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1.
Appl Microbiol Biotechnol ; 107(22): 6985-6998, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37702791

RESUMO

The presence of cypermethrin in the environment and food poses a significant threat to human health. Lactic acid bacteria have shown promise as effective absorbents for xenobiotics and well behaved in wide range of applications. This study aimed to characterize the biosorption behavior of cypermethrin by Lactiplantibacillus plantarum RS60, focusing on cellular components, functional groups, kinetics, and isotherms. Results indicated that RS60 exopolysaccharides played a crucial role removing cypermethrin, with the cell wall and protoplast contributing 71.50% and 30.29% to the overall removal, respectively. Notably, peptidoglycans exhibited a high affinity for cypermethrin binding. The presence of various cellular surface groups including -OH, -NH, -CH3, -CH2, -CH, -P = O, and -CO was responsible for the efficient removal of pollutants. Additionally, the biosorption process demonstrated a good fit with pseudo-second-order and Langmuir-Freundlich isotherm. The biosorption of cypermethrin by L. plantarum RS60 involved complex chemical and physical interactions, as well as intraparticle diffusion and film diffusion. RS60 also effectively reduced cypermethrin residues in a fecal fermentation model, highlighting its potential in mitigating cypermethrin exposure in humans and animals. These findings provided valuable insights into the mechanisms underlying cypermethrin biosorption by lactic acid bacteria and supported the advancement of their application in environmental and health-related contexts. KEY POINTS: • Cypermethrin adsorption by L. plantarum was clarified. • Cell wall and protoplast showed cypermethrin binding ability. • L. plantarum can reduce cypermethrin in a fecal fermentation model.

2.
J Appl Microbiol ; 2022 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-36626738

RESUMO

AIMS: Beads containing heat-inactivated bacterial biomaterial (BBBs) were prepared for removal of cypermethrin (CPM) and the conditions for this removal were evaluated and optimized via orthogonal experiments. The adsorption characteristics of BBBs and the binding mechanism were then explored. METHODS AND RESULTS: Single-factor and orthogonal experiments were carried out to optimize five factors affecting the production and effectivity of the beads. The adsorption rate of CPM could reach 98% with beads prepared under optimized conditions: equal volumes of Lactobacillus cell debris derived from 1 × 1011 CFU; 2% hydroxypropyl-ß-cyclodextrin and 2.5% activated carbon concentration, were mixed to give mixture TM, and this and SA, was mixed 1:4 with sodium alginate (SA) and beads were prepared using a 26-Gauge needle). The best adsorption conditions were initial CPM concentration of 10 mg l-1, incubation time of 24 h, and rotational speed of 180 rpm. BBBs have a well-formed structure and abundant surface functional groups, such as -COOH, -OH, -NH, -CH, -CO, -C = C. The adsorption process conformed to pseudo-second-order kinetic, and it was also a Freundlich monolayer adsorption, and the calculated maximum adsorption capacity was 9.69 mg g-1 under optimized conditions. CONCLUSIONS: BBBs showed the highest CPM removal capacity and a good tolerance ability.

3.
J Appl Microbiol ; 2022 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-36626792

RESUMO

AIMS: Beads containing heat-inactivated bacterial biomaterial (BBBs) were prepared for removal of cypermethrin (CPM) and the conditions for this removal were evaluated and optimized via single-factor coupled orthogonal experiments based on five factors. The adsorption characteristics of BBBs and the binding mechanism were then explored. METHODS AND RESULTS: Results showed that the adsorption rate of CPM could reach 98% with beads prepared under optimized conditions: equal volumes of Lactobacillus cell debris derived from 1×1011 CFU; 2% hydroxypropyl-ß-cyclodextrin and 2.5% activated carbon concentration, were mixed to give mixture TM, and this and SA, was mixed 1:4 with sodium alginate (SA) and beads were prepared using a 26-Gauge needle). The best adsorption conditions were initial CPM concentration of 10 mg l-1, incubation time of 24 h, and rotational speed of 180 rpm. BBBs have a well-formed structure and abundant surface functional groups, such as -COOH, -OH, -NH, -CH, -CO, -C=C. The adsorption process conformed to pseudo-second-order kinetic, and it was also a Freundlich monolayer adsorption, and the calculated maximum adsorption capacity was 9.69 mg g-1 under optimized conditions. CONCLUSIONS: BBBs showed the highest CPM removal capacity and a good tolerance ability. SIGNIFICANCE AND IMPACT OF THE STUDY: Our results provided a theoretical foundation for developing an adsorbent with heat-inactivated Lactobacillus plantarum (L. plantarum) RS60 for removing CPM in wastewater or drinks.

4.
Int J Mol Sci ; 23(10)2022 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-35628620

RESUMO

3-PBA is a major degradation intermediate of pyrethroids. Its widespread existence in the environment poses a severe threat to the ecosystem and human health. This study evaluated the adsorption capacity of L. plantarum RS20 toward 3-PBA. Batch adsorption experiments indicated that the optimal adsorption conditions were a temperature of 37 °C and initial pH of 6.0-8.0, under which the removal rate was positively correlated with the cell concentration. In addition, there was no link between the incubation time and adsorption rate. The kinetic study showed that the adsorption process fitted well with the pseudo-second-order model, and the adsorption isotherms could be described by both Langmuir and Freundlich equations. Heat and acid treatments showed that the ability of strain RS20 in removing 3-PBA was independent of microbial vitality. Indeed, it was involved with chemisorption and physisorption via the cell walls. The cell walls made the highest contribution to 3-PBA removal, according to the adsorption experiments using different cellular components. This finding was further reconfirmed by SEM. FTIR spectroscopy analysis indicated that carboxyl, hydroxyl, amino groups, and -C-N were the functional sites for the binding of 3-PBA. The co-culture experiments showed that the adsorption of strain RS20 enhanced the degradation of 3-PBA by strain SC-1. Strain RS20 could also survive and effectively remove 3-PBA in simulated digestive juices. Collectively, strain RS20 could be employed as a biological detoxification agent for humans and animals by eliminating 3-PBA from foods, feeds, and the digestive tract in the future.


Assuntos
Lactobacillus plantarum , Poluentes Químicos da Água , Adsorção , Benzoatos , Ecossistema , Poluentes Químicos da Água/química
5.
BMC Microbiol ; 20(1): 147, 2020 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-32503433

RESUMO

BACKGROUND: Earthen sites are immobile cultural relics and an important part of cultural heritage with historical, artistic and scientific values. The deterioration of features in earthen sites result in permanent loss of cultural information, causing immeasurable damage to the study of history and culture. Most research on the deterioration of earthen sites has concentrated on physicochemical factors, and information on microbial communities in earthen sites and their relationship with the earthen site deterioration is scarce. We used high-throughput sequencing to analyze bacterial and fungal communities in soils from earthen walls with different degree of deterioration at Jinsha earthen site to characterize the microbial communities and their correlation with environmental factors, and to compare microbial community structures and the relative abundances of individual taxa associated with different degree of deterioration for identifying possible marker taxa. RESULTS: The relative abundances of Proteobacteria and Firmicutes were higher and that of Actinobacteria lower with higher degree of deterioration. At the genus level, the relative abundances of Rubrobacter were highest in all sample groups except in the most deteriorated samples where that of Bacteroides was highest. The relative abundance of the yeast genus Candida was highest in the severely deteriorated sample group. The bacterial phylum Bacteroidetes and genus Bacteroides, and fungal class Saccharomycetes that includes Candida sp. were specific for the most deteriorated samples. For both bacteria and fungi, the differences in community composition were associated with differences in EC, moisture, pH, and the concentrations of NH4+, K+, Mg2+, Ca2+ and SO42-. CONCLUSION: The microbial communities in soil with different degree of deterioration were distinctly different, and deterioration was accompanied with bigger changes in the bacterial than in the fungal community. In addition, the deteriorated soil contained higher concentrations of soluble salts. Potentially, the accumulation of Bacteroides and Candida plays an important role in the deterioration of earthen features. Further work is needed to conclude whether controlling the growth of the bacteria and fungi with high relative abundances in the deteriorated samples can be applied to alleviate deterioration.


Assuntos
Bactérias/classificação , Fungos/classificação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA/métodos , Solo/química , Arqueologia , Bactérias/genética , Bactérias/isolamento & purificação , China , DNA Bacteriano/genética , DNA Fúngico/genética , DNA Ribossômico/genética , Fungos/genética , Fungos/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala , Filogenia , Microbiologia do Solo
6.
Anal Bioanal Chem ; 412(5): 1049-1062, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31853602

RESUMO

Magnetic molecular imprinted polymers with ionic liquid used as an auxiliary solvent (IL@MMIPs) for the recognition of the methyl carbamate pesticide carbaryl (CBR) in foodstuff have been synthesized. The properties and application of IL@MMIPs were determined. The kinetic and isotherm adsorption processes were found to follow the pseudo-second-order and the Scatchard models, respectively. The selective experiment showed that the IL@MMIPs exhibited good selectivity to CBR compared to magnetic nonimprinted polymers with IL (IL@MNIPs). By using the IL@MMIPs as an adsorbent for the enrichment of CBR in food samples, the limit of detection (LOD, S/N = 3) and the limit of quantitation (LOQ, S/N = 10) of this method were 3 µg kg-1 and 10 µg kg-1, respectively. Compared with the traditional method, the IL@MMIP method has better recoveries (83.23-99.83%), precision (1.12-2.09%), and stabilization (intraday, 1.08-2.81%; interday, 2.26-3.30%). IL@MMIPs are an ideal adsorbent that could be applied to conveniently detect CBR in complex food, and the proposed method can be considered as a selective and sensitive alternative to traditional methods with affordable cost, avoiding the complex pretreatment procedure. Graphical abstract .


Assuntos
Carbaril/isolamento & purificação , Contaminação de Alimentos/análise , Inseticidas/análise , Líquidos Iônicos/química , Nanopartículas de Magnetita/química , Impressão Molecular , Polímeros/química , Adsorção , Cristalografia por Raios X , Cinética , Limite de Detecção , Microscopia Eletrônica de Varredura , Reprodutibilidade dos Testes , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica
7.
Biodegradation ; 31(1-2): 139-152, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32306137

RESUMO

Pesticides introduced inadvertently or deliberately into environment by anthropogenic activity have caused growing global public concern, therefore the search of approaches for elimination of such xenobiotics should be encouraged. A cypermethrin-degrading bacterial strain Bacillus licheniformis B-1 was found to efficiently degrade carbaryl in LB medium at concentrations of 50-300 mg L-1 within 48 h, during which temperature and pH played important roles as reflected by increase in pollutant depletion. A stimulatory effect of Fe3+ and Mn2+ on microbial growth was observed, whereas Cu2+ caused inhibition of degradation. Results showed that 1-naphthol was a major transformation product of carbaryl which was further metabolised. An approximately 29 kDa carbaryl-degrading enzyme was purified from B-1 with 15.93-fold purification and an overall yield of 6.02% was achieved using ammonium sulphate precipitation, DEAE-Sepharose CL-6B anion-exchange chromatography and Sephadex G-100 gel filtration. The enzyme was identified through nano reversed-phase liquid chromatography coupled with hybrid triple quadrupole time-of-flight mass spectrometry as a phosphodiesterase (PDE). This is the first report on the characterization of carbaryl-degrading by Bacillus spp. and the role of a PDE in carbaryl-detoxifying. Also, strain B-1 showed versatile in carbosulfan, isoprocarb and chlorpyrifos degradation, demonstrating as ideal candidate for environment bioremediation.


Assuntos
Bacillus licheniformis , Clorpirifos , Biodegradação Ambiental , Carbaril , Hidrolases
8.
Mikrochim Acta ; 187(1): 40, 2019 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-31828439

RESUMO

The authors have synthesized a phosphorescent probe of type SiO2-QD-MIP, where QD stands for Mn:ZnS quantum dots and MIP is a polymer coating that was molecularly imprinted with cephalexin. The nanoprobe with high specificity was prepared via sol-gel polymerization using thioglycolic acid (TGA)-modified QDs as luminescent materials, cephalexin as the template, 3-aminopropyltriethoxysilane as the functional monomer, and tetraethoxysilane as the crosslinking agent. The SiO2-QD-MIPs were characterized by X-ray powder diffraction, transmission electron microscopy, scanning electron microscopy, and Fourier transform infrared spectrometry. The orange emission of the probe, with excitation/emission maxima at 295/590 nm, decreases linearly in the 2.5-50 µg·L-1 cephalexin concentration range with a limit of detection (LOD) of 0.81 µg·L-1. The nanoprobe was successfully applied to the determination of cephalexin in (spiked) raw milk and milk powder. The recoveries ranged from 91.7 to 103.7%.


Assuntos
Cefalexina/análise , Substâncias Luminescentes/química , Impressão Molecular , Polímeros/química , Pontos Quânticos/química , Tioglicolatos/química , Substâncias Luminescentes/síntese química , Manganês/química , Estrutura Molecular , Tamanho da Partícula , Porosidade , Sulfetos/química , Propriedades de Superfície , Compostos de Zinco/química
9.
Artigo em Inglês | MEDLINE | ID: mdl-38683273

RESUMO

Phthalate acid esters (PAEs) and their metabolites, such as di-n-butyl phthalate (DBP) and mono-n-butyl phthalate (MBP), are known to cause male reproductive damage. Lactiplantibacillus plantarum RS20D has demonstrated the ability to remove both DBP and MBP in vitro, suggesting its potential as a detoxifying agent against these compounds. This study aimed to investigate the protective effects of RS20D on DBP or MBP-induced male reproductive toxicity in adolescent rats. Oral administration of RS20D significantly mitigated the histological damage to the testes caused by MBP or DBP, restored sperm concentration, morphological abnormalities, and the proliferation index in MBP-exposed rats, and partially reversed spermatogenic damage in DBP-exposed rats. Furthermore, RS20D restored serum levels of estradiol (E2) and testosterone, and superoxide dismutase (SOD) activity in DBP-exposed rats, significantly increased testosterone levels in MBP-exposed rats, and restored copper (Cu) concentrations in the testes after exposure to DBP or MBP. Additionally, RS20D effectively modulated the intestinal microbiota in DBP-exposed rats and partially ameliorated dysbiosis induced by MBP, which may be associated with the alleviation of reproductive toxic effects induced by DBP or MBP. In conclusion, this study demonstrates that RS20D administration can alleviate male reproductive toxicity and gut dysbacteriosis induced by DBP or MBP exposure, providing a dietary strategy for the bioremediation of PAEs and their metabolites.

10.
Front Microbiol ; 14: 1226031, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37520381

RESUMO

Several lactic acid bacteria (LAB) are double-edged swords in the production of Sichuan bran vinegar; on the one hand, they are important for the flavour of the vinegar, but on the other hand, they result in vinegar deterioration because of their gas-producing features and their acid resistance. These characteristics intensify the difficulty in managing the safe production of vinegar using strains such as Acetilactobacillus jinshanensis subsp. aerogenes Z-1. Therefore, it is necessary to characterize the mechanisms underlying their acid tolerance. The results of this study showed a survival rate of 77.2% for Z-1 when exposed to pH 3.0 stress for 1 h. This strain could survive for approximately 15 days in a vinegar solution with 4% or 6% total acid content, and its growth was effectively enhanced by the addition of 10 mM of arginine (Arg). Under acidic stress, the relative content of the unsaturated fatty acid C18:1 (n-11) increased, and eight amino acids accumulated in the cells. Meanwhile, based on a transcriptome analysis, the genes glnA, carA/B, arcA, murE/F/G, fabD/H/G, DnaK, uvrA, opuA/C, fliy, ecfA2, dnaA and LuxS, mainly enriched in amino acid transport and metabolism, protein folding, DNA repair, and cell wall/membrane metabolism processes, were hypothesized to be acid resistance-related genes in Z-1. This work paves the way for further clarifying the acid tolerance mechanism of Z-1 and shares applicable perspectives for vinegar brewing.

11.
Front Microbiol ; 14: 1135912, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36876092

RESUMO

Cereal vinegar is usually produced through solid-state fermentation, and the microbial community plays an important role in fermentation. In this study, the composition and function of Sichuan Baoning vinegar microbiota at different fermentation depths were evaluated by high-throughput sequencing combined with PICRUSt and FUNGuild analysis, and variations in volatile flavor compounds were also determined. The results revealed that no significant differences (p > 0.05) were found in both total acid content and pH of vinegar Pei collected on the same day with different depths. There were significant differences between the bacterial community of samples from the same day with different depths at both phylum and genus levels (p < 0.05), however, no obvious difference (p > 0.05) was observed in the fungal community. PICRUSt analysis indicated that fermentation depth affected the function of microbiota, meanwhile, FUNGuild analysis showed that there were variations in the abundance of trophic mode. Additionally, differences in volatile flavor compounds were observed in samples from the same day with different depths, and significant correlations between microbial community and volatile flavor compounds were observed. The present study provides insights into the composition and function of microbiota at different depths in cereal vinegar fermentation and quality control of vinegar products.

12.
Int J Food Microbiol ; 404: 110319, 2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-37473468

RESUMO

Salmonella has presented increasingly alarming rates of antimicrobial resistance believed to be a result of a high prevalence of integrons. It is speculated that disinfectant-resistant isolates are due to the expression of qacEΔ1, an efflux pump located in the 3' conserved sequence (3'CS) of class 1 integrons. With this concern, we tested the antibiotic and disinfectant resistance of 581 Salmonella strains collected from different sources, and characterized their integron structures. Gene expression and induction experiments were also performed. Results showed that Salmonella have high resistance to antimicrobials, especially to sulfonamides (SAs, 78.83 %), tetracyclines (TCs, 75.04 %) and benzalkonium chloride (BC, 87.26 %). The multi-drug resistance (MDR) frequency reached up to 63.17 %, and the prevalence of intI1 was 45.78 %. Molecular characterization of class 1 integrons exhibited nine different gene cassette arrays, of these, dfrA12-orf-aadA2 (n = 75), EstX (n = 25) and aadA2 (n = 14) were the most frequent. Importantly, 74.06 % of intI1-positive isolates were carrying qacEΔ1-sul1 genes in the 3'CS. This study also demonstrated that phenotypic resistance to both antibiotics and disinfectants was significantly correlated with the emergence of intI1 (p < 0.05). 91.37 % of qacEΔ1-sul1 positive Salmonella were found with disinfectant resistance. Additionally, expression of qacEΔ1 gene in Escherichia coli confirmed qacEΔ1 is predominantly involved in conferring disinfectant resistance. Disinfectant induction experiments further implicated qacEΔ1 in disinfectant resistance. RT-qPCR revealed a disinfectant-mediated increase in the relative expression of antibiotic-resistant genes (ARGs), aadA2 and dfrA12 on the integron, and efflux pump genes (mdtH and acrD) indicating that disinfectant could trigger co or cross-resistance. Therefore, our study confirmed that using disinfectant could provide selection pressure for strains with acquired resistance to antibiotics, providing new insights into the public health impact of Salmonella and guide continued efforts in antimicrobial stewardship and prevention of antibiotic resistance.


Assuntos
Desinfetantes , Integrons , Integrons/genética , Antibacterianos/farmacologia , Desinfetantes/farmacologia , Salmonella , Escherichia coli , Farmacorresistência Bacteriana Múltipla/genética , Farmacorresistência Bacteriana/genética , Testes de Sensibilidade Microbiana
13.
Int J Food Microbiol ; 394: 110167, 2023 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-36913840

RESUMO

To understand the deterioration of vinegar that has frequently occurred in China recently and to address such a concern, the physicochemical indicators and bacterial structure of the spoiled vinegar collected from Sichuan were preliminarily investigated. Results showed that Lactobacillaceae was most likely responsible for the decrease of vinegar total sugar and furfural, through which total acid and furfuryl alcohol were generated. Then, an unreported difficult-to-cultivate gas-producing bacterium named Z-1 was isolated using a modified MRS medium. Strain Z-1 was identified as Acetilactobacillus jinshanensis subsp. aerogenes on the basis of physiological, biochemical, molecular biological and whole genome analyses. According to the investigation, such species was present throughout the fermentation process and not limited in Sichuan. The analysis of genetic diversity indicated that all the obtained A. jinshanensis isolates displayed high sequence similarity and an absence of recombination. Although it demonstrated acid resistance, Z-1 could be completely deactivated through heating (60 °C). Based on the above results, suggestions for safe production are made for vinegar enterprises.


Assuntos
Ácido Acético , Bactérias , Ácido Acético/farmacologia , Ácido Acético/análise , Bactérias/genética , Fermentação , Lactobacillaceae , China
14.
Microorganisms ; 11(11)2023 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-38004736

RESUMO

In order to explore the structural changes and products of histamine degradation by multicopper oxidase (MCO) in Lactiplantibacillus plantarum LPZN19, a 1500 bp MCO gene in L. plantarum LPZN19 was cloned, and the recombinant MCO was expressed in E. coli BL21 (DE3). After purification by Ni2+-NTA affinity chromatography, the obtained MCO has a molecular weight of 58 kDa, and it also has the highest enzyme activity at 50 °C and pH 3.5, with a relative enzyme activity of 100%, and it maintains 57.71% of the relative enzyme activity at 5% salt concentration. The secondary structure of MCO was determined by circular dichroism, in which the proportions of the α-helix, ß-sheet, ß-turn and random coil were 2.9%, 39.7%, 21.2% and 36.1%, respectively. The 6xj0.1.A with a credibility of 68.21% was selected as the template to predict the tertiary structure of MCO in L. plantarum LPZN19, and the results indicated that the main components of the tertiary structure of MCO were formed by the further coiling and folding of a random coil and ß-sheet. Histamine could change the spatial structure of MCO by increasing the content of the α-helix and ß-sheet. Finally, the LC-MS/MS identification results suggest that the histamine was degraded into imidazole acetaldehyde, hydrogen peroxide and ammonia.

15.
Foods ; 12(19)2023 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-37835356

RESUMO

Traditional fermented milk from the western Sichuan plateau of China has a unique flavor and rich microbial diversity. This study explored the quality formation mechanism in fermented milk inoculated with Lactobacillus brevis NZ4 and Kluyveromyces marxianus SY11 (MFM), the dominant microorganisms isolated from traditional dairy products in western nan. The results indicated that MFM displayed better overall quality than the milk fermented with L. brevis NZ4 (LFM) and K. marxianus SY11 (KFM), respectively. MFM exhibited good sensory quality, more organic acid types, more free amino acids and esters, and moderate acidity and ethanol concentrations. Non-targeted metabolomics showed a total of 885 metabolites annotated in the samples, representing 204 differential metabolites between MFM and LFM and 163 between MFM and KFM. MFM displayed higher levels of N-acetyl-L-glutamic acid, cysteinyl serine, glaucarubin, and other substances. The differential metabolites were mainly enriched in pathways such as glycerophospholipid metabolism, arginine biosynthesis, and beta-alanine metabolism. This study speculated that L. brevis affected K. marxianus growth via its metabolites, while the mixed fermentation of these strains significantly changed the metabolism pathway of flavor-related substances, especially glycerophospholipid metabolism. Furthermore, mixed fermentation modified the flavor and quality of fermented milk by affecting cell growth and metabolic pathways.

16.
Wei Sheng Wu Xue Bao ; 52(4): 519-25, 2012 Apr 04.
Artigo em Zh | MEDLINE | ID: mdl-22799218

RESUMO

OBJECTIVE: To investigate the bacteria community and biodiversity of four-years pickled Yanshan Dongcai. METHODS: We studied the bacterial communities of Dongcai by 16S rDNA diversity analysis and the cultured species isolated from Dongcai sample by Restriction Fragment Length Polymorphism (RFLP) and 16S rRNA gene sequence analysis. RESULTS: The 16S rDNA diversity showed that the bacteria belonged to the phyla Proteobacteria (87.9% ) and Firmicutes (7.1% ), including many moderately halophilic bacteria such as Virgibacillus kekensis, Marinococcus albus, Salinicoccus sp., Lactobacillus halophilus and Halomonas. Only 5% of clone sequences belonged to the phylum Actinobacteria. Thirty-five strains were isolated from Dongcai sample, and 16S rDNA-RFLP analysis indicated that 34 isolates affiliated with the phylum Firmicutes, including Virgibacillus, Bacillus megaterium and Gracilibacillus saliphilus which were moderately halophilic bacteria, but only one isolate belonged to the phylum Actinobacteria. CONCLUSION: The bacterial diversity is low in Dongcai, dominated by moderately halophilic bacteria.


Assuntos
Bactérias/isolamento & purificação , Mostardeira/microbiologia , Bactérias/classificação , Polimorfismo de Fragmento de Restrição , RNA Ribossômico 16S/genética
17.
Front Microbiol ; 13: 924398, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35783382

RESUMO

Bakery products are nutritious, but they are susceptible to fungal contamination, which leads to a decline in quality and safety. Chemical preservatives are often used to extend the shelf-life of bakery products, but long-term consumption of these preservatives may increase the risk of chronic diseases. Consumers increasingly demand food with fewer chemical preservatives. The application of lactic acid bacteria (LAB) as a novel biological preservative not only prolongs the shelf-life of bakery products but also improves the baking properties of bakery products. This review summarizes different types and action mechanisms of antifungal compounds produced by LAB, factors affecting the production of antifungal compounds, and the effects of antifungal LAB on bakery products, providing a reference for future applications of antifungal LAB in bakery products.

18.
Food Chem ; 374: 131743, 2022 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-34915365

RESUMO

Pleioblastus amarus (P. amarus) shoots, belong to the grass family Gramineae, a traditional green vegetable in China, are rich in nutritional properties, and can provide various health benefits. This study isolated four compounds, namely (1-4), 3-O-coumaroylquinic acid (1), 3-O-feruloylquinic acid (2), 4-O-feruloylquinic acid (3), and 5-O-feruloylquinic acid (4) from Pleioblastus amarus shoots for the first time. The structures of the extracted compounds were determined using detailed spectroscopic (1D/2D NMR), high resolution electrospray ionization mass spectrometry (HR-ESI-MS), and infrared (IR) spectroscopy. The antioxidant capacity of 3-O-feruloylquinic acid (2) was stronger than that of the other compounds, while it also exhibited anti-inflammatory activity, significantly restricting the release of nitric oxide (NO) by lipopolysaccharide (LPS)-induced RAW 264.7 cells, displaying an inhibitory rate of 60.92 percent at a concentration of 400 µg/mL. Furthermore, 3-O-feruloylquinic acid (2) inhibited interleukin-1ß (IL-1ß), interleukin-6 (IL-6), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and nuclear factor-κB (NF-κB) expression and may be useful for developing novel antioxidant and anti-inflammatory substances.


Assuntos
Anti-Inflamatórios , Antioxidantes , Animais , Ciclo-Oxigenase 2/metabolismo , Lipopolissacarídeos , Camundongos , NF-kappa B/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Poaceae/metabolismo , Células RAW 264.7
19.
Foods ; 11(16)2022 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-36010413

RESUMO

Herein, N, S co-doped carbon quantum dots (N, S-CDs) with high absolute quantitative yield (Abs-QY) of 50.2% were produced by hydrothermal treatment of food residue crayfish shells. A new detection method of thiamphenicol (TAP) and its analogues was established by discovering the obvious fluorescence response between TAP and N, S-CDs, which achieved a wide linear range of 20-300 µg·L-1 with a detection limit (LOD) of 11.12 µg·L-1. This novel probe exhibited strong sensitivity and shows rapid response in complex food matrices (overall detection time is less than 45 min) mainly induced by static quenching. Spiked food sample recovery ranged from 97.3 to 99.34%. Further, the cell experiments of N, S-CDs were conducted, and the cell viability remained 91.76% under high concentration of N, S-CDs due to the environmentally friendly materials. The low cytotoxicity and good cytocompatibility make these N, S-CDs compatible for cell bioimaging and intracellular detection of TAP.

20.
Food Res Int ; 150(Pt A): 110768, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34865783

RESUMO

Vinegar is consumed worldwide as a food condiment, especially in the Chinese diet. The present study optimized the addition of A. niger biofortified-bran Qu (0.3%, 0.45%, and 0.6%) as additional starter to improve total acid content and starch utilization rate in industrial-scale Baoning vinegar production. In addition, this novel study determined the quality and microbial community changes of Baoning vinegar during three-round biofortification in industrial scale. Our results indicated that A. niger biofortified-bran Qu added at 0.6% resulted in higher total acid content and starch utilization rate of vinegar Pei. Biofortification imposed minor changes in the microbial community during three-round biofortification, and more variation was observed in fungal community than that in bacterial community. Most importantly, the quality of Baoning vinegar remained relatively stable. This information further confirmed the feasibility of multiple rounds of A. niger biofortification, and can be used to provide theoretical basis for industrial-scale production.


Assuntos
Ácido Acético , Microbiota , Aspergillus niger , Bactérias , Biofortificação
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