Biphenyl Research Articles

Oral Microbiota Identifies Patients in Early Onset Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is the most common autoimmune inflammatory disease, and single periodontitis-associated bacteria have been suggested in disease manifestation. Here, the oral microbiota was characterized in relation to the early onset of RA (eRA) taking periodontal status into consideration. 16S rRNA gene amplicon sequencing of saliva bacterial DNA from 61 eRA patients without disease-modifying anti-rheumatic drugs and 59 matched controls was performed. Taxonomic classification at 98.5% was conducted against the Human Oral Microbiome Database, microbiota functions were predicted using PICRUSt, and periodontal status linked from the Swedish quality register for clinically assessed caries and periodontitis. The participants were classified into three distinct microbiota-based cluster groups with cluster allocation differences by eRA status. Independently of periodontal status, eRA patients had enriched levels of Prevotella pleuritidis, Treponema denticola, Porphyromonas endodontalis and Filifactor alocis species and in the Porphyromonas and Fusobacterium genera and functions linked to ornithine metabolism, glucosylceramidase, beta-lactamase resistance, biphenyl degradation, fatty acid metabolism and 17-beta-estradiol-17-dehydrogenase metabolism. The results support a deviating oral microbiota composition already in eRA patients compared with healthy controls and highlight a panel of oral bacteria that may be useful in eRA risk assessment in both periodontally healthy and diseased persons.

Stimulation of phenanthrene and biphenyl degradation by biochar-conducted long distance electron transfer in soil bioelectrochemical systems

The bioelectrochemical degradation of organic pollutants has attracted considerable attention owing to its remarkable sustainability and low cost. However, the application of bioelectrochemical system (BES) for the degradation of pollutants in soils is hindered by limitations in the effective distance in the soil matrix. In this study, a biochar-amended BES was constructed to evaluate the degradation of organic pollutants. This system was expected to extend the electron transfer distance via conductive biochar in soils. The results showed that biochar pyrolyzed at 900 °C facilitated the degradation of phenanthrene (PHE) and biphenyl (BP) in the soil BES (SBES), reaching 86.4%–95.1% and 88.8%–95.3% in 27 days, respectively. The effective distance of SBESs was estimated to be 154–271 cm away from the electrode, which increased 1.9–3 fold after the addition of biochar. Microbial community and functional gene analysis confirmed that biochar enriched functional degrading bacteria. These findings demonstrate that the promotion of long-distance electron transfer and the formation of soil conductive networks can be achieved by biochar amendment. Thus, this study provides a basis for the effective degradation of for persistent organic pollutants in petroleum-contaminated soils using bioelectrochemical strategy.

Non-Covalent Interactions in the Biphenyl Crystal: Is the Planar Conformer a Transition State?

A combined experimental and theoretical study of the biphenyl (BP) crystal is presented. The X-ray diffraction data collected at 100 K were subjected to Hirshfeld atom and multipole refinements of the electron density, ρ(r). A theoretical exploration of the potential energy surface (PES) of the crystal was also carried out. This investigation challenges the common assumption that the planar structure of BP in the phase I crystal is an average of two twisted configurations in a double-well potential. The theoretical computations provide compelling evidence that this structure corresponds to a minimum on the PES hence to a stable molecular arrangement. Consistently, the experiment showed no evidence of positional or dynamic disorder. The intramolecular hydrogen-hydrogen bonds detected are not repulsive. The topological analysis of the experimental and theoretical ρ(r) reveals that both the intra- and intermolecular H⋅⋅⋅H and the C-H⋅⋅⋅π contacts stabilize the BP crystal.

Improved mechanical properties of basalt fiber/phthalonitrile composites modified by thermoplastic Poly(phthalazinone ether nitrile)s

Phthalonitrile resin is a potential high-performance composite matrix, its brittleness and weak interaction with fiber are the main obstacles to its wide application. High-performance thermoplastic poly(phthalazinone ether nitrile)s (PPEN) and poly(phthalazinone ether nitrile ketone)s (PPENK) have been used to toughen basalt fiber (BF) reinforced 4,4′-bis(3,4-dicyanophenoxy)biphenyl (BPh) composite. The curing kinetics for the BPh/PPEN and BPh/PPENK blends have been investigated using DSC. The structures and thermal properties of the cured BPh blends have been studied in detail. The effects of PPEN and PPENK on the mechanical properties of the modified BF/BPh composite have been assessed. The non-notched impact strength of BF/BPh/PPENK laminate can be up to 107.7 kJ/m2, which is 64.2% higher than that of the BF/BPh laminate. And the interlaminar shear strength of BF/BPh/PPEN laminate can reach 42.5 MPa, 134.8% higher than that of the BF/BPh laminate. Simultaneously, the fracture surface of the laminate showed that the thermoplastic PPEN and PPENK can significantly inhibit the delamination between the layers and the fiber pullout and debonding.

A photogated photoswitchable [2]rotaxane based on orthogonal photoreactions

A photoswitchable [2]rotaxane with unique photogated macrocyclic shuttling is constructed by incorporating the photoswitchable azobenzene (AB) and nonphotoactive biphenyl (BP) units into the axle as two terminal recognition sites, bridged by a naphthalene (NAP) unit. The UV (λ = 379 nm)/blue (λ = 440–450 nm) lights triggered Z/E photoisomerization of the AB unit can drive the cyclobis(paraquat-p-phenylene) (CBPQT4+) macrocycle to shuttle between the two terminal recognition sites. Such macrocyclic translational movement can be photogated by a steric barrier generating from the green-light (λ = 520–525 nm)-triggered cycloaddition reaction between the NAP unit on the thread and a triazolinedione (TAD) additive. Upon standing in dark, the photocycloadduct undergoes disassociation which restores the phototriggered macrocyclic shuttling ability. The construction of such photogated photoresponsive molecular shuttle can provide new approach to improve the switching controllability of rotaxane, which is beneficial to fabricate rotaxane-based nanosystems and materials with high performance.

Novel clades of soil biphenyl degraders revealed by integrating isotope probing, multi-omics, and single-cell analyses

Most microorganisms in the biosphere remain uncultured and poorly characterized. Although the surge in genome sequences has enabled insights into the genetic and metabolic properties of uncultured microorganisms, their physiology and ecological roles cannot be determined without direct probing of their activities in natural habitats. Here we employed an experimental framework coupling genome reconstruction and activity assays to characterize the largely uncultured microorganisms responsible for aerobic biodegradation of biphenyl as a proxy for a large class of environmental pollutants, polychlorinated biphenyls. We used 13C-labeled biphenyl in contaminated soils and traced the flow of pollutant-derived carbon into active cells using single-cell analyses and protein–stable isotope probing. The detection of 13C-enriched proteins linked biphenyl biodegradation to the uncultured Alphaproteobacteria clade UBA11222, which we found to host a distinctive biphenyl dioxygenase gene widely retrieved from contaminated environments. The same approach indicated the capacity of Azoarcus species to oxidize biphenyl and suggested similar metabolic abilities for species of Rugosibacter. Biphenyl oxidation would thus represent formerly unrecognized ecological functions of both genera. The quantitative role of these microorganisms in pollutant degradation was resolved using single-cell-based uptake measurements. Our strategy advances our understanding of microbially mediated biodegradation processes and has general application potential for elucidating the ecological roles of uncultured microorganisms in their natural habitats.

Genetic mapping of highly versatile and solvent‐tolerant Pseudomonas putida B6‐2 (ATCC BAA‐2545) as a ‘superstar’ for mineralization of PAHs and dioxin‐like compounds

Polycyclic aromatic hydrocarbons (PAHs) and dioxin-like compounds, including sulfur, nitrogen and oxygen heterocycles, are widespread and toxic environmental pollutants. A wide variety of microorganisms capable of growing with aromatic polycyclic compounds are essential for bioremediation of the contaminated sites and the Earth's carbon cycle. Here, cells of Pseudomonas putida B6-2 (ATCC BAA-2545) grown in the presence of biphenyl (BP) are able to simultaneously degrade PAHs and their derivatives, even when they are present as mixtures, and tolerate high concentrations of extremely toxic solvents. Genetic analysis of the 6.37 Mb genome of strain B6-2 reveals coexistence of gene clusters responsible for central catabolic systems of aromatic compounds and for solvent tolerance. We used functional transcriptomics and proteomics to identify the candidate genes associated with catabolism of BP and a mixture of BP, dibenzofuran, dibenzothiophene and carbazole. Moreover, we observed dynamic changes in transcriptional levels with BP, including in metabolic pathways of aromatic compounds, chemotaxis, efflux pumps and transporters potentially involved in adaptation to PAHs. This study on the highly versatile activities of strain B6-2 suggests it to be a potentially useful model for bioremediation of polluted sites and for investigation of biochemical, genetic and evolutionary aspects of Pseudomonas.

Effects of Ni‐Loading on the Performance of Ni/SiO2 Catalysts for the Highly Selective Hydrogenation of Biphenyl to Cyclohexylbenzene

AbstractThis article investigated the effects of Ni loading on the performance of Ni/SiO2 catalysts for the selective hydrogenation of biphenyl (BP) to cyclohexylbenzene (CHB). The catalysts were characterized by the techniques of thermogravimetric analysis, X‐ray powder diffraction, N2‐physisorption, scanning electron microscope, inductively coupled plasma‐atomic emission spectroscopy, transmission electron microscope, H2 temperature‐programmed reduction. It was found that under the given reaction conditions, BP conversion showed an increased trend with the increasing Ni loading. However, 25 % Ni/SiO2 catalyst exhibited the lower CHB yield than 20 % Ni/SiO2 catalyst, which was attributed to the overhydrogenation of BP on the former with the excessive metal active sites. Besides, over 25 % Ni/SiO2 catalyst, BP conversion gradually increased with the extended reaction time, the enhanced hydrogen pressure or the improved temperature, but CHB selectivity and yield increased first and then decreased. Additionally, isopropanol was considered to be the best one among the representative solvents in BP hydrogenation reaction. Moreover, the conversion of BP and the selectivity/yield of CHB could keep above 99 % and 96 %, respectively, after eight consecutive cycles.

Arbuscular mycorrhizal fungus facilitates ryegrass (Lolium perenne L.) growth and polychlorinated biphenyls degradation in a soil applied with nanoscale zero-valent iron

Nanoscale zero-valent iron (nZVI) shows an excellent degradation effect on chlorinated contaminants in soil, but poses a threat to plants in combination with phytoremediation. Arbuscular mycorrhizal (AM) fungus can reduce the phyototoxicity of nZVI, but their combined impacts on polychlorinated biphenyls (PCBs) degradation and plant growth remain unclear. Here, a greenhouse pot experiment was conducted to investigate the influences of nZVI and/or Funneliformis caledonium on soil PCB degradation and ryegrass (Lolium perenne L.) antioxidative responses. The amendment of nZVI significantly reduced not only the total and homolog concentrations of PCBs in the soil, but also the ryegrass biomass as well as soil available P and root P concentrations. Moreover, nZVI significantly decreased leaf superoxide disutase (SOD) activity, while tended to decrease the protein content. In contrast, the additional inoculation of F. caledonium significantly increased leaf SOD activity and protein content, while tended to increase the catalase activity and tended to decrease the malondialdehyde content. The additional inoculation of F. caledonium also significantly increased soil alkaline phosphatase activity, and tended to increase root P concentration, but had no significantly effects on soil available P concentration, the biomass and P acquisition of ryegrass, which could be attributed to the fixation of soil available nutrients by nZVI. Additionally, F. caledonium facilitated PCB degradation in the nZVI-applied soil. Thus, AM fungus can alleviate the nZVI-induced phytotoxicity, showing great application potentials in accompany with nZVI for soil remediation.

Persistent organic pollution in Antarctic marine biota: Level, transport and risk assessment.

Although the Antarctic is considered as a pristine region away from human pollution, traditional and emerging persistent organic pollutants (POPs), such as organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and per-/polyfluoroalkyl substances (PFASs), have been constantly detected in the Antarctic, which received global concerns. POPs are persistent and toxic, prone to accumulate in organisms and further pose environmental risks. In order to understand their biogeochemical processes as well as impacts on organisms in the Antarctic, we summarized the research status of POPs in different trophic levels in the Antarctic marine, combining their living habits. We also proposed the future research directions of POPs in the vulnerable Antarctic ecosystem. Researches showed that the Antar-ctic was the region under the lowest pollution level all over the world. However, the types of POPs in Antarctic marine organisms were increasing in the past decades, meaning the area was affected increasingly by the activities inside and/or outside of this area. Scattered research data and different techniques hamper red the elucidation about the mechanism of POPs transport along the food chain. It is urgent to establish long-term monitoring and assessment program on POPs dynamics of Antarctic marine ecosystem.

Porous N self-doped carbon materials for high-performance supercapacitors via nanosized silica template combined with pyrolysis method

Advanced carbon with tunable priority and composition have been considered as the promising component for electrode materials of high-performance supercapacitor. Herein, the nitrogen self-doped porous carbon materials (NPCM) are fabricated via a one-step pyrolysis using 4,4′-bis (3,4-dicyanophenoxy) biphenyl (BPh) and nanosized silica as the precursor and sacrificial template, respectively. It was found that the obtained NPCM showed moderate specific surface area (550.5 m2 g−1) with nitrogen content of 2.1 at.%. Meanwhile, the electrode material based on the prepared NPCM exhibited great specific capacitance of 248 F g−1 at current density of 1 A g−1. The great capacitive performance is mainly due to the interaction of the following two factors: (i) the appropriate pore structure that facilitates the ion adsorption and transportation; (ii) the C–O, C=O, and N-6 functional groups derived from heteroatom doping, which contribute to increase pseudocapacitance active sites. Thanks to its tunable porosity and electrochemical properties, the novel NPCM electrode materials can have a promising prospect in the application to high-performance supercapacitors.

Validation of biphenyl degradation pathway by polymerase chain reaction, peptide mass fingerprinting and enzyme analysis

Our previous studies showed, bacterium Aquamicrobium sp. SK-2 could degrade biphenyl and polychlorinated biphenyls (PCBs). In the present study, proteins involved in the biphenyl degradation was evaluated using various molecular biology methods. The gene bphC present in the strain SK-2 was identified using the polymerase chain reaction method. Further the key enzyme in biphenyl degradation, 2,3-dihydroxybiphenyl 1,2-dioxygenase (BphC) was purified through anion exchange and gel filtration chromatography, subsequently the enzyme activity was measured. The N-terminal amino acid sequence of the purified enzyme showed 92% homology with BphC enzyme of Gram-negative bacteria (Pseudomonas sp. KKS102, Comamonas testosterone, Burkholderiaceae bacterium, Delftia acidovorans, and Achromobacter denitrificans). Fractions collected during protein purification were applied on SDS-PAGE gel. Significant bands were selected in SDS-PAGE gel, and the gel pieces were cut out to analyze the proteins using peptide mass fingerprinting (PMF) method. PMF method provided useful information about the proteins involved in biphenyl degradation. Apart from BphC, two other enzymes, benzoate dioxygenase and catechol 2,3-dioxygenase which were involved in biphenyl degradation process were identified. The results indicate that catechol can be degraded to 2-hydroxymuconic-semialdehyde and this result is in accordance with the results from our previous study. Based on all these results we can conclude that the strain SK-2 is a potential candidate for the bioremediation of biphenyl contaminated places.

Is benzoyl peroxide detectable under physiological conditions in orthopaedic cement?

Background: Until today, benzoyl peroxide (BPO) as a potential polymethyl methacrylate (PMMA) cement allergen is the subject of controversial discussion. Question/Purposes: Few cases have been reported in literature and ought to be seen critically. To address this issue, the present study aims to determine BPO and their degradation products biphenyl (BP) and benzoic acid (BA) within hardened cement as well as their elution from cement. Methods: Six ordinary cements characterised by different BPO: DmpT ratio were chosen for the study. Subsequently, cements were tested in-vitro under destructive, physiologic and non- physiologic conditions. Results: BPO was not detectable under destructive and physiological conditions. Cements with a N, N-Dimethyl-para-toluidine (DmpT) surplus contained lower BPO, BP and BA concentrations compared to cements with BPO surplus. Conclusions: Furthermore, the ratio of DmpT:BPO had an impact on the turnover of BPO and its degradation products. Clinical Relevance: Moreover, BPO and BP elution under physiological conditions was not detectable (<0.1 μg/mL in saline solution at a ratio of 1+9 cement to saline solution), calling into question whether BPO is relevant as PMMA cement allergen.

Synthesis, Characterization and Antioxidant Activity of Some New Schiff base Derived from Cytosine

Cytosine is used to synthesize several derivatives of Schiff base when reacted with some aldehydes which are refluxed by using ethanol as a solvent and non solvent with adomestic microwave (Compounds A1 – A4). These products of the Schiff base are treated first with chloroacetyl chloride to synthesize four-membered heterocycles (Compounds B1 – B4). After that, they treated with hydroxyl acetic acid to synthesize five-membered heterocyclic (Compounds C1 – C4). In the third step, the products are used to react with amaleic acid anhydride to produce seven-membered heterocyclic (Compound D1 – D4). The antioxidant activity of the compounds (A1 – A4) and two of the compounds (B1, B3), (C1, C3) and (D1, D3) in different concentrations of (100, 200, 300, 400 and 500 mg/ml) are tested with 1,2 – Di Phenyl – 2 – Picryl Hydrazyl (DPPH) for scavenging a radical activity. Finally, these compounds are diagnosed by several technical devices such as IR, proton1HN.M. R and13C N.M.R. spectroscopy.

Screening and metabolic potential of fungal strains isolated from contaminated soil and sediment in the polychlorinated biphenyl degradation

Polychlorinated biphenyls (PCBs) are widespread persistent pollutants deleterious for environment and very dangerous for human kind. As the bioremediation of PCB polluted sites by model white-rot fungi is still unsatisfactory, the use of efficient native strains which have the natural capacity to develop on polluted sites may constitute a relevant alternative strategy. In this study, we isolated 12 fungal strains from PCB contaminated soil and sediment, improved the screening method to obtain the most efficient ones in biodegradation and detoxification of PCBs and characterized potential underlying enzymatic activities. Four strains Penicillium chrysogenum, P. citreosulfuratum, P. canescens and Aspergillus jensenii, showed remarkable biodegradation capacities, greater than 70%. The remaining PCB-toxicity of their culture, including that of Trametes versicolor and Acremonium sclerotigenum, which present interesting ecological and metabolic properties, was studied. Only P. canescens was able to significantly reduce the toxicity related to PCBs and their metabolites. The enzymatic activities induced by PCBs were different according to the strains, namely laccases in T. versicolor and peroxidases in Ac. sclerotigenum. Our promising results show that the use of native fungal strains can constitute an effective strategy in the depollution of PCB polluted sites.

HETEROLOGOUS EXPRESSION OF A GENE ENCODING BIPHENYL 2,3-DIOXYGENASE FROM BURKHOLDERIA CEPACIA IN ESCHERICHIA COLI

Biphenyl 2,3-dioxygenase (BphA) is an enzyme that participates in initiation step of the pathway of biphenyl degradation in bacteria. Biphenyl is an aromatic hydrocarbon including two benzene rings that causes a serious environmental pollution. This report presents the preliminary results on the cloning and expression of BphA gene of B. cepacia strains DF2 and DF4 which were isolated from dioxin contaminated soil in Vietnam. The coding DNA sequences of BphA genes are 897 bp long and 99% identical. Recombinant BphA enzyme (33 kDa) has strongly expressed in E. coli M15 after induction of 0.5 mM IPTG for 4 h at 37ºC.

Chlorinated biphenyl degradation by wild yeasts pre-cultured in biphasic systems

Environmental biotechnology has developed as an offshoot from sanitary engineering, and only recently the biological component of the ecosystems had been recognized as relevant when bioremediation strategies must be chosen to solve environmental problems. Yeasts were isolated on 2,4-dichlorobiphenyl, 2,3',4- and 2,4',5-trichlorobiphenyl, poorly soluble compounds in water, as carbon sources. Debaryomyces castelli , Debaryomyces maramus and Dipodascus aggregatus composed the mixed culture and represented 72% of the isolates; their degradation potential were studied in biphasic and monophasic systems. The biphasic cultures were obtained with phenol as the organic phase and MSM as the aqueous ones, the monophasic medium only with MSM. Both cultures were supplied with 50, 100, 150 and 200 ppm DCB, TCB-3' and TCB-4' as substrate. The growth rates varied with the dispersion degree, agitation rates and cell adhesion to the organic phase. The water-phenolic system improved yeasts selection in pollutant presence with low water solubilities, indeed, the adaptation and degradation were more slowly in the monophasic aqueous medium. Bioremediation is based on the presence of efficient microbial populations and pollutant availability; the tested yeasts and the organic-water system assayed put forward the possibility that hydrophobic substrates could be mineralized in natural habitats by wild yeast consortium.

Bioconversion of biphenyl to a polyhydroxyalkanoate copolymer by Alcaligenes denitrificans A41

A polyhydroxyalkanoate (PHA) copolymer, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)], was biosynthesized from biphenyl as the sole carbon source using Alcaligenes (currently Achromobacter) denitrificans A41. This strain is capable of degrading polychlorinated biphenyls (PCBs) and biphenyl. This proof-of-concept of the conversion of aromatic chemicals such as the environmental pollutant PCBs/biphenyl to eco-friendly products such as biodegradable polyester PHA was inspired by the uncovering of two genes encoding PHA synthases in the A. denitrificans A41 genome. When the carbon/nitrogen (C/N) ratio was set at 21, the cellular P(3HB-co-3HV) content in strain A41 reached its highest value of 10.1% of the cell dry weight (CDW). A two-step cultivation protocol improved the accumulation of P(3HB-co-3HV) by up to 26.2% of the CDW, consisting of 13.0 mol % 3HV when grown on minimum salt medium without nitrogen sources. The highest cellular content of P(3HB-co-3HV) (47.6% of the CDW) was obtained through the two-step cultivation of strain A41 on biphenyl as the sole carbon source. The purified copolymer had ultra-high molecular weight (weight-average molecular weight of 3.5 × 106), as revealed through gel-permeation chromatography. Based on the genomic information related to both polymer synthesis and biphenyl degradation, we finally proposed a metabolic pathway for the production of P(3HB-co-3HV) associated with the degradation of biphenyl by strain A41.

Optimization of Solar-Photocatalytic Degradation of Polychlorinated Biphenyls using Photocatalyst (Nd/Pd/TiO2 ) by Taguchi Technique and Detection by Solid Phase Nano Extraction

Nd/Pd/TiO2 photocatalyst has been synthesized in the presence of Hydroxyl Propyl Cellulose by a sol-gel method with Titanium tetra isopropoxide as titanium precursor. Photocatalyst size and structure properties of the nano-catalyst have been determined by X-ray diffraction. It has contained the anatase phase in advance. The surface area is measured by the Brunauer, Emmett, and Teller(BET) method. The presence of Ti, Nd, and Pd in the nanostructure has been confirmed by EDX, equipped tool with SEM. Photocatalytic degradation of PCB-28 under solar light has been investigated by the Taguchi method with five factors such as the amount of HPC(gg-1sol), the percentage of Pd(%), the percentage of Nd(%), calcination temperature(°C) and calcination time(h). Under optimal conditions such as, 0.003 of HPC (gg-1sol), 0.2 percentage of Pd(%), 0.2 percentage of Nd(%), 700°C of the calcination temperature and 5hours for the calcination time, the best desorption result monitored by Solid-phase nano extraction technique(SPNE) method before degradation process. By GC-ECD, complete degradation of PCBs observed after solar irradiation in 12min, and no PCBs chromatogram observed after this time.

Effect of in vitro gastrointestinal digestion on the antioxidant potential of yogurt added with probiotic culture containing Bacillus subtilis

A adição de cultura probiótica confere potencial biofuncional aos alimentos, devido à capacidade de promover a saúde e aos efeitos bioquímicos e fisiológicos no organismo. O objetivo foi produzir iogurte com lactose e sem lactose com adição de Bacillus subtilis e avaliar o potencial antioxidante de peptídeos solúveis em água durante o período de armazenamento. Para a produção de iogurte, foi utilizado um arranjo fatorial simples para avaliar dois tipos de leite com adição da cultura probiótica contendo B. subtilis UFPEDA 86. As frações foram avaliadas (pré-digestão e pós-digestão) quanto ao potencial antioxidante de eliminação do radical do radical 2 Ácido 2'-azino-bis (ácido 3- etilbenzotiazolina -6-sulfônico) (ABTS), do 2,2'-difenil-1-picril-hidrazil (DPPH) e quelação de cobre e ferro. Na avaliação dos resultados, as frações obtidas das diferentes combinações de leite, cultura probiótica e dias de armazenamento apresentaram potencial antioxidante e capacidade quelante; as atividades apresentaram aumento significativo após o processo de digestão. Além disso, os resultados demonstraram que o B. subtilis pode ser empregado na produção de bio-iogurte com potencial antioxidante.