Resumo
The coastal basins in Northeastern Brazil used in this study make up two different ecoregions for freshwater fishes (Amazonas estuary and coastal drainages, and Parnaiba) and two areas of endemism for Characiformes (Maranhão and Parnaíba), and exhibits a diversified yet poorly explored freshwater fish fauna. The population structure and biogeography of two migratory freshwater fish species that are commercially exploited from Maranhão and Parnaíba regions were herein analyzed. Molecular sequence data and statistical analyses were used to estimate haplotypes networks and lineage divergence times and correlated with hydrographic history of drainage and paleodrainages of the region. A total of 171 sequences was produced for both species, Schizodon dissimilis (coI, n = 70) and Prochilodus lacustris (D-loop, n = 101). All analyses identified the presence of three genetically delimited groups of S. dissimilis and six groups of P. lacustris. The lineage time analyses indicate diversification among these species within the past 1 million year. The results indicate the influence of geodispersal in the formation of the ichthyofauna in the studied area through headwater stream capture events and reticulated connections between the mouths of rivers along the coastal plain due to eustatic sea level fluctuations.(AU)
As bacias costeiras do nordeste do Brasil usadas neste estudo compõem duas ecorregiões diferentes para peixes de água doce (Estuário do Amazonas e drenagens costeiras e Parnaíba) e duas áreas de endemismo para Characiformes (Maranhão e Parnaíba), exibindo uma diversificada e ainda pouco explorada fauna de peixes de água doce. A estrutura populacional e biogeografia de duas espécies migradoras de peixes de água doce exploradas comercialmente nas regiões do Maranhão e Parnaíba foram analisadas. Dados de sequências moleculares e análises estatísticas foram utilizados para estimar redes de haplótipos e tempos de divergência entre linhagens, e foram correlacionados com a história hidrográfica das drenagens e paleodrenagens da região. Um total de 171 sequências foram geradas para ambas espécies, Schizodon dissimilis (coI, n = 70) e Prochilodus lacustris (D-loop, n = 101). Todas análises identificaram a presença de três grupos geneticamente delimitados para S. dissimilis e seis grupos para P. lacustris. A análise de tempo de divergência das linhagens indicou uma diversificação entre estas espécies nos últimos 1 Ma. Os resultados indicam influência da geodispersão na formação da ictiofauna do Maranhão, devido eventos de capturas de cabeceira e conexões reticuladas entre as fozes dos rios ao longo da planície costeira devido às flutuações eustáticas do nível do mar.(AU)
Assuntos
Animais , Filogeografia , Caraciformes/genética , Peixes/genética , Dados de Sequência Molecular , Nível do Mar , FilogeografiaResumo
The coastal basins in Northeastern Brazil used in this study make up two different ecoregions for freshwater fishes (Amazonas estuary and coastal drainages, and Parnaiba) and two areas of endemism for Characiformes (Maranhão and Parnaíba), and exhibits a diversified yet poorly explored freshwater fish fauna. The population structure and biogeography of two migratory freshwater fish species that are commercially exploited from Maranhão and Parnaíba regions were herein analyzed. Molecular sequence data and statistical analyses were used to estimate haplotypes networks and lineage divergence times and correlated with hydrographic history of drainage and paleodrainages of the region. A total of 171 sequences was produced for both species, Schizodon dissimilis (coI, n = 70) and Prochilodus lacustris (D-loop, n = 101). All analyses identified the presence of three genetically delimited groups of S. dissimilis and six groups of P. lacustris. The lineage time analyses indicate diversification among these species within the past 1 million year. The results indicate the influence of geodispersal in the formation of the ichthyofauna in the studied area through headwater stream capture events and reticulated connections between the mouths of rivers along the coastal plain due to eustatic sea level fluctuations.(AU)
As bacias costeiras do nordeste do Brasil usadas neste estudo compõem duas ecorregiões diferentes para peixes de água doce (Estuário do Amazonas e drenagens costeiras e Parnaíba) e duas áreas de endemismo para Characiformes (Maranhão e Parnaíba), exibindo uma diversificada e ainda pouco explorada fauna de peixes de água doce. A estrutura populacional e biogeografia de duas espécies migradoras de peixes de água doce exploradas comercialmente nas regiões do Maranhão e Parnaíba foram analisadas. Dados de sequências moleculares e análises estatísticas foram utilizados para estimar redes de haplótipos e tempos de divergência entre linhagens, e foram correlacionados com a história hidrográfica das drenagens e paleodrenagens da região. Um total de 171 sequências foram geradas para ambas espécies, Schizodon dissimilis (coI, n = 70) e Prochilodus lacustris (D-loop, n = 101). Todas análises identificaram a presença de três grupos geneticamente delimitados para S. dissimilis e seis grupos para P. lacustris. A análise de tempo de divergência das linhagens indicou uma diversificação entre estas espécies nos últimos 1 Ma. Os resultados indicam influência da geodispersão na formação da ictiofauna do Maranhão, devido eventos de capturas de cabeceira e conexões reticuladas entre as fozes dos rios ao longo da planície costeira devido às flutuações eustáticas do nível do mar.(AU)
Assuntos
Animais , Filogeografia , Caraciformes/genética , Peixes/genética , Dados de Sequência Molecular , Nível do Mar , FilogeografiaResumo
The red piranha, Pygocentrus nattereri, is an important resource for artisanal and commercial fisheries. The present study determines the genetic differentiation among P. nattereri populations from the northeastern Brazilian state of Maranhão. The DNA was isolated using a standard phenol-chloroform protocol and the Control Region was amplified by PCR. The PCR products were sequenced using the didesoxyterminal method. A sequence of 1039 bps was obtained from the Control Region of 60 specimens, which presented 33 polymorphic sites, 41 haplotypes, һ =0.978 and π =0.009. The neutrality tests (D and Fs) were significant (P < 0.05) for most of the populations analyzed. The AMOVA indicated that most of the molecular variation (72%) arises between groups. The fixation index was highly significant (FST = 0.707, P < 0.00001). The phylogenetic analyses indicated that the specimens represented a monophyletic group. Genetic distances between populations varied from 0.8% to 1.9%, and were <0.5% within populations. The degree of genetic differentiation found among the stocks of P. nattereri indicates the need for the development of independent management plans for the different river basins in order to preserve the genetic variability of their populations.(AU)
A piranha vermelha, Pygocentrus nattereri, é um recurso importante para pesca artesanal e comercial. O presente estudo determinou a diferenciação genética entre populações de P. nattereri no nordeste do estado brasileiro do Maranhão. O DNA foi isolado utilizando o protocolo de Fenol-clorofórmio e a Região Controle foi amplificada por PCR. Os produtos da PCR foram sequenciados usando o método didesoxiterminal. Uma sequência de 1039 pbs foi obtida da Região Controle de 60 espécimes, que apresentaram 33 sítios polimórficos, 41 haplótipos, һ= 0.978 e π= 0.009. Os testes de neutralidade (D and Fs) foram significativos (P < 0.05) para a maioria das populações analisadas. A AMOVA indicou que a maior parte da variação molecular (72%) surge entre os grupos. O índice de fixação foi altamente significativo (FST = 0.707, P = < 0.00001). As análises filogenéticas indicaram que os espécimes representam um grupo monofilético. Distâncias genéticas entre as populações variaram de 0.8% a 1.9%, e de <0.5% dentro das populações. O grau de diferenciação genética encontrada entre os estoques de P. nattereri indicam a necessidade para o desenvolvimento de planos de manejo independentes para as diferentes bacias hidrográficas, a fim de preservar a variabilidade genética dessas populações.(AU)
Assuntos
Animais , Caraciformes/genética , Haplótipos , Polimorfismo Genético , Brasil , Dados de Sequência Molecular , Filogenia , Rios , Análise de Sequência de DNAResumo
ITS2 (Internal transcribed spacer 2) sequences have been used in systematic studies and proved to be useful in providing a reliable identification of Trichogramma species. DNAr sequences ranged in size from 379 to 632 bp. In eleven T. pretiosum lines Wolbachia-induced parthenogenesis was found for the first time. These thelytokous lines were collected in Peru (9), Colombia (1) and USA (1). A dichotomous key for species identification was built based on the size of the ITS2 PCR product and restriction analysis using three endonucleases (EcoRI, MseI and MaeI). This molecular technique was successfully used to distinguish among seventeen native/introduced Trichogramma species collected in South America.(AU)
Sequências do Espaço Transcrito Interno 2 (ITS2) têm sido utilizadas em estudos taxonômicos e sua utilidade constatada pela confiabilidade que o método confere à identificação das espécies de Trichogramma. Esta técnica molecular foi bem sucedida em distinguir dezessete espécies nativas e introduzidas de Trichogramma, coletadas na América do Sul. As sequências do DNAr variaram de 379 a 632 pb. Em 11 linhagens de T. pretiosum estudadas, o endosinbionte Wolbachia foi detectado pela primeira vez. Estas linhagens telítocas foram encontradas no Peru (9), Colômbia (1) e Estados Unidos (1). Uma chave dicotômica para identificação de espécies foi construída baseada no tamanho do produto da PCR do ITS2 e em análises de restrição utilizando-se três endonucleases (EcoRI, MseI and MaeI).(AU)
Assuntos
Animais , Vespas/classificação , Vespas/fisiologia , DNA Espaçador Ribossômico/genética , Dados de Sequência Molecular , Partenogênese , Análise de Sequência de DNA , América do Sul , Vespas/genética , Vespas/microbiologia , Wolbachia/fisiologiaResumo
Nasonovia ribisnigri is a key pest of lettuce (Lactuca sativa L.) in Brazil that requires alternative control methods to synthetic pesticides. We report, for the first time, the occurrence of Paecilomyces niveus as an entomopathogen of the aphid Nasonovia ribisnigri in Pinhais, Paraná, Brazil. Samples of mummified aphids were collected from lettuce crops. The fungus P. niveus (PaePR) was isolated from the insect bodies and identified by macro and micromorphology. The species was confirmed by sequencing Internal Transcribed Spacer (ITS) rDNA. We obtained a sequence of 528 bp (accession number HQ441751), which aligned with Byssochlamys nivea strains (100% identities). In a bioassay, 120 h after inoculation of N. ribisnigri with pathogenic P. niveus had an average mortality of 74%. The presence of P. niveus as a natural pathogen of N. ribisnigri in Brazil suggests that it may be possible to employ P. niveus to minimize the use of chemical insecticides.(AU)
Nasonovia ribisnigri é uma praga-chave do cultivo de alface (Lactuca sativa L.), exigindo métodos alternativos ao controle químico. Este trabalho registrou pela primeira vez, a ocorrência de Paecilomyces niveus como agente entomopatogenico do afídeo N. ribisnigri em Pinhais, Paraná, Brasil. Amostras de afídeos mumificados foram coletadas em plantas de alface. O fungo P. niveus (PaePR) foi isolado do corpo dos insetos e identificado por macro e micromorfologia e, confirmado por sequenciamento da região ITS do DNA ribossomal. A sequencia parcial de 528 bp (número de acesso HQ441751) apresentou alinhamento com 100% de identidade com sequencias de raças de Byssochlamys nivea. No bioensaio de patogenicidade P. niveus apresentou uma mortalidade média de N. ribisnigri de 74% até 120 horas da inoculação. O registro da presença de P. niveus como um patógeno natural de N. ribisnigri no Brasil sugere o potencial de utilização para minimizar o uso de inseticidas.(AU)
Assuntos
Animais , Afídeos/microbiologia , Paecilomyces/fisiologia , Afídeos/crescimento & desenvolvimento , Brasil , Byssochlamys/classificação , Byssochlamys/isolamento & purificação , Byssochlamys/fisiologia , DNA Fúngico , Dados de Sequência Molecular , Ninfa/crescimento & desenvolvimento , Ninfa/microbiologia , Paecilomyces/classificação , Paecilomyces/isolamento & purificação , RNA Ribossômico 18S , Análise de Sequência de DNAResumo
Pectinolytic enzymes are greatly important in winemaking due to their ability to degrade pectic polymers from grape, contributing to enhance process efficiency and wine quality. This study aimed to analyze the occurrence of pectinolytic yeasts during spontaneous fermentation of Argentine Bonarda grape, to select yeasts that produce extracellular pectinases and to characterize their pectinolytic activity under wine-like conditions. Isolated yeasts were grouped using PCR-DGGE and identified by partial sequencing of 26S rRNA gene. Isolates comprised 7 genera, with Aureobasidium pullulans as the most predominant pectinolytic species, followed by Rhodotorula dairenensis and Cryptococcus saitoi. No pectinolytic activity was detected among ascomycetous yeasts isolated on grapes and during fermentation, suggesting a low occurrence of pectinolytic yeast species in wine fermentation ecosystem. This is the first study reporting R. dairenensis and Cr. saitoi species with pectinolytic activity. R. dairenensis GM-15 produced pectinases that proved to be highly active at grape pH, at 12 °C, and under ethanol and SO2 concentrations usually found in vinifications (pectinase activity around 1.1 U/mL). This strain also produced cellulase activity at 12 °C and pH 3.5, but did not produce β-glucosidase activity under these conditions. The strain showed encouraging enological properties for its potential use in low-temperature winemaking. (AU)
Assuntos
Ascomicetos/enzimologia , Cryptococcus/enzimologia , /metabolismo , Rhodotorula/enzimologia , Vitis/microbiologia , Vinho/microbiologia , Argentina , Ascomicetos/isolamento & purificação , Cryptococcus/isolamento & purificação , Fermentação/fisiologia , Dados de Sequência Molecular , Tipagem Molecular , Técnicas de Tipagem Micológica , Pectinas/metabolismo , RNA Ribossômico/genética , Rhodotorula/isolamento & purificaçãoResumo
Studies investigating rickettsial infections in ticks parasitizing wild animals in the Northeast region of Brazil have been confined to the detection of Rickettsia amblyommii in immature stages of Amblyomma longirostre collected from birds in the state of Bahia, and in immatures and females of Amblyomma auricularium collected from the striped hog-nosed skunk (Conepatus semistriatus) and armadillos (Euphractus sexcinctus) in the state of Pernambuco. The current study extends the distribution of R. amblyommii (strain Aranha), which was detected in A. longirostre collected from the thin-spined porcupine Chaetomys subspinosus and the hairy dwarf porcupine Coendou insidiosus. In addition, we report the first detection of Rickettsia bellii in adults of A. longirostre collected from C. insidiosus in the state of Bahia.(AU)
Assuntos
Animais , Ixodidae/microbiologia , Infecções por Rickettsia/microbiologia , Rickettsia/genética , Rickettsia/isolamento & purificação , Infestações por Carrapato/microbiologia , Tatus , Proteínas da Membrana Bacteriana Externa/genética , Proteínas de Bactérias/genética , Sequência de Bases , Aves , Brasil , Citrato (si)-Sintase/genética , DNA Bacteriano , Proteínas de Choque Térmico/genética , Mephitidae , Dados de Sequência Molecular , Tipagem Molecular , Porcos-Espinhos , Análise de Sequência de DNA , Serina Endopeptidases/genéticaResumo
Strains of
Assuntos
Ar Condicionado , Proteínas de Bactérias/genética , RNA Polimerases Dirigidas por DNA/genética , Flavoproteínas/genética , Francisella , Microbiologia da Água , Sequência de Bases , China , DNA Bacteriano/genética , DNA Ribossômico/genética , Francisella/classificação , Francisella/genética , Francisella/isolamento & purificação , Dados de Sequência Molecular , Tipagem Molecular , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNAResumo
Leptospires are usually classified by methods based on DNA-DNA hybridization and the conventional cross-agglutination absorption test, which uses polyclonal antibodies against lipopolysaccharides. In this study, the amplification of the rpoB gene, which encodes the beta-subunit of RNA polymerase, was used as an alternative tool to identify Leptospira. DNA extracts from sixty-eight serovars were obtained, and the hypervariable region located between 1990 and 2500-bp in the rpoB gene was amplified by polymerase chain reaction (PCR). The 600-bp amplicons of the rpoB gene were digested with the restriction endonucleases TaqI, Tru1I, Sau3AI and MslI, and the restriction fragments were separated by 6% polyacrylamide gel electrophoresis. Thirty-five fragment patters were obtained from the combined data of restriction fragment length polymorphism (PCR-RFLP) analysis and used to infer the phylogenetic relationships among the Leptospira species and serovars. The species assignments obtained were in full agreement with the established taxonomic classifications. Twenty-two serovars were effectively identified based on differences in their molecular profiles. However, the other 46 serovars remained clustered in groups that included more than one serovar of different species. This study demonstrates the value of RFLP analysis of PCR-amplified rpoB as an initial method for identifying Leptospira species and serovars.(AU)
Assuntos
RNA Polimerases Dirigidas por DNA/genética , Leptospira/classificação , Leptospira/genética , Técnicas de Diagnóstico Molecular/métodos , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Análise por Conglomerados , Enzimas de Restrição do DNA/metabolismo , Eletroforese em Gel de Poliacrilamida , Genótipo , Leptospira/isolamento & purificação , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA , SorogrupoResumo
Partial nucleotide sequences of ORF72 (glycoprotein D, gD), ORF64 (infected cell protein 4, ICP4) and ORF30 (DNA polymerase) genes were compared with corresponding sequences of EHV-1 reference strains to characterize the molecular variability of Brazilian strains. Virus isolation assays were applied to 74 samples including visceral tissue, total blood, cerebrospinal fluid (CSF) and nasal swabs of specimens from a total of 64 animals. Only one CSF sample (Iso07/05 strain) was positive by virus isolation in cell culture. EHV-1 Iso07/05 neurologic strain and two abortion visceral tissues samples (Iso11/06 and Iso33/06) were PCR-positive for ORF33 (glycoprotein B, gB) gene of EHV-1. A sequence analysis of the ORF72, ORF64 and ORF30 genes from three EHV-1 archival strains (A3/97, A4/72, A9/92) and three clinical samples (Iso07/05, Iso11/06 and Iso33/06) suggested that among Brazilian EHV-1 strains, the amplified region of the gD gene sequence is highly conserved. Additionally, the analysis of ICP4 gene showed high nucleotide and amino acid identities when compared with genotype P strains, suggesting that the EHV-1 Brazilian strains belonged to the same group. All the EHV-1 Brazilian strains were classified as non-neuropathogenic variants (N752) based on the ORF30 analysis. These findings indicate a high conservation of the gD-, ICP4- and ORF30-encoding sequences. Different pathotypes of the EHV-1 strain might share identical genes with no specific markers, and tissue tropism is not completely dependent on the gD envelope, immediate-early ICP4 and DNA polymerase proteins.(AU)
Assuntos
Animais , Variação Genética , Infecções por Herpesviridae/veterinária , Herpesvirus Equídeo 1/classificação , Herpesvirus Equídeo 1/genética , Doenças dos Cavalos/virologia , Brasil , Análise por Conglomerados , Sequência Conservada , DNA Viral/química , DNA Viral/genética , Genótipo , Infecções por Herpesviridae/virologia , Cavalos , Dados de Sequência Molecular , Fases de Leitura Aberta , Filogenia , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido NucleicoResumo
The fall armyworm Spodoptera frugiperda (Lepidoptera; Noctuidae) is a voracious pest of numerous crops of economic importance throughout the New World. In Brazil, its larvae are attacked by several species of parasitoid wasps, making them potential candidate as biological control agents against this pest. A survey of the parasitoid fauna on S. frugiperda in maize crops throughout Brazil reveals two species of Campoletis, which are morphologicaly very similar species. In this paper we combine these data with pictures from the type material of C. sonorensis and C. flavicincta, as well as their descriptions to provide a redescription to Campoletis sonorensis (Cameron, 1886) using for this both morphological characters and DNA Barcoding (Hebert et al., 2003) information, in an attempt to help with the correct identification of the taxa to improve biological control studies.(AU)
Spodoptera frugiperda é uma praga voraz de diversas culturas de importância econômica no Novo Mundo. No Brasil, suas larvas podem ser atacadas por diversas espécies de vespas parasitóides que são candidatos a agentes de controle biológico contra essa praga. Pesquisando os parasitóides da fauna de Spodoptera frugiperda em cultivos de milho no Brasil foram encontradas duas espécies do gênero Campoletis, muito similares morfologicamente. Este trabalho apresenta uma redescrição para Campoletis sonorensis usando caracteres morfológicos e DNA Barcoding (Hebert et al., 2003) com o objetivo de evitar erros de identificação desse grupo, aprimorando estudos de controle biológico.(AU)
Assuntos
Animais , Masculino , Feminino , Spodoptera/parasitologia , Vespas/anatomia & histologia , Vespas/genética , Brasil , Código de Barras de DNA Taxonômico , Complexo IV da Cadeia de Transporte de Elétrons/genética , Proteínas de Insetos/genética , Microscopia Eletrônica de Varredura , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA , Vespas/fisiologia , Vespas/ultraestruturaResumo
One of the most economically important bacterial pathogens of plants and plant products is
Assuntos
Bacteriófagos/isolamento & purificação , Agentes de Controle Biológico/isolamento & purificação , Dickeya chrysanthemi/crescimento & desenvolvimento , Dickeya chrysanthemi/virologia , Doenças das Plantas/microbiologia , Bacteriófagos/classificação , Sequência de Bases , Agentes de Controle Biológico/classificação , DNA Bacteriano/genética , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Myoviridae/classificação , Myoviridae/isolamento & purificação , Dickeya chrysanthemi , Dickeya chrysanthemi/isolamento & purificação , /genética , Análise de Sequência de DNA , Siphoviridae/classificação , Siphoviridae/isolamento & purificaçãoResumo
This study describes the detection of Borrelia garinii and Borrelia burgdorferi sensu stricto (s.s.) in Brazilian individuals using PCR and DNA sequencing. Our results suggest that these species are emerging pathogens in this country, and additional studies are necessary to determine the epidemiological characteristics of this disease in Brazil.(AU)
Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Grupo Borrelia Burgdorferi/classificação , Grupo Borrelia Burgdorferi/isolamento & purificação , Doenças Transmissíveis Emergentes/microbiologia , Doença de Lyme/microbiologia , Sequência de Bases , Brasil/epidemiologia , Doenças Transmissíveis Emergentes/epidemiologia , DNA Bacteriano/química , DNA Bacteriano/genética , Doença de Lyme/epidemiologia , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , População Rural , Alinhamento de Sequência , Análise de Sequência de DNAResumo
The diversity of thermophilic bacteria was investigated in four hot springs, three salt marshes and 12 desert sites in Morocco. Two hundred and forty (240) thermophilic bacteria were recovered, identified and characterized. All isolates were Gram positive, rod-shaped, spore forming and halotolerant. Based on BOXA1R-PCR and 16S rRNA gene sequencing, the recovered isolates were dominated by the genus Bacillus (97.5%) represented by B. licheniformis (119), B. aerius (44), B. sonorensis (33), B. subtilis (subsp. spizizenii (2) and subsp. inaquosurum (6)), B. amyloliquefaciens (subsp. amyloliquefaciens (4) and subsp. plantarum (4)), B. tequilensis (3), B. pumilus (3) and Bacillus sp. (19). Only six isolates (2.5%) belonged to the genus Aeribacillus represented by A. pallidus (4) and Aeribacillus sp. (2). In this study, B. aerius and B. tequilensis are described for the first time as thermophilic bacteria. Moreover, 71.25%, 50.41% and 5.41% of total strains exhibited high amylolytic, proteolytic or cellulolytic activity respectively.(AU)
Assuntos
Bacillaceae/classificação , Bacillaceae/isolamento & purificação , Bacilos Gram-Positivos/classificação , Bacilos Gram-Positivos/isolamento & purificação , /microbiologia , Microbiologia do Solo , Microbiologia da Água , Bacillaceae/genética , Bacillaceae/efeitos da radiação , Biodiversidade , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Bacilos Gram-Positivos/efeitos da radiação , Dados de Sequência Molecular , Marrocos , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Esporos Bacterianos/citologiaResumo
This work addresses the production of prodigiosin from ram horn peptone (RHP) using MO-1, a local isolate in submerged culture. First, a novel gram-negative and rod-shaped bacterial strain, MO-1, was isolated from the body of the grasshopper (Poecilemon tauricola Ramme 1951), which was collected from pesticide-contaminated fields. Sequence analysis of 16S rDNA classified the microbe as Serratia marcescens. The substrate utilization potential (BIOLOG) and fatty acid methyl ester profile (FAME) of S. marcescens were also determined. The effect of RHP on the production of prodigiosin by S. marcescens MO-1 was investigated, and the results showed that RHP supplementation promoted the growth of MO-1 and increased the production of prodigiosin. A concentration of 0.4% (w/v) RHP resulted in the greatest yield of prodigiosin (277.74 mg/L) after 48 h when mannitol was used as the sole source of carbon. The pigment yield was also influenced by the types of carbon sources and peptones. As a result, RHP was demonstrated to be a suitable substrate for prodigiosin production. These results revealed that prodigiosin could be produced efficiently by S. marcescens using RHP.(AU)
Assuntos
Animais , Meios de Cultura/química , Peptonas/metabolismo , Prodigiosina/metabolismo , Serratia marcescens/crescimento & desenvolvimento , Serratia marcescens/metabolismo , Técnicas de Tipagem Bacteriana , Análise por Conglomerados , Citosol/química , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Ácidos Graxos/análise , Gafanhotos/microbiologia , Dados de Sequência Molecular , Filogenia , Pigmentos Biológicos/metabolismo , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Serratia marcescens/classificação , Serratia marcescens/isolamento & purificaçãoResumo
Endophytes are being considered for use in biological control, and the enzymes they secrete might facilitate their initial colonization of internal plant tissues and direct interactions with microbial pathogens. Microbial proteases are also biotechnologically important products employed in bioremediation processes, cosmetics, and the pharmaceutical, photographic and food industries. In the present study, we evaluated antagonism and competitive interactions between 98 fungal endophytes and Alternaria alternata, Colletotrichum sp., Phyllosticta citricarpa and Moniliophthora perniciosa. We also examined the proteolytic activities of endophytes grown in liquid medium and conducted cup plate assays. The results showed that certain strains in the assemblage of P. hispidum endophytes are important sources of antifungal properties, primarily Lasiodiplodia theobromae JF766989, which reduced phytopathogen growth by approximately 54 to 65%. We detected 28 endophytes producing enzymatic halos of up to 16.40 mm in diameter. The results obtained in the present study highlight the proteolytic activity of the endophytes Phoma herbarum JF766995 and Schizophyllum commune JF766994, which presented the highest enzymatic halo diameters under at least one culture condition tested. The increased activities of certain isolates in the presence of rice or soy flour as a substrate (with halos up to 17.67 mm in diameter) suggests that these endophytes have the potential to produce enzymes using agricultural wastes.(AU)
Assuntos
Antifúngicos/metabolismo , Endófitos/isolamento & purificação , Endófitos/metabolismo , Fungos/isolamento & purificação , Fungos/metabolismo , Peptídeo Hidrolases/metabolismo , Piper/microbiologia , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Fungos/classificação , Fungos , Técnicas Microbiológicas , Dados de Sequência Molecular , Análise de Sequência de DNAResumo
Halophilic microorganisms are able to grow in the presence of salt and are also excellent source of enzymes and biotechnological products, such as exopolysaccharides (EPSs) and polyhydroxyalkanoates (PHAs). Salt-tolerant bacteria were screened in the Organic Composting Production Unit (OCPU) of São Paulo Zoological Park Foundation, which processes 4 ton/day of organic residues including plant matter from the Atlantic Rain Forest, animal manure and carcasses and mud from water treatment. Among the screened microorganisms, eight halotolerant bacteria grew at NaCl concentrations up to 4 M. These cultures were classified based on phylogenetic characteristics and comparative partial 16S rRNA gene sequence analysis as belonging to the genera Staphylococcus, Bacillus and Brevibacterium. The results of this study describe the ability of these halotolerant bacteria to produce some classes of hydrolases, namely, lipases, proteases, amylases and cellulases, and biopolymers. The strain characterized as of Brevibacterium avium presented cellulase and amylase activities up to 4 M NaCl and also produced EPSs and PHAs. These results indicate the biotechnological potential of certain microorganisms recovered from the composting process, including halotolerant species, which have the ability to produce enzymes and biopolymers, offering new perspectives for environmental and industrial applications.(AU)
Assuntos
Bacillus/isolamento & purificação , Produtos Biológicos/análise , Brevibacterium/isolamento & purificação , Hidrolases/análise , Cloreto de Sódio/metabolismo , Microbiologia do Solo , Staphylococcus/isolamento & purificação , Bacillus/classificação , Bacillus/genética , Bacillus/metabolismo , Brasil , Brevibacterium/classificação , Brevibacterium/genética , Brevibacterium/metabolismo , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Solo , Staphylococcus/classificação , Staphylococcus/genética , Staphylococcus/metabolismoResumo
The present work aimed to investigate the microbial dynamics during the anaerobic treatment of the azo dye blue HRFL in bench scale upflow anaerobic sludge bed (UASB) reactor operated at ambient temperature. Sludge samples were collected under distinct operational phases, when the reactor were stable (low variation of color removal), to assess the effect of glucose and yeast extract as source of carbon and redox mediators, respectively. Reactors performance was evaluated based on COD (chemical oxygen demand) and color removal. The microbial dynamics were investigated by PCR-DGGE (Polimerase Chain Reaction - Denaturing Gradient of Gel Electrophoresis) technique by comparing the 16S rDNA profiles among samples. The results suggest that the composition of microorganisms changed from the beginning to the end of the reactor operation, probably in response to the presence of azo dye and/or its degradation byproducts. Despite the highest efficiency of color removal was observed in the presence of 500 mg/L of yeast extract (up to 93%), there were no differences regarding the microbial profiles that could indicate a microbial selection by the yeast extract addition. On the other hand Methosarcina barkeri was detected only in the end of operation when the best efficiencies on color removal occurred. Nevertheless the biomass selection observed in the last stages of UASB operation is probably a result of the washout of the sludge in response of accumulation of aromatic amines which led to tolerant and very active biomass that contributed to high efficiencies on color removal.
Assuntos
Compostos Azo/metabolismo , Biota , Análise da Demanda Biológica de Oxigênio , Biotransformação , Reatores Biológicos/microbiologia , Análise por Conglomerados , Cor , Eletroforese em Gel de Gradiente Desnaturante , DNA Ribossômico/química , Dados de Sequência Molecular , Reação em Cadeia da PolimeraseResumo
Xylanase (EC 3. 2. 1. 8), hydrolyzes xylo-oligosaccharides into D-xylose and required for complete hydrolysis of native cellulose and biomass conversion. It has broad range of applications in the pulp and paper, pharmaceutical and Agri-food industries. Fifty fungal species were isolated from the fouled soil around an oil refinery and screened for the production of xylanase enzyme by enrichment culture techniques. The isolated fungal strain was identified as Hypocrea lixii SS1 based on the results of biochemical tests and 18s rRNA sequencing. The phylogenetic tree was constructed using the MEGA 5 software. Further, Hypocrea lixii SS1 was tested for the ability to utilize the sunflower oil sludge (waste from the oil industry) as the sole carbon source for xylanase production. The growth characteristics of Hypocrea lixii SS1 were also studied and maximum growth was found on the 7th day of incubation. The fungus showed a remarkable xylanase production of 38.9 U/mL. Xylanase was purified using a combination of 0-50% NH4SO2 precipitation, DEAE-sepharose and Sephacryl S-200 chromatography. Single peak obtained in RP-HPLC confirms the purity of xylanase. Further the enzyme produced was affirmed as xylanase with its molecular weight (29 kDa) using SDS-PAGE.
Assuntos
Microbiologia do Solo , Trichoderma/classificação , Trichoderma/isolamento & purificação , Xilosidases/análise , Cromatografia Líquida , Análise por Conglomerados , DNA Fúngico/química , DNA Ribossômico/química , Eletroforese em Gel de Poliacrilamida , Dados de Sequência Molecular , Peso Molecular , Técnicas de Tipagem Micológica , FilogeniaResumo
Magnetotactic bacteria (MTB) are of considerable interest because of their importance in the manufacture of various bioinspired materials. In order to find out the status of magnetotactic bacteria at three different sediment in Czech Republic, samples collected from both standing and running freshwaters were subjected to molecular diversity analysis by using 16S rRNA gene approach. Total community DNA from sediment sample was isolated and used for PCR, cloning and sequence analysis. Of the 24 analyzed sequences, six clones are closely related to Magnetobacterium sp. affiliated with the Nitrospira phylum which showed the dominance of Magnetobacterium phylotypes in the sample. This study will provide useful insight about the community structure of MTB in this particular geographical region. However more detailed and specific studies are warranted in order to properly assess the community structure of MTB's in fresh water sediments.