Revista De Microbiologia最新文献_第5页

Frequency of 2,3,5-triphenyltetrazolium chloride (TTC) non-reducing bacteria in pasteurized milk 巴氏奶中2,3,5-三苯四唑氯(TTC)非还原性细菌的频率

Revista De Microbiologia Pub Date : 1999-04-01 DOI: 10.1590/S0001-37141999000200009

V. Beloti, M. A. F. Barros, J. C. Freitas, L. Nero, Juliana Aparecida de Souza, E. H. W. Santana, B. Franco

{"title":"Frequency of 2,3,5-triphenyltetrazolium chloride (TTC) non-reducing bacteria in pasteurized milk","authors":"V. Beloti, M. A. F. Barros, J. C. Freitas, L. Nero, Juliana Aparecida de Souza, E. H. W. Santana, B. Franco","doi":"10.1590/S0001-37141999000200009","DOIUrl":"https://doi.org/10.1590/S0001-37141999000200009","url":null,"abstract":"ABSTRACT2,3,5-triphenyltetrazolium chloride (TTC) is a dye largely used for enumeration ofmicrobial colonies in solid culture media, being a key component of the dry rehydratablefilm system used for microbiological analysis of food. This dye is colorless in theoxidized form and red when reduced by microorganisms, due to formation of formazan.In this study, TTC was added to Plate Count Agar (PCA) for enumeration ofmicroorganisms in thirty four pasteurized milk samples, with the aim to verify thefrequency of microorganisms that are unable to reduce TTC. Milk samples weredecimally diluted in saline and pour-plated in PCA plus 0.015% TTC. Colonies werecounted after 24h and 48 h of incubation at 35 o C. From a total of 50,574 colonies,19,665 (38.88%) did not reduce TTC in 48h. It was observed that 571 (6.36%) coloniesthat were colorless in 24h became red in 48h. From those that didn™t reduce TTC in48h, 233 were purified and Gram stained. 229 (98.71%) of them were Gram positivecocci and bacilli. The results show that there is a high percentage of microorganismsunable to reduce TTC in pasteurized milk, which cannot be detected by laboratoryprocedures based on the formation of red colonies.Key words: 2,3,5-triphenyltetrazolium chloride, TTC, pasteurized milk, microbial counts","PeriodicalId":21211,"journal":{"name":"Revista De Microbiologia","volume":"8 1","pages":"137-140"},"PeriodicalIF":0.0,"publicationDate":"1999-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90718370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 54

Detection and characterization of bacteriocin-producing Lactococcus lactis strains 产细菌素乳酸乳球菌菌株的检测与鉴定

Revista De Microbiologia Pub Date : 1999-04-01 DOI: 10.1590/S0001-37141999000200008

I. Moreno, A. Lerayer, M. Leitão

引用次数: 26

Purification and characterization of a low molecular weight xylanase from solid-state cultures of Aspergillus fumigatus Fresenius 费森乌斯烟曲霉固态培养低分子量木聚糖酶的纯化与特性研究

Revista De Microbiologia Pub Date : 1999-04-01 DOI: 10.1590/S0001-37141999000200005

C. H. C. Silva, J. Puls, M. V. Sousa, E. Filho

引用次数: 36

Enhancement of gamma-linolenic acid production by the fungus Mucor sp LB-54 by growth temperature 生长温度对真菌Mucor sp LB-54生产γ -亚麻酸的影响

Revista De Microbiologia Pub Date : 1999-04-01 DOI: 10.1590/S0001-37141999000200016

P. Carvalho, Joaquim Gilberto de Oliveira, G. Pastore

{"title":"Enhancement of gamma-linolenic acid production by the fungus Mucor sp LB-54 by growth temperature","authors":"P. Carvalho, Joaquim Gilberto de Oliveira, G. Pastore","doi":"10.1590/S0001-37141999000200016","DOIUrl":"https://doi.org/10.1590/S0001-37141999000200016","url":null,"abstract":"A linhagem de Mucor sp LB-54, considerada uma potencial produtora de acido gama-linolenico (GLA), foi selecionada para o estudo de diferentes temperaturas de cultivo em agitador rotativo. A linhagem usada neste experimento era capaz de acumular uma quantidade alta de lipideos intracelulares, 20,73 % do peso seco de biomassa e conteudo de GLA de 15 % dentre os acidos graxos totais de sua constituicao apos 5 dias de incubacao a 28°C. Quando a temperatura de cultivo foi diminuida de 28oC para 12°C, o conteudo de GLA aumentou de 15 para 24% dentre os acidos graxos totais de sua constituicao. Com o objetivo de otimizar as condicoes de cultivo para a producao rapida de biomassa e producao de lipideos contendo conteudo alto de GLA, o fungo foi cultivado em duas combinacoes de temperaturas associadas com a suplementacao de fonte de carbono (glicose). A producao maxima de GLA (74mg/l) pela linhagem de Mucor sp LB-54 foi obtida apos 5 dias de incubacao a 28°C em meio base, seguida da adicao de glicose (7% p/v) no meio de cultura e uma posterior incubacao por mais 3 dias a 12°C. A identidade do GLA foi confirmada pelo sistema acoplado cromatografo a gas - espectrometro de massa.","PeriodicalId":21211,"journal":{"name":"Revista De Microbiologia","volume":"11 1","pages":"170-175"},"PeriodicalIF":0.0,"publicationDate":"1999-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86475225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 19

The growth of Micrococcus varians by utilizing sugar cane blackstrap molasses as substrate 以甘蔗黑带糖蜜为底物培养变异微球菌

Revista De Microbiologia Pub Date : 1999-04-01 DOI: 10.1590/S0001-37141999000200007

L. A. S. Miranda, E. Sant’Anna, A. C. Porto

{"title":"The growth of Micrococcus varians by utilizing sugar cane blackstrap molasses as substrate","authors":"L. A. S. Miranda, E. Sant’Anna, A. C. Porto","doi":"10.1590/S0001-37141999000200007","DOIUrl":"https://doi.org/10.1590/S0001-37141999000200007","url":null,"abstract":"Comparative studies on the growth of Micrococcus varians were carried out in BHI culture medium (control) as well as in a culture medium with 2% diluted sugar cane blackstrap molasses, enriched with 0.1% yeast extract. The experiment was conducted with three samples of the experimental and control media in a 5 liter fermentor with working volume of 3.5 liters, continuous agitation (150 rpm), 35 ± 0.1°C temperature, 0.7 L air. l-1 medium. min -1, initial pH 7.0 ± 0.2, 24 hour fermentation period, and approximate inoculum of 6.0 log10 CFU/ml. Samples were collected at 2-hour intervals. Micrococcus varians grew in the two culture media studied, which confirms the experimental medium viability for the growth of this species. The final average concentration of biomass was higher in the control medium than in the experimental medium: 0.99 g.l-1 and 0.78 g.l-1, respectively. The final number of viable cells at the end of fermentation was 20.65 log10 CFU/ml for the control medium (BHI), while in the experimental medium the number of viable cells was 19.43 log10 CFU/ml. The consumption of total sugars was higher for the biomass in the control medium (79.78%), while only 50.53% was consumed for the experimental medium.","PeriodicalId":21211,"journal":{"name":"Revista De Microbiologia","volume":"25 1","pages":"125-129"},"PeriodicalIF":0.0,"publicationDate":"1999-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78185718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Production of amylases by Aspergillus tamarii 柽柳曲霉生产淀粉酶的研究

Revista De Microbiologia Pub Date : 1999-04-01 DOI: 10.1590/S0001-37141999000200014

F. Moreira, F. A. D. Lima, S. R. Pedrinho, V. Lenartovicz, C. G. M. Souza, R. Peralta

引用次数: 45

Enzootic bovine Leukosis: development of an indirect enzyme linked immunosorbent assay (I-Elisa) in seroepidemiological studies 牛地方性白血病:血清流行病学研究中间接酶联免疫吸附测定(I-Elisa)的发展

Revista De Microbiologia Pub Date : 1999-01-01 DOI: 10.1590/S0001-37141999000100007

E. T. González, E. Bonzo, M. G. Echeverría, M. Licursi, M. E. Etcheverrigaray

{"title":"Enzootic bovine Leukosis: development of an indirect enzyme linked immunosorbent assay (I-Elisa) in seroepidemiological studies","authors":"E. T. González, E. Bonzo, M. G. Echeverría, M. Licursi, M. E. Etcheverrigaray","doi":"10.1590/S0001-37141999000100007","DOIUrl":"https://doi.org/10.1590/S0001-37141999000100007","url":null,"abstract":"Bovine Leukemia Virus (BLV) is the etiologic agent of Enzootic Bovine Leukosis, a retrovirus exogenous to the bovine species. Once infected, there is no detectable viraemia but instead there is a strong and persistent immunological response to BLV structural proteins, essentially the gp51 envelope glycoprotein and the mayor core protein p24. We describe the test procedure of an indirect ELISA (I-ELISA) using polyclonal reagents for the detection of antibodies to BLV. For comparison, the sera were simultaneously tested by agar gel immunodiffussion (AGID) test, which is currently used as diagnostic standard for BLV infection. The antigen applied does not require a high degree of purification and the data from the analysis of the negative sera showed that the establishment of a cut-off level corresponding to 3 times the standard deviation (SD) above the mean for the negative control set of sera provided acceptable specificity, reducing the risk of false positives results. A comparison of the results obtained by AGID test and I-ELISA showed that considering a total of 465 serum samples, all of the 234 samples (50%) that were positive by AGID were positive to the I-ELISA. Of 225 serum samples which yielded negative results in the AGID test, 69 (15%) were found to be positive by the I-ELISA and 156 (33%) were negative by both techniques. Few sera (2%) that were non-specific by AGID were defined as negative or positive by I-ELISA.","PeriodicalId":21211,"journal":{"name":"Revista De Microbiologia","volume":"25 1","pages":"37-42"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87139848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Susceptibility of cell lines to avian viruses 细胞系对禽流感病毒的易感性

Revista De Microbiologia Pub Date : 1999-01-01 DOI: 10.1590/S0001-37141999000400015

I. C. Simoni, M. J. B. Fernandes, R. M. Custódio, A. Madeira, C. Arns

引用次数: 12

Plasmids in Mycoplasma species isolated from goats and sheep and their preliminary typing 山羊和绵羊支原体分离的质粒及其初步分型

Revista De Microbiologia Pub Date : 1999-01-01 DOI: 10.1590/S0001-37141999000100006

E. R. Nascimento, A. J. Damassa, R. Yamamoto, M. Nascimento

引用次数: 1

Incidence of Campylobacter in pigs with and without diarrhea 有和无腹泻猪中弯曲杆菌的发病率

Revista De Microbiologia Pub Date : 1999-01-01 DOI: 10.1590/S0001-37141999000100004

J. R. Modolo, Luiz Florêncio Fernandes Margato, Arnold Frederico Gottschalk, C. A. Lopes

引用次数: 10