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1.
Bioresour Technol ; 296: 122369, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31732415

RESUMO

The suitable feeding strategy considering both substrate preference (enrichment stage) and flexible regulation (PHA accumulation stage) were investigated, respectively, based on intracellular polymers synthesis peculiarities of the three types of cultures (M-Ac, M-Pr and M-Bu), which were enriched correspondingly using acetic type, propionic type and butyric type substrate. Compared to M-Ac and M-Bu cultures, maximum PHA content (PHAm) of M-Pr exhibited the most stable responses to varying fractions of propionic acid (fPr) of the substrate. The substrate composed of acetic acid and propionic acid (Mix-AP) demonstrated higher efficiency in regulation of polymer composition than that composed of butyric acid and propionic acid (Mix-BP). For the whole process of three-stage MC PHA production, propionic acid-dominated acidification products should be used for the long-term enrichment of PHA producers, and acidification products mainly composed of propionic and acetic acid are preferred considering the regulation of polymer composition in PHA accumulation stage.


Assuntos
Microbiota , Poli-Hidroxialcanoatos , Ácido Acético , Reatores Biológicos , Controle Social Formal
2.
Bull Cancer ; 106(11): 1008-1022, 2019 Nov.
Artigo em Francês | MEDLINE | ID: mdl-31606139

RESUMO

With more than 3300 new cases and almost 2500 deaths each year, cervical cancer (CC) ranks second among female cancers in Moroccan women. The majority of cases occurs in women aged 50 and over. In absence of a national cancer registry, data published in Morocco are limited to the number of cases recorded in some oncology centers, so the incidence of this cancer is likely much higher than estimated. A Moroccan national program against CC based on the practice of visual inspection after application of acetic acid was set up in 2010, allowing both screening and possibly immediate treatment of (pre)cancerous lesions. However, this program has not been implemented in all regions of the country. The CC develops slowly and most often without any symptoms, and so it is diagnosed at an advanced stage of the disease. Virtually, all CC are associated with persistent infection of high risk human papillomavirus (HPV), particularly HPV16 and 18. For more than ten years, two prophylactic vaccines targeting these two HPV genotypes have been marketed. They have proved their excellent immunogenicity and efficacy and they are well tolerated. However, HPV vaccine is not yet recommended by health authorities in Morocco. In this literature review, we focused on the current situation of CC, the prevalence of HPV infection and the prevention strategies against CC in Morocco.


Assuntos
Infecções por Papillomavirus/prevenção & controle , Lesões Pré-Cancerosas/prevenção & controle , Neoplasias do Colo do Útero/prevenção & controle , Ácido Acético/administração & dosagem , Adulto , Algoritmos , Coinfecção/epidemiologia , Detecção Precoce de Câncer/métodos , Feminino , Infecções por HIV/epidemiologia , Papillomavirus Humano 16/imunologia , Papillomavirus Humano 18/imunologia , Humanos , Incidência , Indicadores e Reagentes/administração & dosagem , Pessoa de Meia-Idade , Marrocos/epidemiologia , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/epidemiologia , Vacinas contra Papillomavirus/administração & dosagem , Lesões Pré-Cancerosas/diagnóstico , Lesões Pré-Cancerosas/epidemiologia , Lesões Pré-Cancerosas/virologia , Prevenção Primária , Sistema de Registros/estatística & dados numéricos , Gestão de Riscos , Prevenção Secundária , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/virologia
3.
Int J Food Microbiol ; 310: 108331, 2019 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-31479829

RESUMO

Lack of the prezygotic barrier in the Saccharomyces genus facilitates the construction of artificial interspecific hybrids among different Saccharomyces species. Hybrids that maintain the interesting features of parental strains have been applied in industry for many beneficial purposes. Two of the most important problems faced by wine makers is nitrogen deficiency in grape must and low-temperature fermentation. In our study, hybrids were constructed by using selected low nitrogen-demanding cryotolerant S. eubayanus, S. uvarum strains and S. cerevisiae. The fermentation capacity of the hybrid strains was tested under four conditions by combining two temperatures, 12 °C and 28 °C, and two nitrogen concentrations, 60 mg/L and 300 mg/L. The hybrid strains obtained combined characters of both parental strains and conferred better fermentation rates under low-temperature or low-nitrogen conditions. The hybrid strains also produced larger amounts of acetate esters and higher alcohols, which increase aroma intensity and complexity in wine. Nitrogen sources were more rapidly consumed by the hybrid strains, which allows greater competition ability under nitrogen-deficiency conditions. Therefore, the interspecific hybridisation between low nitrogen-demanding cryotolerant strains and S. cerevisiae is a potential solution for low-temperature or low-nitrogen fermentations.


Assuntos
Temperatura Baixa , Fermentação , Microbiologia de Alimentos/métodos , Hibridização Genética , Nitrogênio , Saccharomyces , Vinho/microbiologia , Ácido Acético/metabolismo , Álcoois/metabolismo , Biotecnologia , Ésteres/metabolismo , Nitrogênio/metabolismo , Odorantes , Saccharomyces/classificação , Saccharomyces/genética , Saccharomyces/metabolismo , Vitis/microbiologia
4.
Bioresour Technol ; 293: 122032, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31491647

RESUMO

Two de-lignified cellulose of loofah sponge and sawdust were applied in two ways to enhance the lipid production from oleaginous yeast using acetic acid. When 30 g/L of acetic acid was used as a carbon source, direct addition of de-lignified loofah sponge or sawdust increased the extracellular lipid content to 33.94% and 53.25%, respectively. The latter reduced the energy input of lipid extraction process from 0.86 to 0.57 GJ per ton of biodiesel production. To relieve the inhibition caused by 40 g/L acetic acid, immobilization of oleaginous yeast on de-lignified sawdust increased the lipid concentration and yield from 3.83 g/L, 0.18 g/g C to 7.15 g/L, 0.20 g/g C, respectively. These improvements occurred due to the cell-immobilized sawdust which play an important role in the loading of cells and adsorption of acetic acid. Immobilized cultivation also increased the fatty acid proportion of C18:1, thereby improving biodiesel performance.


Assuntos
Ácido Acético , Celulose , Biocombustíveis , Ácidos Graxos , Lipídeos
5.
Forensic Sci Int ; 302: 109936, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31493923

RESUMO

Stomach content is a matrix often applied in post-mortem cases. It is especially important in oral intoxication cases. The main advantages are the usually high concentration of analytes and the lack of biotransformation process. Still, even with extensive sample preparation, the final extract is not always suitable for analysis. The aim of this study was to develop an alternative method using QuEChERS for the extraction of drugs and pesticides from postmortem stomach content. Sample preparation started acetonitrile with 1% of acetic acid and QuEChERS salts. Later, the initial extract was cleaned-up using the EMR-Lipid sorbent. Residual water was withdrawn with MgSO4/NaCl in the third step and a final step with MgSO4. Vigorous shaken and centrifugation was performed after each step. The final supernatant was evaporated, re-suspended, and injected into GC-MS in full scan mode. This approach was successfully applied to stomach content, resulting in clean extracts, with low lipid levels. The method was able to detected target drugs and pesticides (cocaine, tramadol, diazepam, amytriptiline, phenobarbital, prochloraz, diazinon, heptachlor, permethrin, malathion and carbaryl) at the limit of detection of 0.1 mg/g or 0.1 mg/L. Recovery was over 70% for the majority of analytes, precision and accuracy was within acceptable range. The method was also applied to real forensic cases and carbofuran, terbuphos and fluoxetine was detected likewise. This work demonstrates that this method can provide an effective clean-up in high lipids samples such as stomach content, and can be used to analyze of pesticides and drugs in forensic cases.


Assuntos
Toxicologia Forense/métodos , Conteúdo Gastrointestinal/química , Ácido Acético , Acetonitrilos , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Sulfato de Magnésio , Entorpecentes/análise , Praguicidas/análise , Preparações Farmacêuticas/análise , Acetato de Sódio , Cloreto de Sódio
6.
J Microbiol Biotechnol ; 29(8): 1288-1298, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31370116

RESUMO

Bacterial ATP synthases drive ATP synthesis by a rotary mechanism, and play a vital role in physiology and cell metabolism. Corynebacterium glutamicum is well known as an industrial workhorse for amino acid production, and its ATP synthase operon contains eight structural genes and two adjacent genes, cg1360 and cg1361. So far, the physiological functions of Cg1360 (GenBank CAF19908) and Cg1361 (GenBank CAF19909) remain unclear. Here, we showed that Cg1360 was a hydrophobic protein with four transmembrane helices (TMHs), while no TMH was found in Cg1361. Deletion of cg1360, but not cg1361, led to significantly reduced cell growth using glucose and acetic acid as carbon sources, reduced F1 portions in the membrane, reduced ATP-driven proton-pumping activity and ATPase activity, suggesting that Cg1360 plays an important role in ATP synthase function. The intracellular ATP concentration in the Δcg1360 mutant was decreased to 72% of the wild type, while the NADH and NADPH levels in the Δcg1360 mutant were increased by 29% and 26%, respectively. However, the Δcg1361 mutant exhibited comparable intracellular ATP, NADH and NADPH levels with the wild-type strain. Moreover, the effect of cg1360 deletion on L-valine production was examined in the L-valine-producing V-10 strain. The final production of L-valine in the V-10-Δcg1360 mutant reached 9.2 ± 0.3 g/l in shake flasks, which was 14% higher than that of the V-10 strain. Thus, Cg1360 can be used as an effective engineering target by altering energy metabolism for the enhancement of amino acid production in C. glutamicum.


Assuntos
Trifosfato de Adenosina/metabolismo , Corynebacterium glutamicum/genética , Corynebacterium glutamicum/metabolismo , Deleção de Genes , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Valina/biossíntese , Ácido Acético/metabolismo , Adenosina Trifosfatases , Carbono/metabolismo , Corynebacterium glutamicum/crescimento & desenvolvimento , Metabolismo Energético , Fermentação , Ordem dos Genes , Glucose/metabolismo , NAD/metabolismo , NADP/metabolismo , Alinhamento de Sequência
8.
Bioresour Technol ; 291: 121573, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31376665

RESUMO

Upgrading lactate/carbohydrate-rich waste biomass into medium-chain carboxylic acids (MCCAs) by chain elongation (CE) technology exhibits economic and environmental benefits. However, the largely dispersive lactate-carbon-flow decreases MCCAs yield. This work discovered appropriate H2 supply could significantly reduce lactate-carbon-flow loss and improve MCCAs production (∼1.65 times) when the system is not operated according to well-defined operating conditions, and revealed corresponding mechanism. Hydrogen (H2) supply largely enhanced electron efficiency and electron transfer capacity, and H2 could reduce propionate (from competing acrylate pathway, which should be prevented, but when not possible, the carbon recovery from propionate is possible) to propanol, which was used as electron donor to elongate acetate and propionate. Moreover, H2 could react with CO2 (from CE process) to sequentially generate acetate and ethanol, which further contributed to caproate/caprylate generation. Comparing with non-H2-supplemented test, the lactate-carbon-flow used for MCCAs production was enhanced by ∼28.4% after H2 supply, and Clostridium spp. were the key discriminative microorganisms.


Assuntos
Carbono/metabolismo , Ácidos Carboxílicos/metabolismo , Hidrogênio/metabolismo , Ácido Láctico/metabolismo , Ácido Acético/metabolismo , Biomassa , Reatores Biológicos , Caproatos/metabolismo , Caprilatos/metabolismo , Etanol/metabolismo , Fermentação
9.
Bioresour Technol ; 291: 121874, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31377508

RESUMO

Anaerobic digestion is widely employed for treating phenol-containing wastewater, but there are still some drawbacks such as slow phenol degradation rate and vulnerable acetoclastic methanogens. Coupling of magnetite (Fe3O4) and zero valent iron (ZVI) was firstly used to enhance anaerobic digestion of phenol. The results indicated an obvious synergistic effect was generated with coupling of Fe3O4 and ZVI during the whole anaerobic digestion of phenol. The phenol degradation rate and methane production of Fe3O4/ZVI-added group were increased by 8.8-23.1% and 11.9-31.6%, respectively compared with Fe3O4-added group, and enhanced by 5.9-17.1% and 4.4-18.3%, respectively compared with ZVI-added group. ZVI improved the growth of hydrogenotrophic methanogens and Fe3O4 enhanced the growth of syntrophic acetate-oxidizing bacteria. Finally, the syntrophic interaction between acetate-oxidizing bacterium and hydrogenotrophic methanogens played a vital role on the synergistic effect of Fe3O4 and ZVI on the whole anaerobic phenol digestion.


Assuntos
Fenol/metabolismo , Ácido Acético/metabolismo , Anaerobiose , Euryarchaeota/metabolismo , Óxido Ferroso-Férrico , Ferro/metabolismo , Metano/metabolismo
10.
Bioresour Technol ; 292: 121941, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31401358

RESUMO

The ethanol production capability of Clostridium aceticum was investigated and optimized, in order to evaluate the ability of that organism to produce high concentrations of fuel-ethanol. The results showed that C. aceticum can produce significant amounts of ethanol when a natural pH drop occurs in the fermentation broth as a consequence of acetic acid production in a first stage. Applying different pH-regulating strategies allowed to optimize ethanol production, which proved to be more efficient in case of natural acidification due to acetic acid, reaching up to 5.6 g/L ethanol, compared to artificial pH adjustment through the addition of hydrogen chloride. Playing with the pH value and the bioreactor operating conditions showed that, under specific conditions, C. aceticum is able to perform the reverse reaction as well and convert ethanol, produced at low pH, back to acetic acid, impeding, under those specific conditions, further accumulation of ethanol in the fermentation broth.


Assuntos
Clostridium , Etanol , Ácido Acético , Reatores Biológicos , Fermentação
11.
Anticancer Res ; 39(8): 4511-4516, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31366553

RESUMO

BACKGROUND/AIM: Gluconacetobacter hansenii (G. hansenii) is an acetic acid bacterium of vinegar production. Its anti-allergic effect on mice upon oral administration was examined. MATERIALS AND METHODS: The amount of LPS was measured by the Limulus reaction. Mice were sensitized by peritoneal and intranasal administration of cedar pollen and alum followed by oral administration of 30 or 150 mg/kg of heated G. hansenii cells. Pollen was administered intranasally to evaluate nasal symptoms, and at 8 weeks, IgE and IL-10 levels in blood were measured by ELISA. RESULTS: The amount of LPS in dried bacterial cells was 10.4±3.3 mg/g. In the cedar pollinosis model of mice, a significant reduction was observed in nose scratching of both groups administered with the bacterial cells (30, 150 mg/kg). CONCLUSION: G. hansenii contains LPS, and its oral administration showed an anti-allergic effect by a significant mitigation of the symptoms in a pollen allergy mouse model.


Assuntos
Antialérgicos/administração & dosagem , Gluconacetobacter/imunologia , Pólen/efeitos adversos , Rinite Alérgica Sazonal/prevenção & controle , Ácido Acético/química , Administração Oral , Alérgenos/efeitos adversos , Animais , Antialérgicos/imunologia , Modelos Animais de Doenças , Humanos , Imunoglobulina E/imunologia , Camundongos , Rinite Alérgica Sazonal/microbiologia , Rinite Alérgica Sazonal/patologia
12.
Zhongguo Zhong Yao Za Zhi ; 44(12): 2511-2518, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31359718

RESUMO

Both raw and vinegar products of the rhizome of Curcuma phaeocaulis are common drugs for promoting blood circulation and removing blood stasis in traditional Chinese medicine,which could be reflected in the inhibition of tail thrombosis in mice. As the traditional processing theory instructs,vinegar tastes sour and bitter,but can activate blood circulation and remove stasis after being infiltrated into the rhizome of C. phaeocaulis as an excipient. In this study,under the help of the ultrafast liquid chromatography-quadrupole time-offlight mass spectrometry( UFLC-Q-TOF-MS),the spectrum-effect relationship between the inhibition of tail thrombosis in mice and the rhizome of C. phaeocaulis both before and after the vinegar processing,were established to explore the functional changes of blood circulation and stasis after vinegar process. Based on the peak area from the fingerprint of UFLC-Q-TOF-MS of the alcohol extracts from the raw and vinegar-processed rhizome of C. phaeocaulis and their efficacy for inhibiting tail thrombosis,the correlation between the chromatography of UFLC-Q-TOF-MS and the inhibition of tail thrombosis in mice were analyzed by orthogonal partial least squares discriminant analysis( OPLS-DA) method. The results,produced by Simca-P software,showed that effective components consisted of eight peaks 16,24( aromadendrene oxide),3,11,22( dehydro-α-curcumene),19[( R)-(-)-α-curcumene],23 and 10 from the fingerprint,making great contribution to distinguish C. phaeocaulis raw products and the corresponding vinegar processed products. Therefore,from the perspective of inhibiting the formation of tail thrombosis in mice,the marker components could be found through the spectrum-effect relationship to distinguish C.phaeocaulis raw and vinegar products. This study provided new basis to explain the difference between the raw and the processed products of traditional Chinese medicine in the functional change of promoting blood circulation and removing blood stasis.


Assuntos
Curcuma/química , Medicamentos de Ervas Chinesas/farmacologia , Trombose/tratamento farmacológico , Ácido Acético , Animais , Cromatografia Líquida de Alta Pressão , Medicamentos de Ervas Chinesas/química , Espectrometria de Massas , Camundongos , Rizoma/química
13.
Bioresour Technol ; 291: 121760, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31352165

RESUMO

A lab-scale stirred-tank bioreactor was reversibly retrofitted to a packed-bed and a trickle-bed biofilm reactor to study and compare the conversion of CO2/H2 with immobilised Clostridiumaceticum. The biofilm reactors were characterised and their functionality confirmed. Up to 8.6 g of C. aceticum were immobilised onto 300 g sintered ceramic carrier material, proving biofilm formation to be a robust means for cell retention of C. aceticum. Continuous CO2/H2-fermentation studies were performed with both biofilm reactor configurations as function of dilution rates, partial gas pressures and gas flow rates. The experiments showed that in the packed-bed biofilm reactor, the acetate space-time yield was independent of the dilution rate, because of low H2 gas-liquid mass transfer rates (≤17 mmol H2 L-1 h-1). The continuous operation of the trickle-bed biofilm reactor increased the gas-liquid mass transfer rates to up to 56 mmol H2 L-1 h-1. Consequently, the acetate space-time yield of up to 14 mmol acetate L-1 h-1 was improved 3-fold at hydrogen conversions of up to 96%.


Assuntos
Biofilmes , Reatores Biológicos , Dióxido de Carbono/metabolismo , Clostridium/fisiologia , Hidrogênio/metabolismo , Ácido Acético/metabolismo , Fermentação
14.
Bioresour Technol ; 289: 121716, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31323721

RESUMO

This study integrated the sugar and carboxylate platforms to enhance duckweed processing in biorefineries. Two or three bioprocesses (ethanol fermentation, acidogenic digestion, and methanogenic digestion) were sequentially integrated to maximize the carbon-to-carbon conversion of wastewater-derived duckweed into bioproducts, through a series of laboratory-scale experiments. Reactors were fed either raw (dried), liquid-hot-water-pretreated, or enzymatically-saccharified duckweed. Subsequently, the target bioproduct was separated from the reactor liquor and the residues further processed. The total bioproduct carbon yield of 0.69 ±â€¯0.07 g per gram of duckweed-C was obtained by sequential acidogenic and methanogenic digestion. Three sequential bioprocesses revealed nearly as high yields (0.66 ±â€¯0.08 g of bioproduct-C per duckweed-C), but caused more gaseous carbon (dioxide) loss. For this three-stage value cascade, yields of each process in conventional units were: 0.186 ±â€¯0.001 g ethanol/g duckweed; 611 ±â€¯64 mg volatile fatty acids as acetic acid/g VS; and 434 ±â€¯0.2 ml methane/g VS.


Assuntos
Araceae/metabolismo , Águas Residuárias/química , Ácido Acético/metabolismo , Anaerobiose , Araceae/química , Etanol/metabolismo , Euryarchaeota/metabolismo , Fermentação , Metano/biossíntese
15.
Environ Monit Assess ; 191(8): 513, 2019 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-31346830

RESUMO

In this study, a method was developed to evaluate the degradation of haloacetic acids (HAAs) in water by a heterogenous Fenton-like process catalyzed by cobalt-doped magnetite nanoparticles (Fe3 - xCoxO4), extraction of the contaminants by liquid-liquid extraction (LLE), and analysis by gas chromatography-mass spectrometry (GC-MS). The developed method was efficient in the degradation of HAAs, with the following degradation values: 63%, 62%, 30%, 39%, 37%, 50%, 84%, 41%, and 79% for monochloroacetic acid, monobromoacetic acid, dichloroacetic acid, trichloroacetic acid, bromochloroacetic acid, dibromoacetic acid, bromodichloroacetic acid, dibromochloroacetic acid, and tribromoacetic acid compounds, respectively. Through the application of the Allium cepa test, the cytotoxicity, genotoxicity, and mutagenicity of HAAs were evaluated. The results confirm its genotoxic and mutagenic effects on Allium cepa meristematic cells. Through this study, it was possible to verify the effectiveness of the developed method and its potential as a proposal for environmental remediation.


Assuntos
Bioensaio , Cloroacetatos/toxicidade , Mutagênicos/toxicidade , Testes de Toxicidade , Acetatos/toxicidade , Ácido Acético , Dano ao DNA , Ácido Dicloroacético/toxicidade , Monitoramento Ambiental , Cromatografia Gasosa-Espectrometria de Massas , Hidrocarbonetos Bromados/toxicidade , Ácido Tricloroacético/toxicidade , Água/análise , Abastecimento de Água
16.
Pol J Microbiol ; 68(2): 269-280, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31257793

RESUMO

Two glucose-limited realkalized fed-batch cultures of Lactococcus lactis CECT 539 were carried out in a diluted whey medium (DW) using two different feeding media. The cultures were fed a mixture of a 400 g/l concentrated lactose and a concentrated mussel processing waste (CMPW, 101.72 g glucose/l) medium (fermentation I) or a CMPW medium supplemented with glucose and KH2PO4 up to concentrations of 400 g glucose/l and 3.21 g total phosphorus/l, respectively (fermentation II). For an accurate description and a better understanding of the kinetics of both cultures, the growth and product formation by L. lactis CECT 539 were both modelled, for the first time, as a function of the amounts of glucose (G) added and the pH gradient (VpH) generated in every realkalization and feeding cycle, by using an empirical polynomial model. With this modeling procedure, the kinetics of biomass, viable cell counts, nisin, lactic acid, acetic acid and butane-2,3-diol production in both cultures were successfully described (R 2 values > 0.970) and interpreted for the first time. In addition, the optimum VpH and G values for each product were accurately calculated in the two realkalized fed-batch cultures. This approach appears to be useful for designing feeding strategies to enhance the productions of biomass, bacteriocin, and metabolites by the nisin-producing strain in wastes from the food industry.Two glucose-limited realkalized fed-batch cultures of Lactococcus lactis CECT 539 were carried out in a diluted whey medium (DW) using two different feeding media. The cultures were fed a mixture of a 400 g/l concentrated lactose and a concentrated mussel processing waste (CMPW, 101.72 g glucose/l) medium (fermentation I) or a CMPW medium supplemented with glucose and KH2PO4 up to concentrations of 400 g glucose/l and 3.21 g total phosphorus/l, respectively (fermentation II). For an accurate description and a better understanding of the kinetics of both cultures, the growth and product formation by L. lactis CECT 539 were both modelled, for the first time, as a function of the amounts of glucose (G) added and the pH gradient (VpH) generated in every realkalization and feeding cycle, by using an empirical polynomial model. With this modeling procedure, the kinetics of biomass, viable cell counts, nisin, lactic acid, acetic acid and butane-2,3-diol production in both cultures were successfully described (R 2 values > 0.970) and interpreted for the first time. In addition, the optimum VpH and G values for each product were accurately calculated in the two realkalized fed-batch cultures. This approach appears to be useful for designing feeding strategies to enhance the productions of biomass, bacteriocin, and metabolites by the nisin-producing strain in wastes from the food industry.


Assuntos
Antibacterianos/metabolismo , Bacteriocinas/metabolismo , Conservantes de Alimentos/metabolismo , Glucose/metabolismo , Lactococcus lactis/crescimento & desenvolvimento , Nisina/metabolismo , Probióticos/metabolismo , Ácido Acético/metabolismo , Biomassa , Fermentação/fisiologia , Concentração de Íons de Hidrogênio , Ácido Láctico/metabolismo
17.
Sci Total Environ ; 690: 956-964, 2019 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-31302559

RESUMO

In present study, a potential bacterial isolate Acetobacter pasteurianus SKYAA25 was found to be very effective in the bioconversion of apple pomace to acetic acid. The isolated strain was tolerant to high ethanol concentrations of upto 14% and temperature of 42 °C. Fermentation of apple pomace alone in presence of brewing yeast produced 7.3% of bio-ethanol which was further used for acetic acid production. Apple pomace in combination with cane molasses produced 14% of bio-ethanol. The fermented bio-ethanol was used as medium for acetic acid production which yielded 52.4 g of acetic acid/100 g of DM (Dry Matter) of apple pomace. Hence, an ecofriendly process has been developed that is entirely based on microbial processing of apple pomace to produce acetic acid without involving commercial enzymes. The present bio-conversion will prove to be beneficial for utilizing food and beverage industrial waste in the production of acetic acid.


Assuntos
Ácido Acético/metabolismo , Acetobacter/fisiologia , Adaptação Fisiológica/fisiologia , Etanol/metabolismo , Fermentação , Malus/microbiologia , Saccharomyces cerevisiae , Água/metabolismo
18.
Pan Afr Med J ; 32: 174, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31303943

RESUMO

Introduction: Precancerous cervical lesion is significantly a health problem globally. Thus, screening targeting women between the ages of 17-60 is being undertaken in developing countries, including Cameroon. Over 50% (7.8 per 100,000) women die of cervical cancer every year. This study was to determine the prevalence of precancerous cervical lesion, the age demography and access the risk factor. Methods: A hospital-based cross-sectional study was conducted from August 09th to October 17th 2017. A total of 60 women participated, and were screened for precancerous cervical lesion. Data were collected by using a questionnaire. Visual inspection with acetic acid and visual inspection with Lugol's iodine was applied for the screening. SPSS version 16.0 was used for data entry and analysis. Logistic regression analysis was fitted and odds ratios with 95% confidence intervals and p-values were computed to identify factors associated with precancerous cervical cancer lesion. Results: Out of 60 study participants, 2(3.33%) were found to be positive for precancerous cervical cancer lesion. Conclusion: The prevalence of precancerous cervical lesion in women that consulted at the Mezam polyclinic is high.


Assuntos
Colo do Útero/patologia , Programas de Rastreamento/métodos , Lesões Pré-Cancerosas/epidemiologia , Neoplasias do Colo do Útero/diagnóstico , Ácido Acético/química , Adolescente , Adulto , Camarões/epidemiologia , Estudos Transversais , Feminino , Humanos , Iodetos/química , Modelos Logísticos , Pessoa de Meia-Idade , Lesões Pré-Cancerosas/diagnóstico , Prevalência , Fatores de Risco , Inquéritos e Questionários , Neoplasias do Colo do Útero/epidemiologia , Adulto Jovem
19.
Artigo em Inglês | MEDLINE | ID: mdl-31361183

RESUMO

A simultaneous headspace-gas chromatography/mass spectrometry (HS-GC/MS) method was developed and validated to determine the migration of 12 volatile organic compounds (methanol, acetone, methylethylketone, ethylacetate, isopropylalcohol, benzene, toluene, ethylbenzene, xylene, cumene, propylbenzene, and styrene) from food contact materials into food simulants (water, 4% acetic acid, 50% ethanol, and n-heptane). The limits of detection and quantification were 0.007-0.201 mg L-1 and 0.023-0.668 mg L-1, respectively. The method was applied to 205 samples of paper/paperboard, polyethylene, polypropylene, polystyrene, and polyethylene terephthalate. The estimated daily intake (EDI) was calculated using the migration results. Exposure assessments were carried out to compare the EDI to the tolerable daily intake (TDI); the results indicated that the EDI of styrene represented only a small percentage (8.0%) of the TDI. This analytical method will be a useful tool to examine levels of various volatile compounds migrating from food packaging to food simulants using HS-GC/MS method.


Assuntos
Análise de Alimentos , Contaminação de Alimentos/análise , Embalagem de Alimentos , Compostos Orgânicos Voláteis/análise , Ácido Acético/química , Etanol/química , Cromatografia Gasosa-Espectrometria de Massas , Heptanos/química , Temperatura Ambiente , Água/química
20.
J Sci Food Agric ; 99(14): 6546-6551, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31328269

RESUMO

BACKGROUND: Proteins recovery using hydrochloric acid (HCl) in acid-aided solubilization could cause greater loss in its functionality over alkali-aided solubilization. Moreover, using HCl in edible foods is also a health concern. Replacing HCl with organic acids for acid-aided solubilization could address these problems. The aim was to study the effect of organic acid (glacial acetic acid) as a replacement for HCl during pH shift processing on the characteristics and functionality of rohu (Labeo rohita) protein isolates. Rohu proteins were obtained by solubilizing at pH 3.0 and pH 11.0 using glacial acetic acid and sodium hydroxide (10 mol L-1 ). RESULTS: Results showed that solubilization at pH 11.0 gave higher protein yields (766.8 ± 2.4 g kg-1 ) compared to solubilization at pH 3.0 (735.7 ± 7.1 g kg-1 ) (P < 0.05). Isolates from acid-aided solubilization had higher whiteness and total pigment content over isolates obtained by alkali-aided solubilization. Rohu isolates recovered by alkaline solubilization showed higher water and oil holding capacity, gel strength, folding scores, foaming and emulsion capacity than acid processed isolates (P < 0.05). Solubilization of rohu proteins using glacial acetic acid produced isolates with low breaking force (149.0 g), low storage modulus (G') values and low folding test score (1.0) over the alkaline isolates (P < 0.05). CONCLUSION: Results indicated that, recovering rohu proteins using organic acid (glacial acetic acid) could produce isolates with poor functional properties, while using the organic acid to precipitate the proteins solubilized by alkali-aided processing could produce proteins with better yields and functionality. © 2019 Society of Chemical Industry.


Assuntos
Fracionamento Químico/métodos , Proteínas de Peixes/isolamento & purificação , Manipulação de Alimentos/métodos , Ácido Acético/química , Animais , Cyprinidae , Proteínas de Peixes/química , Concentração de Íons de Hidrogênio , Solubilidade
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