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1.
PLoS One ; 15(5): e0233285, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32453779

RESUMO

Fermentation by microorganisms is a key step in the production of traditional food products such as bread, cheese, beer and wine. In these fermentative ecosystems, microorganisms interact in various ways, namely competition, predation, commensalism and mutualism. Traditional wine fermentation is a complex microbial process performed by Saccharomyces and non-Saccharomyces (NS) yeast species. To better understand the different interactions occurring within wine fermentation, isolated yeast cultures were compared with mixed co-cultures of one reference strain of S. cerevisiae with one strain of four NS yeast species (Metschnikowia pulcherrima, M. fructicola, Hanseniaspora opuntiae and H. uvarum). In each case, we studied population dynamics, resource consumed and metabolites produced from central carbon metabolism. This phenotyping of competition kinetics allowed us to confirm the main mechanisms of interaction between strains of four NS species. S. cerevisiae competed with H. uvarum and H. opuntiae for resources although both Hanseniaspora species were characterized by a strong mortality either in mono or mixed fermentations. M. pulcherrima and M. fructicola displayed a negative interaction with the S. cerevisiae strain tested, with a decrease in viability in co-culture. Overall, this work highlights the importance of measuring specific cell populations in mixed cultures and their metabolite kinetics to understand yeast-yeast interactions. These results are a first step towards ecological engineering and the rational design of optimal multi-species starter consortia using modeling tools. In particular the originality of this paper is for the first times to highlight the joint-effect of different species population dynamics on glycerol production and also to discuss on the putative role of lipid uptake on the limitation of some non-conventional species growth although interaction processes.


Assuntos
Fermentação , Hanseniaspora/metabolismo , Metschnikowia/metabolismo , Saccharomyces cerevisiae/metabolismo , Vinho/microbiologia , Dióxido de Carbono/metabolismo , Fermentação/fisiologia , Frutose/metabolismo , Sucos de Frutas e Vegetais/microbiologia , Glucose/metabolismo , Cinética , Nitrogênio/metabolismo , Vitis
2.
Int J Biol Macromol ; 144: 198-207, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31843613

RESUMO

Optimization of the culture parameters used for biocellulose (BC) production by a previously isolated bacterial strain (Komagataeibacter hansenii AS.5) was carried out. The effect of nine culture parameters on BC production was evaluated by implementing the Plackett-Burman design, and the results revealed that, the most significant variables affecting BC production were MgSO4, ethanol, pH and yeast extract. A three-level and four-factor Box-Behnken design was applied to determine the optimum level of each significant variable. According to the results of the Plackett-Burman (PBD) and Box-Behnken designs (BBD), the following medium composition and parameters were calculated to be optimum (g/l): glucose 25, yeast extract 13, MgSO4 0.15, KH2PO4 2, ethanol 7.18 ml/l, pH 5.5, inoclume size 7%, cultivation temperature 20 °C and incubation time 9 days. Characterization of purified BC was performed to determine the network morphology by scanning electron microscopy, crystallinity by X-ray diffraction, chemical structure and functional groups by Fourier-transform infrared spectroscopy, thermal stability by thermogravimetric analysis and mechanical properties such as Young's modulus, tensile strength and elongation at beak % of BC.


Assuntos
Acetobacteraceae/metabolismo , Celulose/biossíntese , Celulose/isolamento & purificação , Celulose/ultraestrutura , Meios de Cultura , Glucose/metabolismo , Fenômenos Mecânicos , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Resistência à Tração , Termogravimetria , Difração de Raios X
3.
mBio ; 10(6)2019 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-31848273

RESUMO

New approaches are needed to control leprosy, but understanding of the biology of the causative agent Mycobacterium leprae remains rudimentary, principally because the pathogen cannot be grown in axenic culture. Here, we applied 13C isotopomer analysis to measure carbon metabolism of M. leprae in its primary host cell, the Schwann cell. We compared the results of this analysis with those of a related pathogen, Mycobacterium tuberculosis, growing in its primary host cell, the macrophage. Using 13C isotopomer analysis with glucose as the tracer, we show that whereas M. tuberculosis imports most of its amino acids directly from the host macrophage, M. leprae utilizes host glucose pools as the carbon source to biosynthesize the majority of its amino acids. Our analysis highlights the anaplerotic enzyme phosphoenolpyruvate carboxylase required for this intracellular diet of M. leprae, identifying this enzyme as a potential antileprosy drug target.IMPORTANCE Leprosy remains a major problem in the world today, particularly affecting the poorest and most disadvantaged sections of society in the least developed countries of the world. The long-term aim of research is to develop new treatments and vaccines, and these aims are currently hampered by our inability to grow the pathogen in axenic culture. In this study, we probed the metabolism of M. leprae while it is surviving and replicating inside its primary host cell, the Schwann cell, and compared it to a related pathogen, M. tuberculosis, replicating in macrophages. Our analysis revealed that unlike M. tuberculosis, M. leprae utilized host glucose as a carbon source and that it biosynthesized its own amino acids, rather than importing them from its host cell. We demonstrated that the enzyme phosphoenolpyruvate carboxylase plays a crucial role in glucose catabolism in M. leprae Our findings provide the first metabolic signature of M. leprae in the host Schwann cell and identify novel avenues for the development of antileprosy drugs.


Assuntos
Carbono/metabolismo , Glucose/metabolismo , Mycobacterium leprae/fisiologia , Células de Schwann/metabolismo , Células de Schwann/microbiologia , Metabolismo dos Carboidratos , Linhagem Celular , Interações Hospedeiro-Patógeno , Humanos , Hanseníase/metabolismo , Hanseníase/microbiologia , Macrófagos/metabolismo , Macrófagos/microbiologia , Redes e Vias Metabólicas
4.
Biotechnol Bioeng ; 116(8): 1923-1933, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31038201

RESUMO

Adaptive laboratory evolution through 12 rounds of culturing experiments of the nanocellulose-producing bacterium Komagataeibacter hansenii ATCC 23769 in a liquid fraction from hydrothermal pretreatment of corn stover resulted in a strain that resists inhibition by phenolics. The original strain generated nanocellulose from glucose in standard Hestrin and Schramm (HS) medium, but not from the glucose in pretreatment liquid. K. hansenii cultured in pretreatment liquid treated with activated charcoal to remove inhibitors also converted glucose to bacterial nanocellulose and used xylose as carbon source for growth. The properties of this cellulose were the same as nanocellulose generated from media specifically formulated for bacterial cellulose formation. However, attempts to directly utilize glucose proved unsuccessful due to the toxic character of the lignin-derived phenolics, and in particular, vanillan and ferulic acid. Adaptive laboratory evolution at increasing concentrations of pretreatment liquid from corn stover in HS medium resulted in a strain of K. hansenii that generated bacterial nanocellulose directly from pretreatment liquids of corn stover. The development of this adapted strain positions pretreatment liquid as a valuable resource since K. hansenii is able to convert and thereby concentrate a dilute form of glucose into an insoluble, readily recovered and value-added product-bacterial nanocellulose.


Assuntos
Acetobacteraceae/metabolismo , Celulose/metabolismo , Polissacarídeos Bacterianos/metabolismo , Glucose/metabolismo , Microbiologia Industrial/métodos , Lignina/metabolismo , Zea mays/metabolismo
5.
Carbohydr Polym ; 207: 684-693, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30600054

RESUMO

Bacterial cellulose (BC) has been gaining importance over the past decades as a versatile material that finds applications in diverse industries. However, a secured supply is hindered by the slow production rate and batch-to-batch variability of the yield. Here, we report a rational approach for characterising the BC production process using Design of Experiment (DoE) methodology to study the impact of different parameters on desired process attributes. Notably, we found that the carbon source used for bacterial growth significantly impacts the interplay between the process variables and affects the desired outcomes. We therefore, propose that the highest priority process outcome in this study, the yield, is a function of the carbon source and optimal reactor design. Our systematic approach has achieved projected BC yields as high as ∼40 g/L for Gluconacetobacter hansenii 53582 grown on sucrose as the carbon source compared to the widely reported yields of ∼10 g/L.


Assuntos
Celulose/biossíntese , Acetobacteraceae/química , Acetobacteraceae/metabolismo , Celulose/química , Meios de Cultura , Fermentação , Gluconacetobacter/química , Gluconacetobacter/metabolismo , Glucose/metabolismo , Sacarose/metabolismo
6.
FEMS Yeast Res ; 19(1)2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30202936

RESUMO

This work reports important results of aromatic profiles produced by native yeasts isolated from desert-grown wine grapes from the south of Chihuahua, México. These grapes stand very high temperatures during the ripening season, developing high sugar concentration and high pH. Yeast species found in grapes were identified by polymerase chain reaction and sequence analysis of the 5.8S internal transcribed spacer ribosomal RNA region. Aureobasidium namibiae, Sporobolomyces johnsonii, Candida apicola, Hanseniaspora uvarum, Candida thaimueangensis, Hanseniaspora opuntiae were identified. All of them can grow at glucose concentration of 35% (w/v) and 100 ppm of SO2, and produce low volatile acidity (0.2-1.0 g acetic acid/L). Volatile organic compounds analysis showed that C. thaimueangensis and one strain of C. apicola produce high levels of esters, and Hanseniaspora species produces high levels of higher alcohols and carbonyl compounds. The results of this study contribute to the knowledge about yeast communities associated with desert-grown winegrape yeasts.


Assuntos
Fermentação , Vitis/microbiologia , Leveduras/classificação , Leveduras/metabolismo , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Glucose/metabolismo , México , Filogenia , RNA Ribossômico 5,8S/genética , Análise de Sequência de DNA , Compostos Orgânicos Voláteis/metabolismo , Leveduras/genética , Leveduras/isolamento & purificação
7.
Front Immunol ; 9: 806, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29755459

RESUMO

For those with leprosy, the extent of host infection by Mycobacterium leprae and the progression of the disease depend on the ability of mycobacteria to shape a safe environment for its replication during early interaction with host cells. Thus, variations in key genes such as those in pattern recognition receptors (NOD2 and TLR1), autophagic flux (PARK2, LRRK2, and RIPK2), effector immune cytokines (TNF and IL12), and environmental factors, such as nutrition, have been described as critical determinants for infection and disease progression. While parkin-mediated autophagy is observed as being essential for mycobacterial clearance, leprosy patients present a prominent activation of the type I IFN pathway and its downstream genes, including OASL, CCL2, and IL10. Activation of this host response is related to a permissive phenotype through the suppression of IFN-γ response and negative regulation of autophagy. Finally, modulation of host metabolism was observed during mycobacterial infection. Both changes in lipid and glucose homeostasis contribute to the persistence of mycobacteria in the host. M. leprae-infected cells have an increased glucose uptake, nicotinamide adenine dinucleotide phosphate generation by pentose phosphate pathways, and downregulation of mitochondrial activity. In this review, we discussed new pathways involved in the early mycobacteria-host interaction that regulate innate immune pathways or metabolism and could be new targets to host therapy strategies.


Assuntos
Autofagia , Interações Hospedeiro-Patógeno/imunologia , Imunidade Inata , Interferon Tipo I/imunologia , Hanseníase/imunologia , Citocinas/imunologia , Progressão da Doença , Glucose/metabolismo , Humanos , Interferon Tipo I/genética , Hanseníase/metabolismo , Infecções por Mycobacterium/imunologia , Infecções por Mycobacterium/terapia , Mycobacterium leprae/imunologia , Receptores de Reconhecimento de Padrão/imunologia , Transdução de Sinais
8.
FEMS Yeast Res ; 18(3)2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29546274

RESUMO

Saccharomyces cerevisiae secretes antimicrobial peptides (AMPs) derived from glyceraldehyde-3-phosphate dehydrogenase (GAPDH), which induce the death of several non-Saccharomyces yeasts. Previously, we demonstrated that the naturally secreted GAPDH-derived AMPs (i.e. saccharomycin) caused a loss of culturability and decreased the intracellular pH (pHi) of Hanseniaspora guilliermondii cells. In this study, we show that chemically synthesised analogues of saccharomycin also induce a pHi drop and loss of culturability in H. guilliermondii, although to a lesser extent than saccharomycin. To assess the underlying causes of the pHi drop, we evaluated the membrane permeability to H+ cations of H. guilliermondii cells, after being exposed to saccharomycin or its synthetic analogues. Results showed that the H+-efflux decreased by 75.6% and the H+-influx increased by 66.5% in cells exposed to saccharomycin at pH 3.5. Since H+-efflux via H+-ATPase is energy dependent, reduced glucose consumption would decrease ATP production and consequently H+-ATPase activity. However, glucose uptake rates were not affected, suggesting that the AMPs rather than affecting glucose transporters may affect directly the plasma membrane H+-ATPase or increase ATP leakage due to cell membrane disturbance. Thus, our study revealed that both saccharomycin and its synthetic analogues induced cell death of H. guilliermondii by increasing the proton influx and inhibiting the proton efflux.


Assuntos
Peptídeos Catiônicos Antimicrobianos/farmacologia , Gliceraldeído-3-Fosfato Desidrogenases/química , ATPases Translocadoras de Prótons/metabolismo , Saccharomyces cerevisiae/química , Saccharomycetales/efeitos dos fármacos , Permeabilidade da Membrana Celular , Glucose/metabolismo , Concentração de Íons de Hidrogênio , Saccharomycetales/enzimologia
9.
Appl Microbiol Biotechnol ; 102(2): 641-653, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29150708

RESUMO

Arabitol is a low-calorie sugar alcohol with anti-cariogenic properties. Enzymatic hydrolysate of soybean flour is a new renewable biorefinery feedstock containing hexose, pentose, and organic nitrogen sources. Arabitol production by Debaryomyces hansenii using soybean flour hydrolysate was investigated. Effects of medium composition, operating conditions, and culture stage (growing or stationary phase) were studied. Production was also compared at different culture volumes to understand the effect of dissolved oxygen concentration (DO). Main factors examined for medium composition effects were the carbon to nitrogen concentration ratio (C/N), inorganic (ammonium) to organic nitrogen ratio (I/O-N), and sugar composition. Arabitol yield increased with increasing C/N ratio and a high I/O-N (0.8-1.0), suggesting higher yield at stationary phase of low pH (3.5-4.5). Catabolite repression was observed, with the following order of consumption: glucose > fructose > galactose > xylose > arabinose. Arabitol production also favored hexoses and, among hexoses, glucose. DO condition was of critical importance to arabitol production and cell metabolism. The yeast consumed pentoses (xylose and arabinose) only at more favorable DO conditions. Finally, arabitol was produced in fermentors using mixed hydrolysates of soy flour and hulls. The process gave an arabitol yield of 54%, volumetric productivity of 0.90 g/L-h, and specific productivity of 0.031 g/g-h.


Assuntos
Fermentação , Farinha , Saccharomycetales/metabolismo , Soja/química , Álcoois Açúcares/metabolismo , Reatores Biológicos , Repressão Catabólica , Meios de Cultura/química , Glucose/metabolismo , Hidrólise , Lignina/metabolismo , Nitrogênio/metabolismo , Pentoses/metabolismo , Xilose/metabolismo
10.
Appl Microbiol Biotechnol ; 101(3): 1003-1012, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27678116

RESUMO

Isolate B17 from Kombucha was estimated to be an efficient producer of bacterial cellulose (BC). The isolate was deposited under the number P 1463 and identified as Komagataeibacter rhaeticus by comparing a generated amplified fragment length polymorphism (AFLP™) DNA fingerprint against a reference database. Static cultivation of the K. rhaeticus strain P 1463 in Hestrin and Schramm (HS) medium resulted in 4.40 ± 0.22 g/L BC being produced, corresponding to a BC yield from glucose of 25.30 ± 1.78 %, when the inoculum was made with a modified HS medium containing 10 g/L glucose. Fermentations for 5 days using media containing apple juice with analogous carbon source concentrations resulted in 4.77 ± 0.24 g/L BC being synthesised, corresponding to a yield from the consumed sugars (glucose, fructose and sucrose) of 37.00 ± 2.61 %. The capacity of K. rhaeticus strain P 1463 to synthesise BC was found to be much higher than that of two reference strains for cellulose production, Komagataeibacter xylinus DSM 46604 and Komagataeibacter hansenii DSM 5602T, and was also considerably higher than that of K. hansenii strain B22, isolated from another Kombucha sample. The BC synthesised by K. rhaeticus strain P 1463 after 40 days of cultivation in HS medium with additional glucose supplemented to the cell culture during cultivation was shown to have a degree of polymerization of 3300.0 ± 122.1 glucose units, a tensile strength of 65.50 ± 3.27 MPa and a length at break of 16.50 ± 0.83 km. For the other strains, these properties did not exceed 25.60 ± 1.28 MPa and 15.20 ± 0.76 km.


Assuntos
Celulose/biossíntese , Fermentação , Gluconacetobacter/metabolismo , Chá de Kombucha/microbiologia , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Carbono/metabolismo , Celulose/metabolismo , Meios de Cultura/química , Gluconacetobacter/classificação , Gluconacetobacter/crescimento & desenvolvimento , Gluconacetobacter/isolamento & purificação , Glucose/metabolismo
11.
J Biol Chem ; 291(41): 21375-21387, 2016 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-27555322

RESUMO

Mycobacterium leprae, the intracellular etiological agent of leprosy, infects Schwann promoting irreversible physical disabilities and deformities. These cells are responsible for myelination and maintenance of axonal energy metabolism through export of metabolites, such as lactate and pyruvate. In the present work, we observed that infected Schwann cells increase glucose uptake with a concomitant increase in glucose-6-phosphate dehydrogenase (G6PDH) activity, the key enzyme of the oxidative pentose pathway. We also observed a mitochondria shutdown in infected cells and mitochondrial swelling in pure neural leprosy nerves. The classic Warburg effect described in macrophages infected by Mycobacterium avium was not observed in our model, which presented a drastic reduction in lactate generation and release by infected Schwann cells. This effect was followed by a decrease in lactate dehydrogenase isoform M (LDH-M) activity and an increase in cellular protection against hydrogen peroxide insult in a pentose phosphate pathway and GSH-dependent manner. M. leprae infection success was also dependent of the glutathione antioxidant system and its main reducing power source, the pentose pathway, as demonstrated by a 50 and 70% drop in intracellular viability after treatment with the GSH synthesis inhibitor buthionine sulfoximine, and aminonicotinamide (6-ANAM), an inhibitor of G6PDH 6-ANAM, respectively. We concluded that M. leprae could modulate host cell glucose metabolism to increase the cellular reducing power generation, facilitating glutathione regeneration and consequently free-radical control. The impact of this regulation in leprosy neuropathy is discussed.


Assuntos
Metabolismo Energético , Glucose/metabolismo , Glucosefosfato Desidrogenase/metabolismo , Ácido Láctico/metabolismo , Hanseníase Tuberculoide/metabolismo , Mycobacterium leprae/metabolismo , Células de Schwann/metabolismo , Linhagem Celular , Humanos , Metionina/análogos & derivados , Metionina/farmacologia , Mitocôndrias/metabolismo , Células de Schwann/microbiologia
12.
Carbohydr Polym ; 144: 33-40, 2016 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-27083790

RESUMO

Bacterial cellulose (BC) samples were obtained using two culture media (glucose and glucose+fructose) and two bacteria (Komagataeibacter rhaeticus and Komagataeibacter hansenii). Nanopaper was obtained from the BC through oxidation and both were studied to determine the impact of culture media and bacteria strain on nanofiber structure and mechanical properties. AFM and SEM were used to investigate fibre dimensions and network morphology; FTIR and XRD to determine cellulose purity and crystallinity; carboxyl content, degree of polymerisation and zeta potential were used to characterise nanofibers. Tensile testing showed that nanopaper has up to 24 times higher Young's modulus (7.39GPa) than BC (0.3GPa). BC displayed high water retention values (86-95%) and a degree of polymerisation up to 2540. Nanofibers obtained were 80-120nm wide and 600-1200nm long with up to 15% higher crystallinity than the original BC. It was concluded that BC is an excellent source for easily obtainable, highly crystalline and strong nanofibers.


Assuntos
Acetobacteraceae/metabolismo , Celulose/química , Celulose/biossíntese , Frutose/metabolismo , Glucose/metabolismo , Nanofibras , Papel , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
13.
s.l; s.n; 2016. 13 p. ilus, tab, graf.
Não convencional em Inglês | SES-SP, HANSEN, SESSP-ILSLPROD, SES-SP, SESSP-ILSLACERVO, SES-SP | ID: biblio-1095631

RESUMO

Mycobacterium leprae, the intracellular etiological agent of leprosy, infects Schwann promoting irreversible physical disabilities and deformities. These cells are responsible for myelination and maintenance of axonal energy metabolism through export of metabolites, such as lactate and pyruvate. In the present work, we observed that infected Schwann cells increase glucose uptake with a concomitant increase in glucose-6-phosphate dehydrogenase (G6PDH) activity, the key enzyme of the oxidative pentose pathway. We also observed a mitochondria shutdown in infected cells and mitochondrial swelling in pure neural leprosy nerves. The classic Warburg effect described in macrophages infected by Mycobacterium avium was not observed in our model, which presented a drastic reduction in lactate generation and release by infected Schwann cells. This effect was followed by a decrease in lactate dehydrogenase isoform M (LDH-M) activity and an increase in cellular protection against hydrogen peroxide insult in a pentose phosphate pathway and GSH-dependent manner. M. leprae infection success was also dependent of the glutathione antioxidant system and its main reducing power source, the pentose pathway, as demonstrated by a 50 and 70% drop in intracellular viability after treatment with the GSH synthesis inhibitor buthionine sulfoximine, and aminonicotinamide (6-ANAM), an inhibitor of G6PDH 6-ANAM, respectively. We concluded that M. leprae could modulate host cell glucose metabolism to increase the cellular reducing power generation, facilitating glutathione regeneration and consequently free-radical control. The impact of this regulation in leprosy neuropathy is discussed.


Assuntos
Humanos , Células de Schwann/metabolismo , Células de Schwann/microbiologia , Hanseníase Tuberculoide/metabolismo , Linhagem Celular , Ácido Láctico/metabolismo , Metabolismo Energético , Glucose/metabolismo , Glucosefosfato Desidrogenase/metabolismo , Metionina/análogos & derivados , Metionina/farmacologia , Mitocôndrias/metabolismo , Mycobacterium leprae/metabolismo
14.
Carbohydr Polym ; 132: 286-94, 2015 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-26256351

RESUMO

The current study was intended to produce bio-cellulose through a cell-free system developed by disrupting Gluconacetobacter hansenii PJK through bead-beating. Microscopic analysis indicated the complete disruption of cells (2.6 × 10(7) cells/mL) in 20 min that added 95.12 µg/mL protein, 1.63 mM ATP, and 1.11 mM NADH into the medium. A liquid chromatography mass spectrometry/mass spectrometry linear trap quadrupole (LC-MS/MS LTQ) Orbitrap analysis of cell-lysate confirmed the presence of all key enzymes for bio-cellulose synthesis. Under static conditions at 30 °C, microbial and cell-free systems produced 3.78 and 3.72 g/L cellulose, corresponding to 39.62 and 57.68% yield, respectively after 15 days. The improved yield based on consumed glucose indicated the superiority of cell-free system. Based on current findings and literature, we hypothesized a synthetic pathway for bio-cellulose synthesis in the cell-free system. This approach can overcome some limitations of cellulose-producing cells and offers a wider scope for synthesizing cellulose composites with bactericidal elements through in situ synthesizing approaches.


Assuntos
Sistema Livre de Células/metabolismo , Celulose/metabolismo , Gluconacetobacter/metabolismo , Glucose/metabolismo , Microbiologia Industrial/métodos , Espectrometria de Massas em Tandem
15.
Microbiology (Reading) ; 161(10): 2008-2018, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26253443

RESUMO

Fructophily has been described in yeasts as the ability to utilize fructose preferentially when fructose and glucose are available in the environment. In Zygosaccharomyces bailii and Zygosaccharomyces rouxii, fructophilic behaviour has been associated with the presence of a particular type of high-capacity and low-affinity fructose transporters designated Ffz. In this study, a PCR screening was performed in several yeasts using degenerate primers suitable to detect FFZ-like genes. In parallel, fructophilic character was evaluated in the same strains by comparing the relative consumption rate of fructose and glucose. For all the strains in which FFZ-like genes were detected, fructophilic behaviour was observed (25 strains). Results show that FFZ genes are ubiquitous in the Zygosaccharomyces and Starmerella clades. Strains of Lachancea fermentati, Torulaspora microellipsoides and Zygotorulaspora florentina were not fructophilic and did not harbour FFZ genes. It is of note that these new species were recently removed by taxonomists from the Zygosaccharomyces clade, supporting the view that the presence of FFZ-like genes is a main characteristic of Zygosaccharomyces. Among the strains tested, only Hanseniaspora guilliermondii NCYC2380 was an exception, having a preference for fructose in medium with high sugar concentrations, despite no FFZ-like genes being detected in the screening. Furthermore, this study supports the previous idea of the emergence of a new family of hexose transporters (Ffz facilitators) distinct from the Sugar Porter family.


Assuntos
Frutose/metabolismo , Proteínas de Transporte de Monossacarídeos/genética , Proteínas de Transporte de Monossacarídeos/metabolismo , Saccharomycetales/genética , Saccharomycetales/metabolismo , DNA Fúngico/química , DNA Fúngico/genética , Testes Genéticos , Glucose/metabolismo , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Análise de Sequência de DNA
16.
Biochimie ; 111: 70-81, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25698613

RESUMO

Hydnocarpus alpina Wt. (Flacourtiaceae) (H. alpina) is a large tree traditionally used to treat leprosy; it also posses antidiabetic property. The present study was undertaken to isolate, characterize and to evaluate the antidiabetic effect of 2R, 3R taxifolin 3-O-rhamnoside. (rhamnoside) and its impact on carbohydrate metabolic key enzymes in control and streptozotocin (STZ)-induced diabetic rats. Diabetes mellitus was induced by a single intraperitoneal injection of streptozotocin (STZ) (40 mg/kg). Oral administration of rhamnoside for 21 days significantly reduced food intake, calorie intake, blood glucose and glycosylated hemoglobin levels, and improved plasma insulin levels. Administration of rhamnoside showed significant increase in the body weight, body composition (Lean body weight (LBW) and retro body fat), glycolytic hexokinase, glucose-6-phophate dehydrogenase and pyruvate kinase levels where as significant decrease was observed in the levels of glucose-6-phosphatase fructose-1, 6-bisphosphatase and lactate dehydrogenase in diabetic treated rats. Further, administration of rhamnoside significantly improved the glycogen content, glycogen synthase and glycogen phosphorylase, suggesting the antihyperglycemic potential of rhamnoside in diabetic rats. The results obtained were compared with glibenclamide a standard hypoglycaemic drug. Immunohistopathological study of pancreas revealed increased number of ß-cells and insulin granules in diabetes-induced rats after treatment with rhamnoside for 21 days. Furthermore, Co-administration of rhamnoside (50 mg/kg) with nifedipine (13.6 mg/kg), a Ca(2+)ion channel blocker, or nicorandil (6.8 mg/kg), an ATP-sensitive K(+) ion channel opener, reveals the insulin secretion property of rhamnoside via a K(+)-ATP channels dependent pathway in diabetic rats. In conclusion, rhamnoside normalized blood glucose, glycosylated hemoglobin, key hepatic enzymes and glycogen content by increasing insulin secretion via K(+)-ATP channels dependent signaling pathway. The results suggest that the rhamnoside from H. alpina could be used as a therapeutic agent to treat diabetes mellitus.


Assuntos
Diabetes Mellitus Experimental , Glicosídeos/farmacologia , Hipoglicemiantes/farmacologia , Fígado/enzimologia , Magnoliopsida/química , Extratos Vegetais/química , Acetatos/química , Animais , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/enzimologia , Glucose/metabolismo , Glicosídeos/química , Glicosídeos/isolamento & purificação , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Fígado/patologia , Masculino , Ratos Wistar
17.
Carbohydr Polym ; 115: 663-9, 2015 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-25439946

RESUMO

This study characterized the cellulosic and non-cellulosic exopolysaccharides (EPS) produced by four Gluconacetobacter strains. The yields of bacterial cellulose and water-soluble polysaccharides were dependent on both carbon source and Gluconacetobacter strain. The carbon substrate also affected the composition of the free EPS. When galactose served as an exclusive carbon source, Gluconacetobacter xylinus (G. xylinus) ATCC 53524 and ATCC 700178 produced a distinct alkaline stable crystalline product, which influenced the crystallization of cellulose. Gluconacetobacter hansenii (G. hansenii) ATCC 23769 and ATCC 53582, however, did not exhibit any significant change in cellulose crystal properties when galactose was used as the carbon source. Microscopic observation further confirmed significant incorporation of EPS into the cellulose composites. The cellulosic network produced from galactose medium showed distinctive morphological and structural features compared to that from glucose medium.


Assuntos
Celulose/química , Gluconacetobacter/metabolismo , Polissacarídeos Bacterianos/química , Celulose/metabolismo , Galactose/metabolismo , Glucose/metabolismo , Microscopia Eletrônica de Varredura , Monossacarídeos/análise , Polissacarídeos Bacterianos/metabolismo , Hidróxido de Sódio/química , Difração de Raios X
18.
Appl Biochem Biotechnol ; 168(8): 2268-84, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23076573

RESUMO

Debaryomyces hansenii NRRL Y-7426 metabolised ferulic acid into different phenolic compounds using a factorial design where glucose concentration (in the range of 1-20 g/L), peptone concentration (2-20 g/L) and yeast extract concentration (0.2-10 g/L) were the independent variables. The interrelationship between dependent and operational variables was well fitted (R (2) > 0.95) to models including linear, interaction and quadratic terms. Depending on the glucose and nitrogen concentrations, which redirected the metabolism, the major degradation products were 1,226.2 mg 4-vinyl guaiacol/L after 72 h (molar yield of 86.0 %), 1,077.8 mg vanillic acid/L after 360 h (molar yield of 91.1 %) or 1,682.6 mg acetovanillone/L after 408 h (molar yield of 98.8 %) in fermentations carried out with 2,000 mg ferulic acid/L. Other metabolites such as vanillin, vanillyl alcohol or 4-ethylguaiacol were present in lower amounts.


Assuntos
Produtos Biológicos/metabolismo , Reatores Biológicos/microbiologia , Ácidos Cumáricos/metabolismo , Fenóis/metabolismo , Saccharomycetales/metabolismo , Acetofenonas/metabolismo , Biotransformação , Glucose/metabolismo , Guaiacol/análogos & derivados , Guaiacol/metabolismo , Peptonas/metabolismo , Ácido Vanílico/metabolismo
19.
J Food Sci ; 77(6): M337-42, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22583004

RESUMO

UNLABELLED: Statistical experimental designs were employed to optimize culture conditions for cold-adapted lysozyme production of a psychrophilic yeast Debaryomyces hansenii. In the first step of optimization using Plackett-Burman design (PBD), peptone, glucose, temperature, and NaCl were identified as significant variables that affected lysozyme production, the formula was further optimized using a four factor central composite design (CCD) to understand their interaction and to determine their optimal levels. A quadratic model was developed and validated. Compared to the initial level (18.8 U/mL), the maximum lysozyme production (65.8 U/mL) observed was approximately increased by 3.5-fold under the optimized conditions. PRACTICAL APPLICATION: Cold-adapted lysozymes production was first optimized using statistical experimental methods. A 3.5-fold enhancement of microbial lysozyme was gained after optimization. Such an improved production will facilitate the application of microbial lysozyme. Thus, D. hansenii lysozyme may be a good and new resource for the industrial production of cold-adapted lysozymes.


Assuntos
Debaryomyces/enzimologia , Conservantes de Alimentos/metabolismo , Proteínas Fúngicas/biossíntese , Muramidase/biossíntese , Regiões Antárticas , Temperatura Baixa , Debaryomyces/crescimento & desenvolvimento , Debaryomyces/isolamento & purificação , Fermentação , Tecnologia de Alimentos , Proteínas Fúngicas/metabolismo , Glucose/metabolismo , Cinética , Modelos Biológicos , Muramidase/metabolismo , Concentração Osmolar , Peptonas/metabolismo , Água do Mar/microbiologia , Cloreto de Sódio/metabolismo , Estatística como Assunto
20.
Bioprocess Biosyst Eng ; 34(7): 869-78, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21461772

RESUMO

A mathematical model describing the kinetics of the sequential production of lactic acid and xylitol from detoxified-concentrated vine trimming hemicellulosic hydrolysates by Lactobacillus rhamnosus and Debaryomyces hansenii, respectively, was developed from the basic principles of mass balance in two stages considering as main reactions: (1) glucose and xylose consumption by L. rhamnosus; and (2) xylitol and arabitol production by D. hansenii. The model allows to evaluate the yields and productivities under microaerobic and oxygen restricted conditions (in particular the effects caused by purging the oxygen with nitrogen), which were particularly important during the xylose to xylitol bioconversion by yeasts. The model was tested using experimental data obtained from detoxified-concentrated hemicellulosic hydrolysates, after CaCO3 addition in both types of fermentation processes, without purges (microaerobic conditions) or purging oxygen with nitrogen (oxygen-limited conditions) after sampling in order to reduce the oxygen dissolved. L. rhamnosus was removed by microfiltration before adding D. hansenii at the beginning of the second stage. Mass balance-based and logistic functions were successfully applied to develop the model of the system which properly predicts the consumption of sugars as well as the metabolites produced and yields. The dynamics of fermentation were also adequately described by the developed model.


Assuntos
Fermentação , Ácido Láctico/biossíntese , Modelos Biológicos , Polissacarídeos/química , Xilitol/biossíntese , Leveduras/metabolismo , Arabinose/metabolismo , Debaryomyces/metabolismo , Etanol/metabolismo , Glucose/metabolismo , Hidrólise , Cinética , Lactobacillus rhamnosus/metabolismo , Modelos Logísticos , Nitrogênio/metabolismo , Oxigênio/metabolismo , Plantas/metabolismo , Plantas/microbiologia , Polissacarídeos/metabolismo , Álcoois Açúcares/metabolismo , Gerenciamento de Resíduos/métodos , Resíduos , Xilose/metabolismo
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