Yeast proteins originated from the production of brazilian bioethanol quantification and content

The purpose of this work was to determine the levels of protein and the amino acid distribution in the cell mass of yeast strains (Saccharomyces sensu stricto) originated from Brazilian bioethanol industries. The protein was analyzed with the Kjeldahl method and the amino acids, by using high-performance liquid chromatography (HPLC). The percentages of the protein found ranged from 39 to 49%. The results show that in spite of some variation in numbers between the different yeast strains, all of them presented an amino acid profile similar to the one in the literature for S. cerevisae. The amino acids that have occurred in the largest amounts were: aspartic, glutamic acids and lysine, and those in the lowest amounts were: cysteine and methionine. Although the characteristics of the feedstock used and the process conditions are determinant of the protein values obtained in dry mass, this work elucidates that the intrinsic properties of the yeast strain influence these values.

Coagulation-flocculation of anaerobically treated sugarcane stillage

Anaerobic digestion applied to stillage usually results in treatment performances. However, effluents from anaerobic reactors still present a residual polluting load due to the presence of organic recalcitrant compounds. Additional treatment methods, such as coagulation-flocculation, may be utilized to improve the final effluent quality. In this study, we assessed the processes of coagulation and flocculation for sugarcane stillage samples previously submitted to anaerobic digestion, aiming to obtain optimal conditions for the physicochemical treatment. Natural corn starch and ferric chloride were tested as coagulants. While starch was considered as not suitable for the treatment for the tested conditions, ferric chloride assays presented satisfactory results. The investigated parameters included coagulant solution dose, rapid mixing gradient and time, flocculation gradient and time, and sedimentation time. Their adjusted values at which better performances obtained were, respectively, 1.6 g L-1, 325 rpm, 10 s, 65 rpm, 20 and 20 min. The best color, turbidity, and chemical oxygen demand removal efficiencies were 95, 97, and 65%, respectively. Stillage pH variation to alkaline conditions did not result in improved removal efficiencies. Although relatively high removal efficiencies of constituents were obtained, the final effluent characteristics did not fit regulations of water reuse in the agriculture through fertigation. However, stillage can definitely become more easily managed if better final effluent quality control parameters are achieved, enabling for example effluents discharge in water bodies. © 2013 Copyright Balaban Desalination Publications.

Effect of plasma and/or yeast extract on performance and intestinal morphology of piglets from 7 to 63 days of age

The objective of this study was to evaluate the effect of diets supplemented with plasma and/or yeast extract on performance (daily weight gain [DWG], daily feed intake [DFI] and feed conversion [FC]) and intestinal morphology of piglets from 7 to 63 days of age. A total of 288 piglets aged 7 days and weighing 2.57±0.05 kg were studied. A randomized block design consisting of four experimental diets, six repetitions and 12 piglets per experimental unit was adopted. The pre-starter I (7 to 21 days), pre-starter II (22 to 35 days) and starter I (36 to 49 days) diets were supplemented as follows: control diet (CD): no plasma or yeast extract; plasma (PL) diet: addition of 6%, 4% and 2% plasma; yeast extract (YE) diet: addition of 6%, 4% and 2% yeast extract; plasma + yeast extract (PL+YE) diet: addition of 3%, 2% and 1% plasma and yeast extract each. From 50 to 63 days of age all piglets received the same diet. No difference in performance was observed from 7 to 21 days and from 7 to 28 days of age, whereas DWG was higher from 7 to 35 days in piglets receiving the PL+YE diet (268, 278, 271 and 288 g/day for CD, PL, YE and PL+YE, respectively). From 7 to 49 days and from 7 to 63 days, DWG (330 and 519 g/day, respectively) and DFI (307 and 647 g/day) were higher in animals receiving the PL-YE diet when compared with those consuming CD (DWG: 295 and 486 g/day; DFI: 266 and 594 g/day). No significant differences in intestinal morphology were observed between piglets receiving the different diets. The combination of plasma and yeast extract elevates DWG, but does not affect the intestinal morphology of piglets from 7 to 63 days of age. © 2013 Sociedade Brasileira de Zootecnia.

Development and Biotechnological Application of a Novel Endoxylanase Family GH10 Identified from Sugarcane Soil Metagenome

Metagenomics has been widely employed for discovery of new enzymes and pathways to conversion of lignocellulosic biomass to fuels and chemicals. In this context, the present study reports the isolation, recombinant expression, biochemical and structural characterization of a novel endoxylanase family GH10 (SCXyl) identified from sugarcane soil metagenome. The recombinant SCXyl was highly active against xylan from beechwood and showed optimal enzyme activity at pH 6,0 and 45°C. The crystal structure was solved at 2.75 Å resolution, revealing the classical (β/α)8-barrel fold with a conserved active-site pocket and an inherent flexibility of the Trp281-Arg291 loop that can adopt distinct conformational states depending on substrate binding. The capillary electrophoresis analysis of degradation products evidenced that the enzyme displays unusual capacity to degrade small xylooligosaccharides, such as xylotriose, which is consistent to the hydrophobic contacts at the +1 subsite and low-binding energies of subsites that are distant from the site of hydrolysis. The main reaction products from xylan polymers and phosphoric acid-pretreated sugarcane bagasse (PASB) were xylooligosaccharides, but, after a longer incubation time, xylobiose and xylose were also formed. Moreover, the use of SCXyl as pre-treatment step of PASB, prior to the addition of commercial cellulolytic cocktail, significantly enhanced the saccharification process. All these characteristics demonstrate the advantageous application of this enzyme in several biotechnological processes in food and feed industry and also in the enzymatic pretreatment of biomass for feedstock and ethanol production. © 2013 Alvarez et al.

Quality of performance of the operation of sugarcane mechanized planting in day and night shifts

The sugarcane mechanized planting is becoming increasingly widespread in Brazil due to a higher operability and better working conditions offered to workers compared to other types of planting. Studies related to this topic are insufficient or scarce in Brazil. In this context, the aim of this study was to evaluate the operation quality of sugarcane mechanized planting in two operation shifts, by means of statistical process control. The mechanized planting was held on March 2012 and statistical design was completely randomized with two treatments, totaling 40 replications for the day shift and 40 replications for the night shift. The variables evaluated were: speed, engine rotation, engine oil pressure, water temperature of the engine, effective field capacity and the time consumption hourly and effective fuel. The use of statistical control charts showed that random intrinsic do not cause this process. The tractor alignment error showed outliers in the day and night shifts operations, indicating a possible delay in receiving the signal. The water temperature of the engine and the effective fuel consumption showed lower variability in nighttime operation with average values of 81°C and 22.66 L ha-1, respectively. The hourly fuel consumption had greater variability and consequently lower quality during the night of the operation, with an average consumption of 25.46 L h-1 while the day shift showed 26.86 L h-1.

Yeast diversity isolated from grape musts during spontaneous fermentation from a brazilian winery

Saccharomyces and non-Saccharomyces yeast species from a winery located in Brazil were identified by ribosomal gene-sequencing analysis. A total of 130 yeast strains were isolated from grape surfaces and musts during alcoholic fermentation from Isabel, Bordeaux, and Cabernet Sauvignon varieties. Samples were submitted to PCR-RFLP analysis and genomic sequencing. Thirteen species were identified: Candida quercitrusa, Candida stellata, Cryptococcus flavescens, Cryptococcus laurentii, Hanseniaspora uvarum, Issatchenkia occidentalis, Issatchenkia orientalis, Issatchenkia terricola, Pichia kluyveri, Pichia guilliermondii, Pichia sp., Saccharomyces cerevisiae, and Sporidiobolus pararoseus. A sequential substitution of species during the different stages of fermentation, with a dominance of non-Saccharomyces yeasts at the beginning, and a successive replacement of species by S. cerevisiae strains at the final steps were observed. This is the first report about the yeast distribution present throughout the alcoholic fermentation in a Brazilian winery, providing supportive information for future studies on their contribution to wine quality. © 2013 Springer Science+Business Media New York.

Soil and crop residue CO2-C emission under tillage systems in sugarcane-producing areas of southern Brazil

Appropriate management of agricultural crop residues could result in increases on soil organic carbon (SOC) and help to mitigate gas effect. To distinguish the contributions of SOC and sugarcane (Saccharum spp.) residues to the short-term CO2-C loss, we studied the infl uence of several tillage systems: heavy offset disk harrow (HO), chisel plow (CP), rotary tiller (RT), and sugarcane mill tiller (SM) in 2008, and CP, RT, SM, moldboard (MP), and subsoiler (SUB) in 2009, with and without sugarcane residues relative to no-till (NT) in the sugarcane producing region of Brazil. Soil CO2-C emissions were measured daily for two weeks after tillage using portable soil respiration systems. Daily CO2-C emissions declined after tillage regardless of tillage system. In 2008, total CO2-C from SOC and/or residue decomposition was greater for RT and lowest for CP. In 2009, emission was greatest for MP and CP with residues, and smallest for NT. SOC and residue contributed 47% and 41%, respectively, to total CO2-C emissions. Regarding the estimated emissions from sugarcane residue and SOC decomposition within the measurement period, CO2-C factor was similar to sugarcane residue and soil organic carbon decomposition, depending on the tillage system applied. Our approach may define new emission factors that are associated to tillage operations on bare or sugarcane-residue-covered soils to estimate the total carbon loss.

Estrogenic and mutagenic activities of crotalaria pallida measured by recombinant yeast assay and ames test

Background: Crotalaria pallida Ailton is a plant belonging to the Fabaceae family, popularly known as rattle or rattlesnake and used in traditional medicine to treat swelling of the joints and as a vermifuge. Previous pharmacological studies have also reported anti-inflammatory, antimicrobial and antifungal activities. Nevertheless, scientific information regarding this species is scarce, and there are no reports related to its possible estrogenic and mutagenic effects. Thus, the purpose of the present study was to investigate the estrogenic potential of C. pallida leaves by means of the Recombinant Yeast Assay (RYA), seeking an alternative for estrogen replacement therapy during menopause; and to reflect on the safe use of natural products to assess the mutagenic activity of the crude extract from C. pallida leaves, the dichloromethane fraction and stigmasterol by means of the Ames test.Methods: The recombinant yeast assay with the strain BY4741 of Saccharomyces cerevisiae, was performed with the ethanolic extract, dichloromethane fraction and stigmasterol isolated from the leaves of C. pallida. Mutagenic activity was evaluated by the Salmonella/microsome assay (Ames test), using the Salmonella typhimurium tester strains TA100, TA98, TA97 and TA102, with (+S9) and without (-S9) metabolization, by the preincubation method.Results: All samples showed estrogenic activity, mainly stigmasterol. The ethanolic extract from C. pallida leaves showed mutagenic activity in the TA98 strain (-S9), whereas dichloromethane fraction and stigmasterol were found devoid of activity.Conclusion: Considering the excellent estrogenic activity performed by stigmasterol in the RYA associated with the absence of mutagenic activity when evaluated by the Ames test, stigmasterol becomes a strong candidate to be used in hormone replacement therapy during menopause. © 2013 Boldrin et al.; licensee BioMed Central Ltd.

Greenhouse gas mitigation potential from green harvested sugarcane scenarios in São Paulo State, Brazil

Brazil is a major sugarcane producer and São Paulo State cultivates 5.5 million hectares, close to 50% of Brazil's sugarcane area. The rapid increase in production has brought into question the sustainability of biofuels, especially considering the greenhouse gas (GHG) emissions associated to the agricultural sector. Despite the significant progress towards the green harvest practices, 1.67 million hectares were still burned in São Paulo State during the 2011 harvest season. Here an emissions inventory for the life cycle of sugarcane agricultural production is estimated using IPCC methodologies, according to the agriculture survey data and remote sensing database. Our hypothesis is that 1.67 million hectares shall be converted from burned to green harvest scenarios up to years 2021 (rate 1), 2014 (rate 2) or 2029 (rate 3). Those conversions would represent a significant GHG mitigation, ranging from 50.5 to 70.9 megatons of carbon dioxide equivalent (Mt CO2eq) up to 2050, depending on the conversion rate and the green harvest systems adopted: conventional (scenario S1) or conservationist management (scenario S2). We show that a green harvest scenario where crop rotation and reduced soil tillage are practiced has a higher mitigation potential (70.9 Mt CO2eq), which is already practiced in some of the sugarcane areas. Here we support the decision to not just stop burning prior to harvest, but also to consider other better practices in sugarcane areas to have a more sustainable sugarcane based ethanol production in the most dense cultivated sugarcane region in Brazil. © 2013 Elsevier Ltd. All rights reserved.

Susceptibility profile of a Brazilian yeast stock collection of Candida species isolated from subjects with Candida-associated denture stomatitis with or without diabetes

Objective: This study investigated the susceptibility of 198 clinical isolates of Candida species against caspofungin, amphotericin B, itraconazole, and fluconazole. Study Design: Suspensions of the microorganisms were spread on Roswell Park Memorial Institute (RPMI) agar plates. Etest strips were placed on the plates, and the minimal inhibitory concentration (MIC) was read after incubation (48 h at 37°C). Data were analyzed by a factorial analysis of variance and a 2 × 2 post hoc test (α = .05). Results: C glabrata showed the highest MIC values (P < .001) against caspofungin, itraconazole, and fluconazole. For amphotericin B, the MIC values of C tropicalis and C glabrata (P = .0521) were higher than those of C albicans (P < .001). Itraconazole was the least effective antifungal; 93.3% of the C glabrata isolates, 3.3% of the C albicans, and 1.3% of the C tropicalis were resistant. All microorganisms were susceptible to caspofungin and amphotericin B. Conclusions: Caspofungin and amphotericin B should be recommended as an effective alternative for the management of oral Candida infections when treatment with topical or other systemic drugs has definitely failed. © 2013 Elsevier Inc. All rights reserved.

Anaerobic digestion of stillage to produce bioenergy in the sugarcane-to-ethanol industry

Stillage is the main wastewater from ethanol production, containing a high chemical oxygen demand in addition to acidic and corrosive characteristics. Though stillage may be used as a soil fertilizer, its land application may be considered problematic due its high polluting potential. Anaerobic digestion represents an effective alternative treatment to reduce the pollution load of stillage. In addition, the methane gas produced within the process may be converted to energy, which can be directly applied to the treatment plant. The objective of this paper was to investigate the energetic potential of anaerobic digestion applied to stillage in the sugarcane ethanol industry. An overall analysis of the results indicates energy recovery capacity (ERC) values for methane ranging from 3.5% to 10%, respectively, for sugarcane juice and molasses. The processes employed to obtain the fermentable broth, as well as the distillation step, represent the main limiting factors to the energetic potential feasibility. Considering financial aspects the annual savings could reach up to US$ 30 million due to anaerobic digestion of stillage in relatively large-scale distilleries (365,000 m3 of ethanol per year). The best scenarios were verified for the association between anaerobic digestion of stillage and combustion of bagasse. In this case, the fossil fuels consumption in distilleries could be fully ceased, such the ERC of methane could reach values ranging from 140% to 890%. © 2013 Taylor & Francis.

Evaluation of Estrogenic Potential of Flavonoids Using a Recombinant Yeast Strain and MCF7/BUS Cell Proliferation Assay

Phytoestrogens are of interest because of their reported beneficial effects on many human maladies including cancer, neurodegeneration, cardiovascular disease and diabetes. Furthermore, there is a search for compounds with estrogenic activity that can replace estrogen in hormone replacement therapy during menopause, without the undesirable effects of estrogen, such as the elevation of breast cancer occurrence. Thus, the principal objective of this study was to assess the estrogenic activity of flavonoids with different hydroxylation patterns: quercetin, kaempferol, luteolin, fisetin, chrysin, galangin, flavone, 3-hydroxyflavone, 5-hydroxyflavone and 7-hydroxyflavone via two different in vitro assays, the recombinant yeast assay (RYA) and the MCF-7 proliferation assay (E-screen), since the most potent phytoestrogens are members of the flavonoid family. In these assays, kaempferol was the only compound that showed ERα-dependent transcriptional activation activity by RYA, showing 6.74±1.7 nM EEQ, besides acting as a full agonist for the stimulation of proliferation of MCF-7/BUS cells. The other compounds did not show detectable levels of interaction with ER under the conditions used in the RYA. However, in the E-screen assay, compounds such as galangin, luteolin and fisetin also stimulated the proliferation of MCF-7/BUS cells, acting as partial agonists. In the evaluation of antiestrogenicity, the compounds quercetin, chrysin and 3-hydroxyflavone significantly inhibited the cell proliferation induced by 17-β-estradiol in the E-screen assay, indicating that these compounds may act as estrogen receptor antagonists. Overall, it became clear in the assay results that the estrogenic activity of flavonoids was affected by small structural differences such as the number of hydroxyl groups, especially those on the B ring of the flavonoid. © 2013 Resende et al.

Comparative study of the life cycle assessment of particleboards made of residues from sugarcane bagasse (Saccharum spp.) and pine wood shavings (Pinus elliottii)

This paper presents a research on the environmental impacts of particleboards produced from wastes, based on a comparative Life Cycle Assessment study. The particleboards were manufactured in laboratorial scale from the following residues: sugarcane bagasse (Saccharum spp.) and pine wood shavings (Pinus elliottii). The study was developed following the methodological guidelines of ISO 14040. The functional unit adopted was the m2 of the particleboards produced and the impacts were evaluated by the Environmental Development of Industrial Products method. The results indicated that pine particleboard present the highest environmental impact potential. Our findings suggested that the factors that mostly aggravated the environmental impacts were: the distance between the raw materials and the production site, and formaldehyde emissions (FE). The first is related to the combustion of fossil fuel during the acquisition of raw material, which achieved the values of 2185.94 g/m2 for consumption of non-renewable resources for pine particleboard and 893.53 g/m2 for bagasse particleboard. The second is related to the use of urea-formaldehyde resin, responsible for the FE into the air during production. The FE is accountable for the contamination of approximately 7,800,000.00 m3 of air per m2 of particleboard produced, and was the factor with the greatest impact in human toxicity potential. © 2013 Elsevier Ltd. All rights reserved.

Storage of sugarcane stalks (Saccharum officinarum cv. SP 79-1011) in low oxygen atmospheres and the effects on enzymatic browning

Although sugarcane consumption is very popular worldwide there are few studies regarding the postharvest storage of stalks that focus on controlling enzymatic browning. The objective of this study was to evaluate the quality of sugarcane stalks stored at 10±1°C in controlled atmosphere with various oxygen (O2) levels (1kPa, 5kPa, 10kPa, 15kPa, and 21kPa) and to verify the effect of this storage on the activities of polyphenoloxidase (PPO) and peroxidase (POD). At 1kPa and 5kPa O2, the stalks' respiratory rate, POD activity, and reducing sugar content were significantly less (P<0.05) than at higher O2 concentrations. In contrast, low O2 levels did not affect PPO activity or influence cane coloration. These results can be used to guide the choice of plastic films, making it possible to store sugarcane stalks in a controlled atmosphere. © 2013 Elsevier B.V.

Produção de etanol a partir de mosto hidrolisado hemicelulósico de ponta e palha de cana-de-açúcar

Pós-graduação em Microbiologia Agropecuária - FCAV