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1.
Plants (Basel) ; 13(7)2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38611495

RESUMEN

Hamelia patens (Rubiaceae), known as firebush, is a source of bioactive monoterpenoid oxindole alkaloids (MOAs) derived from monoterpenoid indole alkaloids (MIAs). With the aim of understanding the regulation of the biosynthesis of these specialized metabolites, micropropagated plants were elicited with jasmonic acid (JA) and salicylic acid (SA). The MOA production and MIA biosynthetic-related gene expression were evaluated over time. The production of MOAs was increased compared to the control up to 2-fold (41.3 mg g DW-1) at 72 h in JA-elicited plants and 2.5-fold (42.4 mg g DW-1) at 120 h in plants elicited with SA. The increment concurs with the increase in the expression levels of the genes HpaLAMT, HpaTDC, HpaSTR, HpaNPF2.9, HpaTHAS1, and HpaTHAS2. Interestingly, it was found that HpaSGD was downregulated in both treatments after 24 h but in the SA treatment at 120 h only was upregulated to 8-fold compared to the control. In this work, we present the results of MOA production in H. patens and discuss how JA and SA might be regulating the central biosynthetic steps that involve HpaSGD and HpaTHAS genes.

2.
Planta ; 258(1): 20, 2023 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-37326881

RESUMEN

MAIN CONCLUSION: SA and H2O2, in single and mixed elicitation stimulate specialized metabolism and activate oxidative stress in C. tenuiflora plants. Single elicitation with salicylic acid (SA at 75 µM) and, hydrogen peroxide (at 150 µM), and mixed elicitation (75 µM SA + 150 µM H2O2) were evaluated on specialized metabolism in Castilleja tenuiflora Benth. plants. Total phenolic content (TPC), phenylalanine ammonia-lyase (PAL) activity, antioxidant enzymes and specialized metabolite profiles, as well as the expression levels of eight genes involved in phenolic (Cte-TyrDC, Cte-GOT2, Cte-ADD, Cte-AO3, Cte-PAL1, Cte-CHS1) and terpene pathways (Cte-DXS1 and Cte-G10H) and their correlation with major metabolite (verbascoside and aucubin) concentrations were investigated. TPC content (three-fold) and PAL activity (11.5-fold) increased with mixed elicitation, as well as catalase and peroxidase activity (11.3-fold and 10.8-fold, respectively), compared to single elicitation. Phenylethanoid accumulation was greatest under mixed elicitation, followed by SA and H2O2. Lignan accumulation was differential, depending on the plant part and the elicitor. Flavonoids only appeared after mixed elicitation. The high concentration of verbascoside under mixed elicitation was related to a high gene expression. Single elicitation induced iridoid accumulation in specific parts (H2O2 in aerial parts and SA in roots), whereas under mixed elicitation, it accumulated in both parts. A high concentration of aucubin in the aerial part was related to a high expression level of genes of the terpene pathway Cte-DXS1 and Cte-G10H, and in the root with Cte-G10H, while Cte-DXS1 was downregulated in this tissue in all treatments. Mixed elicitation with SA and H2O2 represents an interesting tool to increase the production of specialized metabolites in plants.


Asunto(s)
Peróxido de Hidrógeno , Orobanchaceae , Peróxido de Hidrógeno/metabolismo , Ácido Salicílico/metabolismo , Iridoides , Fenoles/metabolismo , Antioxidantes/metabolismo , Orobanchaceae/metabolismo
3.
Front Aging Neurosci ; 15: 1125114, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37065459

RESUMEN

Identification of novel, non-invasive, non-cognitive based markers of Alzheimer's disease (AD) and related dementias are a global priority. Growing evidence suggests that Alzheimer's pathology manifests in sensory association areas well before appearing in neural regions involved in higher-order cognitive functions, such as memory. Previous investigations have not comprehensively examined the interplay of sensory, cognitive, and motor dysfunction with relation to AD progression. The ability to successfully integrate multisensory information across multiple sensory modalities is a vital aspect of everyday functioning and mobility. Our research suggests that multisensory integration, specifically visual-somatosensory integration (VSI), could be used as a novel marker for preclinical AD given previously reported associations with important motor (balance, gait, and falls) and cognitive (attention) outcomes in aging. While the adverse effect of dementia and cognitive impairment on the relationship between multisensory functioning and motor outcomes has been highlighted, the underlying functional and neuroanatomical networks are still unknown. In what follows we detail the protocol for our study, named The VSI Study, which is strategically designed to determine whether preclinical AD is associated with neural disruptions in subcortical and cortical areas that concurrently modulate multisensory, cognitive, and motor functions resulting in mobility decline. In this longitudinal observational study, a total of 208 community-dwelling older adults with and without preclinical AD will be recruited and monitored yearly. Our experimental design affords assessment of multisensory integration as a new behavioral marker for preclinical AD; identification of functional neural networks involved in the intersection of sensory, motor, and cognitive functioning; and determination of the impact of early AD on future mobility declines, including incident falls. Results of The VSI Study will guide future development of innovative multisensory-based interventions aimed at preventing disability and optimizing independence in pathological aging.

4.
J Invertebr Pathol ; 195: 107847, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36375617

RESUMEN

Tawera elliptica (commonly known as "Almeja Juliana", is a venerid clam that inhabits sandy bottoms and is distributed from Valparaíso on the Pacific coast up to the Mar del Plata area along the Atlantic coast. Harvests of this clam have declined substantially over the last decade. Therefore, an analysis of common parasites and pathological conditions of this clam was undertaken along with histopathology. Monthly samples were prepared for routine histology for examination under light and electron microscopy. T. elliptica has a sex ratio of 1:1 and the relationship between the shell length and the wet tissue weight is not significantly different between females and males. The maximum values for de condition index and meat yield were found during the austral winter. The following parasites (and their overall prevalence) were detected: intracellular microcolonies of bacteria in digestive gland (22.9%), intestinal epithelium (9.3%) and gills (3.17%), an unidentified cyst in gills (59,3%), a Steinhausia-like intraoocytic microsporidian (5.2%), Gregarine spores (41.3%), ciliated protozoa (16.7%), two metazoa, a Paravortex like flatworm (4.3%), and a digenean trematode (8%). The monthly mean intensity of the most relevant parasites was between 2.3 and 35.6 for digestive gland intracellular microcolonies of bacteria (IMC), 0-5.1 for intestinal epithelium IMC, 0-2 for branchial IMC and 0 - 48 for intraoocytic microsporidium. The prevalence and the infection intensity were low-to very low, and no World Organisation for Animal Health OIE listed parasite was detected. It is concluded that this is a healthy clam, and no disease risks for the cultivation are visualized at present. However, IMC at high prevalence and intensities of infection could be potentially impactful, and the intraoocytic microsporidian could jeopardize reproduction if present in high intensities of infection.


Asunto(s)
Bivalvos , Parásitos , Trematodos , Femenino , Masculino , Animales , Bivalvos/parasitología , Bacterias , Alimentos Marinos
5.
Plants (Basel) ; 11(14)2022 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-35890513

RESUMEN

Galphimia spp. is popularly used in Mexican traditional medicine. Some populations of Galphimia exert anxiolytic and sedative effects due to the presence of the modified triterpenoids galphimines. However, the galphimine synthesis pathway has not yet been elucidated. Hence, in this study, a comparative transcriptome analysis between two contrasting populations of Galphimia spp., a galphimine-producer, and a non-galphimine-producer, is performed using RNA-Seq in the Illumina Next Seq 550 platform to identify putative candidates genes that encode enzymes of this metabolic pathway. Transcriptome functional annotation was performed using the Blast2GO in levels of gene ontology. For differential expression analysis, edgeR, pheatmap, and Genie3 library were used. To validate transcriptome data, qPCR was conducted. In producer and non-producer plants of both populations of Galphimia spp., most of the transcripts were grouped in the Molecular Function level of gene ontology. A total of 680 differentially expressed transcripts between producer and non-producer plants were detected. In galphimine-producer plants, a larger number of highly expressed transcripts related to acyclic and polycyclic terpene synthesis were identified. As putative candidate genes involved in the galphimine synthesis pathway, P450 family members and enzymes with kinase activity were identified.

6.
Enzyme Microb Technol ; 160: 110094, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35810624

RESUMEN

Lignocellulose hydrolysates are rich in fermentable sugars such as xylose, cellobiose and glucose, with high potential in the biotechnology industry to obtain bioproducts of higher economic value. Thus, it is important to search for and study new yeast strains that co-consume these sugars to achieve better yields and productivity in the processes. The yeast Clavispora lusitaniae CDBB-L-2031, a native strain isolated from mezcal must, was studied under various culture conditions to potentially produce ethanol and xylitol due to its ability to assimilate xylose, cellobiose and glucose. This yeast produced ethanol under microaerobic conditions with yields of 0.451 gethanol/gglucose and 0.344 gethanol/gcellobiose, when grown on 1% glucose or cellobiose, respectively. In mixtures (0.5% each) of glucose:xylose and glucose:xylose:cellobiose the yields were 0.367 gethanol/gGX and 0. 380 gethanol/gGXC, respectively. Likewise, in identical conditions, C. lusitaniae produced xylitol from xylose with a yield of 0.421 gxylitol/gxylose. In 5% glucose or xylose, this yeast had better ethanol and xylitol titers and yields, respectively. However, glucose negatively affected xylitol production in the mixture of both sugars (3% each), producing only ethanol. Xylose reductase (XR) and xylitol dehydrogenase (XDH) activities were evaluated in cultures growing on xylose or glucose, obtaining the highest values in cultures on xylose at 8 h (25.9 and 6.22 mU/mg, respectively). While in glucose cultures, XR and XDH activities were detected once this substrate was consumed (4.06 and 3.32 mU/mg, respectively). Finally, the XYL1 and XYL2 genes encoding xylose reductase and xylitol dehydrogenase, respectively, were up-regulated by xylose, whereas glucose down-regulated their expression.


Asunto(s)
Xilitol , Xilosa , Aldehído Reductasa/genética , Aldehído Reductasa/metabolismo , Celobiosa/metabolismo , D-Xilulosa Reductasa/genética , D-Xilulosa Reductasa/metabolismo , Etanol/metabolismo , Fermentación , Glucosa/metabolismo , Saccharomyces cerevisiae/genética , Saccharomycetales , Xilitol/metabolismo , Xilosa/metabolismo
7.
Molecules ; 27(9)2022 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-35566324

RESUMEN

Cedrela odorata L. is a plant species from the Meliaceae family that is cultivated for timber production. Although the C. odorata essential oil (EO) contains mainly sesquiterpenes, its insecticidal potential is unknown. The lipophilic properties and high degradation capacity of EOs have limited their application for use in pest control. However, the currently available knowledge on the nanoemulsification of EOs, in addition to the possibility of improving their dispersion, would allow them to prolong their permanence in the field. The objective of the present work was to develop a nanoemulsion of the C. odorata EO and to evaluate its larvicidal activity against Spodoptera frugiperda. The EO was obtained by the hydrodistillation of C. odorata dehydrated leaves, and the nanoemulsion was prepared with non-ionic surfactants (Tween 80 and Span 80) using a combined method of agitation and dispersion with ultrasound. The stability of the nanoemulsion with a droplet diameter of <200 nm was verified in samples stored at 5 °C and 25 °C for 90 days. Both the C. odorata EO and its corresponding nanoemulsion presented lethal properties against S. frugiperda. The results obtained provide guidelines for the use of wood waste to produce sustainable and effective insecticides in the fight against S. frugiperda. In addition, considering that a phytochemical complex mixture allows the simultaneous activation of different action mechanisms, the development of resistance in insects is slower.


Asunto(s)
Cedrela , Insecticidas , Meliaceae , Aceites Volátiles , Animales , Insecticidas/química , Insecticidas/farmacología , Larva , Aceites Volátiles/farmacología , Spodoptera
8.
Ann Nucl Med ; 35(3): 347-359, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33439440

RESUMEN

PURPOSE: Our purpose was to explore the clinical significance of unexpected osseous foci on 18F-FDG-PET without correlative CT abnormalities (FWCT) in patients referred for oncologic evaluation. The significance of FDG-avid foci without correlative CT abnormalities has been previously explored in tissues such as breast, lung, liver, and prostate; however, osseous foci without correlative CT abnormalities continue to present challenges in diagnostic interpretations. METHODS: This study is a retrospective review of 120 osseous FWCT, reported in 91 patients, and their corresponding clinical follow-up. We included only patients with at least 6 months of clinical follow-up leading to a final diagnosis, reviewing bone biopsy results, follow-up imaging, and clinical notes. We excluded those patients on active chemotherapy at the time of the scan. For reports describing > 3 foci, we only analyzed the one with highest maximum standardized uptake value (SUVmax). As a measure of uptake intensity, we obtained focus-to-liver ratios (F/L) utilizing their SUVmax and corresponding hepatic 3D SUVmean. RESULTS: Of 91 patients, 74 (81%) had biopsy-confirmed primary malignancies and 17 (19%) had suspicious findings on diagnostic imaging, but no proven primary malignancy. 50 of 120 (42%) osseous foci were malignant and 70 (58%) were benign. 49 of 120 (41%) foci were solitary and 71 (59%) were 0 with other foci (non-solitary). Malignancy resulted from 15/49 (31%) solitary foci and 35/71 (49%) non-solitary foci. Malignant lesions had a mean F/L 2.37 ± 0.397 and benign lesions a mean F/L 1.49 ± 0.169. Osseous malignancy correlated with a higher uptake intensity (Spearman = 0.408; P < 0.01) and was significantly associated with F/L ≥ 2.0 (P < 0.001). Osseous FWCT led to restaging and management modification in 12/91 (13%) patients. CONCLUSION: Osseous FWCT frequently represent early stages of malignancy. A higher index of suspicion is warranted for osseous FWCT associated with underlying myeloproliferative neoplasms, breast and lung cancer, and moderate (F/L 1.0-2.0) or high (F/L > 2.0) uptake intensity. Interpreting physicians encountering these variables can recommend interval follow-up with 18F-FDG-PET/CT or correlation with contrast-enhanced MRI or tissue biopsy. In patients with an altered biodistribution of 18F-FDG in the bone marrow (e.g., recent chemotherapy cycle), follow-up FDG-PET can be obtained at an appropriate time interval following oncologic treatment.


Asunto(s)
Neoplasias Óseas/diagnóstico por imagen , Fluorodesoxiglucosa F18 , Procesamiento de Imagen Asistido por Computador , Tomografía Computarizada por Tomografía de Emisión de Positrones , Adulto , Femenino , Humanos , Masculino , Estudios Retrospectivos
9.
Clin Nucl Med ; 46(1): e54-e56, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32956115

RESUMEN

Spinal facet joint septic arthritis is a rare pathology associated with pyogenic organisms. It may present in older adults with back pain, fever, and positive bacterial blood cultures. However, clinical presentation may be equivocal, and diagnosis relies on anatomic imaging for differentiation from other pathologies. Magnetic resonance is considered the imaging modality of choice and has been found superior to CT; however, it is unable to differentiate facet joint septic arthritis from other inflammatory arthropathies. We present a case of lumbosacral facet joint septic arthritis as seen on In-oxine-WBC scintigraphy and SPECT/CT.


Asunto(s)
Artritis Infecciosa/diagnóstico por imagen , Compuestos Organometálicos , Oxiquinolina/análogos & derivados , Tomografía Computarizada por Tomografía Computarizada de Emisión de Fotón Único , Articulación Cigapofisaria/diagnóstico por imagen , Anciano , Artritis Infecciosa/microbiología , Diagnóstico Diferencial , Humanos , Masculino , Articulación Cigapofisaria/microbiología , Articulación Cigapofisaria/patología
10.
Front Microbiol ; 11: 577481, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33193196

RESUMEN

Intracellular microcolonies of bacteria (IMC), in some cases developing large extracellular cysts (bacterial aggregates), infecting primarily gill and digestive gland, have been historically reported in a wide diversity of economically important mollusk species worldwide, sometimes associated with severe lesions and mass mortality events. As an effort to characterize those organisms, traditionally named as Rickettsia or Chlamydia-like organisms, 1950 specimens comprising 22 mollusk species were collected over 10 countries and after histology examination, a selection of 99 samples involving 20 species were subjected to 16S rRNA gene amplicon sequencing. Phylogenetic analysis showed Endozoicomonadaceae sequences in all the mollusk species analyzed. Geographical differences in the distribution of Operational Taxonomic Units (OTUs) and a particular OTU associated with pathology in king scallop (OTU_2) were observed. The presence of Endozoicomonadaceae sequences in the IMC was visually confirmed by in situ hybridization (ISH) in eight selected samples. Sequencing data also indicated other symbiotic bacteria. Subsequent phylogenetic analysis of those OTUs revealed a novel microbial diversity associated with molluskan IMC infection distributed among different taxa, including the phylum Spirochetes, the families Anaplasmataceae and Simkaniaceae, the genera Mycoplasma and Francisella, and sulfur-oxidizing endosymbionts. Sequences like Francisella halioticida/philomiragia and Candidatus Brownia rhizoecola were also obtained, however, in the absence of ISH studies, the association between those organisms and the IMCs were not confirmed. The sequences identified in this study will allow for further molecular characterization of the microbial community associated with IMC infection in marine mollusks and their correlation with severity of the lesions to clarify their role as endosymbionts, commensals or true pathogens.

11.
Clin Nucl Med ; 45(12): 984-985, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33065623

RESUMEN

A 54-year-old woman with smoking history who was diagnosed with invasive adenocarcinoma of the rectosigmoid colon with subsequent surgical resection and chemotherapy was presented. The patient developed local recurrence and pulmonary metastases that required further chemotherapy and surgical resection. During follow-up, the patient had F-FDG PET/CT scan showing asymmetric hypermetabolic tonsils with activity greater on the right compared with the left. The patient underwent bilateral tonsillectomy, and pathology revealed moderately to poorly differentiated adenocarcinoma in the right tonsil, consistent with metastasis from known colonic primary.


Asunto(s)
Neoplasias del Colon/diagnóstico por imagen , Neoplasias del Colon/patología , Fluorodesoxiglucosa F18 , Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias Tonsilares/secundario , Femenino , Humanos , Persona de Mediana Edad , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Neoplasias Tonsilares/diagnóstico por imagen
15.
Biotechnol Lett ; 41(10): 1233-1244, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31388801

RESUMEN

OBJECTIVE: To evaluate the induction of monoterpenoid indole alkaloids (MIA) and phenolic compound production by yeast extract (YE) and its relationship with defense responses in Uncaria tomentosa (Rubiaceae) root cultures. RESULTS: Root cultures were elicited by YE at three concentrations. The 0.5 mg YE ml-1 treatment did not affect cell viability but increased the hydrogen peroxide concentration by 5.7 times; guaiacol peroxidase activity by twofold; and the glucoindole alkaloid 3α-dihydrocadambine (DHC) content by 2.6 times (to 825.3 ± 27.3 µg g-1). This treatment did not affect the contents of monoterpenoid oxindole alkaloids or chlorogenic acids. In response to 0.5 mg YE ml-1 treatment, the transcript levels of MIA biosynthetic genes, TDC and LAMT, increased 5.4 and 1.9-fold, respectively, that of SGD decreased by 32%, and that of STR did not change. The transcript levels of genes related to phenolic compounds, PAL, CHS and HQT, increased by 1.7, 7.7, and 1.2-fold, respectively. Notably, the transcript levels of Prx1 and Prx encoding class III peroxidases increased by 1.4 and 2.5-fold. CONCLUSION: The YE elicitor induced an antioxidant defense response, increased the transcript levels of genes encoding enzymes related to strictosidine biosynthesis precursors and class III peroxidases, and decreased the transcript level of SGD. Thus, YE could stimulate antifungal DHC production in root cultures of U. tomentosa.


Asunto(s)
Antioxidantes/metabolismo , Uña de Gato/metabolismo , Medios de Cultivo/química , Raíces de Plantas/metabolismo , Alcaloides de Triptamina Secologanina/metabolismo , Levaduras/química , Vías Biosintéticas/genética , Ácido Clorogénico/metabolismo , Mezclas Complejas/metabolismo , Perfilación de la Expresión Génica , Genes de Plantas , Peróxido de Hidrógeno/metabolismo , Fenoles/metabolismo
16.
Otolaryngol Head Neck Surg ; 157(3): 439-447, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28608737

RESUMEN

Objective Our objective was to compare the accuracy of preoperative positron emission tomography (PET)/computed tomography (CT) and contrast-enhanced CT (CECT) in detecting cervical nodal metastases in patients treated with neck dissection and to scrutinize the ability of each modality to determine nodal stage. Study Design Case series with chart review. Setting Montefiore Medical Center, Bronx, New York. Subjects and Methods Patients who underwent neck dissection at our institution for primary treatment of head and neck squamous cell carcinoma (HNSCC) and had received preoperative PET/CT and CECT were included in this study. Imaging studies were reinterpreted by 3 specialists within the field and compared for interreader agreement. Concordance between radiology and histopathology was measured using neck levels and sides, along with patient nodal stage. Sensitivity, specificity, accuracy, positive predictive value, negative predictive value, and agreement coefficients were calculated. Results Seventy-three patients were included in the study. Sensitivity was 0.69 and 0.94 (level and side) for PET/CT vs 0.53 and 0.66 for CECT ( P = .056, P = .001). Specificity was 0.86 and 0.56 for PET/CT vs 0.91 and 0.76 for CECT ( P = .014, P = .024). No significant difference was found in overall accuracy ( P = .33, P = .88). The overall agreement percentages between N stage called by imaging modality and pathology were 52% and 55% for PET/CT and CECT, respectively. Conclusion No significant difference in sensitivity was found between PET/CT and CECT. CECT was found to have superior specificity compared with PET/CT. The information gleaned from each modality in the pretreatment evaluation of HNSCC appears to be complementary.


Asunto(s)
Carcinoma de Células Escamosas/diagnóstico por imagen , Carcinoma de Células Escamosas/patología , Medios de Contraste , Fluorodesoxiglucosa F18 , Neoplasias de Cabeza y Cuello/diagnóstico por imagen , Neoplasias de Cabeza y Cuello/patología , Tomografía Computarizada por Tomografía de Emisión de Positrones , Radiofármacos , Tomografía Computarizada por Rayos X/métodos , Carcinoma de Células Escamosas/cirugía , Femenino , Neoplasias de Cabeza y Cuello/cirugía , Humanos , Metástasis Linfática , Masculino , Persona de Mediana Edad , Cuello , Estadificación de Neoplasias , Cuidados Preoperatorios , Reproducibilidad de los Resultados , Estudios Retrospectivos , Carcinoma de Células Escamosas de Cabeza y Cuello
17.
Arch Microbiol ; 199(4): 605-611, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28138738

RESUMEN

Bioethanol is one of the main biofuels produced from the fermentation of saccharified agricultural waste; however, this technology needs to be optimized for profitability. Because the commonly used ethanologenic yeast strains are unable to assimilate cellobiose, several efforts have been made to express cellulose hydrolytic enzymes in these yeasts to produce ethanol from lignocellulose. The C. flavigenabglA gene encoding ß-glucosidase catalytic subunit was optimized for preferential codon usage in S. cerevisiae. The optimized gene, cloned into the episomal vector pRGP-1, was expressed, which led to the secretion of an active ß-glucosidase in transformants of the S. cerevisiae diploid strain 2-24D. The volumetric and specific extracellular enzymatic activities using pNPG as substrate were 155 IU L-1 and 222 IU g-1, respectively, as detected in the supernatant of the cultures of the S. cerevisiae RP2-BGL transformant strain growing in cellobiose (20 g L-1) as the sole carbon source for 48 h. Ethanol production was 5 g L-1 after 96 h of culture, which represented a yield of 0.41 g g-1 of substrate consumed (12 g L-1), equivalent to 76% of the theoretical yield. The S. cerevisiae RP2-BGL strain expressed the ß-glucosidase extracellularly and produced ethanol from cellobiose, which makes this microorganism suitable for application in ethanol production processes with saccharified lignocellulose.


Asunto(s)
Biocombustibles , Celobiosa/metabolismo , Cellulomonas/enzimología , Etanol/metabolismo , Saccharomyces cerevisiae/genética , beta-Glucosidasa/genética , Celulosa/metabolismo , Codón , Lignina/metabolismo , Saccharomyces cerevisiae/metabolismo , beta-Glucosidasa/metabolismo
18.
Biotechnol Prog ; 32(2): 321-6, 2016 03.
Artículo en Inglés | MEDLINE | ID: mdl-26701152

RESUMEN

Cellulase (CMCase) and xylanase enzyme production and saccharification of sugar cane bagasse were coupled into two stages and named enzyme production and sugar cane bagasse saccharification. The performance of Cellulomonas flavigena (Cf) PR-22 cultured in a bubble column reactor (BCR) was compared to that in a stirred tank reactor (STR). Cells cultured in the BCR presented higher yields and productivity of both CMCase and xylanase activities than those grown in the STR configuration. A continuous culture with Cf PR-22 was run in the BCR using 1% alkali-pretreated sugar cane bagasse and mineral media, at dilution rates ranging from 0.04 to 0.22 1/h. The highest enzymatic productivity values were found at 0.08 1/h with 1846.4 ± 126.4 and 101.6 ± 5.6 U/L·h for xylanase and CMCase, respectively. Effluent from the BCR in steady state was transferred to an enzymatic reactor operated in fed-batch mode with an initial load of 75 g of pretreated sugar cane bagasse; saccharification was then performed in an STR at 55°C and 300 rpm for 90 h. The constant addition of fresh enzyme as well as the increase in time of contact with the substrate increased the total soluble sugar concentration 83% compared to the value obtained in a batch enzymatic reactor. This advantageous strategy may be used for industrial enzyme pretreatment and saccharification of lignocellulosic wastes to be used in bioethanol and chemicals production from lignocellulose. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:321-326, 2016.


Asunto(s)
Celulasa/metabolismo , Cellulomonas/enzimología , Celulosa/biosíntesis , Endo-1,4-beta Xilanasas/metabolismo , Saccharum/metabolismo , Reactores Biológicos , Celulasa/biosíntesis , Cellulomonas/citología , Celulosa/química , Centrifugación , Endo-1,4-beta Xilanasas/biosíntesis , Fermentación , Saccharum/química
19.
Arch Microbiol ; 197(10): 1129-39, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26377586

RESUMEN

The primary carotenoid synthesized by Xanthophyllomyces dendrorhous is astaxanthin, which is used as a feed additive in aquaculture. Cell growth kinetics and carotenoid production were correlated with the mRNA levels of the idi, crtE, crtYB, crtI, crtS and crtR genes, and the changes in gene sequence between the wild-type and a carotenoid overproducer XR4 mutant strain were identified. At the late stationary phase, the total carotenoid content in XR4 was fivefold higher than that of the wild-type strain. Additionally, the mRNA levels of crtE and crtS increased during the XR4 growth and were three times higher than the wild-type strain in the late stationary phase. Moreover, the nucleotide sequences of crtYB, crtI and crtR exhibited differences between the strains. Both the higher crtE and crtS transcript levels and the crtYB, crtI and crtR mutations can, at least in part, act to up-regulate the carotenoid biosynthesis pathway in the XR4 strain.


Asunto(s)
Basidiomycota/metabolismo , Carotenoides/biosíntesis , Proteínas Fúngicas/biosíntesis , Regulación Fúngica de la Expresión Génica/genética , Secuencia de Bases , Basidiomycota/genética , Proteínas Fúngicas/genética , Expresión Génica , ARN Mensajero/genética , Análisis de Secuencia de ADN , Xantófilas/biosíntesis , Xantófilas/metabolismo
20.
Biotechnol Lett ; 37(12): 2489-96, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26272395

RESUMEN

OBJECTIVE: To obtain micro propagated Uncaria tomentosa plantlets with enhanced secondary metabolites production, long-term responses to salicylic acid (SA) pre-treatments at 1 and 100 µM were evaluated after propagation of the plantlets in a SA-free medium. RESULTS: SA pre-treatments of single node cuttings OF U. tomentosa produced long-term responses in microplants grown for 75 days in a SA-free medium. Reduction in survival rate, root formation, and stem elongation were observed only with 100 µM SA pre-treatments with respect to the control (0 + DMSO).Both pre-treatments enhanced H2O2 and inhibited superoxide dismutase and catalase activities, while guaiacol peroxidase was increased only with 1 µM SA. Also, both pre-treatments increased total monoterpenoid oxindole alkaloids by ca. 55 % (16.5 mg g(-1) DW), including isopteropodine, speciophylline, mitraphylline, isomitraphylline, rhynchopylline, and isorhynchopylline; and flavonoids by ca. 21 % (914 µg g(-1) DW), whereas phenolic compounds were increased 80 % (599 µg g(-1) DW) at 1 µM and 8.2 % (359 µg g(-1) DW) at 100 µM SA. CONCLUSION: Pre-treatment with 1 µM SA of U.tomentosa microplants preserved the survival rate and increased oxindole alkaloids, flavonoids, and phenolic compounds in correlation with H2O2 and peroxidase activity enhancements, offering biotechnological advantages over non-treated microplants.


Asunto(s)
Antioxidantes/metabolismo , Uña de Gato/efectos de los fármacos , Ácido Salicílico/metabolismo , Metabolismo Secundario/efectos de los fármacos , Alcaloides/análisis , Uña de Gato/enzimología , Uña de Gato/crecimiento & desarrollo , Uña de Gato/metabolismo , Medios de Cultivo/química , Flavonoides/análisis , Peróxido de Hidrógeno/análisis , Indoles/análisis , Monoterpenos/análisis , Oxindoles , Fenoles/análisis , Raíces de Plantas/crecimiento & desarrollo , Tallos de la Planta/crecimiento & desarrollo , Análisis de Supervivencia
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