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Polyploidy, defined as the coexistence of three or more complete sets of chromosomes in an organism's cells, is considered as a pivotal moving force in the evolutionary history of vascular plants and has played a major role in the domestication of several crops. In the last decades, improved cultivars of economically important species have been developed artificially by inducing autopolyploidy with chemical agents. Studies on diverse species have shown that the anatomical and physiological changes generated by either natural or artificial polyploidization can increase tolerance to abiotic and biotic stresses as well as disease resistance, which may positively impact on plant growth and net production. The aim of this work is to review the current literature regarding the link between plant ploidy level and tolerance to abiotic and biotic stressors, with an emphasis on the physiological and molecular mechanisms responsible for these effects, as well as their impact on the growth and development of both natural and artificially generated polyploids, during exposure to adverse environmental conditions. We focused on the analysis of those types of stressors in which more progress has been made in the knowledge of the putative morpho-physiological and/or molecular mechanisms involved, revealing both the factors in common, as well as those that need to be addressed in future research.
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The development of agriculture requires the use of microorganisms in the management of phytopathogens as a way to compensate for the use of chemical pesticides, in order to produce healthy crops. The objective of this study was to characterize a new isolate of Trichoderma sp. based on morphological and molecular features, and its potential ability to control the pathogen Alternaria sp. The antagonistic isolate was isolated from soil samples of potato fields in Guasave Sinaloa, Mexico, whereas the pathogen was collected from infected apple leaves in the orchard "La Escondida" in Guerrero County, Chihuahua, Mexico. For morphological characterization both fungi were grown on solid PDA medium. DNA of Trichoderma sp. was isolated using the CTAB method and PCR analyses were done using ITS1, ITS4 primers resulting in amplified products of 600 bp. These were sequenced, submitted to Genbank (acc. no. MN950427) and used for further phylogenetic analysis through Bayesian inference approach. Five clades were identified and the polytome topography recovered from clade 4 indicates a high genetic similarity with T. asperellum. A BLAST examination of the resulting sequence in GenBank showed 98.11% similarity with T. asperellum. This result together with the morphological and the phylogenetic analyses indicates that the isolate belongs to Trichoderma asperellum Samuels, Lieckfeldt & Nirenberg. Biocontrol tests of this isolate showed inhibition of Alternaria sp. between 50% and 93%. These results are essential for biodiversity research and give some new possibilities for pest management.
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BACKGROUND: Even with different histologic origins, squamous cell carcinoma (SCC) and adenocarcinoma (AC) are considered a single entity, and the first-line treatment is the same. Locally advanced disease at the diagnosis of cervical cancer is the most important prognostic factor, the recurrence rate is high, making it necessary to evaluate prognostic factors other than clinical or radiological staging; histology could be one of them but continues to be controversial. The aim of this study was to evaluate tumor histology as a prognostic factor in terms of treatment outcomes, disease-free survival (DFS) and overall survival (OS) in a retrospective cohort of patients with Locally Advanced Cervical Carcinoma (LACC). METHODS: The records of 1291patients with LACC were reviewed, all of them were treated with 45-50 Gy of external beam radiotherapy with concurrent chemotherapy and brachytherapy. A descriptive and comparative analysis was conducted. Treatment response was analyzed by the chi-square test; DFS and OS were calculated for each histology with the Kaplan-Meier method and compared with the log-rank test; and the Cox model was applied for the multivariate analysis. RESULTS: We included 1291 patients with LACC treated from 2005 to 2014, of which 1154 (89·4%) had SCC and 137 (10·6%) had AC. Complete response to treatment was achieved in 933 (80·8%) patients with SCC and 113 (82·5%) patients with AC. Recurrence of the disease was reported in 29·9% of SCC patients and 31·9% of AC patients. Five-year DFS was 70% for SCC and 62·2% for AC. The five-year OS rates were 74·3% and 60% for SCC and AC, respectively. The mean DFS was 48·8 months for SCC vs 46·10 for AC (p = 0·043), the mean OS was 50·8 for SCC and 47·0 for AC (p = 0·002). CONCLUSION: Our findings support the hypothesis that SCC and AC are different clinical entities. TRIAL REGISTRATION: NCT04537273 .
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Adenocarcinoma , Carcinoma de Células Escamosas , Neoplasias do Colo do Útero , Adenocarcinoma/patologia , Carcinoma de Células Escamosas/patologia , Feminino , Humanos , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Neoplasias do Colo do Útero/patologiaRESUMO
Organizing pneumonia is a nonspecific pulmonary response pattern associated with a variety of clinical contexts including viral infections. The classic radiological manifestations are peribronchovascular/peripheral ground glass opacities or consolidations and may be accompanied by nodules, masses, and interstitial opacities. We describe the case of a 62-year-old male patient with SARS-CoV-2 pneumonia and torpid clinical and radiological evolution in whom organizing pneumonia was documented through transbronchial biopsy and imaging findings, with a good response to corticosteroids. The importance of recognizing the development of organizing pneumonia lies in the better prognosis and outcome in those patients who receive treatment with corticosteroids, however, the clinical and radiological suspicion must be confirmed with biopsy because radiological findings associated with bacterial coinfection may overlap.
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AIM: Describe the results of the first national census of radiotherapy in Mexico in order to make a situational diagnosis of radiotherapy availability, offer more accurate information to radiation oncologists, and promote an adequate scientific based investment for the country. BACKGROUND: According to the Organisation for Economic Co-operation and Development (OECD), the density of radiotherapy (RT) machines per million habitants in Mexico is approximately 1.7-1.8. Other international organizations such as DIRAC-IAEA report 1.15 per million habitants. National organizations collect data indirectly and previous surveys had a low accrual rate (32.5%). Therefore, a precise census is required. MATERIAL AND METHODS: The Mexican Radiation Oncology Certification Board (CMRO for its acronym in Spanish) conducted a nationwide census from January through November 2019. Gathered information was combined with CMRO database for sociodemographic information and human resources. RESULTS: The study included 103 RT centers [95.1% answered the survey], with a median of 2 centers by state (ranging from 0 in Tlaxcala to 20 in Mexico City) and with a report of only 1 center in 11 states (34.4%). Fifty-six (54.3%) of the centers are public. Fourteen centers (13.6%) have residency-training programs. The total number of RT machines is 162 [141 clinical and linear accelerators (87%) and 21 radionuclide units (13%)] with a median of 3 machines by state (0 in Tlaxcala to 46 in Mexico City) and with ≤3 machines in 18 states (56.25%). The overall calculated density of RT machines per million habitants is 1.32, varying from 0 in Tlaxcala to 5.16 in Mexico City. The density of linear and clinical accelerators per million population is 1.19. The total number of brachytherapy units is 66, with a median of 1 center with brachytherapy unit per state and 29 states with ≤3 centers with a brachytherapy unit (90.6%). Thirty-seven brachytherapy units (56.1%) have automated afterload high-dose rate. The overall rate of brachytherapy units per million inhabitants is 0.55, varying from 0 in 5 states (15.6%), 0.1-0.49 in 8 states (25%), 0.5-0.99 in 13 states (40.6%), 1-1.49 in 5 states (15.6%) and 1.5-1.99 in Mexico City (3.1%). The Mexican CMRO has 368 radiation oncologists certified (99 women and 269 men), of whom only 346 remain as an active part of Mexico's workforce. CONCLUSIONS: This is the first time the CMRO conducts a national census for a radiotherapy diagnostic situation in Mexico. The country currently holds a density of clinical and linear accelerators of 1.19 per million habitants. Brachytherapy density is 0.55 devices per million habitants, and 57% of radiotherapy centers have brachytherapy units.
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AIM: Describe characteristics and outcomes of three patients treated with pelvic radiation therapy after kidney transplant. BACKGROUND: The incidence of pelvic cancers in kidney transplant (KT) recipients is rising. Currently it is the leading cause of death. Moreover, treatment is challenging because anatomical variants, comorbidities, and associated treatments, which raises the concern of using radiotherapy (RT). RT has been discouraged due to the increased risk of urethral/ureteral stricture and KT dysfunction. MATERIALS AND METHODS: We reviewed the electronic health records and digital planning system of patients treated with pelvic RT between December 2013 and December 2018 to identify patients with previous KT. CASES DESCRIPTION: We describe three successful cases of KT patients in which modern techniques allowed full standard RT for pelvic malignances (2 prostate and 1 vaginal cancer) with or without elective pelvic nodal RT, without allograft toxicity at short and long follow-up (up to 60 months). CONCLUSION: When needed, RT modern techniques remain a valid option with excellent oncologic results and acceptable toxicity. Physicians should give special considerations to accomplish all OAR dose constraints in the patient's specific setting. Recent publications recommend KT mean dose <4â¯Gy, but graft proximity to CTV makes this unfeasible. We present 2 cases where dose constraint was not achieved, and to a short follow-up of 20 months renal toxicity has not been documented. We recommend the lowest possible mean dose to the KT, but never compromising the CTV coverage, since morbimortality from recurrent or progressive cancer disease outweighs the risk of graft injury.
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AIM: Our goal was to compare conformal 3D (C3D) radiotherapy (RT), modulated intensity RT (IMRT), and volumetric modulated arc therapy (VMAT) planning techniques in treating pituitary adenomas. BACKGROUND: RT is important for managing pituitary adenomas. Treatment planning advances allow for higher radiation dosing with less risk of affecting organs at risk (OAR). MATERIALS AND METHODS: We conducted a 5-year retrospective review of patients with pituitary adenoma treated with external beam radiation therapy (C3D with flattening filter, flattening filter-free [FFF], IMRT, and VMAT). We compared dose-volume histogram data. For OARs, we recorded D2%, maximum, and mean doses. For planning target volume (PTV), we registered V95%, V107%, D95%, D98%, D50%, D2%, minimum dose, conformity index (CI), and homogeneity index (HI). RESULTS: Fifty-eight patients with pituitary adenoma were included. Target-volume coverage was acceptable for all techniques. The HI values were 0.06, IMRT; 0.07, VMAT; 0.08, C3D; and 0.09, C3D FFF (pâ¯<â¯0.0001). VMAT and IMRT provided the best target volume conformity (CI, 0.64 and 0.74, respectively; pâ¯<â¯0.0001). VMAT yielded the lowest doses to the optic pathway, lens, and cochlea. The position of the neck in extreme flexion showed that it helps in planning mainly with VMAT by allowing only one arc to be used and achieving the desired conformity, decreasing the treatment time, while allowing greater protection to the organs of risk using C3D, C3DFFF. CONCLUSIONS: Our results confirmed that EBRT in pituitary adenomas using IMRT, VMAT, C3D, C3FFF provide adequate coverage to the target. VMAT with a single arc or incomplete arc had a better compliance with desired dosimetric goals, such as target coverage and normal structures dose constraints, as well as shorter treatment time. Neck extreme flexion may have benefits in treatment planning for better preservation of organs at risk. C3D with extreme neck flexion is an appropriate treatment option when other treatment techniques are not available.
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In this work, the dispersive solid-phase extraction of sulfonamide antibiotics was evaluated using magnetic porous carbons derived from cobalt(ii)-based metal-organic frameworks. By direct carbonization under the inert atmosphere of Co-SIM-1, Co-MOF-74 and Co-DABCO MOFs, different magnetic porous carbons were prepared and characterized to study their structural, morphological, chemical and textural properties. Their performance for the simultaneous extraction of three sulfonamides (sulfadiazine, sulfamerazine and sulfamethazine), prior to HPLC analysis, was also evaluated, obtaining the best results (>95%) in the case of C/Co-SIM-1 carbon, probably due to its bimodal pore structure, high surface area and large amount of surface defects. Using this adsorbent, the effect of the solution pH and contact time on the adsorption of the sulfonamides, and the reusability of the carbon were studied.
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AIM: Describe the anatomical changes and tumor displacement due to a rapid response of a patient's small cell lung cancer (SCLC) during definitive chemoradiotherapy (CRT). BACKGROUND: The treatment for SCLC is based on CRT. If interfractional changes during RT are incorrectly assessed they might compromise adequate coverage of the tumor or increase dose to organs at risk. Image guided RT with cone-beam computed tomography (CBCT) allows to identify daily treatment variations. MATERIAL AND METHODS: Describe a SCLC case with rapid changes in size, shape and location of the primary tumor during RT. CASE REPORT: A 62-year-old woman was diagnosed with SCLC with complete obstruction of the anterior and lingular bronchi and incomplete left thorax expansion due to a 12 × 15 cm mass. During CRT (45 Gy in 1.5 Gy per fraction, twice daily) the patient presented rapid tumor response, leading to resolution of bronchi obstruction and hemithorax expansion. Tumor shifted up to 4 cm from its original position. The identification of variations led to two new simulations and planning in a 3-week treatment course. CONCLUSIONS: The complete radiological response was possible due to systematic monitoring of the tumor during CRT. We recommend frequent on-site image verification. Daily CBCT should be considered with pretreatment tumor obstruction, pleural effusion, atelectasis, large volumes or radiosensitive histology that might resolve early and rapidly and could lead to a miss of the tumor or increased toxicity. Further research should be made in replanning effect in coverage of microscopic disease since it increases uncertainty in this scenario.
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Ultraviolet-B radiation (UV-B, 280-315 nm) is an important environmental signal that regulates growth and development in plants. Two dose-dependent UV-B response pathways were described in plants: a specific one, mediated by UVR8 (the specific UV-B receptor) and an unspecific one, activated by the oxidative damage produced by radiation. The constitutively expressed receptor appears inactive as a dimer, with the two monomers dissociating upon UV-B irradiation. The monomer then interacts with COP1, an ubiquitin ligase, hindering its ability to poly-ubiquitinate transcriptional factor HY5, thus averting its degradation and activating the photomorphogenic response. HY5 induces the synthesis of proteins RUP1 and RUP2, which interact with UVR8, releasing COP1, and inducing the re-dimerization of UVR8. This mechanism has been thoroughly characterized in Arabidopsis, where studies have demonstrated that the UVR8 receptor is key in UV-B response. Although Arabidopsis importance as a model plant many mechanisms described in this specie differ in other plants. In this paper, we review the latest information regarding UV-B response mediated by UVR8 in different species, focusing on the differences reported compared to Arabidopsis. For instance, UVR8 is not only induced by UV-B but also by other agents that are expressed differentially in diverse tissues. Also, in some of the species analyzed, proteins with low homology to RUP1 and RUP2 were detected. We also discuss how UVR8 is involved in other developmental and stress processes unrelated to UV-B. We conclude that the receptor is highly versatile, showing differences among species.
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Medicinal and aromatic plants are biologically and economically valuable species because of their intrinsic value as plants, ability to produce secondary metabolites, possible use in the pharmaceutical and food industries, germplasm availability and applications in traditional medicine. In addition, they hold social and economic importance due to the ancestral knowledge they represent and because they are part of the livelihood of many families. Most of them are collected from the wild and are in serious danger of extinction. Through biotechnological tools it is possible to develop their germplasm and obtain new and improved varieties from wild material, while advocating the alternative of production by cultivation instead of extracting it from nature. The objective of this review is to provide an updated perspective on the traditional uses, conservation status and biotechnological advances in a group of 30 plant species native to the American continent.
Las plantas medicinales y aromaÌticas deben ser valoradas tanto por su valor intriÌnseco como tales, por su capacidad de producir metabolitos secundarios, su posible uso en las industrias farmaceÌutica y alimentaria y por sus aplicaciones en medicina tradicional. AdemaÌs, tienen importancia social y econoÌmica debido al conocimiento ancestral que representan y porque son parte del sustento de muchas familias. La mayoriÌa de estas especies son recolectadas de la naturaleza y estaÌn en grave peligro de extincioÌn. A traveÌs de herramientas biotecnoloÌgicas es posible desarrollar su germoplasma y obtener variedades nuevas y mejoradas a partir de material silvestre; esta estrategia propicia la alternativa de produccioÌn por cultivo en lugar de extraerla de la naturaleza. El objetivo de esta revisioÌn es proporcionar una perspectiva actualizada de los usos tradicionales, el estado de conservacioÌn y los avances biotecnoloÌgicos en un grupo de 30 especies de plantas nativas del continente americano.
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Plantas Medicinais , Biotecnologia , Fitoterapia , Medicina Tradicional , Farmacognosia , América , Exploração de Recursos Naturais , Conservação dos Recursos NaturaisRESUMO
Metarhizium rileyi (Farlow) Samson is an important entomopathogenic fungus of more than 30 species of Lepidoptera larvae. The aim of this research was to characterize isolate of M. rileyi from Quivicán, Cuba on the basis of morphological and molecular approaches. The fungus was isolated from samples of S. frugiperda larvae collected from maize fields of Quivicán municipality, Mayabeque province, Cuba, and it was cultured on PDA + Ampicillin solid media for morphological characterization. The DNA was isolated using CTAB method and internal transcribed spacer (ITS1, ITS4) were used as the primers for the amplification. The amplified products of 1335 bp were purified and sequenced at CINVESTAV-IPN in both the directions using the above primers. A consensus sequence was obtained by alignment of the forward and reverse sequences for this region and deposited in GenBank (MG637450). The fungus produced slightly cottony colony of pale green color and dispersed conidia and septal mycelium were observed under the optical microscope. A BLAST search of the sequence in GenBank revealed a 99% of identity with several strains of N. rileyi (e.g., AF368501.1, AB268359.1 and EU553337.1) and M. rileyi (e.g., KY436756.1). This is the first report of M. rileyi isolate from maize fields of Quivicán in Cuba and this is important for biodiversity studies and is another possibility for Integrated Pest Management.
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The present work was carried out in greenhouse conditions at the Centro de Investigación en Alimentación y Desarrollo AC in Delicias, Chihuahua, México. Four different concentrations (0, 25, 50 and 100 µM L-1) of Zn chelate and sulfate were used to study the antioxidant system of Phaseolus vulgaris L. Three genes related with antioxidant activity [superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT)] were selected for expression study. Results showed that when Zn chelate at 50 and 100 µM L-1 were applied SOD was repressed and GSH-Px expression was low at 0, 25 and 100 µM L-1 while with sulfate form SOD expression was low and GSH-Px expression was strong in all treatment. CAT was highly expressed in all form and treatments. For a biochemical study the same enzymes were spectrophotometrically measured. SOD activity shows differences in both forms of Zn, chelate form was different at 25, 50 and 100 µM L-1 with less activity at 100 µM L-1 and sulfate treatment shows differences in all concentrations used. GSH-Px activity shows significant differences with sulfate form at 25, 50 µM L-1 where at 50 µM the activity was higher and low at 100 µM L-1, CAT does not exhibit significant differences but with chelate treatment at 50-100 µM L-1 the activity was higher compared to sulfate. Finally, to raise the Zn concentration in bean under biofortification program is a promising strategy in cropping systems in order to increase the ingestion of zinc and antioxidant capacity in the general population and provided the benefits that this element offered in human health.
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Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the ideal treatment for several diseases. However, the morbidity and mortality associated with the procedure might limit its widespread use; therefore, we implemented reduced BUCY2 as conditioning method along with the use of G-CSF-primed bone marrow (G-BM) in order to reduce complications, including graft-versus-host-disease (GVHD), and to improve survival in these patients. An analysis of transplant characteristics, complications, and survival of patients undergoing an allo-HSCT using this conditioning regimen (busulfan 12 mg/kg and cyclophosphamide 80 mg/kg) plus G-BM was performed. Forty patients were included from 1999 to 2015. All of them had a HLA-matched donor, with a median age of 32 years (range 16-59), and 55% were male. The most frequent diagnosis was myelodysplastic syndrome (MDS) in 14 patients (35%), followed by acute lymphoid leukemia (ALL) in 12 (30%). The mean of CD34+ was 2.09 × 106/kg. The mean time to neutrophil and platelet recovery was 20 and 18 days, respectively. The most common toxicity was mucositis (75%) with grade III-IV in 53% of cases. Acute GVHD appeared in 12.5 and 35% of patients developed chronic GVHD. Transplant-related mortality (TRM) was 10%. Five-year relapse-free survival was 69%, and the 5-year overall survival was 69.5%. Our conditioning method along with G-BM preserves an immunosuppressive and myeloablative effect allowing eradication of the malignant clone and achieving adequate bone marrow engraftment with acceptable toxicity, low incidence of GVHD, and low TRM, representing a favorable alternative for allo-HSCT.
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Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Medula Óssea/metabolismo , Doença Enxerto-Hospedeiro , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Transplante de Células-Tronco Hematopoéticas , Condicionamento Pré-Transplante , Adolescente , Adulto , Aloenxertos , Medula Óssea/patologia , Bussulfano/administração & dosagem , Ciclofosfamida/administração & dosagem , Intervalo Livre de Doença , Feminino , Doença Enxerto-Hospedeiro/metabolismo , Doença Enxerto-Hospedeiro/mortalidade , Doença Enxerto-Hospedeiro/patologia , Doença Enxerto-Hospedeiro/prevenção & controle , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Taxa de SobrevidaRESUMO
One of the major causes of crop stress is soil or water salinity. Thus, selection of the best species for cultivation in semiarid and arid climates is fundamental. Salvadora persica is an evergreen perennial halophyte that can grow under extreme conditions, from very dry environments to highly saline soils. Based on international bibliography, the authors outlined an agro-ecological zoning model to determine the potential cultivation zones for S. persica in Argentina. This model may be applied to any part of the world, using the agro-ecological limits presented in this work. All the maps were developed by the implementation of a geographic information system (GIS) that can be updated by the further incorporation of complementary information, with the consequent improvement of the original database. The overlap of the agroclimatic suitability map on the drylands' saline soils and the drylands' alkaline soils maps, determined the agro-ecological zoning. Since some areas in the agro-ecological zoning can overlap with land that is already assigned for other uses, protected areas, current land use/cover of the different zones, and urban areas maps were incorporated into the GIS and subtracted by a mask. This resulted in the delimitation of "potential cultivation zoning", thus avoiding possible conflicts surrounding the use of land and making the agro-ecological zonation more efficient. There is a broad agro-ecological zone for cultivation of S. persica that extends from Northern Argentina to approximately 41° South latitude, under dry-subhumid to semiarid climates. Lands classified with different degrees of suitability in the potential cultivation zoning could be used for production of this species for energy purposes on lands that are either unsuitable for food production or currently assigned for other purposes. This paper represents pioneering work since there are no previous studies concerning the introduction of S. persica in Argentina.
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Campos de Petróleo e Gás , Salinidade , Salvadoraceae/fisiologia , Solo/química , Argentina , Biodegradação Ambiental , Clima DesérticoRESUMO
BACKGROUND: Transient elastography (TE) is a useful tool for the assessment of hepatic fibrosis as an alternative to liver biopsy, but it has not been validated as a screening procedure in apparently healthy people. AIM: To determine the prevalence of advanced liver fibrosis diagnosed by TE in a socioeconomically challenged rural population. MATERIAL AND METHODS: We enrolled 299 participants aged over 18 years old from a vulnerable population in Mexico who responded to an open invitation. All participants had their history recorded and underwent a general clinical examination and a liver stiffness measurement, performed by a single operator according to international standards. RESULTS: Overall, 7.35% participants were found to be at high risk for cirrhosis. Three variables correlated with a risk for a TE measure ≥ 9 kPa and significant fibrosis: history of alcohol intake [7.95 vs. 92.04%, odds ratio (OR) 4.47, 95% confidence interval (CI) 1.45-13.78, P = 0.0167], body mass index (BMI) ≥ 30 kg/m2 (30.87 vs. 69.12%, OR 4.25, 95%CI 1.04-6.10, P = 0.049), and history of diabetes mellitus (14.87 vs. 85.12%, OR 2.76, 95%CI 1.002-7.63, P = 0.0419). In the multivariate analyses BMI ≥ 30 kg/m2 was the only significant risk factor for advanced liver fibrosis or cirrhosis (OR 2.54, 95%CI 1.02-6.3, P = 0.0460). CONCLUSION: TE could be useful as a screening process to identify advanced liver fibrosis in the general and apparently healthy population.
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Técnicas de Imagem por Elasticidade , Cirrose Hepática/diagnóstico por imagem , Cirrose Hepática/epidemiologia , População Rural , Populações Vulneráveis , Adulto , Consumo de Bebidas Alcoólicas , Distribuição de Qui-Quadrado , Comorbidade , Feminino , Humanos , Modelos Logísticos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Valor Preditivo dos Testes , Prevalência , Fatores de Risco , Saúde da População Rural , Fatores SocioeconômicosRESUMO
Chitin biopolymer production and its by-product chitosan show great potential. These biomaterials have great applicability in various fields because they are non-toxic, biodegradable, biocompatible, and have antimicrobial effects. The most common source of chitin and chitosan is the crustaceous shell; however, mushrooms are an alternative source for isolating these biopolymers because their cellular wall has a high content of chitin, which may be transformed into chitosan through a deacetylation reaction. The main objective of this research was to obtain chitosan through the deacetylation of chitin isolated from the Ganoderma lucidum basidiomycetes mushroom, which is obtained through biotechnological culture. The material characterization was performed using X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, and an evaluation of cytotoxicity comparing the results obtained with results for commercial chitosan. Protocol results showed that chitosan obtained from this mushroom had a significant similitude with commercial chitosan, yet the one obtained using P2 protocol was the one that rendered the best results: including diffractogram peaks, characteristic infrared analysis bands, and an 80.29 % degree of deacetylation. Cytotoxicity in vitro testing showed that the material was non-toxic; furthermore, it rendered very promising information regarding the evaluation of future applications of this biomaterial in the field of biomedicine.
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Materiais Biocompatíveis , Quitosana/isolamento & purificação , Reishi/química , Acetilação , Animais , Biomassa , Linhagem Celular , Quitosana/química , Camundongos , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Difração de Raios XRESUMO
The chitin was isolated from the Ganoderma lucidum submerged cultures mycelium as potential source of chitin under biotechnological processes. The extraction of chitin was carried out through 5 different assays which involved mainly three phases: pulverization of the mushroom, deproteinization of the mycelia with NaOH solution, and a process of decolorization with potassium permanganate and oxalic acid. The chitin contents extracted from 9-day mycelia were 413, 339, 87, 78, and 144 mg/g(-1) (milligrams of chitin/grams of dry biomass) for A1, A2, A3, A4, and A5, respectively. Obtained chitin was characterized by X-Ray Diffraction (XRD), by Fourier transform infrared spectroscopy (FTIR), and by thermal analysis (TGA). The results showed that Ganoderma lucidum chitin has similar characteristic of chitin from different fonts. The advantage of the biotechnological processes and the fact that Ganoderma lucidum fungus may be used as a potential raw material for chitin production were demonstrated.