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2.
Bioresour Technol ; 301: 122706, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31945682

RESUMO

Bioemulsifiers are surface active compounds which could be potentially used in food processing, cosmetic sector and oil recovery. Sugarcane straw (SS), was used as the raw substrate for the production of bio-emulsifiers (BE) by Cutaneotrichosporon mucoides. Three different delignification strategies using dilute sodium hydroxide, sodium sulfite and ammonium hydroxide followed by enzymatic hydrolysis (Cellic CTec 2, 7.5% total solids, 15 FPU/g, 72 h) were studied. Enzyme hydrolysis of ammonium hydroxide pretreated SS showed a maximum of 62.19 ± 0.74 g/l total reducing sugars with 88.35% hydrolytic efficiency (HE) followed by sodium hydroxide (60.06 ± 0.33 g/l; 85.40% HE) and sodium sulfite pretreated SS (57.22 ± 0.52 g/l; 84.71% HE), respectively. The ultrastructure of SS (native and delignified) by fourier transform-infrared and near infrared spectroscopy, revealed notable structural differences. The fermentation of hydrolysates by C. mucoides into bioemulsifiers showing emulsification index (EI) of 54.33%, 48.66% and 32.66% from sodium sulfite, sodium hydroxide, and ammonium hydroxide pretreated SS, respectively.


Assuntos
Saccharum , Trichosporon , Hidróxido de Amônia , Fermentação , Hidrólise , Hidróxido de Sódio
3.
Bioresour Technol ; 297: 122413, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31761628

RESUMO

MgO/N-doped active carbon (Mg/N-C) derived from sugarcane bagasse was prepared for the removal of methyl orange (MO). Mg/N-C composites presented the better adsorption capacity than that of active carbon and N-doped active carbon, of which the maximum adsorption capacity of 2-Mg/N-C-b2 for the MO removal is 384.61 mg g-1. The effects of MgO dosage, N-doped content, pyrolysis temperature, pH value, inorganic ions and solution temperature on the adsorption performance of Mg/N-C composites in the MO removal were investigated in detail. The pseudo-second order model and Langmuir isotherm model fitted well with the adsorption kinetics and isotherms of Mg/N-C. The rate-determining step was the boundary diffusion and intra-particle diffusion. The adsorption process of 2-Mg/N-C-b2 was a spontaneous and physisorption process.


Assuntos
Saccharum , Poluentes Químicos da Água , Adsorção , Carbono , Celulose , Concentração de Íons de Hidrogênio , Cinética , Óxido de Magnésio
4.
Bioresour Technol ; 297: 122494, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31813817

RESUMO

The present work aims to determine a suitable yield-productivity balance in bioethanol production from hydrothermally pretreated sugarcane straw via pre-saccharification (PS) and simultaneous saccharification and fermentation (SSF). PS experiments were carried out evaluating effects of enzymatic dosage, biomass loading, and PS time. The performance of the whole process (PSSSF) was evaluated based on overall ethanol yield and productivity considering a simultaneous optimization (desirability function) of both variables. The multi-criteria optimization enabled to reach 5.7% w/w ethanol concentration yielding 290 L of ethanol per ton of pretreated sugarcane straw within 45 h of total processing time. Furthermore, a techno-economic analysis was performed under optimized conditions (14.5 FPU/gcellulose, 19.3% w/v biomass loading and 33 h PS time). This process was integrated into a first-generation plant. Although the economic evaluation exhibited a negative performance, a sensitivity analysis indicated that a decrease of 23.3% in operational expenditure would be enough to achieve feasibility.


Assuntos
Saccharum , Biomassa , Celulose , Etanol , Fermentação
5.
Bioresour Technol ; 297: 122364, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31732416

RESUMO

Sugarcane scum (SCS) is a waste from the non-centrifugal cane sugar making process. Due to its physicochemical characteristics, it has a high-energy potential to produce biomethane via anaerobic digestion (AD). However, (i) the total solids concentration in the SCS exceeds the limit for wet digestion and (ii) the SCS has a low pH. The aim of this research was to evaluate the utilization capacity of the SCS for methane production through a biochemical methane potential test and extent of disintegration, using dilution pretreatment. The highest methane yield, 0.227 N m3 CH4 kg-1 VS, was achieved at a 12.5% SCS dilution, with an organic matter removal greater than 70% and an extent of disintegration of 34.5%. This is evidence that the AD process is a feasible alternative for SCS treatment.


Assuntos
Biocombustíveis , Saccharum , Anaerobiose , Reatores Biológicos , Bengala , Países em Desenvolvimento , Metano , Açúcares
6.
Bioresour Technol ; 298: 122523, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31830657

RESUMO

Low H2 yield from biomass impedes the industrial application of biohydrogen production. To improve H2 yield, the effect of Ginkgo biloba leaf (GL) on H2 production was investigated in this study. In batch fermentation with sugarcane molasses (SM), the addition of GL improved H2 yield by 28.03%. SM medium was optimized with response surface methodology (RSM) to determine the best concentrations of GL, SM, and an inexpensive nitrogen source-corn steep liquor (CSL). A maximum yield of 1.58 mol-H2/mol-hexose from SM was obtained when GL, CSL and SM hexose were 2.31 g/L, 2.28 g/L and 10 g/L, respectively. As observed with metabolic flux analysis, GL enhanced H2 conversion from SM via altering the metabolic flux distribution of E. harbinense from ethanol pathway towards acetate pathway. This study demonstrated the promotion effect of GL on H2 production from SM, raising a novel method for enhanced biohydrogen production in large scales.


Assuntos
Melaço , Saccharum , Fermentação , Ginkgo biloba , Folhas de Planta
7.
Food Chem ; 303: 125405, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31466029

RESUMO

The study aimed at evaluating the influence of fermented sugarcane molasses ageing on lees and the distillation process used for the production of rums. Molasses were freshly fermented or 3-months lees aged. Batch (PS: Pot Still) or continuous (CS: Coffey Still) distillation was carried out resulting in four different rum distillates. Gas chromatography and 3D-fluorescence enabled to differentiate rum distillates chemical composition according to the distillation process, regardless of the ageing on lees of fermented molasses. Differences in fluorescent PARAFAC components and volatile acids, acetals and carbonyls contents revealed the predominance of the physicochemical processes driven at the liquid-vapor interface of fermented molasses, generated by the distillation systems. Notwithstanding the distilling conditions, the long chain fatty ester content was significantly higher in the 3-months lees aged condition. Multivariate analysis highlighted that CS rum distillates were chemically more homogeneous than those obtained by PS that preserved the lees effect.


Assuntos
Bebidas Alcoólicas/análise , Destilação/métodos , Manipulação de Alimentos/métodos , Melaço/análise , Saccharum/química , Cromatografia Gasosa , Fermentação , Fatores de Tempo
8.
Bioresour Technol ; 299: 122625, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31881437

RESUMO

The production of high-purity xylobiose from lignocellulose is an expensive and tedious process. In this work, the production of xylobiose from enzymatic hydrolysis of alkaline oxidation pretreated sugarcane bagasse was investigated. Furthermore, a simple process for the separation of xylobiose from enzymatic hydrolysate by activated carbon absorption, water washing, and ethanol-water desorption was developed. Under the optimized separation conditions, 96.77% xylobiose was adsorbed at 16% activated carbon loadings. Moreover, xylose and acetate could not be detected after washing by 3-fold volume of water. Xylobiose with 80.16% yield was eluted by 5-fold volume of 5% (v/v) ethanol-water. The reusability of activated carbon was evaluated by 5 cycles of adsorption-desorption process, suggesting that the activated carbon exhibited good reusability. The separated xylobiose sample with high-purity (97.29%) was confirmed by HPLC, ESI-MS, and NMR. Overall, this study provided a low-cost and robust technology for the production and separation of high-purity xylobiose from lignocellulose.


Assuntos
Saccharum , Celulose , Dissacarídeos , Hidrólise
9.
Bioresour Technol ; 299: 122635, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31882200

RESUMO

The sustainability of a biofuel is severely affected by the technological route of its production. Chemical pretreatment can be considered the traditional method of decomposition of the lignocellulose into its mono and oligomeric units, which can be further bioconverted to ethanol. The evaluation of the recent advances in chemical pretreatments of sugarcane bagasse, especially diluted acids, alkaline, organosolv and ionic liquids, identified the critical points for sustainability. In this context, chemicals recovery and reutilization or their substitution by green solvents, heat and electricity generation through bioenergy, reutilization of water from evaporators, vinasse concentration and the upgrading of lignin were discussed as strategic routes for developing sustainable chemical-based lignocellulose pretreatment. The advances in the technologies that allow greater fractionation of lignocellulosic biomass should be focused on the minimization of the use of natural resources, effluent generation and energy expenditure.


Assuntos
Saccharum , Biomassa , Biotecnologia , Lignina
10.
Chemosphere ; 238: 124512, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31430718

RESUMO

Lindane is an organochlorine pesticide that, due to its persistence in the environment, is still detected in different matrices. Bioremediation using actinobacteria consortia proved to be promising for the restoration of contaminated soils. Another alternative to remove xenobiotics is to use agricultural residues, which stimulates microbial activity, increasing its capacity to degrade organic pollutants. The present work studies the coupling of sugarcane bagasse biostimulation and bioaugmentation with the actinobacteria consortium composed of Streptomyces sp. A2, A5, A11 and M7 on lindane removal in different soil types. In this sense, factorial designs with three factors (proportion and size of sugarcane bagasse particles, and moisture content) were employed. A response optimizer identified the combination of factors levels that jointly allowed obtaining the maximum lindane removal in the evaluated conditions. In the optimal conditions, the effect of the bioremediation process on soil microbiota was studied by evaluating different parameters. The highest lindane removal percentages were detected in biostimulated microcosms bioaugmented with the microbial consortium, which were accompanied by a decrease in lindane half-life respect to the controls. Also, the bioaugmentation of biostimulated microcosms increased the microbial counts and enhanced soil enzymatic activities, corroborating the bioremediation process efficiency. The survival of the four actinobacteria at the end of the assay confirmed the ability of all Streptomyces strains to colonize amended soils. Bioremediation by simultaneous application of biostimulation with sugarcane bagasse and bioaugmentation with the actinobacteria consortium, in the optimized conditions, represents an efficient strategy to restore lindane contaminated soils.


Assuntos
Hexaclorocicloexano/isolamento & purificação , Hexaclorocicloexano/metabolismo , Poluentes do Solo/isolamento & purificação , Poluentes do Solo/metabolismo , Solo/química , Streptomyces/efeitos dos fármacos , Streptomyces/metabolismo , Biodegradação Ambiental/efeitos dos fármacos , Celulose/química , Celulose/farmacologia , Consórcios Microbianos/efeitos dos fármacos , Saccharum/química
11.
Carbohydr Polym ; 227: 115368, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31590842

RESUMO

This paper reveals the structural variations of cellulose nanocrystals (CNC) prepared from sugarcane bagasse (SCB) using different methods and the organic-inorganic hybrid nanomaterials were constructed with polyhedral oligomeric silsesquioxane (POSS). First, pure cellulose was extracted from SCB, and four CNCs were successfully obtained. The huge differences in structure and properties provide a choice for various applications. Subsequently, novel CNC/POSS hybrid nanomaterials were prepared from carboxylated CNC via carbodiimide-assisted coupling chemistry. The morphology and properties of hybrids were investigated in detail. The hybrids exhibit great differences in structure and properties due to the difference in CNC. The incorporation of POSS has improved the thermal performance of the CNC, and the mass ratio has a significant impact on molecular structure. This work provides useful information for the preparation of multi-type CNCs using agricultural and forestry by-products, and the novel CNC/POSS hybrid has opened up new ideas for the application of nanocellulose.


Assuntos
Celulose/química , Nanopartículas/química , Compostos de Organossilício/química , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Nanopartículas/ultraestrutura , Saccharum
12.
Rev Soc Bras Med Trop ; 53: e20190119, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31859942

RESUMO

INTRODUCTION: Oral transmission of acute Chagas disease is an emerging public health concern. This study aimed to detect insect fragments in experimentally contaminated food, by comparing triatomines with other insects. METHODS: Food samples were experimentally contaminated with insects, processed to recover their fragments by light filth, and analyzed by microscopy and Polymerase Chain Reaction (PCR). RESULTS: Morphological differences between coleopteran and triatomine insects were observed in microscopic images. PCR was efficient in amplifying Triatominae DNA in the experimentally contaminated food. CONCLUSIONS: This methodology could be utilized by food analysts to identify possible insect contamination in food samples.


Assuntos
Besouros/classificação , Parasitologia de Alimentos , Sucos de Frutas e Vegetais/parasitologia , Insetos Vetores/classificação , Saccharum/parasitologia , Triatominae/classificação , Animais , Doença de Chagas/transmissão , Humanos , Reação em Cadeia da Polimerase
13.
Bull Environ Contam Toxicol ; 103(6): 834-840, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31676938

RESUMO

Sugarcane is a potential species for use in heavy metal remediation. To analyze the effect of excess copper on sugarcane, the biomass, mineral nutrient content and activities of antioxidative enzymes were measured under copper stress. The results revealed that the biomass of roots and shoots significantly decreased with increasing copper concentration in solution. Most copper accumulated in the roots, and the translocation factor of copper decreased with an increase in copper stress. The MDA content in sugarcane roots notably increased under copper stress. The POD activity in sugarcane roots increased, and CAT activity decreased under copper stress. The Zn, Fe and Mn contents in shoots increased significantly under 200 µmol L-1 Cu2+ treatments. The Zn and Mg contents in roots notably decreased under copper stress, while the Zn and Mg translocation factors increased. These results indicated that the increase in POD activity and the modification of mineral nutrient uptake and transfer might play an important role in reducing the detrimental effects of excess copper.


Assuntos
Antioxidantes/metabolismo , Cobre/toxicidade , Saccharum/efeitos dos fármacos , Plântula/efeitos dos fármacos , Poluentes do Solo/toxicidade , Biomassa , Cobre/análise , Minerais/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Saccharum/enzimologia , Saccharum/crescimento & desenvolvimento , Plântula/enzimologia , Plântula/crescimento & desenvolvimento , Poluentes do Solo/análise
14.
Environ Monit Assess ; 191(11): 702, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31667629

RESUMO

Human activities altering ecosystems structure and function worldwide strongly affect rivers. We studied aquatic macroinvertebrate communities (taxonomic and functional diversity) from rivers immersed in a forest matrix and rivers flowing through croplands. As rivers of the region experience a monsoon climate, high and low water seasons were also considered and their effect tested. We expected lower taxonomic and functional diversity in rivers flowing through croplands, and also during high water periods. We selected five Piedmont forest and three sugarcane crop rivers in Austral Yungas piedmont forests (Argentina), where marginal vegetation, land use, and hydromorphological variables were studied. Samplings were performed in these 8 sites during high and low water seasons of three consecutive years, totaling 32 samples. We analyzed differences between categories through nonparametric analyses of variance and SIMPER analysis. We studied taxonomic diversity through effective number of species and functional diversity using feeding groups with a factorial ANOVA. We calculated different biotic indices to test differences in water quality. We identified 11,034 specimens from 58 families of aquatic macroinvertebrates. Piedmont forest rivers showed higher richness (order 0) than crop rivers, but diversities of orders 1 and 2 showed the opposite pattern. Functional feeding groups were different between both situations. Season greatly influenced the assemblages, with reduced diversity and abundances during high water periods. Biotic indices showed good water quality, except during high water season for crop sites. A complex response of aquatic communities was found, but generally crop sites were more markedly affected during high water season.


Assuntos
Biodiversidade , Monitoramento Ambiental , Invertebrados/classificação , Animais , Argentina , Ecossistema , Florestas , Atividades Humanas , Humanos , Invertebrados/fisiologia , Rios/química , Saccharum , Estações do Ano , Qualidade da Água
15.
J Agric Food Chem ; 67(49): 13665-13672, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31686508

RESUMO

Fructooligosaccharides (FOSs) are excellent food ingredients or feed additives by stimulating probiotics. In this paper, a CREA gene encoding a glucose repressor in the ß-fructofuranosidase producer Aureobasidium melanogenum 33 with high-level FOS biosynthesis was disrupted, and glucose repression in disruptant D28 was relieved. The disruptant D28 produced up to 2100 U/mL of ß-fructofuranosidase activity, whereas the enzyme activities produced by parent strain 33 and complemented strain C11 were below 600 U/mL. The whole cells of the disruptant D28 was used to convert cane molasses into FOSs, and 0.58 g of FOSs/g of molasses sugar was synthesized from 350 g/L cane molasses sugar within 4 h. Results demonstrated that the industrial waste cane molasses can be efficiently converted into FOSs by the glucose derepression mutant D28 with high ß-fructofuranosidase activity. This low-cost and environmentally friendly bioprocess has great potential applications in bioengineering and biotechnology for FOS production.


Assuntos
Ascomicetos/metabolismo , Proteínas Fúngicas/metabolismo , Melaço/análise , Oligossacarídeos/biossíntese , Saccharum/microbiologia , beta-Frutofuranosidase/genética , Ascomicetos/enzimologia , Ascomicetos/genética , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Glucose/metabolismo , Mutação , Saccharum/metabolismo , beta-Frutofuranosidase/metabolismo
16.
World J Microbiol Biotechnol ; 35(11): 171, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31673786

RESUMO

Fungal endo-ß-1,4-xylanases (endo-xylanases) can hydrolyze xylan into xylooligosaccharides (XOS), and have potential biotechnological applications for the exploitation of natural renewable polysaccharides. In the current study, we aimed to screen and characterize an efficient fungal endo-xylanase from 100 natural humus-rich soil samples collected in Guizhou Province, China, using extracted sugarcane bagasse xylan (SBX) as the sole carbon source. Initially, 182 fungal isolates producing xylanases were selected, among which Trichoderma sp. strain TP3-36 was identified as showing the highest xylanase activity of 295 U/mL with xylobiose (X2) as the main product when beechwood xylan was used as substrate. Subsequently, a glycoside hydrolase family 11 endo-xylanase, TXyn11A, was purified from strain TP3-36, and its optimal pH and temperature for activity against beechwood xylan were identified to be 5.0 and 55 °C, respectively. TXyn11A was stable across a broad pH range (3.0-10.0), and exhibited strict substrate specificity, including xylan from beechwood, wheat, rye, and sugarcane bagasse, with Km and Vmax values of 5 mg/mL and 1250 µmol/mg min, respectively, toward beechwood xylan. Intriguingly, the main product obtained from hydrolysis of beechwood xylan by TXyn11A was xylobiose, whereas SBX hydrolysis resulted in both X2 and xylotriose. Overall, these characteristics of the endo-xylanase TXyn11A indicate several potential industrial applications.


Assuntos
Dissacarídeos/metabolismo , Endo-1,4-beta-Xilanases/química , Endo-1,4-beta-Xilanases/isolamento & purificação , Trichoderma/enzimologia , Xilanos/metabolismo , Celulose , China , Estabilidade Enzimática , Proteínas Fúngicas/isolamento & purificação , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Saccharum/metabolismo , Microbiologia do Solo , Especificidade por Substrato , Temperatura Ambiente , Trichoderma/genética , Trichoderma/isolamento & purificação
17.
An Acad Bras Cienc ; 91(4): e20180990, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31778453

RESUMO

The growing need for the use of clean energy has led society to seek alternatives to fossil fuels in order to less pollute the environment. Sugarcane has been known to produce enough biomass and to have associative microorganisms, such as plant growth-promoting bacteria (PGPB), which have the potential to improve the yield of crops. The objective of this study is to evaluate the efficiency and the isotopic dilution of 15N of microbial inoculants containing endophytic diazotrophic bacteria, individually inoculated and in mixture, on productivity, technological quality and biological nitrogen fixation (BNF) of sugarcane variety RB92579. The experiment was conducted for three consecutive years, comprising different crop cycles, in a completely randomized block design with four replications. The evaluations were at 11 months after planting for plant-cane, and at 12 months after cutting for ratoon cane and second ratoon cane. The contribution of BNF by 15N natural abundance technique to inoculated treatments ranged from 18% to 57.31%. This study showed that no strain promoted the improvement on yield and biological nitrogen fixation during the three cycles of sugarcane (plant-cane, ratoon cane and second ratoon cane). However, industrial characteristics of sugar cane can be affectd by PGPB inoculation.


Assuntos
Bactérias/metabolismo , Biomassa , Produtos Agrícolas , Nitrogênio/metabolismo , Saccharum/microbiologia , Endófitos , Fixação de Nitrogênio , Saccharum/crescimento & desenvolvimento
18.
Environ Sci Technol ; 53(22): 13495-13505, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31644877

RESUMO

Biomass, a renewable energy source, via available thermo-chemical processes has both engineering and environmental advantages. However, the understanding of the kinetics, evolved gases, and mechanisms for biomass pyrolysis is limited. We first propose a novel temperature response mechanism for the pyrolysis of sugar cane residue using thermogravimetric analysis-Fourier transform infrared spectrometry-mass spectrometry (TG-FTIR-MS) combined with Gaussian model and two-dimensional correlation spectroscopy (2D COS). The existence and contribution of distinct peaks in TG-FTIR spectra were innovatively distinguished and quantified, and the temperature-dependent dynamics of gas amounts were determined using Gaussian deconvolution. The 2D-TG-FTIR/MS-COS results revealed for the first time that the primary sequential temperature responses of gases occurred in the order: H2O/CH4 > phenols/alkanes/aromatics/alcohols > carboxylic acids/ketones > CO2/ethers > aldehyde groups/acetaldehyde. Subtle sequential changes even occurred within the same gases during pyrolysis. The quantity dynamics and sequential responses of gases were fitted to the combined effects of the order-based, diffusion, and chemical reaction mechanisms for the component degradation. The combination of TG-FTIR-MS, Gaussian model, and 2D COS is a promising approach for the online monitoring and real-time management of biomass pyrolysis, providing favorable strategies for pyrolysis optimization, byproduct recovery, energy generation, and gas emission control in engineering and environmental applications.


Assuntos
Gases , Saccharum , Biomassa , Cinética , Pirólise , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria
19.
World J Microbiol Biotechnol ; 35(10): 158, 2019 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-31595344

RESUMO

Presence of bacterial contaminants at levels > 107 colony forming units per milliliter (CFU/mL) during ethanol production processes reduces the alcoholic fermentation yield by 30%. Antibiotics are currently used to control contamination, but their residues may be detected in yeast extract, restricting this by-product trade to several countries. Thus, the objective of this study was to assess antimicrobial activity of the natural compounds hops extract, 4-hydroxybenzoic acid, nisin Z, and lysozyme against Lactobacillus fermentum, Leuconostoc mesenteroides, and Saccharomyces cerevisiae, aiming development of a formula. Minimum Inhibitory Concentration of each antimicrobial was determined for bacteria and subsequently, nisin (30 mg/L) and hops extract (5 mg/L) were tested together, showing inhibitory effects combining doses of each antimicrobial that were equivalent to an eightfold reduction of their original Minimum Inhibitory Concentrations (3.75 and 0.625 mg/L, respectively), resulting in a FICIndex of 0.25. Thereon, a formula containing both compounds was developed and tested in fermentation assays, promoting reductions on bacterial population and no severe interferences in yeast viability or population even at extreme doses. Therefore, these compounds have great potential to successfully substitute conventional antibiotics in the ethanol industry.


Assuntos
Anti-Infecciosos/farmacologia , Etanol/metabolismo , Fermentação/fisiologia , Humulus/química , Extratos Vegetais/farmacologia , Antibacterianos/farmacologia , Microbiologia Industrial , Lactobacillales/efeitos dos fármacos , Lactobacillus fermentum/efeitos dos fármacos , Leuconostoc mesenteroides/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Muramidase/farmacologia , Nisina/análogos & derivados , Nisina/farmacologia , Parabenos/farmacologia , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharum/química
20.
Plant Dis ; 103(12): 3251-3258, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31596691

RESUMO

Ratoon stunting disease (RSD), one of the most important diseases of sugarcane, is caused by the bacterium Leifsonia xyli subsp. xyli (Lxx). Lxx infects sugarcane worldwide and RSD results in high yield losses and varietal degeneration. It is highly challenging to diagnose RSD based on visual symptomatology because this disease does not exhibit distinct external and internal symptoms. In this study, a novel Lxx-specific primer pair Lxx-F1/Lxx-R1 was designed to detect this pathogen using a conventional PCR assay. These primers were then compared with four published Lxx-specific primers and one universal Leifsonia generic primer pair LayF/LayR. Sugarcane leaf samples were collected from Saccharum spp. hybrids in commercial fields (315 samples) and from germplasm clones of five Saccharum species and Erianthus arundinaceus (216 samples). These samples were used for comparative field diagnosis with six conventional PCR assays. Sensitivity tests suggested that the PCR assay with primers Lxx-F1/Lxx-R1 had the same detection limit (1 pg of Lxx genomic DNA) as the primer pairs Cxx1/Cxx2 and CxxITSf#5/CxxITSr#5 and had 10-fold higher sensitivity than the primer pairs Pat1-F2/Pat1-R2, LayF/LayR, and C2F/C2R. Comparison of PCR assays revealed that natural Lxx-infection incidence (6.1%) in field sample evaluation identified by Lxx-F1/Lxx-R1 primers was higher than incidences (0.7 to 3.0%) determined by other primer pairs. Moreover, no nonspecific DNA amplification occurred within these field samples with Lxx-F1/Lxx-R1 primers, unlike with the primer pairs Cxx1/Cxx2 and LayF/LayR. Diverse Leifsonia strains were identified by PCR detection with LayF/LayR primers in the field samples, whereas whether these Leifsonia strains were pathogenic to sugarcane requires further research. Our investigations revealed that the PCR assay with the newly designed primers Lxx-F1/Lxx-R1 could be widely used for RSD diagnosis and Lxx-pathogen detection with satisfactory sensitivity and specificity.


Assuntos
Actinomycetales , Reação em Cadeia da Polimerase , Saccharum , Actinomycetales/genética , Primers do DNA/genética , Saccharum/microbiologia , Sensibilidade e Especificidade
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