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1.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 51(1): 60-66, 2020 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-31950791

RESUMO

Objective: To optimize the preparation parameters of the new silk birth-canal microecology transporter (BMT) for transferring the symbiotic bacteria of the birth canal efficiently. Methods: Birth canal microbial samples of 30 full term pregnant women at admission were collected as the control group (NC, n=30). The experimental group included 18 pregnant women terminated by Cesarean section, who were divided into 6 sub-groups (M1-M6, n=3) to complete the transfer tests of the birth-canal microecology. The new silk BMT was processed in the sterile liquid of the different osmotic pressure with the different immersion depth, and was placed in the vagina of the pregnant women for 1 h before sealed. All extracted DNA specimens were amplified in the V3-V4 region of the 16S rDNA, and were sequenced by Illumina Hiseq2500. Microbial diversity analysis was performed by Mothur, QIIME, Lefse and Metastat. Welch's t-test and Anosim nonparametric test were used to compare the difference between groups. Results: The new silk BMT with 70% immersion depth could be fully covered by the solution, and had good solution preserving and adhesion. The subjects had no foreign body sensation with satisfied experience. Both of the microbes on the new BMT and the control group were lactobacillus as the dominant bacteria genus. The microbial diversity and bacteria constitution in the new BMT was similar to the control group in the condition of 0.45% NaCl solution and 70% immersion depth, and there was no significant difference between the two groups ( P>0.05). Conclusion: The new silk BMT can transfer the symbiotic microbes of the birth canal efficiently, and the optimal preparation parameters were 0.45% hypotonic saline solution and 70% immersion depth.


Assuntos
Técnicas Microbiológicas , Microbiota , Seda , Vagina , Bactérias/classificação , Biodiversidade , Cesárea , Feminino , Humanos , Lactobacillus/fisiologia , Técnicas Microbiológicas/métodos , Microbiota/fisiologia , Gravidez , Vagina/microbiologia
2.
BMC Infect Dis ; 19(1): 854, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31619188

RESUMO

BACKGROUND: Taenia hydatigena, T. multiceps, T. pisiformis, and Dipylidium caninum are four common large and medium-sized tapeworms parasitizing the small intestine of dogs and other canids. These parasites cause serious impact on the health and development of livestock. However, there are, so far, no commercially available molecular diagnostic kits capable of simultaneously detecting all four parasites in dogs. The aim of the study was therefore to develop a multiplex PCR assay that will accurately detect all four cestode infections in one reaction. METHODS: Specific primers for a multiplex PCR were designed based on corresponding mitochondrial genome sequences, and its detection limit was assessed by serial dilutions of the genomic DNAs of tapeworms examined. Furthermore, field samples of dog feces were tested using the developed assay. RESULTS: A multiplex polymerase chain reaction (PCR) assay was developed based on mitochondrial DNA (mtDNA) that accurately and simultaneously identify four cestode species in one reaction using specific fragment sizes of 592, 385, 283, and 190 bp for T. hydatigena, T. multiceps, T. pisiformis, and D. caninum, respectively. The lowest DNA concentration detected was 1 ng for T. hydatigena, T. multiceps and T. pisiformis, and 0.1 ng for D. caninum in a 25 µl reaction system. This assay offers high potential for the rapid detection of these four tapeworms in host feces simultaneously. CONCLUSIONS: This study provides an efficient tool for the simultaneous detection of T. hydatigena, T. multiceps, T. pisiformis, and D. caninum. The assay will be potentially useful in epidemiological studies, diagnosis, and treatment of these four cestodes infections during prevention and control program.


Assuntos
Cestoides , Infecções por Cestoides , Técnicas Microbiológicas/métodos , Reação em Cadeia da Polimerase Multiplex/métodos , Animais , Cestoides/genética , Cestoides/isolamento & purificação , Infecções por Cestoides/diagnóstico , Infecções por Cestoides/parasitologia , Cães
3.
Plant Dis ; 103(11): 2751-2758, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31509494

RESUMO

Didymella pisi is the primary causal pathogen of Ascochyta blight (AB) of dry pea in Montana. Diagnosis of AB is challenging because there are six different species that cause AB worldwide and that can co-occur. Additionally, agar plate identification of D. pisi is challenging due to its slow growth rate. Currently, there are no PCR-based assays developed for specific detection of D. pisi or any fungal pathogen in the AB complex of dry pea. In this study, we evaluated simple sequence repeat (SSR) primer pairs for their specificity and sensitivity in real-time and conventional SSR-PCR both in vitro and in planta. The specificity of the assay was determined by testing DNA of 10 dry pea varieties, fungal species in the AB complex, and fungal species associated with dry pea. To avoid false-negative results, plant and fungal DNA markers were included as controls in a conventional multiplex SSR-PCR, to amplify any plant or fungal DNA in the absence of the D. pisi SSR target. SYBR Green SSR-quantitative PCR (qPCR) detection was conducted using the same primer pairs but in a uniplex format. D. pisi was specifically amplified, whereas other fungi and host DNA were not. Also, sensitivity experiments showed that the detection limit was 0.01 ng of DNA of D. pisi for both assays and 100 conidia in SSR-qPCR. These assays are valuable diagnostic tools for the detection of D. pisi.


Assuntos
Ascomicetos , Técnicas Microbiológicas , Ervilhas , Reação em Cadeia da Polimerase , Ascomicetos/genética , Limite de Detecção , Técnicas Microbiológicas/métodos , Repetições de Microssatélites/genética , Montana , Ervilhas/microbiologia
4.
Plant Dis ; 103(12): 3142-3149, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31560617

RESUMO

Trunk canker disease caused by Botryosphaeria dothidea with a prolonged latent infection phase poses a serious threat to Chinese hickory production. To further understand the epidemiological characteristics and develop reasonable management techniques, a quantitative loop-mediated isothermal amplification (q-LAMP) assay was developed to quantitatively monitor B. dothidea in hickory plants, water, and air samples. Specific primers were designed based on the different sites of the ß-tubulin sequence between B. dothidea and other fungi commonly found on Chinese hickory. At the optimum reaction temperature of 65.9°C, this loop-mediated isothermal amplification (LAMP) assay can specifically distinguish B. dothidea from other tested fungi. The limit of detection of LAMP assays for B. dothidea was 0.001 ng/µl of pure genomic DNA and 10 spores per 1 ml of water. The q-LAMP assay enables rapid detection of B. dothidea within 60 min in hickory trunk, water in hickory forests, and spores captured on tapes. These results provide a powerful and convenient tool for monitoring B. dothidea, which could be applied widely in epidemiology, forecast, and management of tree canker disease.


Assuntos
Ascomicetos , Carya , Técnicas Microbiológicas , Técnicas de Amplificação de Ácido Nucleico , Microbiologia do Ar , Ascomicetos/genética , Carya/microbiologia , Técnicas Microbiológicas/métodos , Microbiologia da Água
5.
BMC Infect Dis ; 19(1): 769, 2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31481123

RESUMO

BACKGROUND: Health-workers in developing countries rely on clinical algorithms, such as the Integrated Management of Childhood Illnesses (IMCI), for the management of patients, including diagnosis of serious bacterial infections (SBI). The diagnostic accuracy of IMCI in detecting children with SBI is unknown. Prediction rules and guidelines for SBI from well-resourced countries at outpatient level may help to improve current guidelines; however, their diagnostic performance has not been evaluated in resource-limited countries, where clinical conditions, access to care, and diagnostic capacity differ. The aim of this study was to estimate the diagnostic accuracy of existing prediction rules and clinical guidelines in identifying children with SBI in a cohort of febrile children attending outpatient health facilities in Tanzania. METHODS: Structured literature review to identify available prediction rules and guidelines aimed at detecting SBI and retrospective, external validation on a dataset containing 1005 febrile Tanzanian children with acute infections. The reference standard, SBI, was established based on rigorous clinical and microbiological criteria. RESULTS: Four prediction rules and five guidelines, including IMCI, could be validated. All examined rules and guidelines had insufficient diagnostic accuracy for ruling-in or ruling-out SBI with positive and negative likelihood ratios ranging from 1.04-1.87 to 0.47-0.92, respectively. IMCI had a sensitivity of 36.7% (95% CI 29.4-44.6%) at a specificity of 70.3% (67.1-73.4%). Rules that use a combination of clinical and laboratory testing had better performance compared to rules and guidelines using only clinical and or laboratory elements. CONCLUSIONS: Currently applied guidelines for managing children with febrile illness have insufficient diagnostic accuracy in detecting children with SBI. Revised clinical algorithms including simple point-of-care tests with improved accuracy for detecting SBI targeting in tropical resource-poor settings are needed. They should undergo careful external validation against clinical outcome before implementation, given the inherent limitations of gold standards for SBI.


Assuntos
Infecções Bacterianas/diagnóstico , Febre/diagnóstico , Técnicas Microbiológicas/normas , Testes Imediatos/normas , Guias de Prática Clínica como Assunto , Idade de Início , Algoritmos , Infecções Bacterianas/epidemiologia , Infecções Bacterianas/microbiologia , Criança , Pré-Escolar , Feminino , Febre/microbiologia , Humanos , Lactente , Masculino , Técnicas Microbiológicas/métodos , Técnicas Microbiológicas/estatística & dados numéricos , Testes Imediatos/estatística & dados numéricos , Guias de Prática Clínica como Assunto/normas , Valor Preditivo dos Testes , Prognóstico , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Tanzânia/epidemiologia
6.
J Drugs Dermatol ; 18(8): 798-802, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31424710

RESUMO

Cutaneous fungal infections account for millions of office visits per year, yet their varied presentations often lead to misdiagnosis. If dermatology clinics are Clinical Laboratory Improvement Amendment (CLIA) certified, direct microscopy with potassium hydroxide or other stains can be used to inexpensively and rapidly diagnose fungal infections. In this survey, we examined dermatologists' perceptions of fungal preparations and CLIA certification to identify barriers that prevent the use of these bedside diagnostics. The response rate was 13% (n=308, based on the number of emails opened). When a cutaneous fungal infection is suspected, 20.94% rarely/never and 19.86% sometimes perform fungal preparations, often because they think clinical diagnosis is adequate or that preparations take too long. 21.32% reported not having CLIA certification, most frequently because the process requires too much work, or they do not know how to apply. Of providers with CLIA certification, over 25% thought it was difficult to obtain. Our results demonstrate that numerous barriers prevent the common use of fungal preparations, including the perception that clinical diagnosis is sufficient and the lack of required CLIA certification. These barriers emphasize the need for additional education about cutaneous fungal infections and use of bedside diagnostics. Additionally, policy-based interventions are necessary to ease the process of CLIA certification.


Assuntos
Dermatomicoses/diagnóstico , Fungos/isolamento & purificação , Indicadores e Reagentes/química , Adulto , Idoso , Dermatologistas/estatística & dados numéricos , Dermatologia/métodos , Dermatologia/estatística & dados numéricos , Dermatomicoses/microbiologia , Dermatomicoses/patologia , Diagnóstico Diferencial , Feminino , Humanos , Hidróxidos/química , Masculino , Técnicas Microbiológicas/métodos , Técnicas Microbiológicas/estatística & dados numéricos , Microscopia , Pessoa de Meia-Idade , Visita a Consultório Médico/estatística & dados numéricos , Compostos de Potássio/química , Padrões de Prática Médica/estatística & dados numéricos , Pele/microbiologia , Pele/patologia , Inquéritos e Questionários/estatística & dados numéricos
7.
Future Microbiol ; 14: 1011-1012, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31469007

RESUMO

In this exclusive interview, Maurizio Sanguinetti discusses current issues with Candida fungal infection diagnoses, in light of its rising resistance to antifungal drugs. This interview was conducted by Ellen Colvin, Editor of Future Microbiology. Maurizio Sanguinetti, MD, is full Professor of Microbiology at the Università Cattolica del Sacro Cuore of Rome, Italy, and Director of the Institute of Microbiology and Chief of the Department of Laboratory Sciences and Infectious Diseases Sciences at the Fondazione Policlinico Agostino Gemelli IRCCS of Rome, Italy. For several years, the research activity of Maurizio Sanguinetti has mainly focused on the development of molecular methods for the rapid diagnosis of bacterial, mycobacterial and fungal infections; the elucidation of virulence and antimicrobial resistance mechanisms in clinically relevant bacterial and fungal pathogens; the characterization of the human microbiota in relationship to infectious and noninfectious diseases and implementation of new diagnostic strategies for the personalized care of patients with infectious diseases.


Assuntos
Antifúngicos/uso terapêutico , Candida/isolamento & purificação , Candidíase/diagnóstico , Candidíase/tratamento farmacológico , Testes Diagnósticos de Rotina/métodos , Gerenciamento Clínico , Técnicas Microbiológicas/métodos , Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Farmacorresistência Fúngica , História do Século XX , História do Século XXI , Humanos , Itália
8.
Biosci Biotechnol Biochem ; 83(11): 2163-2171, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31272289

RESUMO

Motile bacteria often exhibit chemotaxis toward favorable compounds. However, the diversity of bacteria that are attracted to a given substance is largely unknown. This study aimed to reveal the diversity of bacteria with natural chemotaxis towards methanol. We tried to enrich environmental chemotactic bacteria using a glass capillary that is half-filled with methanol solidified with agarose as a trap ("chemotaxis fishing"). The pilot experiment using methanol-chemotactic Methylobacterium aquaticum strain 22A enriched the cells by 46-fold. The method was then applied to bacterial suspensions from paddy water and plants. Depending on the isolation sources and the methods of motility induction, methylotrophic bacteria were enriched 1.2-330-fold. The fished isolates belong to 32 species in 18 genera, mainly containing Acinetobacter, Methylobacterium and Pseudomonas species. Our chemotaxis fishing unveiled a part of diversity of the bacteria with natural chemotaxis towards methanol.


Assuntos
Bactérias/citologia , Bactérias/efeitos dos fármacos , Quimiotaxia/efeitos dos fármacos , Metanol/farmacologia , Técnicas Microbiológicas/métodos , Plantas/microbiologia
9.
Dokl Biol Sci ; 485(1): 59-61, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31197597

RESUMO

The described microbiotesting technique provides the recording of pH changes, redox potential, electrical conductivity, optical density, light scattering and luminescence intensities, and other parameters of samples with viable test microorganisms incubated in a liquid nutrient medium in the presence and absence of the tested factors. The results of using this system for the analysis of pro- and antibiotic activity of various oil products, as well as weak electromagnetic fields of the megahertz range, are presented. It has been shown that the proposed technique, compared to the standard methods, yields more detailed and objective information and is less time- and labor-consuming.


Assuntos
Técnicas Biossensoriais/métodos , Técnicas Microbiológicas/métodos , Resíduos/análise , Bactérias/metabolismo , Condutividade Elétrica , Concentração de Íons de Hidrogênio , Luz , Técnicas Microbiológicas/normas , Oxirredução , Espalhamento de Radiação , Sensibilidade e Especificidade
10.
Cell Host Microbe ; 26(1): 123-134.e8, 2019 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-31231046

RESUMO

Despite being a frequent cause of severe diarrheal disease in infants and an opportunistic infection in immunocompromised patients, Cryptosporidium research has lagged due to a lack of facile experimental methods. Here, we describe a platform for complete life cycle development and long-term growth of C. parvum in vitro using "air-liquid interface" (ALI) cultures derived from intestinal epithelial stem cells. Transcriptomic profiling revealed that differentiating epithelial cells grown under ALI conditions undergo profound changes in metabolism and development that enable completion of the parasite life cycle in vitro. ALI cultures support parasite expansion > 100-fold and generate viable oocysts that are transmissible in vitro and to mice, causing infection and animal death. Transgenic parasite lines created using CRISPR/Cas9 were used to complete a genetic cross in vitro, demonstrating Mendelian segregation of chromosomes during meiosis. ALI culture provides an accessible model that will enable innovative studies into Cryptosporidium biology and host interactions.


Assuntos
Criptosporidiose/patologia , Criptosporidiose/parasitologia , Cryptosporidium/patogenicidade , Células Epiteliais/parasitologia , Interações Hospedeiro-Patógeno , Modelos Teóricos , Animais , Células Cultivadas , Cryptosporidium/crescimento & desenvolvimento , Genética Microbiana/métodos , Camundongos Endogâmicos C57BL , Técnicas Microbiológicas/métodos
11.
Ann Biol Clin (Paris) ; 77(3): 339-349, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31219424

RESUMO

The quality of the screening of vanA and/or vanB Vancomycin-resistant enterococcal (VRE) carriage by patients transferred from foreign countries plays a role in the management of risks linked to extensively drug resistant organisms (XDRO). Accreditation of the screening according to the NF EN ISO 15189 and NF EN ISO/IEC 17025 standards contributes to satisfy the level of quality. Our laboratory was already accredited according to the NF EN ISO/IEC 17025 standard. We used its quality management system and the type B widened flexible scope to identify the required criteria based on microbiology and infection control standards and those of Afnor and Cofrac, and to validate the screening procedure. Accreditation was obtained for use of the Type B scope, for culture-based detection and identification (codes BA1 and BA5), for determination of the minimal inhibitory concentrations of glycopeptides (code BA6), and for the detection of resistance genes to glycopeptides by polymerase chain reaction (code BA8). The maturity of our quality management system contributed to validate the screening procedures following the required criteria of the NF EN ISO/IEC 17025 standard.


Assuntos
Técnicas de Laboratório Clínico/normas , Infecções por Bactérias Gram-Positivas/diagnóstico , Programas de Rastreamento/normas , Técnicas Microbiológicas/normas , Reto/microbiologia , Enterococos Resistentes à Vancomicina/isolamento & purificação , Acreditação , Adulto , Criança , Infecção Hospitalar/diagnóstico , Infecção Hospitalar/microbiologia , Infecção Hospitalar/transmissão , DNA Bacteriano/análise , DNA Bacteriano/isolamento & purificação , Enterococcus faecium/isolamento & purificação , Infecções por Bactérias Gram-Positivas/microbiologia , Infecções por Bactérias Gram-Positivas/transmissão , Unidades Hospitalares/normas , Humanos , Recém-Nascido , Unidades de Terapia Intensiva/normas , Laboratórios/normas , Programas de Rastreamento/métodos , Técnicas Microbiológicas/métodos , Projetos Piloto , Padrões de Referência
12.
mBio ; 10(2)2019 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-31040238

RESUMO

Ancient fermented food has been studied based on recipes, residue analysis, and ancient-DNA techniques and reconstructed using modern domesticated yeast. Here, we present a novel approach based on our hypothesis that enriched yeast populations in fermented beverages could have become the dominant species in storage vessels and their descendants could be isolated and studied today. We developed a pipeline of yeast isolation from clay vessels and screened for yeast cells in beverage-related and non-beverage-related ancient vessels and sediments from several archaeological sites. We found that yeast cells could be successfully isolated specifically from clay containers of fermented beverages. The findings that genotypically the isolated yeasts are similar to those found in traditional African beverages and phenotypically they grow similar to modern beer-producing yeast strongly suggest that they are descendants of the original fermenting yeast. These results demonstrate that modern microorganisms can serve as a new tool in bio-archaeology research.IMPORTANCE So far, most of the study of ancient organisms has been based mainly on the analysis of ancient DNA. Here we show that it is possible to isolate and study microorganisms-yeast in this case-from ancient pottery vessels used for fermentation. We demonstrate that it is highly likely that these cells are descendants of the original yeast strains that participated in the fermentation process and were absorbed into the clay matrix of the pottery vessels. Moreover, we characterized the isolated yeast strains, their genomes, and the beer they produced. These results open new and exciting avenues in the study of domesticated microorganisms and contribute significantly to the fields of bio- and experimental archaeology that aim to reconstruct ancient artifacts and products.


Assuntos
Arqueologia/métodos , Fósseis/microbiologia , Sedimentos Geológicos/microbiologia , Técnicas Microbiológicas/métodos , Leveduras/isolamento & purificação , Genótipo
13.
Yakugaku Zasshi ; 139(5): 663-672, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-31061333

RESUMO

Marine environments offer a rich source of natural products with potential therapeutic applications because the ocean covers 70% of the earth's surface and approximately 80% of all living organisms live in the sea. Therefore we have investigated bioactive compounds from marine organisms such as marine sponges, ascidians, and marine-derived microorganisms. This review consists of two topics based on marine natural product chemistry. (1) Protein tyrosine phosphatase (PTP) 1B plays a key role as a negative regulator in the insulin and leptin signaling pathways. Accordingly, the development of PTP1B inhibitors is expected to provide new drugs for type 2 diabetes and obesity. We have been searching for new types of PTP1B inhibitors among marine organisms and identified various PTP1B inhibitors from marine sponges and fungi. This review presents their structural diversities and unique biological properties. (2) In the course of our studies on the induced production of new fungal metabolites, the Palauan marine-derived fungus, Trichoderma cf. brevicompactum TPU199, was found to produce the unusual epipolythiodiketopiperazines, gliovirin and pretrichodermamide A. Long-term static fermentation of the strain induced production of a new dipeptide, dithioaspergillazine A, whereas fermentation of the strain with NaCl, NaBr, and NaI produced the Cl and Br derivatives of pretrichodermamide A and a new iodinated derivative, iododithiobrevamide, respectively. Moreover, DMSO-added seawater medium induced the production of diketopiperazine with the unprecedented trithio-bridge, chlorotrithiobrevamide. This fermentation study on the strain as well as the structures of the metabolites obtained are described in this review.


Assuntos
Organismos Aquáticos/química , Técnicas de Cultura/métodos , Inibidores Enzimáticos/isolamento & purificação , Fungos/metabolismo , Técnicas Microbiológicas/métodos , Proteína Tirosina Fosfatase não Receptora Tipo 1/antagonistas & inibidores , Trichoderma/metabolismo , Diabetes Mellitus Tipo 2 , Dicetopiperazinas/metabolismo , Dipeptídeos/metabolismo , Piperazinas/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 1/fisiologia
14.
Environ Res ; 175: 133-141, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31121528

RESUMO

Exposure to Aspergillus conidia may cause adverse effects on human health; however, no specific recommendations for routine assessments of Aspergillus in the clinical environment have been suggested so far. This study intended to determine the prevalence of Aspergillus in the clinical environment, focusing on ten Primary Health Care Centres (PHCC) through a novel multi-approach sampling protocol. Air and passive sampling, culture-based methods and a probe-based real-time assay for the detection of four clinically relevant Aspergillus sections were performed. Aspergillus spp. was observed in all PHCC, with highest prevalence on floor surface swabs (n=81) (18% on MEA; 6.94% on DG18). Regarding air samples (n=81), highest Aspergillus counts were found in the waiting room (94% MEA; 18% DG18), where Nigri was the most prevalent Aspergillus section. The use of a multi-approach sampling protocol to assess Aspergillus burden in the analysed PHCC has greatly contributed to risk characterization, highlighting the need to implement corrective measures in order to avoid fungal presence in those settings.


Assuntos
Aspergillus , Microbiologia Ambiental , Monitoramento Ambiental , Instalações de Saúde , Técnicas Microbiológicas , Monitoramento Ambiental/métodos , Instalações de Saúde/estatística & dados numéricos , Técnicas Microbiológicas/métodos , Prevalência , Manejo de Espécimes
15.
Appl Microbiol Biotechnol ; 103(11): 4347-4362, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30949810

RESUMO

Both strain engineering and process optimization are intensively studied in microbial biosurfactant literature. However, screening of multiple strains and/or medium components in parallel is a very labor-intensive and timely process, considering the only applied technique nowadays is evaluation through shake flask and/or bioreactor experiments. Therefore, in this work, the development, optimization, and application of a more throughput technique-based on 24-deep well plates-are described for a new Starmerella bombicola strain producing bolaform sophorolipids. To develop an optimal setup, the influence of plate position and culture volume and the type of sandwich cover was investigated. Optimal parameters, which did not result in significant differences compared with shake flask experiments concerning growth, glucose consumption, and production of novel sophorolipids, were defined and validated. Next, the new method was applied to evaluate the influence of the use of alternative (commercial) nitrogen sources in comparison with the yeast extract currently applied in the production medium, aiming to increase production efficiency. Self-made yeast extracts from S. bombicola cells were also included to evaluate possible recycling of cells after fermentation. In conclusion, the designed method enabled the efficient and successful comparison of ten different nitrogen sources in varying concentrations (1, 4, and 10 g/L) on bola sophorolipid production, which can now also be performed for other parameters important for growth and/or glycolipid production.


Assuntos
Engenharia Metabólica/métodos , Técnicas Microbiológicas/métodos , Ácidos Oleicos/biossíntese , Saccharomycetales/metabolismo , Meios de Cultura/química , Fermentação , Miniaturização , Saccharomycetales/crescimento & desenvolvimento
17.
Adv Mater ; 31(24): e1900284, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30993782

RESUMO

From the smallest ecological niche to global scale, communities of microbial life present a major factor in system regulation and stability. As long as laboratory studies remain restricted to single or few species assemblies, however, very little is known about the interaction patterns and exogenous factors controlling the dynamics of natural microbial communities. In combination with microfluidic technologies, progress in the manufacture of functional and stimuli-responsive materials makes artificial microbial arenas accessible. As habitats for natural or multispecies synthetic consortia, they are expected to not only enable detailed investigations, but also the training and the directed evolution of microbial communities in states of balance and disturbance, or under the effects of modulated stimuli and spontaneous response triggers. Here, a perspective on how materials research will play an essential role in generating answers to the most pertinent questions of microbial engineering is presented, and the concept of adaptive microbial arenas and possibilities for their construction from particulate microniches to 3D habitats is introduced. Materials as active and tunable components at the interface of living and nonliving matter offer exciting opportunities in this field. Beyond forming the physical horizon for microbial cultivates, they will enable dedicated intervention, training, and observation of microbial consortia.


Assuntos
Consórcios Microbianos , Técnicas Microbiológicas/métodos , Dispositivos Lab-On-A-Chip , Técnicas Microbiológicas/instrumentação
18.
Opt Lett ; 44(8): 1896-1899, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30985769

RESUMO

We propose, to the best of our knowledge, a new method to image fluorescent objects through turbid media based on Airy beam scanning. This is achieved by using the nondiffractive nature of Airy beams, namely their ability to maintain their shape while penetrating through a highly scattering medium. We show that our technique can image fluorescent objects immersed in turbid media with higher resolution and signal to noise than confocal imaging. As proof of principle, we demonstrate imaging of 1 µm sized fluorescent beads through a dense suspension of yeast cells with an attenuation coefficient of 51 cm-1 at a depth of 90 µm. Finally, we demonstrate that our technique can also provide the depth of the imaged object without any additional sectioning.


Assuntos
Técnicas Microbiológicas/métodos , Microscopia de Fluorescência/instrumentação , Saccharomyces cerevisiae/citologia , Processamento de Imagem Assistida por Computador/métodos
19.
Plant Dis ; 103(7): 1536-1543, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31033398

RESUMO

The genus Phlox consists of approximately 65 species that include some of the most prevalent ornamental plants in the temperate zone. These popular ornamentals are extremely susceptible to powdery mildew (PM) caused by the biotrophic fungi Golovinomyces magnicellulatus and Podosphaera sp. In this study, we used Phlox paniculata and P. glaberrima to develop a set of laboratory tools to study these pathogens in vitro, including a detached leaf and a micropropagated plantlet bioassay. We assessed pathogen growth under different experimental conditions, which included the use of four different media variations (1/2 MS medium amended with benzimidazole and tetracycline), three ages of pathogen culture (14, 18, and 22 days), three phenological stages of the host tissue (1st, 3rd, and 5th node leaves), placement of inoculum on both leaf surfaces (abaxial and adaxial), and three different inoculation techniques (single spore transfer, colony tapping, colony brushing). Detached P. paniculata leaves were successfully maintained on benzimidazole-amended 1/2 MS medium for up to 3 weeks. For both pathogens, the use of 18-day-old cultures resulted in a higher number of larger, higher sporulating colonies compared with 1-4 and 22-day-old cultures. The adaxial side of 3rd node leaves supported statistically significant more fungal growth compared with the adaxial side of 1st and 5th node leaves. Both pathogens also successfully infected micropropagated plantlets of P. glaberrima. These newly developed tools should facilitate in vitro studies on PM of Phlox and possibly be applicable to other ornamental species attacked by the same fungi.


Assuntos
Ascomicetos , Bioensaio , Ericales , Técnicas Microbiológicas/métodos , Ascomicetos/fisiologia , Bioensaio/normas , Ericales/microbiologia , Técnicas Microbiológicas/normas , Doenças das Plantas/microbiologia , Folhas de Planta/microbiologia
20.
J Biosci Bioeng ; 128(3): 296-301, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30962100

RESUMO

Soybean meal has been intensively used as a substrate in culture media for several microorganisms. However, the fermentable sugar containing the soybean needs to be released from the solid matrix through different processes. Against this backdrop, the present study explores the use of high-energy ball milling as a one-step treatment method for expedited production of fermentable sugars of textured soybean. The best result is observed after only 5 min of milling, obtaining 34.1 times more fermentable sugars than untreated textured soybean, and 2.5 times more than commercially used soybean meal. Notably, the textured soybean ball-milled has been used as a substrate for Bacillus thuringiensis var. kurstaki HD-73 fermentation. The cell and spore production is also compared with a standard Rowe media. The maximum cell concentration obtained in the entire fermentation process using ball-milled textured soybean media is found to be higher than the concentration obtained using the standard Rowe media. In addition, it is observed that there is a direct correlation between maximum cell production and reducing sugar concentration generated by the high-energy ball milling treatment. No fermentation inhibitors or by-products are generated during the physical treatment.


Assuntos
Bacillus thuringiensis/citologia , Biomassa , Fracionamento Químico/métodos , Meios de Cultura/química , Técnicas Microbiológicas/métodos , Soja/química , Açúcares/isolamento & purificação , Carboidratos/isolamento & purificação , Fermentação , Ondas de Choque de Alta Energia , Açúcares/química
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