrats measuring 50 m × 50 m were assigned in each survey site during the period between July and August from 2015 to 2020 to capture all small mammals in quadrats, and the species of small mammals were identified by morphological characteristics. All captured small mammals were dissected in the field and Echinococcus infection was identified by visual examinations. The affected organs of Echinococcus-infected small mammals were collected, and Echinococcus infection was detected using PCR assay, with Echinococcus species characterized. The prevalence of Echinococcus infection was calculated in small mammals, and the trends in the prevalence of Echinococcus infection were analyzed during the period from 2015 to 2020. In addition, the prevalence of Echinococcus infection was compared in small mammals using visual examinations and PCR assay. Results A total of 2 692 small mammals were captured in the survey sites of Shiqu County from 2015 to 2020, and morphology characterized 1 360 Microtus fuscus (50.52%) and 1 332 Plateau pika (49.48%). The prevalence rates of Echinococcus infection were 35.63%, 19.16%, 21.41%, 8.40%, 7.68% and 4.44% by visual examinations and 18.96%, 5.36%, 5.61%, 4.58%, 3.30% and 0.37% by PCR assay in small mammals in Shiqu County from 2015 to 2020, both showing a tendency towards a decline year by year (χ2 = 215.024 and 117.045, both P values < 0.001). The prevalence of Echinococcus infection was significantly higher in small mammals by visual examinations than by PCR assay during the period from 2015 to 2020 except in 2018 (χ2= 33.597, 21.815, 51.373, 17.268 and 9.537, all P values < 0.01). PCR assay detected a reduction in the prevalence of E. multilocularis infection from 10.21% to 0.37% and a reduction in the prevalence of E. shiquicus infection from 8.75% to 0 in small mammals in Shiqu County from 2015 to 2020, both appearing a tendency towards a decline year by year (χ2 = 117.045 and 43.436, both P values < 0.001). In addition, the prevalence of E. multilocularis and E. shiquicus infections reduced from 15.19% to 0.45% and from 8.23% to 0 in M. fuscus, and the prevalence of E. multilocularis and E. shiquicus infections reduced from 7.76% to 0 and from 9.01% to 0 in P. pika in Shiqu County from 2015 to 2020. Conclusions M. fuscus and P. pika were dominant species of small mammals in Shiqu County, Sichuan Province from 2015 to 2020, and E. multilocularis infection was mainly found in M. fuscus and E. shiquicus infection mainly found in P. pika. The prevalence of Echinococcus infection appeared a tendency towards a decline in both M. fuscus and P. pika year by year during the period from 2015 to 2020.

14.
International Eye Science ; (12): 1409-1412, 2023.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-978644

RESUMO

AIM:To observe the effect of implantable collamer lens V4c(ICL V4c)implantation on high myopia, and the changes in anterior segment morphology.METHODS:A prospective study was conducted on 100 patients(200 eyes)with high myopia who were treated with ICL V4c implantation in the hospital from February 2018 to March 2021. The best corrected visual acuity(BCVA), uncorrected visual acuity(UCVA), intraocular pressure, higher-order aberration, anterior segment morphology [iridocorneal angle(ICA), central anterior chamber depth(ACD), anterior chamber volume(ACV), central corneal thickness(CCT)and K-value(K)], photopic and scotopic contrast sensitivity before operation and 6 and 12mo after operation were comparatively analyzed.RESULTS:All patients were followed-up. UCVA and BCVA were significantly improved at 6 and 12mo after operation(P&#x003C;0.05). Total higher-order aberration, horizontal coma and vertical coma showed no significant difference before and after operation(P&#x003E;0.05). Spherical aberration, ICA, ACD and ACV at 6 and 12mo after operation were significantly smaller than those before operation(P&#x003C;0.05). Under photopic state, the contrast sensitivity of 3.0 and 6.0 c/d was significantly higher at 6 and 12mo after operation when compared with that before operation(P&#x003C;0.05). Under scotopic state, the contrast sensitivity of 6.0 c/d was significantly higher at 6 and 12mo after operation when compared with that before operation(P&#x003C;0.05); there was no significant difference in CCT, K, or intraocular pressure before and after operation(P&#x003E;0.05).CONCLUSION:Although ICA, ACD and ACV in patients with high myopia are reduced after ICL V4c implantation, the operation can effectively improve visual acuity and visual quality.

15.
Sci Rep ; 12(1): 16570, 2022 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-36195651

RESUMO

Natural environments with frequent drainage experience drying and rewetting events that impose fluctuations in water availability and oxygen exposure. These relatively dramatic cycles profoundly impact microbial activity in the environment and subsequent emissions of methane and carbon dioxide. In this study, we mimicked drying and rewetting events by submitting methanogenic communities from strictly anaerobic environments (anaerobic digestors) with different phylogenetic structures to consecutive desiccation events under aerobic (air) and anaerobic (nitrogen) conditions followed by rewetting. We showed that methane production quickly recovered after each rewetting, and surprisingly, no significant difference was observed between the effects of the aerobic or anaerobic desiccation events. There was a slight change in the microbial community structure and a decrease in methane production rates after consecutive drying and rewetting, which can be attributed to a depletion of the pool of available organic matter or the inhibition of the methanogenic communities. These observations indicate that in comparison to the drying and rewetting events or oxygen exposure, the initial phylogenetic structure and the organic matter quantity and quality exhibited a stronger influence on the methanogenic communities and overall microbial community responses. These results change the current paradigm of the sensitivity of strict anaerobic microorganisms to oxygen exposure.


Assuntos
Dióxido de Carbono , Euryarchaeota , Dessecação , Metano , Nitrogênio , Oxigênio , Filogenia , Água
16.
ACS Omega ; 7(36): 32775-32783, 2022 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-36120073

RESUMO

The wide application of surfactants has a harmful effect on the environment, drawing more attention to the development and application of low-toxicity surfactants. A salt-tolerant and low-toxicity biobased zwitterionic surfactant, N,N-dimethyl-N-[2-hydroxy-3-sulfo-propyl]-N-benzyloxyoctadecanoyl-1,3-propanediamine (SPBOPA), was prepared from the oleic acid extracted from waste oils and anise ether extracted from the tarragon. The final surfactant structure was confirmed using gas chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry (LC-MS), and 1H nuclear magnetic resonance (NMR) spectroscopy. The SPBOPA surfactant could reduce the interfacial tension between crude oil and formation brine to ultralow (5.2 × 10-4 mN/m) at a low dosage without extra alkali. It still had good interfacial properties in NaCl up to 60 g/L, Ca2+ up to 2000 mg/L, and temperature up to 100 °C. Furthermore, SPBOPA had strong antidilution and antiadsorption properties with low toxicity as demonstrated by the high LD50 value of >5000 mg/kg·BW. It could also enhance the wetting ability of crude oil surfaces. Meanwhile, it showed a high biodegradability in the environment. All of the results achieved in this work confirmed that the SPBOPA surfactant is a more robust and promising biobased surfactant candidate than traditional surfactants as an eco-friendly surfactant for enhanced oil recovery (EOR).

17.
Microorganisms ; 10(9)2022 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-36144307

RESUMO

Petroleum reservoirs are unique deep-subsurface ecosystems that are generally characterized by such extreme conditions as high temperature, high pressure, high salinity, and anoxia [...].

18.
Environ Microbiol ; 24(7): 3063-3080, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35254697

RESUMO

The recently proposed order Candidatus Thermoprofundales, currently containing only one family-level lineage Marine Benthic Group-D (MBG-D), is distributed in global subsurface ecosystems and ecologically important, but its diversity, evolution and metabolism remain largely unknown. Here we described two novel family-level specialized lineages in Ca. Thermoprofundales, JdFR-43 and HyVt, which are restricted to specific biotopes (primarily in marine hydrothermal vents and occasionally in oil reservoirs and hot springs) in contrast to the cosmopolitan lineage MBG-D. The comparative genomics revealed that the specialized lineages have streamlined genomes, higher GC contents, enriched genes associated with nucleotide biosynthesis, ribosome biogenesis and DNA repair and additional thermostable aminopeptidases, enabling them to adapt to high-temperature habitats such as marine hydrothermal vents, deep subsurface oil reservoirs and hot springs. On the contrary, the unique metabolic traits of the cosmopolitan MBG-D, motility, glycolysis, butanoate metabolism, secondary metabolites production and additional genes for specific peptides and carbohydrates degradation potentially enhance its response to environmental change. Substrate preference is found for most MAGs across all lineages with the ability to utilize both polysaccharides (chitin and starch) and proteinaceous substances, whereas JdFR-43 members from oil reservoirs can only utilize proteins. These results expand the diversity of Ca. Thermoprofundales significantly and further improve our understandings of the adaptations of Ca. Thermoprofundales to various environments.


Assuntos
Fontes Termais , Fontes Hidrotermais , Archaea/genética , Ecossistema , Filogenia
19.
J Basic Microbiol ; 62(11): 1319-1336, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35048396

RESUMO

Polysaccharides are biobased polymers obtained from renewable sources. They exhibit various interesting features including biocompatibility, biodegradability, and nontoxicity. Microbial polysaccharides are produced by several microorganisms including yeast, fungi, algae, and bacteria. Microbial polysaccharides have gained high importance in biotechnology due to their novel physiochemical characteristics and composition. Among microbial polysaccharides, xanthan, alginate, gellan, and dextran are the most commonly reported polysaccharides for the development of biomimetic materials for biomedical applications including targeted drug delivery, wound healing, and tissue engineering. Several chemical and physical cross-linking reactions are performed to increase their technological and functional properties. Owning to the broad-scale applications of microbial polysaccharides, this review aims to summarize the characteristics with different ways of physical/chemical crosslinking for polysaccharide regulation. Recently, several biopolymers have gained high importance due to their biologically active properties. This will help in the formation of bioactive nutraceuticals and functional foods. This review provides a perspective on microbial polysaccharides, with special emphasis given to applications in promising biosectors and the subsequent advancement on the discovery and development of new polysaccharides for adding new products.


Assuntos
Polissacarídeos , Engenharia Tecidual , Sistemas de Liberação de Medicamentos , Polímeros , Alginatos , Biopolímeros
20.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-913062

RESUMO

Currently, the national schistosomiasis control program of China is moving from transmission control and transmission interruption to elimination; however, there is still a threat of schistosomiasis outbreak in area where the transmission of schistosomiasis has not been interrupted, and in areas where transmission interruption and even elimination have been achieved because of the complex factors relating to schistosomiasis transmission, as well as socioeconomic factors and natural environments, which greatly affects the consolidation of schistosomiasis control outcomes and the achievement of the goal of schistosomiasis elimination in the country. Here, we summarized the outbreaks of schistosomiasis in China during the past six decades, evaluated the impact of schistosomiasis outbreak on the national schistosomiasis control program and proposed management of schistosomiasis outbreak and prevention of schistosomiasis resurgence as the key point and difficulty for schistosomiasis control in the current stage. Improving the surveillance-response mechanisms and minimizing the development of schistosomiasis outbreak and the resultant damages and losses are recommended to provide technical supports for elimination of schistosomiasis in China.

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