RESUMO
Biomedical Microelectromechanical Systems (BioMEMS) serve as a crucial catalyst in enhancing IoT communication security and safeguarding smart healthcare systems. Situated at the nexus of advanced technology and healthcare, BioMEMS are instrumental in pioneering personalized diagnostics, monitoring, and therapeutic applications. Nonetheless, this integration brings forth a complex array of security and privacy challenges intrinsic to IoT communications within smart healthcare ecosystems, demanding comprehensive scrutiny. In this manuscript, we embark on an extensive analysis of the intricate security terrain associated with IoT communications in the realm of BioMEMS, addressing a spectrum of vulnerabilities that spans cyber threats, data manipulation, and interception of communications. The integration of real-world case studies serves to illuminate the direct repercussions of security breaches within smart healthcare systems, highlighting the imperative to safeguard both patient safety and the integrity of medical data. We delve into a suite of security solutions, encompassing rigorous authentication processes, data encryption, designs resistant to attacks, and continuous monitoring mechanisms, all tailored to fortify BioMEMS in the face of ever-evolving threats within smart healthcare environments. Furthermore, the paper underscores the vital role of ethical and regulatory considerations, emphasizing the need to uphold patient autonomy, ensure the confidentiality of data, and maintain equitable access to healthcare in the context of IoT communication security. Looking forward, we explore the impending landscape of BioMEMS security as it intertwines with emerging technologies such as AI-driven diagnostics, quantum computing, and genomic integration, anticipating potential challenges and strategizing for the future. In doing so, this paper highlights the paramount importance of adopting an integrated approach that seamlessly blends technological innovation, ethical foresight, and collaborative ingenuity, thereby steering BioMEMS towards a secure and resilient future within smart healthcare systems, in the ambit of IoT communication security and protection.
Assuntos
Sistemas Microeletromecânicos , Privacidade , Humanos , Metodologias Computacionais , Ecossistema , Teoria Quântica , Comunicação , Atenção à Saúde , Segurança ComputacionalRESUMO
The corrosion inhibition of 5-O-ß-D-glucopyranosyl-7-methoxy-3',4'-dihydroxy-4-phenylcoumarin (4-PC) in AISI 1018 steel immersed in 3% NaCl + CO2 was studied by electrochemical impedance spectroscopy (EIS). The results showed that, at just 10 ppm, 4-PC exerted protection against corrosion with Õ² = 90% and 97% at 100 rpm. At static conditions, the polarization curves indicated that, at 5 ppm, the inhibitor presented anodic behavior, while at 10 and 50 ppm, there was a cathodic-type inhibitor. The inhibitor adsorption was demonstrated to be chemisorption, according to the Langmuir isotherm for 100 and 500 rpm. By means of SEM-EDS, the corrosion inhibition was demonstrated, as well as the fact that the organic compound was effective for up to 72 h of immersion. At static conditions, dispersion-corrected density functional theory results reveal that the chemical bonds established by the phenyl group of 4-PC are responsible of the chemisorption on the steel surface. According with Fukui reactivity indices, the molecules adsorbed on the metal surface provide a protective cover against nucleophilic and electrophilic attacks, pointing to the corrosion inhibition properties of 4-PC.
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Cloreto de Sódio , Aço , Dióxido de Carbono , Corrosão , Cumarínicos , Glucosídeos , Modelos Teóricos , Cloreto de Sódio/química , Cloreto de Sódio/farmacologia , Aço/químicaRESUMO
This work relates native lactic acid bacteria (LAB) (Lactobacillus pentosus LPG1, L. pentosus Lp13, and Lactobacillus plantarum Lpl15) and yeast (Wickerhamomyces anomalus Y12) starters to the volatile components (VOCs) produced in green Spanish-style table olives. For this aim, the VOC profile was considered as compositional data (CoDa). The CoDa analysis generated new information on the relationship among inocula and VOCs through the tetrahedral plot, CoDa-biplot, variation array matrix, and CoDa dendrogram. The ilr (which includes pivot) coordinates (Euclidean space) from VOCs produced more reliable starters' clustering than the original data. The potential VOC markers, identified by a test based on the pairwise comparison of the logratio variation arrays from the whole data set and the individual groups, were (starters in the parenthesis): 2-phenylethyl acetate (LPG1, Y12, Y12 + LAB), methanol (Lpl15), cis-2-penten-1-ol (LPG1, Y12, Y12 + LAB), 2-methyl-3-hexanol (LPG1, Y12), U (non-identified) C (m/z 83-112-97) (Y12) and UF (m/z 95-154-110) (LPG1, Y12 + LAB). Besides, some VOCs were partial/totally inhibited by specific starters: 2-methyl-1-propanol (Lp13, Y12 + LAB), 2-phenyl ethanol (Lp13), furfuryl methyl ether (Y12 + LAB), purpurocatechol (Y12, Y12 + LAB), 4-ethyl guaiacol (Lp13, Lpl15), 4-ethyl phenol (Lpl15), 5-tert-butylpyrogallol (Lp13, Lpl15), and UE (m/z 111-198) (Lp13). A better understanding of the relationship between starters and their VOC may facilitate modelling the flavour and quality of Spanish-style green table olive fermentations.
Assuntos
Lactobacillales/metabolismo , Olea/microbiologia , Compostos Orgânicos Voláteis/metabolismo , Leveduras/metabolismo , Análise de Dados , Fermentação , Aromatizantes/metabolismo , Frutas/microbiologia , Lactobacillales/classificação , Lactobacillales/genética , Lactobacillales/isolamento & purificação , Espanha , Leveduras/classificação , Leveduras/genética , Leveduras/isolamento & purificaçãoRESUMO
In this work, Lactobacillus pentosus LPG1, Lactobacillus pentosus Lp13, Lactobacillus plantarum Lpl15, and Wickerhanomyces anomalous Y12, all of them previously isolated from fermented table olive biofilms, were used (alone or in combination) as multifunctional starters for Manzanilla Spanish-style green table olive fermentations. Their performances were evaluated through the changes in the key physico-chemical and microbiological parameters, correlation between AI-2 production and biofilm formation, inoculum imposition, metataxonomic analysis and sensory characteristics of the finished products. Inoculation only with lactic acid bacteria (LAB) strains led to higher titratable acidities and lower pH values than the spontaneous fermentation (non-inoculated control), mainly during the first steps of processing. However, the sequential inoculation of the yeast and then the combination of the 3 LAB strains showed the most favourable evolution. LPG1 strain and, particularly Lp13, were excellent biofilms former and showed the major imposition on the fruit epidermis, as corroborated by rep-PCR analysis. Production of AI-2 was lower in the treatment inoculated exclusively with yeast Y12 but had the highest presence in the sequential yeast-LAB inoculum, with its maximum concentration and maximum LAB population on fruits (19th days) strongly related. Metataxonomic analysis of the biofilms at the end of the fermentation revealed, in addition to Lactobacillus, high proportions of sequences from genera Marinilactobacillus, Alkalibacterium, Halolactobacillus, and low levels of Halomonas and Aerococcus. Compositional data analysis of the omics data revealed that Lpl15 was scarcely efficient for controlling the spontaneous microbiota since its treatment presented the highest proportions of Aerococcus genus. Finally, the sensory analysis showed similar characteristics for the treatment inoculated with LPG1 and the spontaneous process, with olives inoculated with the yeast (alone or in combination with Lactobacillus strains) showing attractive scores. Then, inoculation of Spanish-style table olive fermentations with a sequential yeast and LAB combination could be an advisable practice.
Assuntos
Alimentos Fermentados/microbiologia , Lactobacillus/metabolismo , Olea/microbiologia , Saccharomycetales/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Biofilmes/crescimento & desenvolvimento , Técnicas de Cocultura , Fermentação , Alimentos Fermentados/análise , Microbiologia de Alimentos , Frutas/microbiologia , Homosserina/análogos & derivados , Homosserina/análise , Homosserina/biossíntese , Lactobacillus/classificação , Lactobacillus/crescimento & desenvolvimento , Lactonas/análise , Microbiota/genética , Saccharomycetales/crescimento & desenvolvimentoRESUMO
Directly brined black table olives of Bosana variety are a traditional food product of Sardinia island (Italy), spontaneously fermented by yeasts among other microorganisms. However, as far as we know, the identification, biotechnological and probiotic potential of this yeast community has not been investigated yet. In this work, a total of 72 yeast isolates previously obtained from Bosana olive brines were first genotyped by Random Amplified Polymorphic DNA (RAPD-PCR) analysis with primer M13, and then identified by sequencing of D1/D2 domains of rDNA 26S gene. The dominant species were Wickerhamomyces anomalus and Nakazawaea molendini-olei, albeit Candida diddensiae, Candida boidinii, Zygotorulaspora mrakii, and Saccharomyces cerevisiae were also present in lower proportions. For the different biotypes of yeasts obtained, the multivariate analysis of their technological (esterase, lipase and ß-glucosidase activities, growth in presence of oleuropein, resistance and susceptibility to NaCl) and probiotic (removal of cholesterol, gastric and pancreatic digestions, biofilms assays alone and in co-culture with Lactobacillus pentosus) features, showed that W. anomalus Wa1 exhibited the best technological characteristics, while S. cerevisiae Sc24 and C. boidinii Cb60 showed promising probiotic features. Therefore, they may have potential application as multifunctional starters, alone or in combination with lactic acid bacteria, during olive processing, albeit further studies are necessary to validate these results.
Assuntos
Olea/microbiologia , Leveduras/genética , Leveduras/isolamento & purificação , Fermentação , Manipulação de Alimentos , Frutas/microbiologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Genótipo , Itália , Lipase/genética , Lipase/metabolismo , Técnica de Amplificação ao Acaso de DNA Polimórfico , Leveduras/classificaçãoRESUMO
BACKGROUND: Our objective was to assess the therapeutic noninferiority of dual therapy with darunavir/ritonavir and lamivudine compared to triple therapy with darunavir/ritonavir plus 2 nucleos(t)ides for maintenance of human immunodeficiency virus type 1 (HIV-1) suppression. METHODS: This was a multicenter, open-label, noninferiority trial (margin 12%). Patients with HIV-1 RNA <50 copies/mL for 6 months or longer on triple therapy with darunavir/ritonavir and 2 nucleos(t)ides (tenofovir disoproxil fumarate and emtricitabine or abacavir and lamivudine) and with no resistance were randomized to continue therapy (n = 128) or switch to darunavir/ritonavir and lamivudine (n = 129). The primary endpoint was the proportion of participants with HIV-RNA <50 copies/mL after 48 weeks of follow-up according to the snapshot algorithm. RESULTS: A total of 249 participants received study drugs (intention-to-treat exposed). The proportion of participants with HIV-RNA <50 copies/mL in the dual- and triple-therapy arms was 88.9% (112/126) and 92.7% (114/123; difference, -3.8%; 95% confidence interval, -11.0 to 3.4), respectively. Four participants in the dual-therapy arm and 2 in the triple-therapy arm developed protocol-defined virological failure. Switching to dual therapy was associated with a significant increase in total, low-density lipoprotein, and high-density lipoprotein (HDL) cholesterol, but not in the total-to-HDL cholesterol ratio. Serious adverse events and study drug discontinuations due to adverse events occurred in 4.8% vs 4.9%P = .97) and in 0.8% (1/126) vs 1.6% P = .55) in dual therapy vs triple therapy, respectively. CONCLUSIONS: Dual therapy with darunavir/ritonavir and lamivudine demonstrated noninferior therapeutic efficacy and similar tolerability compared to triple therapy. CLINICAL TRIALS REGISTRATION: NCT02159599.
Assuntos
Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , Inibidores da Protease de HIV/uso terapêutico , HIV-1/efeitos dos fármacos , Carga Viral/efeitos dos fármacos , Adulto , Fármacos Anti-HIV/administração & dosagem , Contagem de Linfócito CD4 , Darunavir/administração & dosagem , Darunavir/uso terapêutico , Didesoxinucleosídeos/administração & dosagem , Didesoxinucleosídeos/uso terapêutico , Emtricitabina/administração & dosagem , Emtricitabina/uso terapêutico , Feminino , Infecções por HIV/virologia , Inibidores da Protease de HIV/administração & dosagem , Humanos , Lamivudina/administração & dosagem , Lamivudina/uso terapêutico , Masculino , Conduta do Tratamento Medicamentoso , Pessoa de Meia-Idade , RNA Viral/sangue , Ritonavir/administração & dosagem , Ritonavir/uso terapêutico , Tenofovir/administração & dosagem , Tenofovir/uso terapêuticoRESUMO
An efficient one-pot synthesis of 1,2,3-triazole derivatives of dihydropyrimidinones has been developed using two multicomponent reactions. The aldehyde-1,2,3-triazoles were obtained in good yields from in situ-generated organic azides and O-propargylbenzaldehyde. The target heterocycles were synthesized through the Biginelli reaction in which the aldehyde-1,2,3-triazoles reacted with ethyl acetoacetate and urea in the presence of Ce(OTf)3 as the catalyst. The corrosion inhibition of steel grade API 5 L X52 in 1 M HCl by the synthesized compounds was investigated using the electrochemical impedance spectroscopy technique. The measurements revealed that these heterocycles are promising candidates to inhibit acidic corrosion of steel.
Assuntos
Pirimidinonas/química , Aço/química , Triazóis/química , Azidas/química , Benzaldeídos/química , Catálise , Corrosão , Pirimidinonas/síntese química , Pirimidinonas/farmacologia , Triazóis/síntese química , Ureia/químicaRESUMO
This work examines the formation of poly-microbial communities adhered to the epidermis of natural green Gordal olives and the application of different methodologies for recovery and counting of the microorganisms embedded in olive biofilms. The fermentation process was physicochemical and microbiologically monitored for 90 days, at which, formation of true biofilms on the skin of fermented fruits was confirmed by scanning electron microscopy. Then, samples of olives were taken and treated with sonication, enzymes, mechanical homogenization with stomacher and ultrasonic bath for biofilm disaggregation. The use of the stomacher for 1 min was the most effective treatment to release the lactic acid bacteria (6.6 log10 cfu g(-1)), whereas sonication for 5 min was the most efficient method for quantification of yeasts (up to 3.5 log10 cfu g(-1)). Molecular identification of isolates obtained from natural Gordal olive biofilms revealed that Lactobacillus pentosus was the only species found among lactic acid bacteria, while Pichia membranifaciens was the dominant yeast species, with higher counts obtained for the bacteria.
Assuntos
Biofilmes/crescimento & desenvolvimento , Biota , Lactobacillales/isolamento & purificação , Olea/microbiologia , Leveduras/isolamento & purificação , Análise por Conglomerados , Genótipo , Lactobacillales/classificação , Microscopia Eletrônica de Varredura , Técnica de Amplificação ao Acaso de DNA Polimórfico , Leveduras/classificaçãoRESUMO
BACKGROUND: Zinc chloride has been used previously as a preservative in directly brined olives with promising results. However, this is the first time that the effects of ZnCl2 addition (0-1 g L(-1) ) on green Spanish-style table olive (cv. Manzanilla) packaging has been studied. RESULTS: The presence of ZnCl2 affected the physico-chemical characteristics of the products; the presence of the Zn led to lower pH values (particularly just after packaging) and titratable and combined acidity values than the control but did not produce clear trends in the colour parameters. No Enterobacteriaceae were found in any of the treatments evaluated. At the highest ZnCl2 concentrations, the lactic acid bacteria were inhibited while, unexpectedly, its presence showed a lower effect than potassium sorbate against the yeast population. Regardless of the use of potassium sorbate or ZnCl2 , the packages had a reduced microbial biodiversity because only Lactobacillus pentosus and Pichia galeiformis were found at the end of the shelf life. With respect to organoleptic characteristics, the presentations containing ZnCl2 were not differentiated from the traditional product. CONCLUSION: Zinc chloride was less efficient than potassium sorbate as a yeast inhibitor in green Spanish-style olives, showing clear presentation style dependent behaviour for this property. Its presence produced significant changes in chemical parameters but scarcely affected colour or sensory characteristics.
Assuntos
Cloretos/farmacologia , Conservantes de Alimentos/farmacologia , Frutas/química , Frutas/efeitos dos fármacos , Olea , Compostos de Zinco/farmacologia , Adulto , Fenômenos Químicos , Enterobacteriaceae/isolamento & purificação , Feminino , Fermentação , Frutas/microbiologia , Humanos , Concentração de Íons de Hidrogênio , Masculino , Pessoa de Meia-Idade , Pichia/isolamento & purificação , Ácido Sórbico/farmacologia , Espanha , PaladarRESUMO
AQP4 is expressed in the endfeet membranes of subpial and perivascular astrocytes and in the ependymal cells that line the ventricular system. The sporadic appearance of obstructive congenital hydrocephalus (OCHC) has been observed in the offspring of AQP4-/- mice (KO) due to stenosis of Silvio's aqueduct. Here, we explore whether the lack of AQP4 expression leads to abnormal development of ependymal cells in the aqueduct of mice. We compared periaqueductal samples from wild-type and KO mice. The microarray-based transcriptome analysis reflected a large number of genes with differential expression (809). Gene sets (GS) associated with ependymal development, ciliary function and the immune system were specially modified qPCR confirmed reduced expression in the KO mice genes: (i) coding for transcription factors for ependymal differentiation (Rfx4 and FoxJ1), (ii) involved in the constitution of the central apparatus of the axoneme (Spag16 and Hydin), (iii) associated with ciliary assembly (Cfap43, Cfap69 and Ccdc170), and (iv) involved in intercellular junction complexes of the ependyma (Cdhr4). By contrast, genes such as Spp1, Gpnmb, Itgax, and Cd68, associated with a Cd11c-positive microglial population, were overexpressed in the KO mice. Electron microscopy and Immunofluorescence of vimentin and γ-tubulin revealed a disorganized ependyma in the KO mice, with changes in the intercellular complex union, unevenly orientated cilia, and variations in the planar cell polarity of the apical membrane. These structural alterations translate into reduced cilia beat frequency, which might alter cerebrospinal fluid movement. The presence of CD11c + microglia cells in the periaqueductal zone of mice during the first postnatal week is a novel finding. In AQP4-/- mice, these cells remain present around the aqueduct for an extended period, showing peak expression at P11. We propose that these cells play an important role in the normal development of the ependyma and that their overexpression in KO mice is crucial to reduce ependyma abnormalities that could otherwise contribute to the development of obstructive hydrocephalus.
Assuntos
Aquaporina 4 , Epêndima , Hidrocefalia , Camundongos Knockout , Microglia , Animais , Epêndima/metabolismo , Epêndima/patologia , Hidrocefalia/metabolismo , Hidrocefalia/genética , Hidrocefalia/patologia , Microglia/metabolismo , Aquaporina 4/metabolismo , Aquaporina 4/genética , Camundongos , Aqueduto do Mesencéfalo/metabolismo , Aqueduto do Mesencéfalo/patologia , Antígenos CD11/metabolismo , Antígenos CD11/genética , Camundongos Endogâmicos C57BLRESUMO
This study evaluates the functional characteristics of the exopolysaccharide (EPS) extracts produced by various strains of Lactiplantibacillus pentosus (LPG1, 119, 13B4, and Lp13) and Lactiplantibacillus plantarum (Lp15) isolated from table olives. None of the EPS crude extracts showed cytotoxicity when administered to THP-1 human macrophage cells at dosages ranging from 6.25 to 50 µg mL-1. Many exhibited anti-inflammatory properties (reduction of pro-inflammatory cytokines TNF-α and IL-6 production) and antioxidant activity (reduction of ROS%) when macrophages were stimulated with Escherichia coli lipopolysaccharide. Notably, the EPS extract produced by the L. pentosus LPG1 strain had the best results corroborated by western blot immune analysis for differential expression of COX-2, Nrf-2, and HO-1 proteins, with the most significant antioxidant and anti-inflammatory response observed at a dosage of 50 µg mL-1. Chemical analysis revealed that the EPS extract produced by this strain contains a heteropolymer composed of mannose (35.45%), glucose (32.99%), arabinose (17.93%), xylose (7.48%), galactose (4.03%), rhamnose (1.34%), and fucose (0.77%). Finally, we conducted response surface methodology to model the EPS extract production by L. pentosus LPG1 considering pH (3.48-8.52), temperature (16.59-33.41 °C) and salt concentration (0.03-8.77% NaCl) as independent variables. The model identified linear effects of salt and pH and quadratic effects of salt as significant terms. The maximum EPS extract production (566 mg L-1) in a synthetic culture medium (MRS) was achieved at pH 7.5, salt 7.0%, and a temperature of 20 °C. These findings suggest the potential for novel applications for the EPS produced by L. pentosus LPG1 as nutraceutical candidates for use in human diets.
Assuntos
Olea , Polissacarídeos Bacterianos , Humanos , Polissacarídeos Bacterianos/química , Suplementos Nutricionais , Meios de Cultura , Antioxidantes/farmacologia , Antioxidantes/química , Anti-InflamatóriosRESUMO
The lack of specific regulatory guidelines for nanotechnology-enabled health products (NHPs) is hampering development and patient access to these innovative technologies. Namely, there is an urgent need for harmonized regulatory definitions and classification systems that allow establishing a standardized framework for NHPs regulatory assessment. In this work, a novel classification system for NHPs is proposed. This classification can be applied for sorting nano-based innovations and regulatory guidelines according to the type of NHPs they address. Said methodology combines scientific and regulatory principles and it is based on the following criteria: principal mode of action, chemical composition, medical purpose and nanomanufacturing approach. This classification system could serve as a useful tool to sensor the state of the art of NHPs which is particularly useful for regulators to support strategy development of regulatory guidelines. Additionally, this tool would also allow manufacturers of NHPs to align their development plans with their applicable guidelines and standards and thus fulfill regulators expectations.
RESUMO
Strategic regulatory development is essential to ensure that new innovations in nanotechnology-enabled health products (NHPs) successfully reach the market and benefit patients. Currently, the lack of specific regulatory guidelines for NHPs is considered one of the primary causes of the so-called "valley of death" in these products, impacting both current and future advancements. In this study, we have implemented a methodology to anticipate key trends in NHP development and compare them with the current regulatory landscape applicable to NHPs. This methodology relies on Horizon Scanning, a tool commonly used by policymakers to foresee future needs and proactively shape a regulatory framework tailored to those needs. Through the application of this methodology, different trends in NHP have been identified, notably NHPs for drug delivery and dental applications. Furthermore, the most disruptive elements involve NHPs that are multicomposite and multifunctional, harnessing nano-scale properties to combine therapeutic and diagnostic purposes within a single product. When compared with the regulatory landscape, current regulations are gradually adapting to accommodate emerging trends, with specific guidelines being developed. However, for the most disruptive elements, multicomposite and multifunctional NHPs, their novelty still poses significant regulatory challenges, requiring a strategic development of guidelines by regulatory agencies to ensure their safe and effective integration into healthcare practices. This study underscores the importance of proactive regulatory planning to bridge the gap between NHP innovation and market implementation.
RESUMO
Different varieties of table olives have suitable morphological characteristics that allow them to be processed as Spanish-style green table olives. However, the Campiñesa cultivar presents difficulties when submitted to a lactic fermentation, in spite of being inoculated with dedicated starter cultures such as OleicaStarter. The strategy followed in this study to facilitate the start of lactic fermentation was to reinforce the OleicaStarter culture with the use of the Lactoplantibacillus pentosus Lp309 a strain that enhanced the survival of lactic acid bacteria (LAB) at the beginning of fermentation, reaching final pH values (4.08 ± 0.01), free acidity (1.00 ± 0.01 g/100 mL of brine), LAB population (6.17 ± 0.09 log CFU/mL), nutrient depletion (0.80 ± 0.09 g/kg of pulp), and lactic acid production (11.85 ± 0.72 g/L). These values allowed stabilization of the final product, thus complying with the quality and food safety standards established by the Codex Alimentarius for table olives.
Assuntos
Lactobacillus pentosus , Olea , Lactobacillus , Olea/microbiologia , Fermentação , Concentração de Íons de Hidrogênio , Microbiologia de AlimentosRESUMO
The utilization of grape juice from low oenological value grape varieties for bioethanol production represent an alternative for diversification and value addition in viticulture. Optimizing Very High Gravity (VHG) fermentation can significantly increase ethanol productivity while reducing water and energy consumption. In this study, the impact of different nitrogen sources on growth and fermentative performance of locally selected yeast strains was investigated. Five yeast strains of species Saccharomyces cerevisiae and Zygosaccharomyces rouxii were cultured in both synthetic culture media and natural grape juice supplemented with ammonium sulfate (NH), yeast extract (YE), Fermaid K (FERM), and urea (U) at varying concentrations. Due to the very low fermentation rate, the Z. rouxii strain was excluded from the selection. The results obtained in synthetic medium showed that nitrogen sources that promoted growth (NH and YE) had minimal effects on fermentative performance and were highly dependent on the specific yeast strain. However, the combination of urea and ammonium favored the rate of sugar consumption. When validated in natural grape juice, urea combined with ammonium (U + NH 300 + 75 mg/L) improved both growth parameters and ethanol yield. Doubling the concentration (U + NH 600 + 150 mg/L) further enhanced sugar consumption and ethanol production while reducing unwanted by-products. The combined use of urea and ammonium exhibited a synergistic effect, making it a cost-effective nitrogen supplement for VHG fermentations.
RESUMO
This survey uses a multivariate classification analysis to discriminate yeast strains with interesting biochemical activities for the processing of table olives among a collection of 32 isolates belonging to 16 different yeast species. Lipase, esterase and ß-glucosidase activities (desirable characteristics) were quantitatively evaluated in both extracellular and cellular fractions for all isolates in different types of culture media. The study of the quantitative data by cluster and principal component analyses led to the identification of several Wickerhamomyces anomalus, Candida boidinii and Candida diddensiae isolates with promising characteristics (the best global activity levels), clearly differentiated from the rest of the yeasts. The results obtained in this work open up new alternatives to this methodology for the study, classification and selection of the most suitable yeasts to be used as starters, alone or in combination with lactic acid bacteria, during table olive processing.
Assuntos
Manipulação de Alimentos , Microbiologia de Alimentos , Olea/microbiologia , Leveduras/classificação , Leveduras/isolamento & purificação , Análise por Conglomerados , Esterases/análise , Microbiologia Industrial/métodos , Lipase/análise , Análise Multivariada , Leveduras/enzimologia , Leveduras/metabolismo , beta-Glucosidase/análiseRESUMO
Table olives can suffer different types of spoilage during fermentation. In this work, a multi-statistical approach (standard and compositional data analysis) was used for the study of the volatile organic compounds (VOCs) associated with altered (butyric, sulfidic, and putrid) and non-altered (normal) Manzanilla Spanish-style table olive fermentations. Samples were collected from two industrial fermentation yards in Seville (Spain) in the 2019/2020 season. The VOC profiles of altered (n = 4) and non-altered (n = 6) samples were obtained by headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS). Ninety-one VOCs were identified and grouped into alcohols (30), esters (21), carbonyl compounds (12), acids (10), terpenes (6), phenols (6), sulfur compounds (2), and others (4). The association of the VOCs with spoilage samples depended on the standard or compositional statistical methodology used. However, butyric spoilage was strongly linked by several techniques to methyl butanoate, ethyl butanoate, and butanoic acid; sulfidic spoilage with 2-propyl-1-pentanol, dimethyl sulfide, methanol, 2-methylbutanal, 2-methyl-2-butenal, ethanol, 2-methyl-3-buten-2-ol, and isopentanol, while putrid was mainly related to D-limonene and 2-pentanol. Our data contribute to a better characterisation of non-zapatera spoiled table olive fermentations and show the convenience of using diverse statistical techniques for a most robust selection of spoilage VOC markers.
RESUMO
This work applies metataxonomic, standard statistics, and compositional data (CoDa) techniques to study the bacterial diversity of spoiled and normal Spanish-style table olive fermentations, analysing a total of 10-tons of industrial fermentation containers from two processing yards. Forty percent were affected by butyric, sulfidic, or putrid spoilage, while 60% followed the ordinary fermentation course. The samples were obtained at 30 days of fermentation, determining their 16S rRNA gene Amplicon Sequence Variant compositions (ASVs). The butyric containers showed a bacterial profile strongly associated with the genera Enterococcus, Leuconostoc, and Atlantibacter, but also with Lactiplantibacillus and Melissococcus, and less confident to Raoultella, Enterobacter, Serratia, and Celerinatantimonas. The sulfidic fermentation was linked to Alkalibacterium and, to a lesser extent, Marinilactibacillus and the absence of Lactiplantibacillus. Putrid spoilage was mainly related to Halolactibacillus and Alkalibacterium. Sulfidic/putrid (together) differed from butyric spoilage by the presence of Alkalibacterium/Marinilactibacillus as well as by Halomonas/Halanaerobium. Lactiplantibacillus dominated normal fermentations, but Vibrio was also frequently found (0-46%), apparently not causing any alteration. These results contribute to a better microbial characterisation of non-zapatera spoiled table olive fermentations. They also suggest using several statistical techniques to discriminate normal vs spoiled fermentations adequately.
Assuntos
Olea , Bactérias/genética , Fermentação , Microbiologia de Alimentos , RNA Ribossômico 16S/genéticaRESUMO
Aloreña de Málaga is a table olive especially characterised by its natural freshness and short shelf-life. In this work, we applied a metataxonomic approach to unravel the microbial diversity of bacterial and fungi populations through the shelf-life of traditionally packed Aloreña de Málaga. A significant increase in lactic acid bacteria and mesophilic aerobic populations was observed during shelf-life, reaching the maximum population levels (4-5 log10 CFU) at the end of the study (260 days). On the contrary, a rapid reduction in yeast and mould populations was reported. The use of a metataxonomic analysis based on the amplification of 16S (bacteria) and internal transcribed spacer (ITS) region (fungi) regions revealed a low diversity for both microbial groups. Lactiplantibacillus (65.05 ± 8.65% in brine vs. 58.70 ± 15.70% in fruit), Pediococcus (28.17 ± 7.36% in brine vs. 27.20 ± 15.95% in fruit), and Celerinatantimonas (4.64 ± 1.08% in brine vs. 11.82 ± 18.17% in fruit) were the main genera found among bacteria, and an increase in Lactiplantibacillus and a reduction in Celerinatantimonas populations during the shelf-life were observed. On the other hand, Citeromyces was the dominant fungi genus (54.11 ± 2.00% in brine vs. 50.91 ± 16.14% in fruit), followed by Candida (8.80 ± 2.57% in brine vs. 12.32 ± 8.61% in fruit) and Penicillium (6.48 ± 1.87% vs. 8.48 ± 4.43% in fruit). No food-borne pathogen genera were detected in any of the samples analysed, indicating the high level of food safety found in this ready-to-eat fermented vegetable. Data obtained in this work will help in the design of new strategies for the control of microbial populations during the shelf-life of Aloreña de Málaga.
RESUMO
The presence of Vibrio species in table olive fermentations has been confirmed by molecular biology techniques in recent studies. However, there has been no report of any foodborne outbreak caused by Vibrio due to the consumption of table olives, and their role as well as the environmental conditions allowing their survival in table olives has not been elucidated so far. The aims of this work were to model the behavior of an inoculated Vibrio cocktail in diverse table olive environments and study the possible behavior of an inoculated Vibrio cocktail in table olives. First, an in vitro study has been performed where the microbial behavior of a Vibrio cocktail was evaluated in a laboratory medium and in olive brines using predictive models at different NaCl concentrations (2-12%) and pH levels (4.0-9.0). Afterward, a challenge testing was done in lye-treated olives inoculated at the beginning of fermentation with the Vibrio cocktail for 22 days. The Vibrio cocktail inoculated in table olives has not been detected in olive brines during fermentation at different pH levels. However, it was observed that this microorganism in a laboratory medium could reach an optimal growth at pH 9 and 2% salt, without time of constant absorbance (t A), and the maximum absorbance value (y end) observed was at pH 8 and 2% salt conditions. The statistical analysis demonstrated that the effect of salt concentration was higher than pH for the kinetic growth parameters (µmax, t A, and y end). On the other hand, it was confirmed that no growth of the Vibrio cocktail on any sample was noticed in lye-treated olive fermentations. Thus, it was concluded that the presence of olive compounds (unknown) did not allow the development of Vibrio strains, so it is a very safety product as it has a natural antimicrobial compound, but the possibility that a native Vibrio sp. is able to acquire the capacity to adapt to this compound should be considered in further studies.