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1.
World J Microbiol Biotechnol ; 35(12): 180, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31728755

RESUMO

Derived from RNA, 5'-ribonucleotides, especially Inosine-5'-monophosphate (IMP) and guanosine-5'-monophosphate (GMP), can enhance the umami taste of soy sauce. In this study, the RNA content of three different salt-tolerant yeasts was examined. The most valuable strain was subjected to atmospheric and room-temperature plasma (ARTP) mutagenesis, which improved its RNA content by 160.54%. Regular fermentation with RNA-enhanced strain failed to increase the amount of 5'-ribonucleotides in the soy sauce due to hydrolysis by phosphatase. A two-stage fermentation strategy was then carried out. Aroma compounds were mainly synthesized in the first stage, and RNA-enriched biomass was massively produced in the second stage followed by heat treatment to inactivate phosphatase. After the proposed strategy was applied, IMP and GMP in the soy sauce reached 68.54 and 89.37 mg/L, respectively. Moreover, the amounts of key aroma compounds and organic acids significantly increased. Results may provide new insights for improving the quality of soy sauce through microorganism breeding and fermentation control.


Assuntos
Mutagênese , Gases em Plasma , RNA , Tolerância ao Sal/genética , Tolerância ao Sal/efeitos da radiação , Alimentos de Soja , Zygosaccharomyces/genética , Zygosaccharomyces/efeitos da radiação , Cruzamento , Fermentação , Microbiologia de Alimentos , Cloreto de Sódio , Paladar , Temperatura Ambiente , Zygosaccharomyces/fisiologia
2.
Environ Sci Pollut Res Int ; 24(22): 18630-18639, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28647878

RESUMO

Cd2+ resistance and bioaccumulation capacity were selected from parental Zygosaccharomyces rouxii (CRZ-0) while maintaining NaCl tolerance using protoplast mutagenesis technology. Ultraviolet-diethyl sulfate (UV-DES) cooperative mutagenesis, followed by preliminary screening and rescreening, was used to select the mutant strain CRZ-9. CRZ-9 grew better than CRZ-0 in YPD medium with 20 or 50 mg L-1 of Cd2+. Scanning electron microscopy observations and flow cytometry tests indicated that CRZ-9 was more effective at eliminating reactive oxygen species (ROS) generated by Cd2+, which led to less cellular structural damage and lower lethality. Furthermore, compared with CRZ-0, CRZ-9 exhibited increased potential for application with higher Cd2+ removal ratio, wider working pH range, and lower biomass dosage in Cd2+ bioaccumulation. The mutant strain CRZ-9 possessed improved Cd2+ resistance and bioaccumulation capacity and therefore is a promising strain to remove Cd2+ from wastewater.


Assuntos
Cádmio/metabolismo , Ecotoxicologia/métodos , Mutagênese , Raios Ultravioleta , Zygosaccharomyces/fisiologia , Cádmio/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Cloreto de Sódio/metabolismo , Ésteres do Ácido Sulfúrico/toxicidade , Purificação da Água , Zygosaccharomyces/efeitos dos fármacos , Zygosaccharomyces/genética , Zygosaccharomyces/efeitos da radiação
3.
J Food Prot ; 74(10): 1751-5, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22004826

RESUMO

Zygosaccharomyces bailii inactivation suspended in apple juice was evaluated under the effects of selected treatments: short-wave UV light (UVC, using one or two lamps), or low-frequency ultrasound (US), or their simultaneous combination. US treatments (20 kHz, 120-µm wave amplitude) were performed at 35°C in a double-wall vessel by using a 13-mm probe. The UVC device consists of two 90-cm-long stainless steel tubes with 40-W UVC lamps covered with quartz tubes, each one inside a stainless steel tube (annular inside diameter of 2.6 cm) connected to a peristaltic pump. Inoculated systems were recirculated through individual or simultaneous US and UVC treatments, samples were taken periodically, and yeast survivors were determined by the plate-count technique. Yeast survival curves demonstrated that UVC alone or in combination with US produced higher inactivation than US alone. Survival curves were appropriately described by the Weibull distribution of resistances model, obtaining model parameter values that adequately reflected the effect of the studied treatments. For every tested case, the distribution of resistances model revealed an absence of mode, while mean values and variances decreased when simultaneous UVC irradiation with two lamps and US were applied, reaching a 7-log cycle reduction after 40 min of treatment. Combined treatment was more effective than individual US or UVC treatments.


Assuntos
Bebidas/microbiologia , Irradiação de Alimentos , Malus/microbiologia , Ultrassom/métodos , Zygosaccharomyces/crescimento & desenvolvimento , Contagem de Colônia Microbiana , Qualidade de Produtos para o Consumidor , Contaminação de Alimentos/prevenção & controle , Manipulação de Alimentos/métodos , Microbiologia de Alimentos , Humanos , Cinética , Viabilidade Microbiana , Raios Ultravioleta , Zygosaccharomyces/efeitos da radiação
4.
J Radiat Res ; 42(4): 361-9, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11951660

RESUMO

A synergistic interaction of hyperthermia with ionizing or UV light (254 nm) radiation was analyzed in experiments with yeast cells. For a fixed dose rate of radiation, the synergism was shown to be observed only within a definite temperature range (40-45 degrees C), inside of which there was an optimal temperature to achieve the highest synergism. The effectiveness of the synergistic interaction was smaller for haploid cells than for diploid cells. Experimental data from diploid yeast cells evidenced the significance of the exposure rate in the synergistic interaction of heat combined with ionizing or ultraviolet radiation. The data show that the less is the intensity of radiation, the lower is the temperature that should be used to provide some definite, or highest, synergistic interaction with the radiation. To demonstrate the significance of this rule for other cellular systems, the results of other authors published for bacterial spores and mammalian cells are discussed. Calculations from these results have confirmed the revealed relationship between the dose rate and the exposure temperature. On this basis, it is inferred that synergism may take place at small intensities of harmful environmental factors existing in the biosphere. Hence, any assessment of the health or environmental risks should take into account synergistic interactions between harmful agents.


Assuntos
Sobrevivência Celular/efeitos da radiação , Radiação Ionizante , Raios Ultravioleta , Temperatura Alta , Fatores de Tempo , Zygosaccharomyces/efeitos da radiação
5.
Life Sci Space Res ; 10: 113-8, 1972.
Artigo em Inglês | MEDLINE | ID: mdl-11898831

RESUMO

Radiobiological studies have been carried out on board the Cosmos 368 satellite, launched on 8 October 1970 and returning to earth on 14 October 1970. Yeast diploid cells Saccharomyces ellipsoides, Megri strain 139-B, haploid cells Zygosaccharomyces Baili, hydrogen bacteria Hydrogenomonas eutropha, strain Z-1, Berlin variety lettuce seeds and Capital variety pea seeds were used in these experiments. The biological specimens were irradiated with gamma-rays at dose rates of 71.8 and 6.7 rad d-1 suring the packaging of containers and after returning the samples to the laboratory. It was found that both on pre-radiation and post-radiation exposure space flight factors did not greatly influence radiobiological effects.


Assuntos
Radiação Cósmica , Raios gama , Voo Espacial , Ausência de Peso , Alface/crescimento & desenvolvimento , Alface/efeitos da radiação , Ervilhas/crescimento & desenvolvimento , Ervilhas/efeitos da radiação , Pseudomonas/metabolismo , Pseudomonas/efeitos da radiação , Radiobiologia , Saccharomyces/metabolismo , Saccharomyces/efeitos da radiação , Sementes/crescimento & desenvolvimento , Sementes/efeitos da radiação , Zygosaccharomyces/metabolismo , Zygosaccharomyces/efeitos da radiação
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