Over the last decades researchers have focused to enhance the electrocatalytic activity of the bi... more Over the last decades researchers have focused to enhance the electrocatalytic activity of the biosystems, increasing the energy generation and electronic conductivity into the biofilms. The use of enzymes immobilized onto the surface of electrodes as the main catalyst in biological fuel cells has been extensively reported. A biofuel cell provides a means to obtain clean, renewable energy and have great potential to be used as alternative energy source for low power devices. There still a lot of important issues in the development of these device, one of them, is to obtain the maximum energy from the fuel. In order to enhance the power density of enzymatic biofuel cell (EBFC) it is necessary to increase the degree of oxidation of the fuel, so that all the electrons from the fuel can be harvested. One approach is the immobilization of a group of enzymes to perform a cascade in order to maximize the fuel oxidation. Recently, we have concentrated our goal to the develop hybrid biofilms employing MWCNT in order to immobilize efficiently the enzymes. In this context we added organic catalyst (TEMPO (2,2,6,6- tetramethylpiperidin-1-yl) oxyl) or metallic nanoparticles (MWCNT/Pt, MWCNT/PtSn and MWCNT/Au) to the biofilms to create a hybrid catalytic system able to catalyze the complete electrooxidation of ethanol (ET) and ethylene glycol (EG) into CO2. In the case of ethanol extraction of 12 electrons per molecule at a single hybrid anode has been obtained with success. This simple methodology can replace the use of enzymatic cascade (7-8 enzymes) and may improve the application in biofuel cells. The electrochemical response of the enzyme system (MWCNT-COOH/LPEI/OxOx) at increasing concentrations of ethanol confirms the excellent activity of these hybrid bioanodes. Product analysis by HPLC techniques allowed us to correlate the increase in current with the formation of CO2or other more oxidable compounds as main product. In the case of EG the metallic catalyst was shifting the onset oxidation potential to lower potentials (200 mV) compared with TEMPO. The maximum power densities reached values around 351 µW cm-2 in the case of MWCNT/PtSn-OxOx for EG and 315 µW cm-2 for MWCNT-COOH/Pyrene-TEMPO/OxDc bioanode. Fig 1 show the products formed for EG. The modification of nanomaterials to obtain a large energy output form an enzymatic system will be highlighted. Therefore, the system open a new alternative of high performance hybrid-EBFC-based enabling the development of efficient EBFC based on alcohols. Acknowledge: FAPESP (grants # 2017/20431-7 and 2014/50945-4 ), CNPq (grant (465571/2014-0) and CAPES 001. Army Research Office MURI (W911NF-14-1-0263). Figure 1
Advances of Basic Science for Second Generation Bioethanol from Sugarcane, 2017
This chapter introduces the role of enzymes in the biomass degradation, namely sugarcane bagasse ... more This chapter introduces the role of enzymes in the biomass degradation, namely sugarcane bagasse and straw, leading to the formation of fermentable sugars and second-generation ethanol. The chapter begins with a retrospective of the structuring of the ethanol production chain and then presents current aspects where the deficit of production and its consequences in business can be seen. Subsequently, we list the role of enzymes involved in the biomass hydrolysis, the commercial cocktails, and the proposal of our laboratory in this context. On the other hand, the efficiency of enzymes on the biomass is increased when the bagasse and straw are pretreated. Thus, some technologies that may facilitate the enzymatic hydrolysis and the formation of fermentable sugars are described. Lastly, recent analytical methods that enable a better analysis of the composition and viewing of fiber in the sugarcane biomass are presented.
Plant materials represent a strategic energy source because they can give rise to sustainable bio... more Plant materials represent a strategic energy source because they can give rise to sustainable biofuels through the fermentation of their carbohydrates. A clear example of a plant-derived biofuel resource is the sugar cane bagasse exhibiting 60-80% of fermentable sugars in its composition. However, the current methods of plant bioconversion employ severe and harmful chemical/physical pretreatments raising biofuel cost production and environmental degradation. Replacing these methods with co-cultivated enzymatic cocktails is an alternative. Here we propose a pretreatment for sugarcane bagasse using a multi-enzymatic cocktail from the co-cultivation of four Aspergillus nidulans recombinant strains. The co-cultivation resulted in the simultaneous production of GH51 arabinofuranosidase (AbfA), GH11 endo-1,4-xylanase (XlnA), GH43 endo-1,5-arabinanase (AbnA) and GH12 xyloglucan specific endo-β-1,4-glucanase (XegA). This core set of recombinant enzymes was more efficient than the alternativ...
Amylases are enzymes with important biotechnological applications that are produced by several mi... more Amylases are enzymes with important biotechnological applications that are produced by several microorganisms in the form of filamentous fungi. Penicillium citrinum was recently isolated from the decomposed materials of Atlantic Forest, Bra-zil. It was identified by internal transcribed spacer (ITS) and beta-tubulin, and presented with excellent amylolytic levels. Thin layer chromatography showed that the amylase system was constituted by glucoamylase. This enzyme showed high activity at 60°C, pH 5.5, and an increment of 160% of the relative activity in the presence of 2 mM MgCl 2. The thermostabil-ity was increased after the immobilization on ionic supports. The enzyme immobilized on DEAE-sepharose retained 100% of its residual activity and when immobilized on MANAE-sepharose derivatives retained 72% at temperatures of 50°C and 60°C after 120 minutes of incubation. CNBr was used as a control. In contrast, the free enzyme only retained 50% of its residual activity after 90 minutes, ...
Aims: Prospectingdifferentfilamentousfungiforhigh production ofamylasesinstandard conditionsforfu... more Aims: Prospectingdifferentfilamentousfungiforhigh production ofamylasesinstandard conditionsforfutureapplicationin biotechnologyindustries. Methodo logy:Sampleswerecollectedindifferentfield areasinthestateofBahia,Brazil, for isolating filamentous fungi .Fungiwere grown in Petridishes in a culture medium containing 4% QuakerAEoatmeal and 2% bacteriologicalagar.Fungi screening was carried outin liquid mediumcontaining1% starch at30∞C and pH6.0 under static conditions for4 days. Proteins and enzyme activities were de termined byBradford and DNS methods, respectively. A submerged fermentation was performed with different liquidmediainorder toobtainthebestgrowthcomposition andenzymeproduction forthe selected fungus. Several conditions such as time course of inactivation, pH, temperature, carbon and nitrogen sources were determined in the culture medium with the aim of
Journal of industrial microbiology & biotechnology, 2014
Endophytic fungi, mostly belonging to the Ascomycota, are found in the intercellular spaces of th... more Endophytic fungi, mostly belonging to the Ascomycota, are found in the intercellular spaces of the aerial plant parts, particularly in leaf sheaths, sometimes even within the bark and root system without inducing any visual symptoms of their presence. These fungi appear to have a capacity to produce a wide range of enzymes and secondary metabolites exhibiting a variety of biological activities. However, they have been only barely exploited as sources of enzymes of industrial interest. This review emphasizes the suitability and possible advantages of including the endophytic fungi in the screening of new enzyme producing organisms as well as in studies aiming to optimize the production of enzymes through well-known culture processes. Apparently endophytic fungi possess the two types of extracellular enzymatic systems necessary to degrade the vegetal biomass: (1) the hydrolytic system responsible for polysaccharide degradation consisting mainly in xylanases and cellulases; and (2) the...
Phytase hydrolyzes phytic acid from the plant components of animal feed, releasing inorganic phos... more Phytase hydrolyzes phytic acid from the plant components of animal feed, releasing inorganic phosphorus. The phytase production by Aspergillus japonicus was optimized using Plackett-Burman designs (PBD), composite central rotational designs (CCRD), and response surface methodology from standard Czapek medium. The enzyme was applied in broiler chicken and laying hen foods. Analysis from PBD showed that KH2 PO2, MgSO4 · 7H2O, and yeast extract had significant influences on phytase secretion (p < 0.05). The best results from the CCRD experiments were obtained using (A) 0.040% KH2 PO4, (B) 0.050% MgSO4 · 7H2O, and (C) 0.040% yeast extract, enhancing in 49-53 U mg(-1) protein. The determination coefficient (R(2)) was 0.92 and Fcalc was 7.48 times greater than Flisted . Thus, the reduced coded model: Y (U mg-1) = 50.29 + 4.30A - 3.35(A)2 - 4.80(B)2 + 5.62C - 4.26(C)2 was considered predictive and statistically significant (p < 0.05). The optimized culture medium increased the phytase yield in 250%. A. japonicus phytase released high levels of Pi from broiler chicken and laying hen food. A. japonicus is an excellent phytase producer in a culture medium using inexpensive components and agricultural wastes. Therefore, these results provide sound arguments for the formulation of a low cost culture medium for phytase production.
ABSTRACT Filamentous fungi isolated from soil samples were screened for extracellular lipase prod... more ABSTRACT Filamentous fungi isolated from soil samples were screened for extracellular lipase production. The best producer was Hypocrea pseudokoningii identified by taxonomical criteria, and by rDNA sequencing of the variable internal transcribed spacers (ITS I and II) and the intervening 5.8S gene. The fungus was grown in a complex medium supplemented with 1% Tween 80 and 0.2% yeast extract, for 4 days. The optimum pH for extracellular and intracellular lipases was 7.0 and 8.0, respectively. Both enzymes exhibited maximum activity at 40 degrees C. Extracellular and intracellular lipase activities were highly stable in the pH range 3.0-8.0 at room temperature. The intracellular lipase was thermostable up to 60 degrees C, for 15 min and the extracellular, for 107 min, at the same temperature. The intracellular lipase was stimulated by silver ions. Extracellular lipase was stable in organic solvents, such as DMSO, alcohols, acetone, and acetonitrile, for 24 hours. Lipase activity increased around 80% when detergents were added to the enzymatic assay, such as Tween 80, Triton X-100, and SDS.
Aspergillus phoenicis is an interesting heat tolerant fungus that can synthesize enzymes with sev... more Aspergillus phoenicis is an interesting heat tolerant fungus that can synthesize enzymes with several applications in the food industry due to its great hydrolytic potential. In this work, the fungus produced high enzymatic levels when cultivated on inexpensive culture media consisting of flakes from different origins such as cassava flour, wheat fibre, crushed soybean, agro-industrial wastes, starch, glucose or maltose. Several enzymatic systems were produced from these carbon sources, but amylase was the most evident, followed by pectinase and xylanase. Traces of CMCases, avicelase, lipase, β-xylosidase, β-glucosidase and α-glucosidase activities were also detected. Amylases were produced on rye flakes, starch, oat flakes, corn flakes, cassava flour and wheat fibre. Significant amylolytic levels were produced in the culture medium with glucose or when this sugar was exhausted, suggesting an enzyme in the constitutive form. Cassava flour, rye, oats, barley and corn flakes were also...
This paper describes a bioprocess to obtain omegas-6 and 9 from the hydrolysis of Açaí (Euterpe o... more This paper describes a bioprocess to obtain omegas-6 and 9 from the hydrolysis of Açaí (Euterpe oleracea Martius) and Buriti (Mauritia flexuosa) oils by lipases immobilized on octyl-sepharose. For this, oils and butters were initially selected as the carbon source which resulted in higher production of lipases in Beauveria bassiana and Fusarium oxysporum cultures. The carbon source that provided secretion of lipase by B. bassiana was Açaí oil, and for F. oxysporum, Bacuri butter. Lipases obtained under these conditions were immobilized on octyl-sepharose, and both, the derivatives and the crude extracts were biochemically characterized. It was observed that the immobilization promoted an increase of stability in B. bassiana and F. oxysporum lipase activities at the given temperatures and pH. In addition, the immobilization promoted hyperactivation of B. bassiana and F. oxysporum lipase activities being 23.5 and 11.0 higher than free enzyme, respectively. The hydrolysis of Açaí and B...
Statistical evidence pointing to the very soft change in the ionic composition on the surface of ... more Statistical evidence pointing to the very soft change in the ionic composition on the surface of the sugar cane bagasse is crucial to improve yields of sugars by hydrolytic saccharification. Removal of Li+ by pretreatments exposing -OH sites was the most important factor related to the increase of saccharification yields using enzyme cocktails. Steam Explosion and Microwave:H2SO4 pretreatments produced unrelated structural changes, but similar ionic distribution patterns. Both increased the saccharification yield 1.74-fold. NaOH produced structural changes related to Steam Explosion, but released surface-bounded Li+ obtaining 2.04-fold more reducing sugars than the control. In turn, the higher amounts in relative concentration and periodic structures of Li+ on the surface observed in the control or after the pretreatment with Ethanol:DMSO:Ammonium Oxalate, blocked -OH and O− available for ionic sputtering. These changes correlated to 1.90-fold decrease in saccharification yields. Li...
Over the last decades researchers have focused to enhance the electrocatalytic activity of the bi... more Over the last decades researchers have focused to enhance the electrocatalytic activity of the biosystems, increasing the energy generation and electronic conductivity into the biofilms. The use of enzymes immobilized onto the surface of electrodes as the main catalyst in biological fuel cells has been extensively reported. A biofuel cell provides a means to obtain clean, renewable energy and have great potential to be used as alternative energy source for low power devices. There still a lot of important issues in the development of these device, one of them, is to obtain the maximum energy from the fuel. In order to enhance the power density of enzymatic biofuel cell (EBFC) it is necessary to increase the degree of oxidation of the fuel, so that all the electrons from the fuel can be harvested. One approach is the immobilization of a group of enzymes to perform a cascade in order to maximize the fuel oxidation. Recently, we have concentrated our goal to the develop hybrid biofilms employing MWCNT in order to immobilize efficiently the enzymes. In this context we added organic catalyst (TEMPO (2,2,6,6- tetramethylpiperidin-1-yl) oxyl) or metallic nanoparticles (MWCNT/Pt, MWCNT/PtSn and MWCNT/Au) to the biofilms to create a hybrid catalytic system able to catalyze the complete electrooxidation of ethanol (ET) and ethylene glycol (EG) into CO2. In the case of ethanol extraction of 12 electrons per molecule at a single hybrid anode has been obtained with success. This simple methodology can replace the use of enzymatic cascade (7-8 enzymes) and may improve the application in biofuel cells. The electrochemical response of the enzyme system (MWCNT-COOH/LPEI/OxOx) at increasing concentrations of ethanol confirms the excellent activity of these hybrid bioanodes. Product analysis by HPLC techniques allowed us to correlate the increase in current with the formation of CO2or other more oxidable compounds as main product. In the case of EG the metallic catalyst was shifting the onset oxidation potential to lower potentials (200 mV) compared with TEMPO. The maximum power densities reached values around 351 µW cm-2 in the case of MWCNT/PtSn-OxOx for EG and 315 µW cm-2 for MWCNT-COOH/Pyrene-TEMPO/OxDc bioanode. Fig 1 show the products formed for EG. The modification of nanomaterials to obtain a large energy output form an enzymatic system will be highlighted. Therefore, the system open a new alternative of high performance hybrid-EBFC-based enabling the development of efficient EBFC based on alcohols. Acknowledge: FAPESP (grants # 2017/20431-7 and 2014/50945-4 ), CNPq (grant (465571/2014-0) and CAPES 001. Army Research Office MURI (W911NF-14-1-0263). Figure 1
Advances of Basic Science for Second Generation Bioethanol from Sugarcane, 2017
This chapter introduces the role of enzymes in the biomass degradation, namely sugarcane bagasse ... more This chapter introduces the role of enzymes in the biomass degradation, namely sugarcane bagasse and straw, leading to the formation of fermentable sugars and second-generation ethanol. The chapter begins with a retrospective of the structuring of the ethanol production chain and then presents current aspects where the deficit of production and its consequences in business can be seen. Subsequently, we list the role of enzymes involved in the biomass hydrolysis, the commercial cocktails, and the proposal of our laboratory in this context. On the other hand, the efficiency of enzymes on the biomass is increased when the bagasse and straw are pretreated. Thus, some technologies that may facilitate the enzymatic hydrolysis and the formation of fermentable sugars are described. Lastly, recent analytical methods that enable a better analysis of the composition and viewing of fiber in the sugarcane biomass are presented.
Plant materials represent a strategic energy source because they can give rise to sustainable bio... more Plant materials represent a strategic energy source because they can give rise to sustainable biofuels through the fermentation of their carbohydrates. A clear example of a plant-derived biofuel resource is the sugar cane bagasse exhibiting 60-80% of fermentable sugars in its composition. However, the current methods of plant bioconversion employ severe and harmful chemical/physical pretreatments raising biofuel cost production and environmental degradation. Replacing these methods with co-cultivated enzymatic cocktails is an alternative. Here we propose a pretreatment for sugarcane bagasse using a multi-enzymatic cocktail from the co-cultivation of four Aspergillus nidulans recombinant strains. The co-cultivation resulted in the simultaneous production of GH51 arabinofuranosidase (AbfA), GH11 endo-1,4-xylanase (XlnA), GH43 endo-1,5-arabinanase (AbnA) and GH12 xyloglucan specific endo-β-1,4-glucanase (XegA). This core set of recombinant enzymes was more efficient than the alternativ...
Amylases are enzymes with important biotechnological applications that are produced by several mi... more Amylases are enzymes with important biotechnological applications that are produced by several microorganisms in the form of filamentous fungi. Penicillium citrinum was recently isolated from the decomposed materials of Atlantic Forest, Bra-zil. It was identified by internal transcribed spacer (ITS) and beta-tubulin, and presented with excellent amylolytic levels. Thin layer chromatography showed that the amylase system was constituted by glucoamylase. This enzyme showed high activity at 60°C, pH 5.5, and an increment of 160% of the relative activity in the presence of 2 mM MgCl 2. The thermostabil-ity was increased after the immobilization on ionic supports. The enzyme immobilized on DEAE-sepharose retained 100% of its residual activity and when immobilized on MANAE-sepharose derivatives retained 72% at temperatures of 50°C and 60°C after 120 minutes of incubation. CNBr was used as a control. In contrast, the free enzyme only retained 50% of its residual activity after 90 minutes, ...
Aims: Prospectingdifferentfilamentousfungiforhigh production ofamylasesinstandard conditionsforfu... more Aims: Prospectingdifferentfilamentousfungiforhigh production ofamylasesinstandard conditionsforfutureapplicationin biotechnologyindustries. Methodo logy:Sampleswerecollectedindifferentfield areasinthestateofBahia,Brazil, for isolating filamentous fungi .Fungiwere grown in Petridishes in a culture medium containing 4% QuakerAEoatmeal and 2% bacteriologicalagar.Fungi screening was carried outin liquid mediumcontaining1% starch at30∞C and pH6.0 under static conditions for4 days. Proteins and enzyme activities were de termined byBradford and DNS methods, respectively. A submerged fermentation was performed with different liquidmediainorder toobtainthebestgrowthcomposition andenzymeproduction forthe selected fungus. Several conditions such as time course of inactivation, pH, temperature, carbon and nitrogen sources were determined in the culture medium with the aim of
Journal of industrial microbiology & biotechnology, 2014
Endophytic fungi, mostly belonging to the Ascomycota, are found in the intercellular spaces of th... more Endophytic fungi, mostly belonging to the Ascomycota, are found in the intercellular spaces of the aerial plant parts, particularly in leaf sheaths, sometimes even within the bark and root system without inducing any visual symptoms of their presence. These fungi appear to have a capacity to produce a wide range of enzymes and secondary metabolites exhibiting a variety of biological activities. However, they have been only barely exploited as sources of enzymes of industrial interest. This review emphasizes the suitability and possible advantages of including the endophytic fungi in the screening of new enzyme producing organisms as well as in studies aiming to optimize the production of enzymes through well-known culture processes. Apparently endophytic fungi possess the two types of extracellular enzymatic systems necessary to degrade the vegetal biomass: (1) the hydrolytic system responsible for polysaccharide degradation consisting mainly in xylanases and cellulases; and (2) the...
Phytase hydrolyzes phytic acid from the plant components of animal feed, releasing inorganic phos... more Phytase hydrolyzes phytic acid from the plant components of animal feed, releasing inorganic phosphorus. The phytase production by Aspergillus japonicus was optimized using Plackett-Burman designs (PBD), composite central rotational designs (CCRD), and response surface methodology from standard Czapek medium. The enzyme was applied in broiler chicken and laying hen foods. Analysis from PBD showed that KH2 PO2, MgSO4 · 7H2O, and yeast extract had significant influences on phytase secretion (p < 0.05). The best results from the CCRD experiments were obtained using (A) 0.040% KH2 PO4, (B) 0.050% MgSO4 · 7H2O, and (C) 0.040% yeast extract, enhancing in 49-53 U mg(-1) protein. The determination coefficient (R(2)) was 0.92 and Fcalc was 7.48 times greater than Flisted . Thus, the reduced coded model: Y (U mg-1) = 50.29 + 4.30A - 3.35(A)2 - 4.80(B)2 + 5.62C - 4.26(C)2 was considered predictive and statistically significant (p < 0.05). The optimized culture medium increased the phytase yield in 250%. A. japonicus phytase released high levels of Pi from broiler chicken and laying hen food. A. japonicus is an excellent phytase producer in a culture medium using inexpensive components and agricultural wastes. Therefore, these results provide sound arguments for the formulation of a low cost culture medium for phytase production.
ABSTRACT Filamentous fungi isolated from soil samples were screened for extracellular lipase prod... more ABSTRACT Filamentous fungi isolated from soil samples were screened for extracellular lipase production. The best producer was Hypocrea pseudokoningii identified by taxonomical criteria, and by rDNA sequencing of the variable internal transcribed spacers (ITS I and II) and the intervening 5.8S gene. The fungus was grown in a complex medium supplemented with 1% Tween 80 and 0.2% yeast extract, for 4 days. The optimum pH for extracellular and intracellular lipases was 7.0 and 8.0, respectively. Both enzymes exhibited maximum activity at 40 degrees C. Extracellular and intracellular lipase activities were highly stable in the pH range 3.0-8.0 at room temperature. The intracellular lipase was thermostable up to 60 degrees C, for 15 min and the extracellular, for 107 min, at the same temperature. The intracellular lipase was stimulated by silver ions. Extracellular lipase was stable in organic solvents, such as DMSO, alcohols, acetone, and acetonitrile, for 24 hours. Lipase activity increased around 80% when detergents were added to the enzymatic assay, such as Tween 80, Triton X-100, and SDS.
Aspergillus phoenicis is an interesting heat tolerant fungus that can synthesize enzymes with sev... more Aspergillus phoenicis is an interesting heat tolerant fungus that can synthesize enzymes with several applications in the food industry due to its great hydrolytic potential. In this work, the fungus produced high enzymatic levels when cultivated on inexpensive culture media consisting of flakes from different origins such as cassava flour, wheat fibre, crushed soybean, agro-industrial wastes, starch, glucose or maltose. Several enzymatic systems were produced from these carbon sources, but amylase was the most evident, followed by pectinase and xylanase. Traces of CMCases, avicelase, lipase, β-xylosidase, β-glucosidase and α-glucosidase activities were also detected. Amylases were produced on rye flakes, starch, oat flakes, corn flakes, cassava flour and wheat fibre. Significant amylolytic levels were produced in the culture medium with glucose or when this sugar was exhausted, suggesting an enzyme in the constitutive form. Cassava flour, rye, oats, barley and corn flakes were also...
This paper describes a bioprocess to obtain omegas-6 and 9 from the hydrolysis of Açaí (Euterpe o... more This paper describes a bioprocess to obtain omegas-6 and 9 from the hydrolysis of Açaí (Euterpe oleracea Martius) and Buriti (Mauritia flexuosa) oils by lipases immobilized on octyl-sepharose. For this, oils and butters were initially selected as the carbon source which resulted in higher production of lipases in Beauveria bassiana and Fusarium oxysporum cultures. The carbon source that provided secretion of lipase by B. bassiana was Açaí oil, and for F. oxysporum, Bacuri butter. Lipases obtained under these conditions were immobilized on octyl-sepharose, and both, the derivatives and the crude extracts were biochemically characterized. It was observed that the immobilization promoted an increase of stability in B. bassiana and F. oxysporum lipase activities at the given temperatures and pH. In addition, the immobilization promoted hyperactivation of B. bassiana and F. oxysporum lipase activities being 23.5 and 11.0 higher than free enzyme, respectively. The hydrolysis of Açaí and B...
Statistical evidence pointing to the very soft change in the ionic composition on the surface of ... more Statistical evidence pointing to the very soft change in the ionic composition on the surface of the sugar cane bagasse is crucial to improve yields of sugars by hydrolytic saccharification. Removal of Li+ by pretreatments exposing -OH sites was the most important factor related to the increase of saccharification yields using enzyme cocktails. Steam Explosion and Microwave:H2SO4 pretreatments produced unrelated structural changes, but similar ionic distribution patterns. Both increased the saccharification yield 1.74-fold. NaOH produced structural changes related to Steam Explosion, but released surface-bounded Li+ obtaining 2.04-fold more reducing sugars than the control. In turn, the higher amounts in relative concentration and periodic structures of Li+ on the surface observed in the control or after the pretreatment with Ethanol:DMSO:Ammonium Oxalate, blocked -OH and O− available for ionic sputtering. These changes correlated to 1.90-fold decrease in saccharification yields. Li...
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Papers by Maria Polizeli