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1.
GM Crops Food ; 12(1): 47-56, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32862762

RESUMO

The sugarcane (Saccharum X officinarum) is one of the most important crops used to produce sugar and raw material for biofuel in the world. One of the main causes for sucrose content and yield losses is the attack by insect. In this investigation, cry1Ac gene was introduced into sugarcane variety GT54-9(C9) using the Agrobacterium tumefaciens transformation method for transgenic sugarcane production presenting insect-resistance. The A. tumefaciens strain GV1303 including pARTcry1Ac vector was used for the production of transformed sugarcane. The Bacillus thuringiensis cry gene were successfully used to produce transgenic plants used for the improvement of both agronomic efficiency and product quality by acquiring insect resistance. PCR and Southern hybridization techniques were used to confirm the cry1Ac gene incorporation into sugarcane genome. Transformation percentage was 22.2% using PCR analysis with specific primers for cry1Ac and npt-II (Neomycin phosphotransferase) genes. The expression of cry1Ac gene was determined using reverse transcriptase polymerase chain reaction (RT-PCR), QuickStix test, and insect bioassays. Bioassays for transformed sugarcane plants showed high level of toxicity to Sesamia cretica giving 100% mortality of the larvae. Sugarcane insect resistance was improved significantly by using cry1Ac gene transformation.


Assuntos
Saccharum/genética , Agrobacterium , Animais , Proteínas de Bactérias/genética , Endotoxinas , Proteínas Hemolisinas/genética , Plantas Geneticamente Modificadas
2.
Sci Total Environ ; 750: 141498, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32882491

RESUMO

This work examined the adsorption capacity of sugarcane bagasse (SB) for the removal of ciprofloxacin (CPX) from water using batch experiments and a fixed bed column and compared its adsorption performance with a powdered activated commercial carbon (PAC). Both adsorbents achieved a similar percentage removal of about 78% with doses of 3 g L-1 of SB and 0.3 g L-1 of PAC (20 mg L-1 initial CPX concentration at 30 °C). The maximum removal was obtained at a pH between 6 and 8. SB adsorption isotherms were fitted to the Langmuir, BET and Freundlich models showing a maximum adsorption capacity of 13.6 mg g-1. The kinetic data for both SB and PAC fitted the pseudo second-order model (R2 = 0.99). The adsorption process was faster on the SB (65% of elimination in the first 5 min) than on the PAC. The study of the adsorbent properties shows that SB is a macroporous solid with a specific surface area 250 times smaller than PAC. The thermodynamic results show that SB adsorption was physical and exothermic. The main suggested interactions between CPX and SB are electrostatic attraction, hydrogen bonding and dipole-dipole interactions. The experiments carried out in a fixed bed show that the adsorption capacity at breakthrough increases with the bed height. The adsorption capacity at saturation time was 9.47 mg g-1 at a flow rate of 3 mL min-1, a bed height of 14 cm, and a diameter of 1.5 cm. The experimental data were fitted to the Bohart-Adams model (R2 = 0.98). These results highlight the capacity of sugarcane bagasse to adsorb ciprofloxacin from water, illustrating its potential as a low-cost adsorbent.


Assuntos
Saccharum , Poluentes Químicos da Água , Purificação da Água , Adsorção , Celulose , Carvão Vegetal , Ciprofloxacino , Equador , Concentração de Íons de Hidrogênio , Cinética , Pós
3.
Sci Total Environ ; 752: 141795, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32892043

RESUMO

Sugarcane is the second largest bioenergy crop in the world and it accounts for 80% of global sugar production. Grown mostly in wet and warm tropics with relatively high nitrogen (N) fertiliser input and crop residue retention, sugarcane production is a significant source of nitrous oxide (N2O) emission. Yet, a global evaluation of research on N2O emission from sugarcane crop is lacking. Here, we conducted a meta-analysis using data from 141 measurements compiled from 15 sugarcane field studies reported from different countries to i) quantify N2O emissions and emission factors (EFs) globally, and for tropics and sub-tropics, and ii) identify the key factors that promote N2O emission. Our analysis shows that the global mean total N2O emission from sugarcane production reached 2.26 (CI: 1.93-2.62) kg N2O-N ha-1 yr-1 with an estimated EF of 1.21% (CI: 0.971-1.46%). N2O emissions increased exponentially with increase in N fertiliser rate, questioning the adequacy of Intergovernmental Panel on Climate Change (IPCC) default EF value (1%) for sugarcane N2O emission estimation. Mean total N2O emissions and EFs in tropics and sub-tropics did not vary significantly. Supplementing synthetic N fertiliser (SN) with organic amendments (OA) significantly increased mean N2O emission (~1.4-fold) and EF (~2.5-fold) compared to SN. A remarkable reduction in N2O emission (38.6%) and EF (61.5%) was evident when enhanced efficiency fertilisers (EEF) replaced SN. In contrast, crop residue removal had little impact on N2O emission and EF, but both parameters showed an upward trend with irrigation and increased rainfall. Soil carbon content and pH were emerged as key regulators of sugarcane N2O emission and EF. It is concluded that global sugarcane N2O emission could be significant and that there is considerable prospect for mitigating the emission through innovative nutrient formulations and precision agriculture that help meet crop nutrient demand without compromising environmental imperatives.


Assuntos
Óxido Nitroso , Saccharum , Agricultura , Fertilizantes/análise , Nitrogênio , Óxido Nitroso/análise , Solo
4.
J Environ Sci (China) ; 99: 296-310, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33183709

RESUMO

Physical characteristics and quantitative elemental composition of PM and residual ash produced from sugarcane leaves (SCL) combustion were investigated using TEM-EDS compared with forest leaves (FRL). SEM-EDS was used to analyze the microstructure and chemical composition of biomass raw leaves and PM. XRD analysis was also performed to investigate the characterization of the crystalline nanostructure, structure of PM, and residual ash compared to the TEM image processing method. The oxidation kinetics of biomass raw materials, PM, and residual ash were investigated by TGA. The morphology of fine and ultrafine agglomerate structure of SCL soot and residual ash are not significantly different from the FRL soot and residual ash. The average diameter sizes of single primary nanoparticles of SCL and FRL soot are approximately 37 nm and 35 nm, while the sizes of residual ash are about 18 nm and 22 nm, respectively. The single primary nanoparticles of soot are mainly composed of curve line crystallites of carbon fringes, while residual ash is composed of straight-line lattice fringes. The average fringe lengths of SCL and FRL soot are about 1.25 nm and 1.04 nm from the outer shell and 0.89 nm and 0.74 nm from the inner core. The interlayer spacing of curve line carbon fringes of SCL and FRL soot is approximately 0.359 nm and 0.362 nm by the TEM image analysis and it was matched with XRD analysis. The biomass PMs are mainly composed of soot, Si, Ca, and K compounds: SiO2, CaCO3, and KCl.


Assuntos
Material Particulado , Saccharum , Florestas , Microscopia Eletrônica , Material Particulado/análise , Folhas de Planta/química , Dióxido de Silício
5.
Nat Commun ; 11(1): 5442, 2020 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-33116128

RESUMO

Miscanthus is a perennial wild grass that is of global importance for paper production, roofing, horticultural plantings, and an emerging highly productive temperate biomass crop. We report a chromosome-scale assembly of the paleotetraploid M. sinensis genome, providing a resource for Miscanthus that links its chromosomes to the related diploid Sorghum and complex polyploid sugarcanes. The asymmetric distribution of transposons across the two homoeologous subgenomes proves Miscanthus paleo-allotetraploidy and identifies several balanced reciprocal homoeologous exchanges. Analysis of M. sinensis and M. sacchariflorus populations demonstrates extensive interspecific admixture and hybridization, and documents the origin of the highly productive triploid bioenergy crop M. × giganteus. Transcriptional profiling of leaves, stem, and rhizomes over growing seasons provides insight into rhizome development and nutrient recycling, processes critical for sustainable biomass accumulation in a perennial temperate grass. The Miscanthus genome expands the power of comparative genomics to understand traits of importance to Andropogoneae grasses.


Assuntos
Poaceae/genética , Biomassa , Cromossomos de Plantas/genética , Elementos de DNA Transponíveis , Diploide , Evolução Molecular , Regulação da Expressão Gênica de Plantas , Variação Genética , Genoma de Planta , Genômica , Modelos Genéticos , Filogenia , Poaceae/classificação , Poaceae/crescimento & desenvolvimento , Poliploidia , Saccharum/genética , Estações do Ano , Sorghum/genética
6.
Plant Genome ; 13(1): e20006, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-33016641

RESUMO

Sugarcane (Saccharum spp.) is an important economic crop, contributing up to 80% of sugar and approximately 60% of biofuel globally. To meet the increased demand for sugar and biofuel supplies, it is critical to breed sugarcane cultivars with robust performance in yield traits. Therefore, dissection of causal DNA sequence variants is of great importance, as it provides genetic resources and fundamental information for crop improvement. In this study, we analyzed nine yield traits in a sugarcane diversity panel consisting of 308 accessions primarily selected from the World Collection of Sugarcane and Related Grasses. By genotyping the diversity panel via target enrichment sequencing, we identified a large number of sequence variants. Genome-wide association studies between the markers and traits were conducted, taking dosages and gene actions into consideration. In total, 217 nonredundant markers and 225 candidate genes were identified to be significantly associated with the yield traits, which can serve as a comprehensive genetic resource database for future gene identification, characterization, and selection for sugarcane improvement. We further investigated runs of homozygosity (ROH) in the sugarcane diversity panel. We characterized 282 ROHs and found that the occurrence of ROHs in the genome were nonrandom and probably under selection. The ROHs were associated with total weight and dry weight, and high ROHs resulted in a decrease in the two traits. This study suggests that genomic inbreeding has led to negative impacts on sugarcane yield.


Assuntos
Saccharum , Estudo de Associação Genômica Ampla , Genômica , Humanos , Fenótipo , Poliploidia , Saccharum/genética
7.
Water Sci Technol ; 82(6): 1111-1119, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33055401

RESUMO

Vinasse, an effluent generated during sugar and alcohol production, has great potential for soil and water pollution; however, it can be treated, used in biomass production and reused in sugarcane plantations. Thus, this work uses different types of biodigested vinasse to produce more biomass. The effect is the removal of ammonia nitrogen quickly and the end of the exponential growth phase of microalgae at different levels from the sixth day of cultivation. Among the concentrations used, the use of 50% biodigested vinasse showed the highest biomass concentration (255 mg L-1) after 10 days of growth, coinciding with the end of ammoniacal nitrogen availability and stabilization of effluent color removal. The addition of biodigested vinasse also provides an increase in Chlorophyll a (5.33 mg L-1) and b (4.66 mg L-1) levels, obtained on the sixth day with 40% of vinasse, as well as protein (40.50%) with 50% effluent. Therefore, with the obtained results we noticed the variation of the biomass composition according to the vinasse concentration and increase of the pigment concentration in the presence of the effluent with higher nutrient concentration. Thus, the higher concentration of vinasse was more productive of the cultivation of Chlorella vulgaris.


Assuntos
Chlorella vulgaris , Microalgas , Saccharum , Biomassa , Clorofila A
8.
J Plant Res ; 133(6): 897-909, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33094397

RESUMO

Climate change has caused serious problems related to the productivity of agricultural crops directly affecting human well-being. Plants have evolved to produce molecular mechanisms in response to environmental stresses, such as transcription factors (TFs), to cope with abiotic stress. The NAC proteins constitute a plant-specific family of TFs involved in plant development processes and tolerance to biotic and abiotic stress. Sugarcane is a perennial grass that accumulates a large amount of sucrose and is a crucial agro-industry crop in tropical regions. Our previous transcriptome analyses on sugarcane that were exposed to drought conditions revealed significant increases in the expression of several NAC TFs through all of the time-point stress conditions. In this work, we characterize all previously detected sugarcane NAC genes, utilizing phylogenetics and expression analyses. Furthermore, we characterized a sugarcane NAC gene orthologous to the senescence-associated genes AtNAP and OsNAP via transient expression in tobacco calluses, from Arabidopsis and rice respectively, thus we named it the SoNAP gene. Transient localization assays on onion epidermal cells confirmed the nuclear localization of the SoNAP. Expression analysis showed that the SoNAP gene was induced by high salinity, drought, and abscisic acid treatments. The overexpression of the SoNAP gene in tobacco calluses caused a senescence associated phenotype. Overall, our results indicated that the SoNAP gene from sugarcane is transcriptionally induced under abiotic stress conditions and conserved the predicted senescence-associated functions when it was overexpressed in a heterologous plant model. This work provides key insights about the senescence mechanisms related to abiotic stress and it provides a benchmark for future work on the improvement of this economically important crop.


Assuntos
Pressão Osmótica , Proteínas de Plantas/genética , Saccharum , Estresse Salino , Fatores de Transcrição/genética , Secas , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Saccharum/genética , Saccharum/metabolismo , Fatores de Transcrição/metabolismo
9.
J Environ Manage ; 276: 111228, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32866750

RESUMO

As population and consumption grow, so does crop production and its residue. Crop residue is traditionally burned in developing countries, which impacts environment, economy, society and health. Thailand faces similar challenges as it is among the largest producers of rice paddy and sugarcane in the world with 83% of its total burnt residue coming from these crops. To address this problem, the Government of Thailand has implemented some policies (e.g. Alternative Energy Development Plan (AEDP) and zero burning policy for sugarcane) targeting both, the use of residue, and the practice of burning. While these policies appear to control residue burning to some extent, there are still challenges, especially for poorer farmers, who rely on manual harvesting practices. The paper looks into the current status of rice and sugarcane residue burning, its impacts on the environment, existing policies, current challenges, and future solutions through sustainable management practices. To achieve reduction in residue burning, the best possible solution is to use residue for alternative purposes. Some sustainable management practices include use of residue for energy production, green harvesting to improve soil nutrients, biochar production and composting. Thailand can also learn from solutions implemented in other countries, to reduce some of the impacts of crop residue burning.


Assuntos
Oryza , Saccharum , Agricultura , Solo , Tailândia
10.
J Environ Manage ; 276: 111272, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32871466

RESUMO

In this study, carbonized material was produced using sodium hydroxide treated Sugar cane bagasse (SB), and synthesized materials ware used to prepare Sodium Alginate/SBAC composite beads which were further used as an adsorbent to remove malachite green dye (MG) present in water. Physiochemical characteristics of composite beads were analyzed using FTIR, SEM, TGA, and BET. Adsorption equilibrium data showed excellent fit to the Freundlich model (R2 = 0.994) than to the Langmuir model (R2 = 0.925). Adsorption kinetics study indicated that the MG removal process would be better described by the pseudo-second-order kinetic model. The thermodynamic study suggested the spontaneous and endothermic nature of MG adsorption. By using response surface methodology, the optimum conditions for MG adsorption on composite beads were found to be 115.43 min, 0.3 g/L and pH 8 for contact time, adsorbent mass, and pH respectively and MG adsorption efficiency was 97.88%. The fixed-bed column data were evaluated using several kinetic models and among them, Thomas model showed the best agreement with investigation results. These results revealed that synthesized composite beads have a high affinity toward MG and it could be reasonable, eco-friendly adsorbent for dye removal from wastewater.


Assuntos
Saccharum , Poluentes Químicos da Água , Adsorção , Alginatos , Carvão Vegetal , Concentração de Íons de Hidrogênio , Cinética , Corantes de Rosanilina , Hidróxido de Sódio
11.
Bioresour Technol ; 318: 124059, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32911367

RESUMO

Acid-catalysed crude glycerol (ACG) pretreatment was carried out at 110 °C and 130 °C for mild fractionation of sugarcane bagasse into fermentable sugars and high-quality lignin. ACG pretreatment at 110 °C led to sugar yields of 71%-74%, comparable to those with acid-catalysed reagent-grade glycerol (AG). ACG pretreatment removed more lignin (53%-75%) than AG pretreatment (38%-49%), likely due to the presence of organic impurities in ACG. Hence, 28% more lignin was recovered from ACG pretreatment hydrolysate than with the AG pretreatment. NMR analysis revealed that recovered lignin was modified by glycerol through etherification of ß-aryl ethers and esterification of hydroxycinnamic acids, which prevented lignin condensation and led to the generation of ß-O-4 linkage-rich lignin at mild conditions (110 °C for 3 h and 5 h). This study suggests that crude glycerol is a suitable low-cost solvent for mild fractionation of lignocellulosic biomass into fermentable sugars and high-quality lignin for value-adding applications.


Assuntos
Lignina , Saccharum , Celulose , Glicerol , Hidrólise , Açúcares
12.
Bioresour Technol ; 318: 124053, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32942092

RESUMO

Economical removal of fermentation inhibitors from lignocellulosic hydrolysate plays a considerable role in bioconversion of lignocellulose biomass. In this work, the textural properties of polyacrylamide/polystyrene interpenetrating polymer networks (PAM/PS IPNs) on adsorption of fermentation inhibitors from sugarcane bagasse hydrolysate (SCBH) were investigated for the first time. The results showed that, the specific surface area, pore diameter and surface polarity had important influence on its adsorption performance towards sugars, organic acids, furans and acid-soluble lignin. The PAM/PS IPNs under the optimal copolymerization situation achieved the high selectivity coefficients of 4.07, 14.9, 21.2 and 25.8 with respective to levulinic acid, furfural, hydroxymethylfurfural (HMF) and acid-soluble lignin, and had a low total sugar loss of 2.09%. Overall, this research puts forward a design and synthetic strategy for adsorbent to remove fermentation inhibitors from lignocellulosic hydrolysate.


Assuntos
Saccharum , Resinas Acrílicas , Adsorção , Celulose , Fermentação , Hidrólise , Lignina/metabolismo , Polímeros , Poliestirenos , Saccharum/metabolismo
13.
Artigo em Inglês | MEDLINE | ID: mdl-32882881

RESUMO

Prolonged or intense exposure to heat can lead to a range of health effects. This study investigated heat exposure and heat-related symptoms which sugarcane workers (90 sugarcane cutters and 93 factory workers) experienced during a harvesting season in Thailand. During the hottest month of harvesting season, wet bulb globe temperature was collected in the work environment, and workloads observed, to assess heat stress. Urine samples for dehydration test, blood pressure, heart rate, and body temperature were measured pre- and post-shift to measure heat strain. Fluid intake and heat-related symptoms which subjects had experienced during the harvesting season were gathered via interviews at the end of the season. From the results, sugarcane cutters showed high risk for heat stress and strain, unlike factory workers who had low risk based on the American Conference of Governmental Industrial Hygiene (ACGIH) threshold limit values (TLVs) for heat stress. Dehydration was observed among sugarcane cutters and significant physiological changes including heart rate, body temperature, and systolic blood pressure occurred across the work shift. Significantly more sugarcane cutters reported experiencing heat-related symptoms including weakness/fatigue, heavy sweating, headache, rash, muscle cramp, dry mouth, dizziness, fever, dry/cracking skin, and swelling, compared to sugarcane factory workers. We conclude that the heat stress experienced by sugarcane cutters working in extremely hot environments, with high workloads, is associated with acute health effects. Preventive and control measures for heat stress are needed to reduce the risk of heat strain.


Assuntos
Transtornos de Estresse por Calor , Exposição Ocupacional , Saccharum , Adolescente , Adulto , Transtornos de Estresse por Calor/epidemiologia , Resposta ao Choque Térmico , Temperatura Alta , Humanos , Masculino , Pessoa de Meia-Idade , Exposição Ocupacional/efeitos adversos , Estresse Fisiológico , Tailândia , Adulto Jovem
14.
PLoS One ; 15(9): e0232566, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32941421

RESUMO

Hydathode is a plant organ responsible for guttation in vascular plants, i.e. the release of droplets at leaf margin or surface. Because this organ connects the plant vasculature to the external environment, it is also a known entry site for several vascular pathogens. In this study, we present a detailed microscopic examination of leaf apical hydathodes in monocots for three crops (maize, rice and sugarcane) and the model plant Brachypodium distachyon. Our study highlights both similarities and specificities of those epithemal hydathodes. These observations will serve as a foundation for future studies on the physiology and the immunity of hydathodes in monocots.


Assuntos
Brachypodium/ultraestrutura , Produtos Agrícolas/ultraestrutura , Oryza/ultraestrutura , Folhas de Planta/ultraestrutura , Saccharum/ultraestrutura , Zea mays/ultraestrutura
15.
Waste Manag ; 118: 110-121, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32892088

RESUMO

Sewage sludge (SS) exhibits a relevant agronomic potential due to the high content of organic matter and nutrients. However, the presence of several toxic substances can prevent its agricultural application. This study evaluated if the incorporation of stimulating agents (coffee grounds and sugarcane bagasse) could contribute to an effective increase of the SS biodegradability in order to decrease its toxicity. The samples were prepared mixing aerobic or anaerobic sludge with soil, soil and bagasse, and soil and coffee grounds. Respirometric tests showed that stimulating agents enhanced the CO2 production. However, in terms of biodegradation efficiency, more satisfactory results were verified for the anaerobic SS, especially when mixed with coffee grounds. The biodegradation also favored the SS sanitization, eliminating the Enterobacteria. For baseline toxicity (Microtox with Aliivibrio fischeri) and phytotoxicity (Lactuca sativa), all the initial samples showed higher effects. Nevertheless, after the biodegradation, this toxicity was significantly decreased and the best results were obtained for the mixtures containing only soil and sludge. For the AREc32 assay (NRF2 mediated oxidative stress response), although a very weak response was observed, this effect was attenuated for the aerobic SS or completely eliminated for the anaerobic SS after the biodegradation. Thus, even though the use of biostimulation agents during the biodegradation led to an enhancement of microbial respiration, their incorporation to the samples do not seem to interfere in the decrease of the toxic potential of the studied SSs. However, the SS biodegradation in aerobiosis was crucial for toxicity reduction and to accelerate its maturity.


Assuntos
Saccharum , Esgotos , Celulose , Café , Solo
16.
Plant Mol Biol ; 104(4-5): 411-427, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32813231

RESUMO

KEY MESSAGE: A sugarcane MYB present in the culm induces suberin biosynthesis and is involved both with fatty acid and phenolics metabolism. Few transcription factors have been described as regulators of cell wall polymers deposition in C4 grasses. Particularly, regulation of suberin biosynthesis in this group of plants remains poorly understood. Here, we showed that the sugarcane MYB transcription factor ShMYB78 is an activator of suberin biosynthesis and deposition. ShMYB78 was identified upon screening genes whose expression was upregulated in sugarcane internodes undergoing suberization during culm development or triggered by wounding. Agrobacterium-mediated transient expression of ShMYB78 in Nicotiana benthamiana leaves induced the ectopic deposition of suberin and its aliphatic and aromatic monomers. Further, the expression of suberin-related genes was induced by ShMYB78 heterologous expression in Nicotiana benthamiana leaves. ShMYB78 was shown to be a nuclear protein based on its presence in sugarcane internode nuclear protein extracts, and protoplast transactivation assays demonstrated that ShMYB78 activates the promoters of the sugarcane suberin biosynthetic genes ß-ketoacyl-CoA synthase (ShKCS20) and caffeic acid-O-methyltransferase (ShCOMT). Our results suggest that ShMYB78 may be involved in the transcriptional regulation of suberin deposition, from fatty acid metabolism to phenylpropanoid biosynthesis, in sugarcane internodes.


Assuntos
Lipídeos/biossíntese , Proteínas de Plantas/genética , Saccharum/genética , Tabaco/metabolismo , Fatores de Transcrição/genética , Núcleo Celular , Regulação da Expressão Gênica de Plantas , Lipídeos/genética , Filogenia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Tabaco/genética , Fatores de Transcrição/metabolismo
17.
Ecotoxicol Environ Saf ; 202: 110929, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800215

RESUMO

The aim of this study was to investigate the bioremediation potential of polychlorinated biphenyls (PCBs) in soil, mimicking three strategies: (a) mycoaugmentation: by the addition of Trametes sanguinea and Pleurotus sajor-caju co-cultures immobilized on sugarcane bagasse; (b) biostimulation: by supplementation of sugarcane bagasse; and (c) natural attenuation: no amendments. The experiments were done in microcosms using Ultisol soil. Remediation effectiveness was assessed based on pollutants content, soil characteristics, and ecotoxicological tests. Biostimulation and mycoaugmentation demonstrated the highest PCBs-removal (approx. 90%) with a significant toxicity reduction at 90 d. The studied strains were able to survive during the incubation period in non-sterilized soil. Laccase, manganese-peroxidase and endoxylanase activities increased significantly in co-cultures after 60 d. Sugarcane bagasse demonstrated to be not only a suitable support for fungal immobilization but also an efficient substrate for fungal colonization of PCBs-contaminated soils. Mycoaugmentation and biostimulation with sugarcane bagasse improved oxidable organic matter and phosphorous contents as well as dehydrogenase activity in soil. Therefore, biostimulation with sugarcane bagasse and mycoaugmentation applying dual white-rot fungal cultures constitute two efficient bioremediation alternatives to restore PCBs-contaminated soils.


Assuntos
Biodegradação Ambiental , Poluentes do Solo/metabolismo , Celulose , Ecotoxicologia , Lacase , Peroxidases , Fósforo , Bifenilos Policlorados , Saccharum , Solo/química , Microbiologia do Solo , Poluentes do Solo/análise , Trametes
18.
Bioresour Technol ; 316: 123918, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32763802

RESUMO

Cello-oligosaccharides (COS) are oligomers with 2 to 6 ß-1,4-linked glucose units, with potential applications in the food/feed and bioenergy industrial sectors. In this study, the combination of five heterologous expressed endoglucanases varying the temperature and pH conditions were evaluated by design of experiments for COS production. Afterwards, the best combination was tested to produce COS from different pretreated sugarcane straws: ionic liquid, diluted acid, hydrothermal and steam-explosion. The results showed that steam explosion pretreated sugarcane straw treated with CtCel9R enzyme at 50 °C and pH 5.0 yielded 13.4 mg COS g biomass-1, 5-18-fold higher compared to the other pretreated straws. Under the conditions evaluated, the removal of hemicellulose and decrease in the cellulose crystallinity can benefits the enzymatic hydrolysis. This is the first study that combined the evaluation of different enzymes, conditions, and sugarcane straw pretreatments to optimize COS production in a single step without glucose formation.


Assuntos
Celulase , Saccharum , Celulose , Hidrólise , Oligossacarídeos
19.
Bull Environ Contam Toxicol ; 105(3): 474-480, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32757042

RESUMO

Thiamethoxam 75 SG has recently got registered for use against shoot borer and termites of sugarcane. It is the only neonicotinoid having label claim against both the major pests of sugarcane. The dissipation kinetics and environmental risk assessment of thiamethoxam 75 SG were studied in a typical tropical sugarcane crop ecosystem as detailed reports are lacking. Rapid and sensitive method adopted to determine the residues of thiamethoxam in the soil employing HPLC could provide more than 95.5% recoveries. The insecticide was observed to persist in the sandy clay loam soil for 60 days and reached below the detectable level of less than 0.01 mg/kg (LOQ = 0.01 mg/kg) on 75th day when applied @ 120 g a.i./ha. The half-life was worked out to be 16.50 days. At double the recommended dose (240 g a.i./ha), the insecticide persisted up to 75 days with the half-life of 16.91 days. The risk quotient values indicated medium to low level of risk to earthworms during the course of degradation of thiamethoxam in the soil.


Assuntos
Inseticidas/análise , Poluentes do Solo/análise , Tiametoxam/análise , Argila , Ecossistema , Meia-Vida , Cinética , Neonicotinoides , Medição de Risco , Saccharum/metabolismo , Areia , Solo/química
20.
Plant Dis ; 104(10): 2665-2668, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32749946

RESUMO

Sugarcane white leaf (SCWL) is a devastating sugarcane (Saccharum officinarum) disease caused by a 16SrXI group phytoplasma, which is extremely harmful to sugarcane production. To determine the occurrence of SCWL in different varieties in 2018, we conducted a field survey and performed nested PCR detection of SCWL phytoplasma in cane-planting areas of Mangweng and Hepai in Gengma, Yunnan province, which are the areas most severely affected by SCWL in China. The results of the field survey showed that the symptomatic incidence of SCWL differed among varieties. The mean symptomatic incidence of SCWL on variety Yuetang60 was the highest (73.50%), and it was the lowest on Liucheng05-136 (13.67%). Using nested PCR, the SCWL phytoplasma was detected in symptomatic plants of all varieties more than 90% of the time; the SCWL phytoplasma was detected in 91 and 97% of symptomatic plants of Yingyu91-59 and Liucheng05-136 varieties, respectively. The SCWL phytoplasma was detected by PCR in 82% of the asymptomatic plant samples. The results of this study showed that field survey based on white leaf symptoms did not accurately reflect the actual occurrence of the SCWL phytoplasma.


Assuntos
Saccharum , China , Incidência , Doenças das Plantas , Reação em Cadeia da Polimerase , Inquéritos e Questionários
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