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Daniel Tinôco,Lucy Seldin,Paulo Luiz de Andrade Coutinho,Denise Maria Guimarães Freire 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.125 No.-
Optimization of culture conditions can be used as an alternative metabolic control strategy to geneticengineering to improve bio-based 2,3-butanediol (2,3-BDO) production, especially its yield and opticalpurity. In this study, a first-order model was determined to predict the 2,3-BDO yield, which reachedabout 90% in batch cultures at 32 C, pH = 5, and kLa 5.0 ± 2.7 h1, using a new and safe Paenibacilluspeoriae NRRL BD-62. No acetoin accumulation and an absolute levo-2,3-BDO optical purity were also verified. About 39.4 g/L of 2,3-BDO, with a yield of 0.43 g/g, and a levo-:meso-2,3-BDO ratio of 1.9:1, wasobtained at the expense of acetoin, lactic acid, and ethanol in fed-batch fermentation at kLa adjustedwithin its optimized range (7.5 h1) to overcome operational limitations using high initial glucose concentrations. The low pH contributed to the carbon flux shift toward the levo-isomer synthesis, possiblydue to the preferential butanediol dehydrogenase activation, while the highly oxygen-limited environmentfavored the complete acetoin conversion, enhancing the 2,3-BDO yield. These results provide significantcontributions to the high-yield, acetoin-free, and safe bio-based 2,3-BDO production ofparticular interest in large-scale fermentations.
Fabio Faria Da Mota,Eliane Aparecida Gomes,Lucy Seldin 한국미생물학회 2008 The journal of microbiology Vol.46 No.3
Different species of Paenibacillus are considered to be plant growth-promoting rhizobacteria (PGPR) due to their ability to repress soil borne pathogens, fix atmospheric nitrogen, induce plant resistance to diseases and/or produce plant growth-regulating substances such as auxins. Although it is known that indole-3-acetic acid (IAA) is the primary naturally occurring auxin excreted by Paenibacillus species, its transport mechanisms (auxin efflux carriers) have not yet been characterized. In this study, the auxin production of P. polymyxa and P. graminis, which are prevalent in the rhizospheres of maize and sorghum sown in Brazil, was evaluated. In addition, the gene encoding the Auxin Efflux Carrier (AEC) protein from P. polymyxa DSM36T was sequenced and used to determine if various strains of P. polymyxa and P. graminis possessed this gene. Each of the 68 P. polymyxa strains evaluated in this study was able to produce IAA, which was produced at concentrations varying from 1 to 17 μg/ml. However, auxin production was not detected in any of the 13 P. graminis strains tested in this study. Different primers were designed for the PCR amplification of the gene coding for the AEC in P. polymyxa, and the predicted protein of 319 aa was homologous to AEC from Bacillus amyloliquefaciens, B. licheniformis, and B. subtilis. However, no product was observed when these primers were used to amplify the genomic DNA of seven strains of P. graminis, which suggests that this gene is not present in this species. Moreover, none of the P. graminis genomes tested were homologous to the gene coding for AEC, whereas all of the P. polymyxa genomes evaluated were. This is the first study to demonstrate that the AEC protein is present in P. polymyxa genome.
Renata Estebanez Vollu,Rafael Fogel,Silvia Cristina Cunha dos Santos,Fabio Faria da Mota,Lucy Seldin 한국미생물학회 2006 The journal of microbiology Vol.44 No.6
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 RSA19T, 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.
Alvarez, Vanessa Marques,Santos, Silvia Cristina Cunha dos,Casella, Renata da Costa,Vitae, RonaIt Leite,Sebastin, Gina Vazquez,Seldin, Lucy The Korean Society for Microbiology and Biotechnol 2008 Journal of microbiology and biotechnology Vol.18 No.12
A typical tropical soil from the northeast of Brazil, where an important terrestrial oil field is located, was accidentally contaminated with a mixture of oil and saline production water. To study the bioremediation potential in this area, molecular methods based on PCR-DGGE were used to determine the diversity of the bacterial communities in bulk and in contaminated soils. Bacterial fingerprints revealed that the bacterial communities were affected by the presence of the mixture of oil and production water, and different profiles were observed when the contaminated soils were compared with the control. Halotolerant strains capable of degrading crude oil were also isolated from enrichment cultures obtained from the contaminated soil samples. Twenty-two strains showing these features were characterized genetically by amplified ribosomal DNA restriction analysis (ARDRA) and phenotypically by their colonial morphology and tolerance to high NaCl concentrations. Fifteen ARDRA groups were formed. Selected strains were analyzed by 16S rDNA sequencing, and Actinobacteria was identified as the main group found. Strains were also tested for their growth capability in the presence of different oil derivatives (hexane, dodecane, hexadecane, diesel, gasoline, toluene, naphthalene, o-xylene, and p-xylene) and different degradation profiles were observed. PCR products were obtained from 12 of the 15 ARDRA representatives when they were screened for the presence of the alkane hydroxylase gene (alkB). Members of the genera Rhodococcus and Gordonia were identified as predominant in the soil studied. These genera are usually implicated in oil degradation processes and, as such, the potential for bioremediation in this area can be considered as feasible.
Vollu Renata Estebanez,Fogel Rafael,Santos Silvia Cristina Cunha dos,Mota Fabio Faria da,Seldin Lucy The Microbiological Society of Korea 2006 The journal of microbiology Vol.44 No.6
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.
Juliana Mendes Monteiro,Renata Estebanez Vollú,Marcia Reed Rodrigues Coelho,Celuta Sales Alviano,Arie Fitzgerald Blank,Lucy Seldin 한국미생물학회 2009 The journal of microbiology Vol.47 No.4
Molecular approaches [PCR-denaturing gradient gel electrophoresis (DGGE)] were used to determine whether three different vetiver (Chrysopogon zizanioides) genotypes, commercially used in Brazil and considered economically important over the world, select specific bacterial populations to coexist in their rhizospheres. DGGE profiles revealed that the predominant rhizospheric bacterial community hardly varies regarding the vetiver genotype. Moreover, using traditional cultivation methods, bacterial strains were isolated from the different rhizospheres. Colonies presenting different morphologies (83) were selected for determining their potential for plant growth promotion. More than half of the strains tested (57.8%) were amplified by PCR using nifH-based primers, specific for the enzyme nitrogenase reductase. The production of siderophores was observed in 88% of the strains, while the production of antimicrobial substances was detected in only 14.5% of the isolates when Micrococcus sp. was used as the indicator strain. Production of indole-3-acetic acid and the solubilization of phosphate were observed in 55.4% and 59% of the isolates, respectively. In total, 44 strains (53%) presented at least three characteristics of plant growth promotion and were submitted to amplified ribosomal DNA restriction analysis. Twenty-four genetic groups were formed at 100% similarity and one representative of each group was selected for their identification by partial 16S rRNA gene sequencing. They were affiliated with the genera Acinetobacter, Comamonas, Chryseobacterium, Klebsiella, Enterobacter, Pantoea, Dyella, Burkholderia, or Pseudomonas. These strains can be considered of great importance as possible biofertilizers in vetiver.