• Journal of Microbiology and Biotechnology
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• 제18권5호
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• pp.805-814
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• 2008

Liming of acidic soils can prevent aluminum toxicity and improve crop production. Some maize lines show aluminum (Al) tolerance, and exudation of organic acids by roots has been considered to represent an important mechanism involved in the tolerance. However, there is no information about the impact of liming on the structures of bacterial and fungal communities in Cerrado soil, nor if there are differences between the microbial communities from the rhizospheres of Al-tolerant and Al-sensitive maize lines. This study evaluated the effects of liming on the structure of bacterial and fungal communities in bulk soil and rhizospheres of Al-sensitive and Al-tolerant maize (Zea mays L.) lines cultivated in Cerrado soil by PCR-DGGE, 30 and 90 days after sowing. Bacterial fingerprints revealed that the bacterial communities from rhizospheres were more affected by aluminum stress in soil than by the maize line (Al-sensitive or Al-tolerant). Differences in bacterial communities were also observed over time (30 and 90 days after sowing), and these occurred mainly in the Actinobacteria. Conversely, fungal communities from the rhizosphere were weakly affected either by liming or by the rhizosphere, as observed from the DGGE profiles. Furthermore, only a few differences were observed in the DGGE profiles of the fungal populations during plant development when compared with bacterial communities. Cloning and sequencing of 16S rRNA gene fragments obtained from dominant DGGE bands detected in the bacterial profiles of the Cerrado bulk soil revealed that Actinomycetales and Rhizobiales were among the dominant ribotypes.

• The Plant Pathology Journal
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• 제28권3호
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• pp.306-310
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• 2012

Populations of plant-parasitic nematodes were evaluated in soil and root samples from areas planted with passion fruit, or covered with adjacent native cerrado vegetation, in five different cropping regions of the Brazilian Federal District. From July 2007 to January 2008, twenty samples had been collected in five Rural Centers (N$\acute{u}$cleo Rural-NR) planted with passion fruit. In five sites, samples were also collected in native cerrado vegetation. Specimens of nine genera of plant-parasitic nematodes (Meloidogyne, Helicotylenchus, Rotylenchulus, Scutellonema, Pratylenchus, Paratylenchus, Hemicycliophora, Xiphinema and Criconemoides) were found in the present survey. Important nematode pathogens, such as Rotylenchulus reniformis and Meloidogyne spp. were observed in the passion fruit plantations throughout five major producing regions of the Brazilian Federal District.

• Journal of Microbiology and Biotechnology
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• 제23권10호
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• pp.1403-1412
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• 2013

Ethanol fuel production from lignocellulosic biomass is emerging as one of the most important technologies for sustainable development. To use this biomass, it is necessary to circumvent the physical and chemical barriers presented by the cohesive combination of the main biomass components, which hinders the hydrolysis of cellulose and hemicellulose into fermentable sugars. This study evaluated the hydrolytic capacity of enzymes produced by yeasts, isolated from the soils of the Brazilian Cerrado biome (savannah) and the Amazon region, on sugarcane bagasse pre-treated with $H_2SO_4$. Among the 103 and 214 yeast isolates from the Minas Gerais Cerrado and the Amazon regions, 18 (17.47%) and 11 (5.14%) isolates, respectively, were cellulase-producing. Cryptococcus laurentii was prevalent and produced significant ${\beta}$-glucosidase levels, which were higher than the endo- and exoglucanase activities. In natura sugarcane bagasse was pre-treated with 2% $H_2SO_4$ for 30 min at $150^{\circ}C$. Subsequently, the obtained fibrous residue was subjected to hydrolysis using the Cryptococcus laurentii yeast enzyme extract for 72 h. This enzyme extract promoted the conversion of approximately 32% of the cellulose, of which 2.4% was glucose, after the enzymatic hydrolysis reaction, suggesting that C. laurentii is a good ${\beta}$-glucosidase producer. The results presented in this study highlight the importance of isolating microbial strains that produce enzymes of biotechnological interest, given their extensive application in biofuel production.

• 동아시아식생활학회지
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• 제23권3호
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• pp.382-390
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• 2013

The purpose of this study is to provide the basic findings concerning a quality evaluation. The first conclusion is the coffee's $CO_2$ gas production between a roast brewed at 0 hour and 72 hours after grinding. The espresso, 48 hours after its grind, emits a small amount of $CO_2$ gas, whereas 72 hours after being grinded there is no discharge. In the sensory evaluation, the overall preference is the 72 hours later grind, in accordance to the decrease of the bitter, acid, and sour taste with the increase of the sweet, nutty, and chocolaty flavors. The foam index indicates a significant reduction between the roasts brewed at 0 hour and 72 hours after grinding. A persistence of crema in the Colombian Colombia and Ethiopian Yirgacheffe decline for the 72 hours after its grind coffee. The Tanzanian Kilimanjaro and Brazilian Cerrado roasts show no difference. The pH is decreased in the 72 hours after its grind roast. Moreover, sugar contents in the Colombian Excelso and Brazilian Cerrado are increased, whereas the Tanzanian Kilimanjaro sugar contents are decreased, along with its density.

• Journal of Microbiology
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• 제44권6호
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• pp.591-599
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• 2006

To address the diversity of cyclodextrin-producing P. graminis strains isolated from wheat roots and rhizospheres of maize and sorghum sown in Australia, Brazil, and France, restriction fragment length polymorphism analysis of part of genes encoding RNA polymerase (rpoB-RFLP) and DNA gyrase subunit B (gyrB-RFLP) was used to produce genetic fingerprints. A phylogenetic tree based on rpoB gene sequences was also constructed. The isolates originated from Brazil could be separated from those from Australia and France, when data from the rpoB-based phylogenetic tree or gyrB-RFLP were considered. These analyses also allowed the separation of all P. graminis strains studied here into four clusters; one group formed by the strains GJK201 and $RSA19^T$, second group formed by the strains MC22.02 and MC04.21, third group formed by the strains TOD61, TOD 221, TOD302, and TOD111, and forth group formed by all strains isolated from plants sown in Cerrado soil, Brazil. As this last group was formed by strains isolated from sorghum and maize sown in the same soil (Cerrado) in Brazil, our results suggest that the diversity of these P. graminis strains is more affected by the soil type than the plant from where they have been isolated.

• Journal of Microbiology and Biotechnology
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• 제17권5호
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• pp.753-760
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• 2007

The diversity of Paenibacillus species was assessed in the rhizospheres of four cultivars of sorghum sown in Cerrado soil amended with two levels of nitrogen fertilizer(12 and 120 kg/ha). Two cultivars(IS 5322-C and IS 6320) demanded the higher amount of nitrogen to grow, whereas the other two(FBS 8701-9 and IPA 1011) did not. Using the DNA extracted from the rhizospheres, a Paenibacillus-specific PCR system based on the RNA polymerase gene(rpoB) was chosen for the molecular analyses. The resulting PCR products were separated into community fingerprints by DGGE and the results showed a clear distinction between cultivars. In addition, clone libraries were generated from the rpoB fragments of two cultivars(IPA 1011 and IS 5322-C) using both fertilization conditions, and 318 selected clones were sequenced. Analyzed sequences were grouped into 14 Paenibacillus species. A greater diversity of Paenibacillus species was observed in cultivar IPA 1011 compared with cultivar IS 5322-C. Moreover, statistical analyses of the sequences showed that the bacterial diversity was more influenced by cultivar type than nitrogen fertilization, corroborating the DGGE results. Thus, the sorghum cultivar type was the overriding determinative factor that influenced the community structures of the Paenibacillus communities in the habitats investigated.