Revista de Microbiologiahttps://www.scielo.br/feed/rm/1999.v30n4/2020-08-09T08:14:14.329000ZVol. 30 No. 4 - 1999WerkzeugExtremely thermophilic microorganisms and their polymer-hidrolytic enzymes10.1590/S0001-371419990004000012020-08-09T08:14:14.329000Z2020-08-09T06:49:18.686000ZAndrade, Carolina M.M.C.Pereira Jr., NeiAntranikian, Garo
<em>Andrade, Carolina M.m.c.</em>;
<em>Pereira Jr., Nei</em>;
<em>Antranikian, Garo</em>;
<br/><br/>
Thermophilic and hyperthermophilic microorganisms are found as normal inhabitants of continental and submarine volcanic areas, geothermally heated sea-sediments and hydrothermal vents and thus are considered extremophiles. Several present or potential applications of extremophilic enzymes are reviewed, especially polymer-hydrolysing enzymes, such as amylolytic and hemicellulolytic enzymes. The purpose of this review is to present the range of morphological and metabolic features among those microorganisms growing from 70oC to 100°C and to indicate potential opportunities for useful applications derived from these features.Screening of bacterial strains for pectinolytic activity: characterization of the polygalacturonase produced by Bacillus sp10.1590/S0001-371419990004000022020-08-09T08:14:14.329000Z2020-08-09T06:49:18.686000ZSoares, Márcia M.C.N.Silva, Roberto daGomes, Eleni
<em>Soares, Márcia M.c.n.</em>;
<em>Silva, Roberto Da</em>;
<em>Gomes, Eleni</em>;
<br/><br/>
One hundred sixty eight bacterial strains, isolated from soil and samples of vegetable in decomposition, were screened for the use of citrus pectin as the sole carbon source. 102 were positive for pectinase depolymerization in assay plates as evidenced by clear hydrolization halos. Among them, 30% presented considerable pectinolytic activity. The cultivation of these strains by submerged and semi-solid fermentation for polygalacturonase production indicated that five strains of Bacillus sp produced high quantities of the enzyme. The physico-chemical characteristics, such as optimum pH of 6.0 - 7.0, optimum temperatures between 45oC and 55oC, stability at temperatures above 40oC and in neutral and alkaline pH, were determined.Production of extracellular lipase by the phytopathogenic fungus Fusarium solani FS110.1590/S0001-371419990004000032020-08-09T08:14:14.329000Z2020-08-09T06:49:18.686000ZMaia, Maria de Mascena DinizMorais, Marcia Maria Camargo deMorais Jr., Marcos Antonio deMelo, Eduardo Henrique MagalhãesLima Filho, José Luiz de
<em>Maia, Maria De Mascena Diniz</em>;
<em>Morais, Marcia Maria Camargo De</em>;
<em>Morais Jr., Marcos Antonio De</em>;
<em>Melo, Eduardo Henrique Magalhães</em>;
<em>Lima Filho, José Luiz De</em>;
<br/><br/>
A Brazilian strain of Fusarium solani was tested for extracellular lipase production in peptone-olive oil medium. The fungus produced 10,500 U.l-1 of lipase after 72 hours of cultivation at 25oC in shake-flask at 120 rpm in a medium containing 3% (w/v) peptone plus 0.5% (v/v) olive oil. Glucose (1% w/v) was found to inhibit the inductive effect of olive oil. Peptone concentrations below 3% (w/v) resulted in a reduced lipase production while increased olive oil concentration (above 0.5%) did not further stimulate lipase production. The optimum lipase activity was achieved at pH 8.6 and 30oC and a good enzyme stability (80% activity retention) was observed at pH ranging from 7.6 to 8.6, and the activity rapidly dropped at temperatures above 50oC. Lipase activity was stimulated by the addition of n-hexane to the culture medium supernatants, in contrast to incubation with water-soluble solvents.Growth and endoglucanase activity of Acetivibrio cellulolyticus grown in three different cellulosic substrates10.1590/S0001-371419990004000042020-08-09T08:14:14.329000Z2020-08-09T06:49:18.686000ZSanchez, Cássia ReginaPeres, Clarita SchvartzBarbosa, Heloiza Ramos
<em>Sanchez, Cássia Regina</em>;
<em>Peres, Clarita Schvartz</em>;
<em>Barbosa, Heloiza Ramos</em>;
<br/><br/>
The growth kinetics of Acetivibrio cellulolyticus grown in medium containing different carbon sources (cellobiose, amorphous or crystalline cellulose) was investigated. The specific growth rate was higher in cellobiose fed cultures than in the presence of the other two substrates. Endoglucanase production was greater in cultures grown on amorphous cellulose; enzyme activity increased during the stationary phase in cultures grown on crystalline cellulose.Some enzymatic properties of cholesterol oxidase produced by Brevibacterium sp10.1590/S0001-371419990004000052020-08-09T08:14:14.329000Z2020-08-09T06:49:18.686000ZSalva, Terezinha J.G.Liserre, Alcina M.Moretto, Aloísia L.Zullo, Marco A.T.Ventrucci, GisleineMenezes, Tobias J.B.
<em>Salva, Terezinha J.g.</em>;
<em>Liserre, Alcina M.</em>;
<em>Moretto, Aloísia L.</em>;
<em>Zullo, Marco A.t.</em>;
<em>Ventrucci, Gisleine</em>;
<em>Menezes, Tobias J.b.</em>;
<br/><br/>
In this study we determined some properties of the cholesterol oxidase from a Brevibacterium strain isolated from buffalo's milk and identified the cholesterol degradation products by the bacterial cell. A small fraction of the enzyme synthesized by cells cultured in liquid medium for 7days was released into the medium whereas a larger fraction remained bound to the cell membrane. The extraction of this fraction was efficiently accomplished in 1 mM phosphate buffer, pH 7.0, containing 0.7% Triton X-100. The enzyme stability under freezing and at 45oC was improved by addition of 20% glycerol. The optimum temperature and pH for the enzyme activity were 53°C and 7.5, respectively. The only steroidal product from cholesterol oxidation by the microbial cell and by the crude extract of the membrane-bound enzyme was 4-colesten-3-one. Chromatographic analysis showed that minor no steroidal compounds as well as 4-colesten-3-one found in the reaction media arose during fermentation process and were extracted together with the enzyme in the buffer solution. Cholesterol oxidation by the membrane-bound enzyme was a first order reaction type.Purification of microbial b-galactosidase from Kluyveromyces fragilis by bioaffinity partitioning10.1590/S0001-371419990004000062020-08-09T08:14:14.329000Z2020-08-09T06:49:18.686000ZSilva, Maria Estela daFranco, Telma Teixeira
<em>Silva, Maria Estela Da</em>;
<em>Franco, Telma Teixeira</em>;
<br/><br/>
This work investigated the partitioning of b-galactosidase from Kluyveromyces fragilis in aqueous two-phase systems (ATPS) by bioaffinity. PEG 4000 was chemically activated with thresyl chloride, and the biospecific ligand p-aminophenyl 1-thio-b-D-galactopyranoside (APGP) was attached to the activated PEG 4000. A new two-step method for extraction and purification of the enzyme b-galactosidase from Kluyveromyces fragilis was developed. In the first step, a system composed of 6% PEG 4000-APGP and 8% dextran 505 was used, where b-galactosidase was strongly partitioned to the top phase (K = 2,330). In the second step, a system formed of 13% PEG-APGP and 9% phosphate salt was used to revert the value of the partition coefficient of b-galactosidase (K = 2 x 10-5) in order to provide the purification and recovery of 39% of the enzyme in the bottom salt-rich phase.Production of bacteriocin-like inhibitory substances (BLIS) by Streptococcus salivarius strains isolated from the tongue and throat of children with and without sore throat10.1590/S0001-371419990004000072020-08-09T08:14:14.329000Z2020-08-09T06:49:18.686000ZFantinato, VeraJorge, A. O. C.Shimizu, Mário. T.
<em>Fantinato, Vera</em>;
<em>Jorge, A. O. C.</em>;
<em>Shimizu, Mário. T.</em>;
<br/><br/>
Streptococcus salivarius strains, isolated from children with and without sore throat, were tested for bacteriocin production against Streptococcus pyogenes. S. salivarius strains producing bacteriocin-like inhibitory substances (BLIS) against S. pyogenes were more frequently found in children without sore throat. These results suggest that these children may be protected against sore throat by the presence of BLIS-positive S. salivarius strains.Candida sp in the oral cavity with and without lesions: maximal inhibitory dilution of Propolis and Periogard10.1590/S0001-371419990004000082020-08-09T08:14:14.329000Z2020-08-09T06:49:18.686000ZAzevedo, Rosa Vitória PalaminKomesu, Marilena ChinalliCandido, Regina CeliaSalvetti, CristianeRezende, Fausto Hanaoka Caetano
<em>Azevedo, Rosa Vitória Palamin</em>;
<em>Komesu, Marilena Chinalli</em>;
<em>Candido, Regina Celia</em>;
<em>Salvetti, Cristiane</em>;
<em>Rezende, Fausto Hanaoka Caetano</em>;
<br/><br/>
Fifty individuals of both sexes aged on average 45.2 years were evaluated at the Semiology Clinic of FORP-USP in order to isolate and identify yeasts from the oral cavity, with and without lesions, and to determine the maximal inhibitory dilution (MID) of the commercial products Propolis (Apis-Flora) and Periogard (Colgate) against the strains isolated. Yeasts of the genus Candida were detected in the saliva of 9/19 (47.4%) individuals with a clinically healthy mouth, 18/22 (81.8%) of individuals with oral lesions, and in 4/9 (44.4%) of patients with deviation from normality, and were detected in 19/22 (86.4%) of the lesions. In the group with oral candidiasis, we isolated in tongue and lesion, respectively for each specie: C.tropicalis (8% and 10.7%), C.glabrata (4% and 3.6%) and C.parapsilosis (2% and 3.6%), in addition to C.albicans (71.4% and 67.8%) as the only species and the prevalent. The total cfu counts/ml saliva showed a higher mean value in the group with oral candidiasis (171.5% x 10(3)) than in the control group (72.6 x 10(3)) or the group with abnormalities (8.3 x 10(3)). Most of the test strains 67/70 (95.71%) were sensitive to the antiseptics, with Propolis presenting a MID of 1:20 for 54/70/77.1%), and Periogard a MID of 1:160 for 42/70 (60%) strains from healthy sites, results similar to those obtained with strains from oral lesions. Different results were mainly observed among different species. The results indicate the possibility of using the antiseptics Propolis and Periogard (chlorhexidine) for the prevention and treatment of oral candidiasis.Bacteriocin-like activity of oral Fusobacterium nucleatum isolated from human and non-human primates10.1590/S0001-371419990004000092020-08-09T08:14:14.329000Z2020-08-09T06:49:18.686000ZGaetti-Jardim Júnior, ElersonAvila-Campos, Mario Julio
<em>Gaetti-Jardim Júnior, Elerson</em>;
<em>Avila-Campos, Mario Julio</em>;
<br/><br/>
Fusobacterium nucleatum is indigenous of the human oral cavity and has been involved in different infectious processes. The production of bacteriocin-like substances may be important in regulation of bacterial microbiota in oral cavity. The ability to produce bacteriocin-like substances by 80 oral F. nucleatum isolates obtained from periodontal patients, healthy individuals and Cebus apella monkeys, was examinated. 17.5% of all tested isolates showed auto-antagonism and 78.8% iso- or hetero-antagonism. No isolate from monkey was capable to produce auto-inhibition. In this study, the antagonistic substances production was variable in all tested isolates. Most of the F. nucleatum showed antagonistic activity against tested reference strains. These data suggest a possible participation of these substances on the oral microbial ecology in humans and animals. However, the role of bacteriocins in regulating dental plaque microbiota in vivo is discussed.Critical control points for meat balls and kibbe preparations in a hospital kitchen10.1590/S0001-371419990004000102020-08-09T08:14:14.329000Z2020-08-09T06:49:18.686000ZPedroso, Débora Midori MyakiIaria, Sebastião TimoGamba, Rosa CarvalhoHeidtmann, SandraRall, Vera Lúcia Mores
<em>Pedroso, Débora Midori Myaki</em>;
<em>Iaria, Sebastião Timo</em>;
<em>Gamba, Rosa Carvalho</em>;
<em>Heidtmann, Sandra</em>;
<em>Rall, Vera Lúcia Mores</em>;
<br/><br/>
Hazards and critical control points (CCP) associated with meat balls and kibbe preparations in a hospital kitchen were determined using flow diagrams and microbiological testing of samples collected along the production line. Microbiological testing included counts of mesophilic and psicrothrophic microorganisms, yeasts and molds, total and fecal coliforms, C. perfringens, coagulase positive staphylococci, bacteria of the B. cereus group and detection of Salmonella. Time/temperature binomial was measured in all steps of preparation. A decision tree was used to help in the determination of CCPs. The detected hazards were: contamination of raw meat and vegetables, multiplication of the microorganisms during meat manipulation, poor hygiene of utensils and equipment, and survival of microorganisms to the cooking process. Cooking and hot-holding were considered CCPs. The results stress the importance of the implementation of a training program for nutricionists and foodhandlers and the monitoring of CCPs and other measures to prevent foodborne diseases.Molecular characterization of Listeria monocytogenes isolated from foods10.1590/S0001-371419990004000112020-08-09T08:14:14.329000Z2020-08-09T06:49:18.686000ZPimenta, Fabiana CristinaFurlanetto, Sirdéia Maura PerroneMayer, Leonard W.Timenetsky, JorgeSantos, Manoel Armando Azevedo dos
<em>Pimenta, Fabiana Cristina</em>;
<em>Furlanetto, Sirdéia Maura Perrone</em>;
<em>Mayer, Leonard W.</em>;
<em>Timenetsky, Jorge</em>;
<em>Santos, Manoel Armando Azevedo Dos</em>;
<br/><br/>
A total of 30 strains of Listeria monocytogenes isolated from different foods (16 of differents kinds of sausage, 14 cheese,) purchased at groceries of São Paulo City were ribotyped and analysed for the presence and expression of hemolysin gene and production of phosphatidylinositol-specific phosphalipase C - PI-PLC enzyme. The L. monocytogenes strains were differentiated into six ribotype classes. A total of 13 (43.3%) from these strains belong to the same ribotype (ribotype I), and was coincident to the ribotype of the standard L. monocytogenes prototype strain (ATCC-15313). The hemolytic activity was observed in 29 (96.7%) strains when incubated at 37oC, but not at 4oC. The direct colony hybridization method for hemolysin gene detection showed a positive reaction whit all the 30 L. monocytogenes strains, while showed negative reaction with other Listeria spp. The PI-PLC was produced by 27 (90%) of the strains analysed. There was no correlation between the six identified ribotypes and the virulence factors (hemolysin and PI-PLC) studied.Occurrence of Listeria monocytogenes in salami10.1590/S0001-371419990004000122020-08-09T08:14:14.329000Z2020-08-09T06:49:18.686000ZBorges, Maria de FatimaSiqueira, Regina S. deBittencourt, Anna MariaVanetti, Maria Cristina D.Gomide, Lúcio Alberto M.
<em>Borges, Maria De Fatima</em>;
<em>Siqueira, Regina S. De</em>;
<em>Bittencourt, Anna Maria</em>;
<em>Vanetti, Maria Cristina D.</em>;
<em>Gomide, Lúcio Alberto M.</em>;
<br/><br/>
Eighty-one samples of four different types of salami (Friolan, Hamburguese, Italian and Milanese), belonging to five brands, and purchased at Rio de Janeiro market, were evaluated for the occurrence of Listeria monocytogenes. The pathogen was detected in 13.3% of Italian type samples of salami, while L. innocua occurred in 6.5% of the Italian type and in 16.6% of the Milanese type. The remaining samples were negative for Listeria spp.Characterization of typical and atypical enteropathogenic Escherichia coli (EPEC) strains of the classical O55 serogroup by RAPD analysis10.1590/S0001-371419990004000132020-08-09T08:14:14.329000Z2020-08-09T06:49:18.686000ZGirão, Dennys M.Bando, Sílvia Y.Girão, Valéria Brígido de C.Moreira-Filho, Carlos A.Fracalanzza, Sérgio Eduardo L.Trabulsi, Luiz R.Monteiro-Neto, Valério
<em>Girão, Dennys M.</em>;
<em>Bando, Sílvia Y.</em>;
<em>Girão, Valéria Brígido De C.</em>;
<em>Moreira-Filho, Carlos A.</em>;
<em>Fracalanzza, Sérgio Eduardo L.</em>;
<em>Trabulsi, Luiz R.</em>;
<em>Monteiro-Neto, Valério</em>;
<br/><br/>
The genetic diversity of 41 typical and atypical enteropathogenic Escherichia coli (EPEC) strains of the serogroup O55 was analyzed by using the random amplified polymorphic DNA (RAPD) method. All typical EPEC O55 strains were grouped in two clusters (A and C) and belonged to the serotype O55:H6, while cluster B included all atypical strains, which were of the serotype O55:H7. The three groups also included non-motile strains. RAPD may be a useful method for epidemiological studies on E. coli O55 infection.An experimental study of nanoflagellate bacterivory10.1590/S0001-371419990004000142020-08-09T08:14:14.329000Z2020-08-09T06:49:18.686000ZFernandes, Ana JúliaMesquita, Hilda de Souza Lima
<em>Fernandes, Ana Júlia</em>;
<em>Mesquita, Hilda De Souza Lima</em>;
<br/><br/>
Heterotrophic nanoflagellate Pseudobodo tremulans (4.8 to 7.0 µm) and heterotrophic bacteria, isolated from coastal waters in Ubatuba, SP, Brazil, were used in experiments to analyze quantitatively the relationships between bacteria and nanoflagellates. The meaning of these results for the role of heterotrophic nanoflagellates in the Ubatuba coastal ecosystem is discussed.Susceptibility of cell lines to avian viruses10.1590/S0001-371419990004000152020-08-09T08:14:14.329000Z2020-08-09T06:49:18.686000ZSimoni, Isabela CristinaFernandes, Maria Judite BittencourtCustódio, Renata MarconiMadeira, Alda Maria Backx NoronhaArns, Clarice Weis
<em>Simoni, Isabela Cristina</em>;
<em>Fernandes, Maria Judite Bittencourt</em>;
<em>Custódio, Renata Marconi</em>;
<em>Madeira, Alda Maria Backx Noronha</em>;
<em>Arns, Clarice Weis</em>;
<br/><br/>
The susceptibility of the five cell lines - IB-RS-2, RK-13, Vero, BHK-21, CER - to reovirus S1133 and infectious bursal disease virus (IBDV vaccine GBV-8 strain) was studied to better define satisfactory and sensitive cell culture systems. Cultures were compared for presence of CPE, virus titers and detection of viral RNA. CPE and viral RNA were detected in CER and BHK-21 cells after reovirus inoculation and in RK-13 cell line after IBDV inoculation and with high virus titers. Virus replication by production of low virus titers occurred in IB-RS-2 and Vero cells with reovirus and in BHK-21 cell line with IBDV.Pathogenicity characteristics of filamentous fungi strains isolated from processed oat10.1590/S0001-371419990004000162020-08-09T08:14:14.329000Z2020-08-09T06:49:18.686000ZSilva, Eliane N. B. daCavalcanti, Maria Auxiliadora de Q.Souza-Motta, Cristina Maria de
<em>Silva, Eliane N. B. Da</em>;
<em>Cavalcanti, Maria Auxiliadora De Q.</em>;
<em>Souza-Motta, Cristina Maria De</em>;
<br/><br/>
Nineteen strains of filamentous fungi isolated from processed oat were tested for pathogenicity factors, based on three parameters: growth at 37oC, production of phospholipase and urease. Aspergillus niveus, Oidiodendron gryseum and Sporothrix cyanescens were positive for the three parameters. The other species were positive only for one or two of them.