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Bacteriophage ("Phage") products are gaining interest in controlling foodborne pathogens as they are natural, specific, and can replicate at the site of contamination. One challenge in determining the efficacy of phage biocontrol is accounting for residual phages that may impact the recovery and the enumeration of surviving bacteria downstream from the treatment on food surface (FS) or food contact surface (FCS). Typically, the efficacy of a phage formulation is tested by applying it to a FS or FCS that has been pre-inoculated with the target pathogen and incubating the treatment for a set period of time. The food sample is transferred into a liquid buffer and stomached to release the surviving bacteria for their enumeration. During these final steps, there is a potential for residual phage to interact with bacterial survivors, which could affect the calculated efficacy of the phage. Limited studies demonstrated that bacterial reductions in these experiments occur specifically during treatment and not during sample recovery. This review highlights the importance of including appropriate controls to determine if residual phages are impacting bacterial recovery and the methods used to mitigate those impacts, which involves either neutralizing residual phages or separating residual phages from the surviving bacteria.
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l-Lactic acid (l-LA) is a platform chemical obtained via microbial fermentation at a near-neutral pH value. Large amounts of neutralizers are required during this process, which increases the production costs in downstream processing as well as environmental burden. To address this challenge, an acid-tolerant yeast Pichia kudriavzevii E1 was isolated and metabolically engineered to produce l-LA without neutralizers. The genome of strain E1 was sequenced and a CRISPR-Cas9 system was developed in this newly isolated strain. Subsequently, the gene encoding pyruvate decarboxylase (pdc) was knocked out to subdue ethanol formation. Furthermore, the l-lactate dehydrogenase gene from Weizmannia coagulans 2-6 and the codon-optimized L-ldhA gene from Bos taurus were introduced into P. kudriavzevii E1 chromosome to redirect the ethanol fermentation pathway to l-LA production. Deletion of the dld(chr3) gene further increased the optical purity of l-LA. After optimizing fermentation conditions, the maximum titer of l-LA in the 5 L fermenter reached 74.57 g/L without any neutralizers, with an optical purity of 100% and a maximum yield of 0.93 g/g glucose. This is the first report of optically pure l-LA production without neutralizers and the engineered acid-tolerant yeast paves the way for the sustainable production of l-LA via a green route.
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Ácido Láctico , Saccharomyces cerevisiae , Animales , Bovinos , Saccharomyces cerevisiae/metabolismo , Ácido Láctico/metabolismo , Ácidos/metabolismo , Pichia/genética , Pichia/metabolismo , Fermentación , Etanol/metabolismoRESUMEN
L-lactic acid (L-LA) is widely used in the food, pharmaceutical, and cosmetic industries. In recent years, the production of L-LA using microbial fermentation has been favored. Herein, a Saccharomyces cerevisiae TAM strain tolerant to pH 2.4, was used as the starting strain. Exogenous L-lactate dehydrogenase expressing S. cerevisiae TAM strain with downregulated glycerol and ethanol synthesis pathways produced an L-LA titer of 29.8 g/L, and it increased to 50.5 g/L after carboxylic acid transport pathway modulation at the shake-flask level. Subsequently, increased energy supply and redox balancing increased the L-LA titer to 72.7 g/L in shake-flask fermentation without a neutralizer, with the yield of 0.66 g/g. Finally, optimization of the fermentation conditions, such as the seed quantity, oxygen level, and pH in a 15-L bioreactor, increased the L-LA titer to 192.3 g/L at pH 4.5, with a yield of 0.78 g/g. Overall, this study proposes an efficient L-LA bioproduction method.
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Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Ingeniería Metabólica/métodos , Fermentación , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Ácido LácticoRESUMEN
In industrial bioproduction of organic acids, numerous neutralizers are required which substantially increases production costs and burdens the environment. To address this challenge, a Saccharomyces cerevisiae mutant (named TAMC) with a low pH tolerance (pH 2.3) was isolated by adaptive laboratory evolution. Taking the synthesis of l-malic acid as an example, the malate dehydrogenase 3 without signal peptide (MDHΔSKL) and pyruvate carboxylase 2 (PYC2) were overexpressed in cytoplasmic synthesis pathway, and the l-malic acid titer increased 5.6-fold. Subsequently, the malic acid transporter SpMae1 was designed, and the extracellular l-malic acid titer was increased from 7.3 to 73.6 g/L. Furthermore, by optimizing the synthesis of the precursor pyruvate, the titer reached 81.8 g/L. Finally, without any neutralizer, the titer in the 3-L bioreactor reached 232.9 g/L, the highest l-malic acid titer reported to date. Herein, the engineered l-malic acid overproducer paves the way for the large-scale green production of l-malic acid.
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Malatos , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Malatos/metabolismo , Vías Biosintéticas , Ingeniería MetabólicaRESUMEN
There is a great concern regarding the safety of milk not only for human health but also for its economic consequences. The portable sensing devices, which can collect and analyze data within food supply chains at critical control points are lacking. Smart phones have now emerged as an integral part of each home, lab, farm and factory. It is having a provision of digital camera and computation; with widespread applicability including food analysis. The use of soda as a milk neutralizer is a usual practice but has a detrimental human health impact. This investigation explored an easy, economic, fast, repeatable, and field applicable Smartphone-based sensing technology, which was standardized and in-house validated for the quantitative determination of neutralizer in milk samples. The method had simple steps of spot-test response and digital image evaluation with the Red Green Blue process. The linearity of the method was shown by analytical curves ranging from 0.125% (1250 ppm) to 1% (10,000 ppm) that were characterized by R2 > 0.99. The limit of detection of 0.11% demonstrated the sensitivity of the method which was found better than the existing wet chemical spot test. Comparison with the existing spectroscopic method revealed no statistically significant difference between the observations using paired t-test at a confidence level of 95%.
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The high genetic diversity of hepatitis C virus (HCV) complicates effective vaccine development. We screened a cohort of 435 HCV-infected individuals and found that 2%-5% demonstrated outstanding HCV-neutralizing activity. From four of these patients, we isolated 310 HCV antibodies, including neutralizing antibodies with exceptional breadth and potency. High neutralizing activity was enabled by the use of the VH1-69 heavy-chain gene segment, somatic mutations within CDRH1, and CDRH2 hydrophobicity. Structural and mutational analyses revealed an important role for mutations replacing the serines at positions 30 and 31, as well as the presence of neutral and hydrophobic residues at the tip of the CDRH3. Based on these characteristics, we computationally created a de novo antibody with a fully synthetic VH1-69 heavy chain that efficiently neutralized multiple HCV genotypes. Our findings provide a deep understanding of the generation of broadly HCV-neutralizing antibodies that can guide the design of effective vaccine candidates.
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Anticuerpos ampliamente neutralizantes/genética , Hepacivirus/inmunología , Anticuerpos contra la Hepatitis C/genética , Linfocitos B/inmunología , Anticuerpos ampliamente neutralizantes/química , Anticuerpos ampliamente neutralizantes/inmunología , Regiones Determinantes de Complementariedad/química , Regiones Determinantes de Complementariedad/genética , Regiones Determinantes de Complementariedad/inmunología , Epítopos , Femenino , Genotipo , Hepacivirus/genética , Hepatitis C/inmunología , Anticuerpos contra la Hepatitis C/química , Anticuerpos contra la Hepatitis C/inmunología , Humanos , Cadenas Pesadas de Inmunoglobulina/química , Cadenas Pesadas de Inmunoglobulina/genética , Cadenas Pesadas de Inmunoglobulina/inmunología , Masculino , Persona de Mediana Edad , Mutación , Proteínas del Envoltorio Viral/química , Proteínas del Envoltorio Viral/inmunologíaRESUMEN
In order to improve the capability of Klebsiella pneumoniae to produce an important chemical raw material, 1,3-propanediol (1,3-PDO), a new type of K. pneumoniae x546 was obtained by glycerol acclimation and subsequently was used to produce 1,3-PDO. Under the control of pH value using Na+ pH neutralizer, the 1,3-PDO yield of K. pneumoniae x546 in a 7.5-L fermenter was 69.35 g/L, which was 1.5-fold higher than the original strain (45.91 g/L). After the addition of betaine, the yield of 1,3-PDO reached up to 74.44 g/L at 24 h, which was 40% shorter than the original fermentation time of 40 h. To study the potential mechanism of the production improvement of 1,3-PDO, the Tandem Mass Tags (TMT) technology was applied to investigate the production of 1,3-PDO in K. pneumoniae. Compared with the control group, 170 up-regulated proteins and 291 down-regulated proteins were identified. Through Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis, it was found that some proteins [such as homoserine kinase (ThrB), phosphoribosylglycinamide formyltransferase (PurT), phosphoribosylaminoimidazolesuccinocarboxamide synthase (PurC), etc.] were involved in the fermentation process, whereas some other proteins (such as ProX, ProW, ProV, etc.) played a significant role after the addition of betaine. Moreover, combined with the metabolic network of K. pneumoniae during 1,3-PDO, the proteins in the biosynthesis of 1,3-PDO [such as DhaD, DhaK, lactate dehydrogenase (LDH), BudC, etc.] were analyzed. The process of 1,3-PDO production in K. pneumoniae was explained from the perspective of proteome for the first time, which provided a theoretical basis for genetic engineering modification to improve the yield of 1,3-PDO. Because of the use of Na+ pH neutralizer in the fermentation, the subsequent environmental pollution treatment cost was greatly reduced, showing high potential for industry application in the future.
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Phenolic yellowing is a complex physicochemical phenomenon of cotton, especially for white and pastel-colored fabrics. This study tried to analyze the effect of neutralizers and silicone softeners on this. Three types of neutralizers of different chemical characteristics (acetic acid, citric acid, and commercial complex acid) were used to achieve core neutralization whereas two unlike ionic nature of silicone softeners (cationic & non-ionic) for the finishing process used. The acetic acid and nonionic softener treated fabric gives the maximum CIE (International Commission on Illumination) whiteness index value of 151 while citric acid and cationic softener have the least rating of 140.93 with a similar chemical dosage of 1.5 g/l by immediate testing. However, after repeated testing for one-month conditioning in atmospheric conditions, complex acid, and nonionic softener treated samples exhibited the maximum whiteness index of 145.86; on the other hand, citric acid and cationic softener treated one had the least rating of 125.85. Moreover, fabric core pH, reading was found to be 6.68, 6.15 & 5.13 for acetic acid, citric acid, and complex acid through immediate testing. After one month of conditioning, the values were 7.2, 6.61, and 5.25, respectively. Finally, a maximum phenolic yellowing rating of 4-5 was found with complex acid & nonionic softener in contrast poor rating of 2 with acetic acid & cationic softener for immediate testing. Storage of the samples has a significant impact on phenolic yellowing for all types of chemical concentrations. Lightfastness rating was found identical for all samples while bursting strength had a very negligible impact, Fourier transform infrared (FT-IR) spectroscopy also revealed the presence of noticeable chemical functional groups.
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In the present research, an optimized liquid medium which had no neutralizing effect to chitosan was developed. Moreover, magnesium chloride (MgCl2) was identified to be able to absolutely neutralize the antibacterial activity of chitosan and its derivatives. Took the two results together, the minimum bactericidal concentration (MBC) and minimum inhibitory concentration (MIC) of chitosan were precisely quantified through a further improved method based on the optimized medium and the relation curve between antibacterial rate and reaction time was obtained with the help of MgCl2 neutralizer. The MBC and MIC of chitosan were all 30 µg/mL against Staphylococcus aureus and Escherichia coli, and 100 µg/mL of chitosan acetate could reach 100 % of antibacterial rate within 3 min. Furthermore, coordination between magnesium ions and chitosan as well as reduced zeta potential of chitosan caused by coordination were inferred to be the neutralizing mechanism of MgCl2 neutralizer.
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Antibacterianos/farmacología , Quitosano/farmacología , Escherichia coli/efectos de los fármacos , Cloruro de Magnesio/farmacología , Pruebas de Sensibilidad Microbiana , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Staphylococcus aureus/efectos de los fármacosRESUMEN
Background: The mechanism of Interleukin-17 (IL-17) induced ventricular arrhythmia (VA) remains unclear. This study aimed to investigate the effect of intracellular calcium (Cai) handling and VA susceptibility by IL-17. Methods: The electrophysiological properties of isolated perfused rabbit hearts under IL-17 (20 ng/ml, N = 6) and the IL-17 with neutralizer (0.4 µg/ml, N = 6) were evaluated using an optical mapping system. The action potential duration (APD) and Cai transient duration (CaiTD) were examined, and semiquantitative reverse transcriptase-polymerase chain reaction analysis of ion channels was performed. Results: There were longer APD80, CaiTD80 and increased thresholds of APD and CaiTD alternans, the maximum slope of APD restitution and induction of VA threshold in IL-17 group compared with those in IL-17 neutralizer and baseline groups. During ventricular fibrillation, the number of phase singularities and dominant frequency were both significantly greater in IL-17 group than in baseline group. The mRNA expressions of the Na+/Ca2+ exchanger, phospholamban, and ryanodine receptor Ca2+ release channel were upregulated, and the subunit of L-type Ca2+ current and sarcoplasmic reticulum Ca2+-ATPase 2a were significantly reduced in IL-17 group compared to baseline and IL-17 neutralizer group. Conclusions: IL-17 enhanced CaiTD and APD alternans through disturbances in calcium handling, which may increase VA susceptibility.
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Xylo-oligosaccharides with high value could be obtained by acidolysis of lignocellulosic biomass with acetic acid, which was an urgent problem to solve for the separation of acetic acid from crude xylo-oligosaccharides solution. Four neutralizers, CaCO3, CaO, Na2CO3, and NaOH, were used for in situ chemically locking the acetic acid in the acidolyzed hydrolysate of corncob. The chemically locked hydrolysate was analyzed and compared using vacuum evaporation and spray drying. After CaCO3, CaO, Na2CO3, and NaOH treatment, the locking rates of acetic acid were 92.62%, 94.89%, 95.05%, and 95.58%, respectively, and 39.55 g, 41.13 g, 41.78 g, and 41.87 g of the compound of xylo-oligosaccharide and acetate were obtained. Sodium neutralizer had lesser effect on xylo-oligosaccharide content, and Na2CO3 was the best chemical for locking acetic acid among these four neutralizers. This process provides a novel method for effectively utilizing acetic acid during the industrial production of xylo-oligosaccharides via acetic acid.
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Ácido Acético/química , Lignina/química , Oligosacáridos/química , HidrólisisRESUMEN
The effects of neutralizer species on the transparency of injection-molded plates were studied using isotactic polypropylene (PP) containing a crystal nucleating agent-i.e., 1,3:2,4-bis-o-(4-methylbenzylidene)-d-sorbitol (MDBS). A plate containing lithium stearate (StLi) was more transparent than one containing calcium stearate (StCa) when the MDBS content was 0.1 wt. %. The addition of StLi accelerated the formation of MDBS fibers and the crystallization of PP. However, when the MDBS content was 1.0 wt. %, StCa improved the transparency more effectively than StLi. These results indicate that the combination of an appropriate amount of MDBS and the correct neutralizer species is critical for enhancing the transparency of injection-molded PP plates.
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The induction of broadly neutralizing antibodies (bNAbs) is a major goal in vaccine research. HIV-1-infected individuals that develop exceptionally strong bNAb responses, termed elite neutralizers, can inform vaccine design by providing blueprints for the induction of similar bNAb responses. We describe a new recombinant native-like envelope glycoprotein (Env) SOSIP trimer, termed AMC009, based on the viral founder sequences of an elite neutralizer. The subtype B AMC009 SOSIP protein formed stable native-like trimers that displayed multiple bNAb epitopes. Overall, its structure at 4.3-Å resolution was similar to that of BG505 SOSIP.664. The AMC009 trimer resembled one from a second elite neutralizer, AMC011, in having a dense and complete glycan shield. When tested as immunogens in rabbits, the AMC009 trimers did not induce autologous neutralizing antibody (NAb) responses efficiently while the AMC011 trimers did so very weakly, outcomes that may reflect the completeness of their glycan shields. The AMC011 trimer induced antibodies that occasionally cross-neutralized heterologous tier 2 viruses, sometimes at high titer. Cross-neutralizing antibodies were more frequently elicited by a trivalent combination of AMC008, AMC009, and AMC011 trimers, all derived from subtype B viruses. Each of these three individual trimers could deplete the NAb activity from the rabbit sera. Mapping the polyclonal sera by electron microscopy revealed that antibodies of multiple specificities could bind to sites on both autologous and heterologous trimers. These results advance our understanding of how to use Env trimers in multivalent vaccination regimens and the immunogenicity of trimers derived from elite neutralizers.IMPORTANCE Elite neutralizers, i.e., individuals who developed unusually broad and potent neutralizing antibody responses, might serve as blueprints for HIV-1 vaccine design. Here, we studied the immunogenicity of native-like recombinant envelope glycoprotein (Env) trimers based on viral sequences from elite neutralizers. While immunization with single trimers from elite neutralization did not recapitulate the breadth and potency of neutralization observed in these infected individuals, a combination of three subtype B Env trimers from elite neutralizers resulted in some neutralization breadth within subtype B viruses. These results should guide future efforts to design vaccines to induce broadly neutralizing antibodies.
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Anticuerpos Neutralizantes/inmunología , Antígenos Virales/inmunología , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Vacunas contra el SIDA/inmunología , Animales , Anticuerpos Neutralizantes/química , Antígenos Virales/química , Microscopía por Crioelectrón , Epítopos/inmunología , Glicoproteínas , Infecciones por VIH/virología , Inmunización , Conejos , Proteínas Recombinantes/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genéticaRESUMEN
ß-poly(L-malic acid) (PMLA) has attracted industrial interest for its potential applications in medicine and other industries. For a sustainable PMLA production, it requires replacing/reducing the CaCO3 usage, since the residual CaCO3 impeded the cells' utilization, and a large amount of commercially useless gypsum was accumulated. In this study, it was found that more glucose was converted into CO2 using soluble alkalis compared with CaCO3 usage. Moreover, since the high ion strength and respiration effect of soluble alkalis also inhibited PMLA production, they could not effectively replace CaCO3. Furthermore, comparing the fermentations with different neutralizers (soluble alkali vs. CaCO3), it was found that the differential genes are mainly involved in the pathway of starch and sucrose metabolism, pentose and glucuronate interconversions, histidine metabolism, ascorbate and aldarate metabolism, and phagosome. In detail, in the case with CaCO3, 562 genes were downregulated and 262 genes were upregulated, and especially, those genes involved in energy production and conversion were downregulated by 26.7%. Therefore, the irreplaceability of CaCO3 was caused by its effect on the PMLA metabolic pathway rather than its usage as neutralizer. Finally, a combined pH shift control strategy with CaCO3 addition was developed. After the fermentation, 64.8 g/L PMLA and 38.9 g/L biomass were obtained with undetectable CaCO3 and less CO2 emission. KEY POINTS: ⢠The effect of CaCO3 on PMLA metabolic pathway resulted in its irreplaceability. ⢠A pH shift control strategy with CaCO3 addition was developed. ⢠Undetectable CaCO3 and less CO2 emission were detected with the new strategy. Graphical abstract.
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Aureobasidium , Polímeros , Fermentación , Glucanos , Concentración de Iones de Hidrógeno , Malatos , Polímeros/metabolismoRESUMEN
BACKGROUND: Milk is considered to be a balanced food rich in fats, proteins, vitamins, and minerals, which is complete nutrition in a balanced proportion. However, most of milk sold in India does not match standards laid down by the Food Safety and Standards Authority of India. OBJECTIVE: The objective was to understand the perception of community regarding the acceptance of packaged and unpackaged milk, to assess the quality of milk with respect to adulterants, and to assess the difference in the quality of milk at a level of vendor/hawker and end user. MATERIALS AND METHODS: A cross-sectional study was conducted among 100 households in the peri-urban area of Kangan Heri, Delhi. A structured questionnaire and checklist were used for data collection. Purposive sampling was used. The analysis was done with the Statistical Package for the Social Sciences version 22. Descriptive statistics and cross tabulation were used. RESULTS: A total of 22.5% respondents preferred packaged milk over unpackaged milk. Only 8% of packaged milk samples contained no adulterant. Majority of the respondents were preferred unpacked milk for daily consumption. CONCLUSION: Community perceives good taste as traits of good quality milk followed by good smell, digestibility, and color and economical. The presence of neutralizer in packaged milk followed by detergent and urea. There was no difference in the presence of adulterants in packaged milk at the level of end user or vendor. There is a slight difference in the presence of adulterants in unpackaged milk at level of end user.
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The induction of broadly neutralizing antibodies (bnAbs) is highly desired for an effective vaccine against HIV-1. Typically, bnAbs develop in patients with high viremia, but they can also evolve in some untreated HIV-1 controllers with low viral loads. Here, we identify a subgroup of neutralizer-controllers characterized by myeloid DCs (mDCs) with a distinct inflammatory signature and a superior ability to prime T follicular helper (Tfh)-like cells in an STAT4-dependent fashion. This distinct immune profile is associated with a higher frequency of Tfh-like cells in peripheral blood (pTfh) and an enrichment for Tfh-defining genes in circulating CD4+ T cells. Correspondingly, monocytes from this neutralizer controller subgroup upregulate genes encoding for chemotaxis and inflammation, and they secrete high levels of IL-12 in response to TLR stimulation. Our results suggest the existence of multi-compartment immune networks between mDCs, Tfh, and monocytes that may facilitate the development of bnAbs in a subgroup of HIV-1 controllers.
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Anticuerpos Neutralizantes/inmunología , Linfocitos T CD4-Positivos/inmunología , Células Dendríticas/inmunología , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Monocitos/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Adulto , Anciano , Linfocitos B/inmunología , Linfocitos B/metabolismo , Linfocitos T CD4-Positivos/metabolismo , Línea Celular , Supervivencia Celular/inmunología , Células Dendríticas/metabolismo , Femenino , Regulación de la Expresión Génica/inmunología , Humanos , Interleucina-12/metabolismo , Masculino , Persona de Mediana Edad , Monocitos/metabolismo , RNA-Seq , Factor de Transcripción STAT4/genética , Factor de Transcripción STAT4/metabolismo , Linfocitos T Colaboradores-Inductores/metabolismo , Células TH1/inmunología , Células TH1/metabolismoRESUMEN
Broadly neutralizing antibodies (bNAbs) have demonstrated protective effects against HIV-1 in primate studies and recent human clinical trials. Elite neutralizers are potential candidates for isolation of HIV-1 bNAbs. The coexistence of bNAbs such as BG18 with neutralization-susceptible autologous viruses in an HIV-1-infected adult elite controller has been suggested to control viremia. Disease progression is faster in HIV-1-infected children than in adults. Plasma bNAbs with multiple epitope specificities are developed in HIV-1 chronically infected children with more potency and breadth than in adults. Therefore, we evaluated the specificity of plasma neutralizing antibodies of an antiretroviral-naive HIV-1 clade C chronically infected pediatric elite neutralizer, AIIMS_330. The plasma antibodies showed broad and potent HIV-1 neutralizing activity with >87% (29/33) breadth, a median inhibitory dilution (ID50) value of 1,246, and presence of N160 and N332 supersite-dependent HIV-1 bNAbs. The sorting of BG505.SOSIP.664.C2 T332N gp140 HIV-1 antigen-specific single B cells of AIIMS_330 resulted in the isolation of an HIV-1 N332 supersite-dependent bNAb, AIIMS-P01. The AIIMS-P01 neutralized 67% of HIV-1 cross-clade viruses, exhibited substantial indels despite limited somatic hypermutations, interacted with native-like HIV-1 trimer as observed in negative stain electron microscopy, and demonstrated high binding affinity. In addition, AIIMS-P01 neutralized the coexisting and evolving autologous viruses, suggesting the coexistence of vulnerable autologous viruses and HIV-1 bNAbs in the AIIMS_330 pediatric elite neutralizer. Such pediatric elite neutralizers can serve as potential candidates for isolation of novel HIV-1 pediatric bNAbs and for understanding the coevolution of virus and host immune response.IMPORTANCE More than 50% of the HIV-1 infections globally are caused by clade C viruses. To date, there is no effective vaccine to prevent HIV-1 infection. Based on the structural information of the currently available HIV-1 bNAbs, attempts are under way to design immunogens that can elicit correlates of protection upon vaccination. Here, we report the isolation and characterization of an HIV-1 N332 supersite-dependent bNAb, AIIMS-P01, from a clade C chronically infected pediatric elite neutralizer. The N332 supersite is an important epitope and is one of the current HIV-1 vaccine targets. AIIMS-P01 potently neutralized the contemporaneous and autologous evolving viruses and exhibited substantial indels despite low somatic hypermutations. Taken together with the information on infant bNAbs, further isolation and characterization of bNAbs contributing to the plasma breadth in HIV-1 chronically infected children may help provide a better understanding of their role in controlling HIV-1 infection.
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Anticuerpos Neutralizantes/uso terapéutico , VIH-1/inmunología , Adulto , Antirretrovirales , Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/inmunología , Evolución Biológica , Niño , Epítopos/inmunología , Femenino , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/virología , Seropositividad para VIH , Humanos , Masculino , Pruebas de Neutralización , Vacunación , Viremia , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunologíaRESUMEN
Sanitizer neutralizers can assist foodborne pathogen detection during routine testing by counteracting sanitizer residues carried over into fluids collected and tested from food samples. This study tested sanitizer-matched neutralizers applied at increasing concentrations to facilitate Salmonella enterica survival following exposure to cetylpyridinium chloride (CPC) or peracetic acid (PAA), identifying minimum required concentrations of neutralizers to facilitate pathogen survival. Salmonella isolates were individually inoculated into a non-selective medium followed immediately by CPC (0.1 to 0.8% v/v) or PAA (0.0125 to 0.2% v/v) application, followed by neutralizers application. CPC was neutralized by lecithin and polysorbate 80, each supplemented into buffered peptone water (BPW) at 0.125 to 2.0X its respective content in Dey-Engley (D/E) neutralizing buffer. PAA was neutralized in BPW supplemented with disodium phosphate, potassium monophosphate, and sodium thiosulfate, each at 0.25 to 3.0X its respective concentration in BPW (phosphates) or D/E buffer (thiosulfate). Addition of neutralizers at 1X their respective concentrations in D/E buffer was required to allow Salmonella growth at the maximum CPC concentration (0.8%), while 2X neutralizer addition was required for Salmonella growth at the maximum PAA level (0.2%). Sanitizer neutralizers can assist pathogen survival and detection during routine food product testing.
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Sporolactobacillus inulinus is a superior D-lactic acid-producing bacterium and proposed species for industrial production. The major pathway for D-lactic acid biosynthesis, glycolysis, is mainly regulated via the two irreversible steps catalyzed by the allosteric enzymes, phosphofructokinase (PFK) and pyruvate kinase. The activity level of PFK was significantly consistent with the cell growth and D-lactic acid production, indicating its vital role in control and regulation of glycolysis. In this study, the ATP-dependent PFK from S. inulinus was expressed in Escherichia coli and purified to homogeneity. The PFK was allosterically activated by both GDP and ADP and inhibited by phosphoenolpyruvate; the addition of activators could partly relieve the inhibition by phosphoenolpyruvate. Furthermore, monovalent cations could enhance the activity, and Na+ was the most efficient one. Considering this kind activation, NaOH was investigated as the neutralizer instead of the traditional neutralizer CaCO3. In the early growth stage, the significant accelerated glucose consumption was achieved in the NaOH case probably for the enhanced activity of Na+-activated PFK. Using NaOH as the neutralizer at pH 6.5, the fermentation time was greatly shortened about 22 h; simultaneously, the glucose consumption rate and the D-lactic acid productivity were increased by 34 and 17%, respectively. This probably contributed to the increased pH and Na+-promoted activity of PFK. Thus, fermentations by S. inulinus using the NaOH neutralizer provide a green and highly efficient D-lactic acid production with easy subsequent purification.
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Bacillales/enzimología , Activadores de Enzimas/metabolismo , Ácido Láctico/metabolismo , Fosfofructoquinasas/metabolismo , Hidróxido de Sodio/metabolismo , Adenosina Difosfato/metabolismo , Bacillales/genética , Cationes/metabolismo , Clonación Molecular , Inhibidores Enzimáticos/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Expresión Génica , Guanosina Difosfato/metabolismo , Fosfoenolpiruvato/metabolismo , Fosfofructoquinasas/genética , Fosfofructoquinasas/aislamiento & purificación , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismoRESUMEN
In addition to chemical composition, the site of deposition of inhaled particles is important for determining the potential health effects from an exposure. As a result, the International Organization for Standardization adopted a particle deposition sampling convention. This includes extrathoracic particle deposition sampling conventions for the anterior nasal passages (ET1) and the posterior nasal and oral passages (ET2). This study assessed how well a polyurethane foam insert placed in an Institute of Occupational Medicine (IOM) sampler can match an extrathoracic deposition sampling convention, while accounting for possible static buildup in the test particles. In this way, the study aimed to assess whether neutralized particles affected the performance of this sampler for estimating extrathoracic particle deposition. A total of three different particle sizes (4.9, 9.5, and 12.8 µm) were used. For each trial, one particle size was introduced into a low-speed wind tunnel with a wind speed set a 0.2 m/s (â¼40 ft/min). This wind speed was chosen to closely match the conditions of most indoor working environments. Each particle size was tested twice either neutralized, using a high voltage neutralizer, or left in its normal (non neutralized) state as standard particles. IOM samplers were fitted with a polyurethane foam insert and placed on a rotating mannequin inside the wind tunnel. Foam sampling efficiencies were calculated for all trials to compare against the normalized ET1 sampling deposition convention. The foam sampling efficiencies matched well to the ET1 deposition convention for the larger particle sizes, but had a general trend of underestimating for all three particle sizes. The results of a Wilcoxon Rank Sum Test also showed that only at 4.9 µm was there a statistically significant difference (p-value = 0.03) between the foam sampling efficiency using the standard particles and the neutralized particles. This is interpreted to mean that static buildup may be occurring and neutralizing the particles that are 4.9 µm diameter in size did affect the performance of the foam sampler when estimating extrathoracic particle deposition.