Artigos - Bioquímica e Microbiologia - IBRC

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  • ItemCapítulo de livro
    Metabolic engineering as a tool for biosurfactant production by microorganisms
    (2023-06-13) Lovaglio, Roberta Barros; da Silva, Vinícius Luiz; Contiero, Jonas [UNESP]; Universidade Federal de São Carlos (UFSCar); MicroGreen-Soluções Biotecnológicas; Universidade Estadual Paulista (UNESP)
    Biosurfactants produced by microorganisms are products with excellent physicochemical properties in addition to being produced from renewable sources and presenting low toxicity and environmental compatibility. Despite their advantages, they are still not widely produced on an industrial scale, due to the high production costs. Metabolic engineering tools have contributed to bypassing this hurdle in different ways, such as the metabolic flux deviation or heterologous expression of genes associated with the synthesis of these compounds. This chapter deals with different strategies of metabolic engineering, which can support the establishment of biosurfactants on the market.
  • ItemArtigo
    Sustainable Waste Recycling from the Fruit Pulp Industry Applied as an Adsorbent of Textile Dye
    (2022-12-01) Mendes, Carolina Rosai [UNESP]; Dilarri, Guilherme [UNESP]; Stradioto, Marcia Regina [UNESP]; Schuch, Joyce Maria [UNESP]; Bidoia, Ederio Dino [UNESP]; Montagnolli, Renato Nallin; Universidade Estadual Paulista (UNESP); Universidade Federal de São Carlos (UFSCar)
    Dyes are the main contaminant from the textile industry wastes. Dyes can severely harm the environment, disturbing all the water cycle and organisms living in these environments. The juice industry generates waste of the peel from a great number of fruits. The peel of Passiflora edulis is rich in pectin, a polymer with great adsorption potential for textile dye sorption. However, the lack of applicability and adsorption interaction knowledge of the use of pectin as textile dye adsorbent makes it impossible to apply them, being necessary more studies with different dyes for its application and understanding of the chemical interactions of adsorbent/adsorbate. Thus, the aim of the present study was to evaluate the adsorptive potential of pectin present in the peel residue of P. edulis. Adsorption experiments were carried out to analyze the kinetics, isotherm, and thermodynamics, seeking the optimization of the adsorption treatment. Scanning electron microscopy and Fourier transform infrared spectrophotometry were used to characterize and analyze the main adsorption sites of the pectin from P. edulis peels. Bioassays using the Lactuca sativa seeds confirmed the reduction of the toxicity of the solution after the adsorption treatment. The results also confirmed a chemisorption occurrence, confirming the strong interaction between the pectin and the textile dye. Therefore, the material tested in the present study can potentially be applied for textile waste treatment, removing dyes from effluents, in addition to giving a noble destination for a residue from the juice industry.
  • ItemCapítulo de livro
    Natural attenuation of soil with biodiesel and its potential ecotoxicological impacts
    (2022-08-10) Dilarri, Guilherme [UNESP]; Mendes, Carolina Rosai [UNESP]; de Moraes Ruy Sapata, Vinícius [UNESP]; Tamada, Ivo Shodji [UNESP]; Lopes, Paulo Renato Matos [UNESP]; Montagnolli, Renato Nallin; Bidoia, Ederio Dino [UNESP]; Universidade Estadual Paulista (UNESP); Universidade Federal de São Carlos (UFSCar)
    Petroleum and its derivatives cause numerous toxicity-related impacts on the environment. The evaluation of such impacts can promote adequate treatments of oil-based residues. A better understanding of the degradation of hydrocarbons aids researchers to predict the environmental impacts and the biodegradation processes that yield decreased toxicity levels. However, petroleum derivatives are not the sole matter of concern. Another important discussion targeting the environmental behavior of biodiesel should be brought up. Soil microorganisms may improve the biodegradation of hydrocarbons due to their diversity and robust enzymatic apparatus during natural attenuation processes. Still, some compounds can have their negative impacts on biota evaluated according to three parameters: ecotoxicological potential in soil (i), specific biodegradation processes (ii), and post-treatment bioassays (iii). This review presents how microbial biodegradation may ultimately affect the overall degradation of hydrocarbons.
  • ItemArtigo
    Metabolomic- and Molecular Networking-Based Exploration of the Chemical Responses Induced in Citrus sinensis Leaves Inoculated with Xanthomonas citri
    (2022-11-23) Saldanha, Luiz Leonardo; Allard, Pierre-Marie; Dilarri, Guilherme; Codesido, Santiago; González-Ruiz, Víctor; Queiroz, Emerson Ferreira; Ferreira, Henrique; Wolfender, Jean-Luc; Universidade de São Paulo (USP); University of Geneva; University of Fribourg
    Citrus canker, caused by the bacterium Xanthomonas citri subsp. citri (X. citri), is a plant disease affecting Citrus crops worldwide. However, little is known about defense compounds in Citrus. Here, we conducted a mass spectrometry-based metabolomic approach to obtain an overview of the chemical responses of Citrus leaves to X. citri infection. To facilitate result interpretation, the multivariate analyses were combined with molecular networking to identify biomarkers. Metabolite variations among untreated and X. citri-inoculated Citrus samples under greenhouse conditions highlighted induced defense biomarkers. Notably, the plant tryptophan metabolism pathway was activated, leading to the accumulation of N-methylated tryptamine derivatives. This finding was subsequently confirmed in symptomatic leaves in the field. Several tryptamine derivatives showed inhibitory effects in vitro against X. citri. This approach has enabled the identification of new chemically related biomarker groups and their dynamics in the response of Citrus leaves to Xanthomonas infection.
  • ItemCarta
    Reply to the letter to the editor regarding the article Lourencetti et al. (2023)
    (2023-08-01) Paula Salomé Lourencetti, Ana; Azevedo, Patricia; Miotelo, Lucas [UNESP]; Malaspina, Osmar [UNESP]; Cornélio Ferreira Nocelli, Roberta; Universidade Federal de São Carlos (UFSCar); Universidade Estadual de Campinas (UNICAMP); Universidade Estadual Paulista (UNESP)
  • ItemArtigo
    Fungal Screening for Potential PET Depolymerization
    (2023-03-01) Malafatti-Picca, Lusiane [UNESP]; Bucioli, Elaine Cristina [UNESP]; de Barros Chaves, Michel Ricardo; de Castro, Aline Machado; Valoni, Érika; de Oliveira, Valéria Maia; Marsaioli, Anita Jocelyne; Govone, José Silvio [UNESP]; de Franceschi de Angelis, Dejanira [UNESP]; Brienzo, Michel [UNESP]; Attili-Angelis, Derlene [UNESP]; Universidade Estadual Paulista (UNESP); Federal University of Maranhão (UFMA); PETROBRAS; Universidade Estadual de Campinas (UNICAMP)
    Approximately 400 billion PET bottles are produced annually in the world, of which from 8 to 9 million tons are discarded in oceans. This requires developing strategies to urgently recycle them. PET recycling can be carried out using the microbial hydrolysis of polymers when monomers and oligomers are released. Exploring the metabolic activity of fungi is an environmentally friendly way to treat harmful polymeric waste and obtain the production of monomers. The present study addressed: (i) the investigation of potential of strains with the potential for the depolymerization of PET bottles from different manufacturers (crystallinity of 35.5 and 10.4%); (ii) the search for a culture medium that favors the depolymerization process; and (iii) gaining more knowledge on fungal enzymes that can be applied to PET recycling. Four strains (from 100 fungal strains) were found as promising for conversion into terephthalic acid from PET nanoparticles (npPET): Curvularia trifolii CBMAI 2111, Trichoderma sp. CBMAI 2071, Trichoderma atroviride CBMAI 2073, and Cladosporium cladosporioides CBMAI 2075. The fermentation assays in the presence of PET led to the release of terephthalic acid in concentrations above 12 ppm. Biodegradation was also confirmed using mass variation analyses (reducing mass), scanning electron microscopy (SEM) that showed evidence of material roughness, FTIR analysis that showed band modification, enzymatic activities detected for lipase, and esterase and cutinase, confirmed by monomers/oligomers quantification using high performance liquid chromatography (HPLC-UV). Based on the microbial strains PET depolymerization, the results are promising for the exploration of the selected microbial strain.
  • ItemArtigo
    Biocontrol of post-harvest tomato rot caused by Alternaria arborescens using Torulaspora indica
    (2023-01-01) Bosqueiro, Ariane Silva; Bizarria Jr, Rodolfo [UNESP]; Rosa-Magri, Márcia Maria; Universidade Federal de São Carlos (UFSCar); Universidade Estadual Paulista (UNESP)
    An important concern in modern agriculture is the production of healthy foods. This has resulted in an increasing number of studies on alternative plant protection strategies such as biological control. Yeasts have received considerable attention as biological control agents against postharvest fungal diseases of fruits and vegetables. Here, we describe the potential of the yeast strain Torulaspora indica as a biological control agent against Alternaria arborescens, causal agent of tomato fruits decay. In vitro and in vivo assays were used to evaluate the interaction of Torulaspora indica (CCA5S55) and Alternaria arborescens (ABS2). This was followed by the evaluation of putative mechanisms controlling fungal development. Our results suggest that the production of volatile compounds and competition for nutrients are putative mechanisms by which T. indica inhibits A. arborescens growth in vitro. The results of in vivo assays indicate a reduction in the number of A. arborescens-induced lesions in tomato fruits in the presence of T. indica.
  • ItemArtigo
    Surrogate species in pesticide risk assessments: Toxicological data of three stingless bees species
    (2023-02-01) Lourencetti, Ana Paula Salomé; Azevedo, Patricia; Miotelo, Lucas [UNESP]; Malaspina, Osmar [UNESP]; Nocelli, Roberta Cornélio Ferreira; Universidade Federal de São Carlos (UFSCar); Universidade Estadual de Campinas (UNICAMP); Universidade Estadual Paulista (UNESP)
    Discussions about environmental risk reassessment of pesticides have grown in the last decades, especially in tropical and subtropical regions since the diversity of bee species in these places is quite different. Stingless bees are highly affected by pesticides, and toxicity information is necessary to include them in the regulatory process of countries that hosts a diversity of these species. Therefore, the present study aimed to evaluate the Median Lethal Concentration (LC50), estimate the Median Lethal Dose (LD50) and compared the sensitivity of three species of stingless bees exposed to the commercial formulation of the neonicotinoid thiamethoxam (TMX). The LD50 was estimated based on the LC50 determined in the present study (LC50 = 0.329 ng a.i./μL for Tetragonisca angustula; 0.624 ng a.i./μL for Scaptotrigona postica, and 0.215 ng a.i./μL for Melipona scutellaris). Considering these data, toxicity endpoints were used to fit species sensitive distribution curves (SSD) and determine the sensitivity ratio. The results showed that all the stingless bees tested are more sensitive to TMX than the Apis mellifera, the model organism used in ecotoxicological tests. Regarding the oral LC50, the most susceptible and most tolerant species were M. scutellaris > T. angustula > S. postica > A. mellifera. Following the same evaluated pattern, for the LD50 (considering the weight of the bees - ng a.i./g bee), we have: M. scutellaris > S. postica > T. angustula > A. mellifera, and without the weight considered (ng a.i./bee): T. angustula > M. scutellaris > S. postica > A. mellifera. The different sensitivities among stingless bee species highlight the importance of inserting more than one surrogate species with a variety of sizes in research and protocol development. Additionally, the research suggests the need to investigate patterns regarding the influence of body mass on pesticide sensitivity among stingless bee species.
  • ItemEditorial
    Toxicity and Biodegradation Testing Preface
    (Humana Press Inc, 2018-01-01) Bidoia, Ederio Dino [UNESP]; Montagnolli, Renato Nallin [UNESP]; Bidoia, E. D.; Montagnolli, R. N.; Universidade Estadual Paulista (UNESP)
  • ItemArtigo
    Ligninolytic enzymes from marine-derived fungi: production and applications
    (Woodhead Publ Ltd, 2013-01-01) Sette, Lara Duraes [UNESP]; Bonugli Santos, Rafaella Costa; Trincone, A.; Universidade Estadual Paulista (UNESP); Universidade Estadual de Campinas (UNICAMP)
    The demand for microbial industrial enzymes is ever-increasing due to their use in a wide variety of processes. Ligninolytic enzymes play a crucial role in the global carbon cycle. One of the most important current applications of these enzymes is in the environmental remediation domain, in processes in which biological systems are used to degrade or neutralize pollutants or to decolorize dyes. Taking into account that much environmental pollution occurs in saline conditions, the use of marine-derived fungal enzymes can be considered strategic, since these micro-organisms are adapted to the marine ecosystem.
  • ItemArtigo
    Edible coatings based on hydroxypropyl methyl cellulose and beeswax in pinecone
    (Univ Federal Rural Pernambuco, 2022-01-01) Brasil, Yasmin Lima; Formiga, Anderson dos Santos; Cruz, Renata Ranielly Pedroza; Silva, Marcio Santos da; Silva, Alvaro Gustavo Ferreira da; Mattiuz, Ben-Hur [UNESP]; Costa, Franciscleudo Bezerra da; Ribeiro, Wellington Souto; Universidade Estadual de Campinas (UNICAMP); Universidade Federal de Viçosa (UFV); Fundacao Univ Fed Grande Dourados; Universidade Estadual Paulista (UNESP); Univ Fed de Campina Grande
    The pinecone (Annona squamosa L.) is an Annonaceae that provides much appreciated fruit. However, these fruits have a limited shelf life due to their intense metabolic activity after harvest. The application of post-harvest conservation techniques, such as edible coatings, has been used to minimize the deleterious effects after the harvest of fruits, such as pinecone. The objective of this work was to evaluate the effects of coatings based on hydroxypropyl methyl cellulose (HPMC) and beeswax (BW) on the quality of pinecones stored at room temperature of 20 degrees C, from the local market in the city of Juazeiro, BA, Brazil. The fruits were selected for the absence of damage and sanitized by immersion in chlorinated water. The coatings were prepared by diluting the HPMC solution in deionized water at 90 degrees C under stirring, followed by cooling and addition of BW in different proportions, stearic acid, and glycerol. The coatings were applied to the surface of the fruits by immersion in the film-forming solution and dried at room temperature of 20 degrees C. The HPMC-based coatings associated with BW maintained the firmness and the whitening index of the pulp of the cones for a longer time, as well as led to lower activity of the enzymes polyphenoloxidase (PPO) and peroxidase (POD) during storage.
  • ItemArtigo
    Guava Seed Oil: Potential Waste for the Rhamnolipids Production
    (2022-08-01) Yoshimura, Ingrid [UNESP]; Salazar-Bryam, Ana Maria [UNESP]; Faria, Adriano Uemura de [UNESP]; Leite, Lucas Prado [UNESP]; Lovaglio, Roberta Barros; Contiero, Jonas [UNESP]; Universidade Estadual Paulista (UNESP); Universidade Federal de São Carlos (UFSCar)
    Guava is consumed in natura and is also of considerable importance to the food industry. The seeds and peel of this fruit are discarded, however, guava seeds yield oil (~13%) that can be used for the bioproducts synthesis. The use of a by-product as a carbon source is advantageous, as it reduces the environmental impact of possible harmful materials to nature, while adding value to products. In addition, the use of untested substrates can bring new yield and characterization results. Thus, this research sought to study rhamnolipids (RLs) production from guava seed oil, a by-product of the fructorefinery. The experiments were carried out using Pseudomonas aeruginosa LBI 2A1 and experimental design was used to optimize the variables Carbon and Nitrogen concentration. Characterization of RLs produced occurred by LC-MS. In this study, variables in the quadratic forms and the interaction between them influenced the response (p < 0.05). The most significant variable was N concentration. Maximum RLs yield achieved 39.97 g/L, predominantly of mono-RL. Characterization analysis revealed 9 homologues including the presence of RhaC10C14:2 (m/z 555) whose structure has not previously been observed. This research showed that guava seed oil is an alternative potential carbon source for rhamnolipid production with rare rhamnolipid homologues.
  • ItemArtigo
    Bacterial ectosymbionts in cuticular organs chemically protect a beetle during molting stages
    (2022-01-01) Janke, Rebekka S.; Kaftan, Filip; Niehs, Sarah P.; Scherlach, Kirstin; Rodrigues, Andre [UNESP]; Svatoš, Aleš; Hertweck, Christian; Kaltenpoth, Martin; Flórez, Laura V.; Johannes Gutenberg University; Max Planck Institute for Chemical Ecology; HKI; Universidade Estadual Paulista (UNESP); Friedrich Schiller University Jena; University of Copenhagen
    In invertebrates, the cuticle is the first and major protective barrier against predators and pathogen infections. While immune responses and behavioral defenses are also known to be important for insect protection, the potential of cuticle-associated microbial symbionts to aid in preventing pathogen entry during molting and throughout larval development remains unexplored. Here, we show that bacterial symbionts of the beetle Lagria villosa inhabit unusual dorsal invaginations of the insect cuticle, which remain open to the outer surface and persist throughout larval development. This specialized location enables the release of several symbiont cells and the associated protective compounds during molting. This facilitates ectosymbiont maintenance and extended defense during larval development against antagonistic fungi. One Burkholderia strain, which produces the antifungal compound lagriamide, dominates the community across all life stages, and removal of the community significantly impairs the survival probability of young larvae when exposed to different pathogenic fungi. We localize both the dominant bacterial strain and lagriamide on the surface of eggs, larvae, pupae, and on the inner surface of the molted cuticle (exuvia), supporting extended protection. These results highlight adaptations for effective defense of immature insects by cuticle-associated ectosymbionts, a potentially key advantage for a ground-dwelling insect when confronting pathogenic microbes. [Figure not available: see fulltext.]
  • ItemResenha
    Risks associated with the presence of SARS-CoV-2 in sewage and possible approaches to limit its spread through aquatic matrices
    (Fundacao Oswaldo Cruz, Inst Nacional Controle Qualidade & Saude, 2022-05-01) Mainardi, Pedro Henrique [UNESP]; Bidoia, Ederio Dino [UNESP]; Universidade Estadual Paulista (UNESP)
    Introduction: SARS-CoV-2 is a new type of coronavirus capable of infecting humans and cause the Coronavirus Disease (COVID-19), an illness that has causing enormous impacts in Brazil and worldwide. The disease, due to its high-level dissemination and lethality rates, was declared pandemic by the World Health Organization in the first half of 2020. Several studies have frequently indicated the detection of SARS-CoV-2 RNA fragments in samples from sewage networks, treatment plants and natural waters. The presence of SARS-CoV-2 in those environments has raised the possibility of transmission through the contact with contaminated waters and aerosols generated during their flow or treatment. Objective: Describe detection reports of the new coronavius in samples obtained from sewage networks, from waste sludges of treatment plants and from natural water bodies, and present the viability of this virus when artificially inoculated in those environments. Method: Integrative literature review based on scientific articles written in English or Portuguese, indexed in the Web of Science, Scopus, PubMed, ScienceDirect, Google Scholar and MedRxiv databases. Results: It was possible to highlight the risks that the SARS-CoV-2 poses to human and wildlife populations when present in wastewater, appropriate strategies to be used to limit the spread of this pathogen in aquatic matrices, and the importance of implementing epidemiological monitoring systems in those places. Conclusions: In order to reduce the risks of emerging and re-emerging outbreaks of COVID-19 through aqueous matrices, precautionary approaches regarding the presence of SARS-CoV-2 in those environments have been strongly recommended.
  • ItemArtigo
    Processos convencionais e promissores de inativação ou remoção do SARS-COV-2 de esgotos: revisão de princípios e mecanismos de ação
    (Salvador BA: Universidade Federal da Bahia, 2022-07-22) Mainardi, Pedro Henrique [UNESP]; Bidoia, Ederio Dino [UNESP]; Universidade Estadual Paulista (Unesp)
    O SARS-CoV-2 é um novo tipo de coronavírus capaz de infectar humanos e causar a síndrome respiratória aguda grave COVID-19, uma doença que, devido ao seu alto índice de disseminação e fatalidade, tem causado enormes impactos no Brasil e no mundo. Estudos publicados por diversos pesquisadores indicaram a frequente detecção de fragmentos do SARS-CoV-2 em amostras obtidas de redes de esgoto ou de estações de tratamento dos mesmos. A presença do novo coronavírus nesses ambientes tem levantado a possiblidade da transmissão indireta da COVID-19 via rota fecal-oral, ou seja, por meio do contato com águas residuais contaminadas. Além disso, a presença do novo coronavírus nesses ambientes também tem levantado a possibilidade da disseminação do SARS-CoV-2 em animais domesticados e selvagens, assim, propiciar a propagação do patógeno em surtos futuros por meio de infecções cruzadas. Sabendo que inibir a propagação do SARS-CoV-2 através de matrizes aquáticas tem se demonstrado de grandíssima importância como controle da COVID-19, e que o descarte ou reutilização das águas residuais de forma segura tem dependido diretamente da eficácia dos processos de tratamento das mesmas, o objetivo desta revisão foi de descrever os métodos convencionais de inativação ou remoção do SARS-CoV-2 de esgotos, e tecnologias promissoras que poderiam ser utilizadas com estas finalidades. No artigo, foram destacados os mecanismos de ação das técnicas e também breves recomendações que visavam fomentar práticas eficientes e seguras caso implementadas.
  • ItemArtigo
    Riscos associados à presença do SARS-CoV-2 em esgotos e possíveis abordagens para limitar sua propagação através de matrizes aquáticas
    (Rio de Janeiro RJ: Fundação Oswaldo Cruz Instituto Nacional de Controle de Qualidade em Saúde, 2022-05-31) Mainardi, Pedro Henrique [UNESP]; Bidoia, Ederio Dino [UNESP]; Universidade Estadual Paulista (Unesp)
    Introdução: O SARS-CoV-2 é um novo tipo de coronavírus capaz de infectar humanos e causar a Coronavirus Disease (COVID-19), enfermidade que tem causado enormes impactos no Brasil e no mundo. A doença, devido às suas altas taxas de disseminação e letalidade, foi declarada pandêmica pela Organização Mundial da Saúde no primeiro semestre de 2020. Vários estudos têm frequentemente indicado a detecção de fragmentos de RNA do SARS-CoV-2 em amostras de redes de esgoto, estações de tratamento e águas naturais. A presença do SARS-CoV-2 nesses ambientes tem levantado a possibilidade de transmissão pelo contato com águas contaminadas e aerossóis gerados durante seus fluxos ou tratamentos. Objetivo: Descrever relatos de detecção do novo coronavírus em amostras obtidas em redes de esgotos, em lodos residuais de plantas de tratamento e em corpos d’água naturais, e apresentar a viabilidade desse vírus quando inoculado artificialmente nesses ambientes. Método: Revisão integrativa de literatura fundamentada em artigos científicos escritos em inglês ou português, indexados nas bases de dados do Web of Science, Scopus, PubMed, ScienceDirect, Google Scholar e MedRxiv. Resultados: Foi possível destacar os riscos que o SARS-CoV-2 proporciona às populações de humanos e de animais selvagens quando presente nas águas residuais, estratégias cabíveis de serem utilizadas para limitar a propagação desse patógeno nas matrizes aquáticas, e a importância da implementação de sistemas de monitoramento epidemiológico nesses locais. Conclusões: A fim de reduzir os riscos de surtos emergentes e reemergentes da COVID-19 por meio de matrizes aquosas, abordagens preventivas em relação à presença do SARS-CoV-2 nesses ambientes têm sido fortemente recomendadas.
  • ItemArtigo
    Agave syrup as a substrate for inulinase production by Kluyveromyces marxianus NRRL Y-7571
    (2016-07-01) de Oliveira, Luana Paula de Azevedo; de Oliveira, Tiago Felipe; Contiero, Jonas [UNESP]; Cazetta, Márcia Luciana; Universidade Federal do Recôncavo da Bahia; Universidade Estadual Paulista (UNESP)
    The factorial planning was used to plan and optimize inulinase production by the yeast Kluyveromyces marxianus NRRL Y-7571. The experiments were conducted using a Central Composite Design (CCD) 22, at different concentrations of agave syrup (3.6 to 6.4%) and yeast extract (2.2 to 3.0%). After 96 hours of fermentation, the best condition for the inulinase production was 5% agave syrup and 2.5% yeast extract, which yielded an average of 129.21 U mL-1 of inulinase. Partial characterization of the crude enzyme showed that the optimal pH and temperature were 4.0 and 60°C, respectively. The enzyme showed thermal stability at 55°C for 4 hours.
  • ItemCapítulo de livro
    Polyhydroxyalkanoates: Naturally occurring microbial polymers suitable for nanotechnology applications
    (2021-01-01) De Paula-Elias, Fabrício C.; De Paula, Carolina B. C. [UNESP]; De Oliveira, Nayra M. L.; De Almeida, Alex F.; Contiero, Jonas [UNESP]; Federal University of Tocantins; Universidade Estadual Paulista (UNESP)
    Polyhydroxyalkanoates (PHAs) are intracellular microbial polyesters synthesized by many species of Bacteria and Archaea, generally under nutrient limitation and excess of carbon source as storage granules of energy and also conferring stress resistance to prokaryotes. PHAs are naturally occurring, and the choice of microbial strains and carbon sources for cell cultivations results in biopolymers with different physicochemical properties. Cupriavidus necator is a bacterial strain able to synthesize a high crystalline polymer, poly(3-hydroxybutyrate), the most common of all PHAs; whereas Pseudomonas species produce PHAs with medium chain-length monomers, which exhibit elastomeric properties as natural rubbers. This variety of monomer composition associated with high biocompatibility and biodegradability makes PHAs also feasible for compostable applications and meet the standard specification for marine degradability. Due to their high versatility as natural chemicals and their ecologically friendly properties, PHAs have drawn attention for a wide range of applications from which the PHA nanocomposites have become a promising alternative to petrochemical polymers for nanoscale applications, especially those involved in biomedical materials. This review chapter introduces PHAs from their microbial synthesis, polymer structure to recent applications, with special focus on nanoscience applications. PHA as scaffolds for tissue engineering, nanofibers and particles for catalyst immobilization and drug delivery systems are topics addressed in this chapter. Finally, the future prospects and economical challenges to be overcome by the PHA industry are discussed in this review chapter from a green chemistry background.
  • ItemArtigo
    (2022-03-04) Mainardi, Pedro Henrique [UNESP]; Bidoia, Ederio Dino [UNESP]; Universidade Estadual Paulista (UNESP)
    Factorial designs have been increasingly used in scientific investigations and technological development. The designs, through the use of matrices with all the treatment combinations, have been capable to effectively characterize the relationships between the variables of multi-factor experiments, assess the experimental variabilities, and derive mathematical functions that represent the behavior of the responses. Factorial designs were fractionalized, which substantially reduced the number of treatments without the loss of relevant information. The addition of central and star points to the factorial arrays has given them the orthogonality and rotatability characteristics, frequently used to fit models with curvature and identify critical regions of interest. Literature reports indicated that factorial designs, also called factorial experiments, were successfully applied in different types of investigations, including in cost evaluations and time-series studies. They were capable to estimate important features of the experiments, like the individual and combined effects of factors, the magnitude of residuals, additionally to express the relationships of the variables in polynomial equations, draw response surface and contour plots, and determine optimal combinations of parameters. In this review, the fundamental aspects of the Complete, Fractional, Central Composite Rotational and Asymmetrical factorial designs were conceptualized, and recent applications of these powerful tools were described.
  • ItemArtigo
    Antibacterial action and target mechanisms of zinc oxide nanoparticles against bacterial pathogens
    (2022-12-01) Mendes, Carolina Rosai [UNESP]; Dilarri, Guilherme [UNESP]; Forsan, Carolina Froes [UNESP]; Sapata, Vinícius de Moraes Ruy [UNESP]; Lopes, Paulo Renato Matos [UNESP]; de Moraes, Peterson Bueno; Montagnolli, Renato Nallin [UNESP]; Ferreira, Henrique [UNESP]; Bidoia, Ederio Dino [UNESP]; Universidade Estadual Paulista (UNESP); Universidade Estadual de Campinas (UNICAMP); Universidade Federal de São Carlos (UFSCar)
    Zinc oxide nanoparticles (ZnO NPs) are one of the most widely used nanoparticulate materials due to their antimicrobial properties, but their main mechanism of action (MOA) has not been fully elucidated. This study characterized ZnO NPs by using X-ray diffraction, FT-IR spectroscopy and scanning electron microscopy. Antimicrobial activity of ZnO NPs against the clinically relevant bacteria Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and the Gram-positive model Bacillus subtilis was evaluated by performing resazurin microtiter assay (REMA) after exposure to the ZnO NPs at concentrations ranging from 0.2 to 1.4 mM. Sensitivity was observed at 0.6 mM for the Gram-negative and 1.0 mM for the Gram-positive cells. Fluorescence microscopy was used to examine the interference of ZnO NPs on the membrane and the cell division apparatus of B. subtilis (amy