The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Apostolis A Koutinas - One of the best experts on this subject based on the ideXlab platform.
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evaluation of organic fractions of municipal solid waste as renewable feedstock for succinic acid production
Biotechnology for Biofuels, 2020Co-Authors: Eleni Stylianou, Dimitrios Ladakis, Chrysanthi Pateraki, Maria Cruzfernandez, Marcos Latorresanchez, Caterina Coll, Apostolis A KoutinasAbstract:Despite its high market potential, bio-based succinic acid production experienced recently a declining trend because the initial investments did not meet the expectations for rapid market growth. Thus, reducing the succinic acid production cost is imperative to ensure industrial implementation. Succinic acid production has been evaluated using hydrolysates from the organic fraction of municipal solid waste (OFMSW) collected from MSW treatment plants. A tailor-made enzymatic cocktail was used for OFMSW hydrolysate production containing up to 107.3 g/L carbon sources and up to 638.7 mg/L Free Amino Nitrogen. The bacterial strains Actinobacillus succinogenes and Basfia succiniciproducens were evaluated for succinic acid production with the latter strain being less efficient due to high lactic acid production. Batch A. succinogenes cultures supplemented with 5 g/L yeast extract and 5 g/L MgCO3 reached 29.4 g/L succinic acid with productivity of 0.89 g/L/h and yield of 0.56 g/g. Continuous cultures at dilution rate of 0.06 h−1 reached 21.2 g/L succinic acid with yield of 0.47 g/g and productivity of 1.27 g/L/h. Downstream separation and purification of succinic acid was achieved by centrifugation, treatment with activated carbon, acidification with cation exchange resins, evaporation and drying, reaching more than 99% purity. Preliminary techno-economic evaluation has been employed to evaluate the profitability potential of bio-based succinic acid production. The use of OFMSW hydrolysate in continuous cultures could lead to a minimum selling price of 2.5 $/kg at annual production capacity of 40,000 t succinic acid and OFMSW hydrolysate production cost of 25 $/t sugars.
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evaluation of organic fractions of municipal solid waste as renewable feedstock for succinic acid production
Biotechnology for Biofuels, 2020Co-Authors: Eleni Stylianou, Dimitrios Ladakis, Chrysanthi Pateraki, Maria Cruzfernandez, Marcos Latorresanchez, Caterina Coll, Apostolis A KoutinasAbstract:Background: Despite its high market potential, bio-based succinic acid production experienced recently a declining trend because the initial investments did not meet the expectations for rapid market growth. Thus, reducing the succinic acid production cost is imperative to ensure industrial implementation. Results: Succinic acid production has been evaluated using hydrolysates from the organic fraction of municipal solid waste (OFMSW) collected from MSW treatment plants. A tailor-made enzymatic cocktail was used for OFMSW hydrolysate production containing up to 107.3 g/L carbon sources and up to 638.7 mg/L Free Amino Nitrogen. The bacterial strains Actinobacillus succinogenes and Basfia succiniciproducens were evaluated for succinic acid production with the latter strain being less efficient due to high lactic acid production. Batch A. succinogenes cultures supplemented with 5 g/L yeast extract and 5 g/L MgCO3 reached 29.4 g/L succinic acid with productivity of 0.89 g/L/h and yield of 0.56 g/g. Continuous cultures at dilution rate of 0.06 h-1 reached 21.2 g/L succinic acid with yield of 0.47 g/g and productivity of 1.27 g/L/h. Downstream separation and purification of succinic acid was achieved by centrifugation, treatment with activated carbon, acidification with cation exchange resins, evaporation and drying, reaching more than 99% purity. Preliminary techno-economic evaluation has been employed to evaluate the profitability potential of bio-based succinic acid production. Conclusions: The use of OFMSW hydrolysate in continuous cultures could lead to a minimum selling price of 2.5 $/kg at annual production capacity of 40,000 t succinic acid and OFMSW hydrolysate production cost of 25 $/t sugars.
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formulation of fermentation media from flour rich waste streams for microbial lipid production by lipomyces starkeyi
Journal of Biotechnology, 2014Co-Authors: Sofia Tsakona, Seraphim Papanikolaou, Ioannis K Kookos, Nikolaos Kopsahelis, Afroditi Chatzifragkou, Apostolis A KoutinasAbstract:Flour-rich waste (FRW) and by-product streams generated by bakery, confectionery and wheat milling plants could be employed as the sole raw materials for generic fermentation media production, suitable for microbial oil synthesis. Wheat milling by-products were used in solid state fermentations (SSF) of Aspergillus awamori for the production of crude enzymes, mainly glucoamylase and protease. Enzyme-rich SSF solids were subsequently employed for hydrolysis of FRW streams into nutrient-rich fermentation media. Batch hydrolytic experiments using FRW concentrations up to 205 g/L resulted in higher than 90% (w/w) starch to glucose conversion yields and 40% (w/w) total Kjeldahl Nitrogen to Free Amino Nitrogen conversion yields. Starch to glucose conversion yields of 98.2, 86.1 and 73.4% (w/w) were achieved when initial FRW concentrations of 235, 300 and 350 g/L were employed in fed-batch hydrolytic experiments, respectively. Crude hydrolysates were used as fermentation media in shake flask cultures with the oleaginous yeast Lipomyces starkeyi DSM 70296 reaching a total dry weight of 30.5 g/L with a microbial oil content of 40.4% (w/w), higher than that achieved in synthetic media. Fed-batch bioreactor cultures led to a total dry weight of 109.8 g/L with a microbial oil content of 57.8% (w/w) and productivity of 0.4 g/L/h.
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sunflower based biorefinery poly 3 hydroxybutyrate and poly 3 hydroxybutyrate co 3 hydroxyvalerate production from crude glycerol sunflower meal and levulinic acid
Bioresource Technology, 2014Co-Authors: Vasiliki Kachrimanidou, Seraphim Papanikolaou, Ioannis K Kookos, Nikolaos Kopsahelis, Mario De Bruyn, James H Clark, Apostolis A KoutinasAbstract:Abstract Polyhydroxybutyrate (PHB) and poly(3-hydroxybutyrate- co -3-hydroxyvalerate) [P(3HB- co -3HV)] production was developed in bioreactor cultures using the strain Cupriavidus necator DSM 7237 cultivated on crude glycerol, sunflower meal (SFM) hydrolysates and levulinic acid as the sole fermentation feedstocks. Bacterial growth and PHB production was influenced significantly by the Free Amino Nitrogen and inorganic phosphorus content of the SFM hydrolysate. Fed-batch bioreactor fermentations led to the production of 27 g L −1 PHB with an intracellular content of 72.9% (w/w). Continuous feeding of levulinic acid led to the production of up to 23.4 g L −1 P(3HB- co -3HV) with an intracellular content of 66.4% (w/w) and a 3HV content of 22.5 mol%. A maximum 3HV content of 31 mol% was achieved at earlier fermentation time (53 h). Thus, levulinic acid could be combined with biodiesel industry by-products for the production of high P(3HB- co -3HV) concentration, intracellular content and industrially useful 3HV content.
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evaluation of by products from the biodiesel industry as fermentation feedstock for poly 3 hydroxybutyrate co 3 hydroxyvalerate production by cupriavidus necator
Bioresource Technology, 2013Co-Authors: I L Garcia, Seraphim Papanikolaou, Nikolaos Kopsahelis, Jimmy A Lopez, M P Dorado, Maria Alexandri, Marcelo A Villar, Apostolis A KoutinasAbstract:Abstract Utilization of by-products from oilseed-based biodiesel production (crude glycerol, rapeseed meal hydrolysates) for microbial polyhydroxyalkanoate (PHA) production could lead to the replacement of expensive carbon sources, nutrient supplements and precursors for co-polymer production. Batch fermentations in shake flasks with varying amounts of Free Amino Nitrogen led to the production of poly(3-hydroxybutyrate- co -3-hydroxyvalerate) (P(3HB- co -3HV)) with a 2.8–8% 3HV content. Fed-batch fermentations in shake flasks led to the production of 10.9 g/L P(3HB- co -3HV) and a 55.6% P(3HB- co -3HV) content. NaCl concentrations between 2 and 6 g/L gradually became inhibitory to bacterial growth and PHA formation, whereas in the case of K 2 SO 4 , the inhibitory effect was observed only at concentrations higher than 20 g/L. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and nuclear magnetic resonance ( 13 C NMR) demonstrated that the incorporation of 3HV into the obtained P(3HB- co -3HV) lowered glass transition temperature, crystallinity and melting point as compared to polyhydroxybutyrate. Integrating PHA production in existing oilseed-based biodiesel plants could enhance the viability and sustainability of this first generation biorefinery.
Colin Webb - One of the best experts on this subject based on the ideXlab platform.
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bioconversion of rapeseed meal for the production of a generic microbial feedstock
Enzyme and Microbial Technology, 2010Co-Authors: Ruohang Wang, Apostolis A Koutinas, Shalyda Md Shaarani, Leticia Casas Godoy, Mehmet Melikoglu, Carlos Sola Vergara, Colin WebbAbstract:Abstract Rapeseed meal, a major byproduct from biodiesel production, has been used as a low-cost raw material for the production of a generic microbial feedstock through a consolidated bioconversion process. Solid state fermentation by Aspergillus oryzae led to the production of hydrolytic enzymes that could release Free Amino Nitrogen (FAN), inorganic phosphorus (IP), small amount of glucose, and possibly many other microbial nutrients from rapeseed meal. Suspending the fermented solids in water at elevated temperature resulted in further hydrolysis of the remaining meal components for the production of a feedstock containing 2061.2 mg l −1 FAN, 304 mg l h −1 IP, and 1.8 g l −1 glucose. A three-fold dilution of this feedstock provided all essential nutrients except sufficient carbon source to support the production of 6.85 g l −1 dry Saccharomyces cerevisiae cells in aerobic incubation, while consuming 80.6 g l −1 of the glucose supplement. Comparative yeast incubation confirmed the nutritional similarity between the feedstock and a mixture of commercial peptone and yeast extract.
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cereal based biorefinery development utilisation of wheat milling by products for the production of succinic acid
Journal of Biotechnology, 2009Co-Authors: Sze Ki Carol Lin, Apostolis A Koutinas, Ruohang Wang, Pilar M Dorado, Colin WebbAbstract:A novel wheat-based bioprocess for the production of a nutrient-complete feedstock for the fermentative succinic acid production by Actinobacillus succinogenes has been developed. Wheat was fractionated into bran, middlings and flour. The bran fraction, which would normally be a waste product of the wheat milling industry, was used as the sole medium in two solid-state fermentations (SSF) of Aspergillus awamori and Aspergillus oryzae that produce enzyme complexes rich in amylolytic and proteolytic enzymes, respectively. The resulting fermentation solids were then used as crude enzyme sources, by adding directly to an aqueous suspension of milled bran and middlings fractions (wheat flour milling by-products) to generate a hydrolysate containing over 95 g/L glucose, 25 g/L maltose and 300 mg/L Free Amino Nitrogen (FAN). This hydrolysate was then used as the sole medium for A. succinogenes fermentations, which led to the production of 50.6 g/L succinic acid. Supplementation of the medium with yeast extract did not significantly improve succinic acid production though increasing the inoculum concentration to 20% did result in the production of 62.1 g/L succinic acid. Results indicated that A. succinogenes cells were able to utilise glucose and maltose in the wheat hydrolysate for cell growth and succinic acid production. The proposed process could be potentially integrated into a wheat-milling process to upgrade the wheat flour milling by-products (WFMB) into succinic acid, one of the future platform chemicals of a sustainable chemical industry.
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improving wheat flour hydrolysis by an enzyme mixture from solid state fungal fermentation
Enzyme and Microbial Technology, 2009Co-Authors: Ruohang Wang, Apostolis A Koutinas, Shalyda Md Shaarani, Leticia Casas Godoy, Mehmet Melikoglu, Colin WebbAbstract:In traditional cereal-based industrial processes, component separation is often incomplete resulting in a residue of mixed macromolecules including largely starch, protein, phytic acid and many others. The development of a viable cereal-based biorefinery would involve effective bioconversion of cereal components for the production of a nutrient-complete fermentation feedstock. Simultaneous starch and protein hydrolysis represents an effective approach to the production of platform chemicals from wheat. Solid state fermentations of wheat pieces and waste bread by Aspergillus oryzae and Aspergillus awamori have been combined in this study to enhance starch and protein hydrolysis. Kinetic studies confirmed that the proteolytic enzymes from A. oryzae introduced no negative effect on the stability of the amylolytic enzymes from A. awamori under the optimal conditions for starch hydrolysis. When applied to hydrolyse wheat flour, the enzyme solution from A. awamori converted nearly all of the starch into glucose and 23% of the total Nitrogen (TN) into Free Amino Nitrogen (FAN). Under the same reaction conditions the enzyme solution from A. oryzae hydrolysed 38% of the protein but only 18.5% of the starch. A mixture of the two enzyme solutions hydrolysed 34.1% of the protein, a 1.5-fold increase from that achieved by the enzyme solution from A. awamori, while maintaining a near completion of starch hydrolysis.
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development of novel wheat biorefining effect of gluten extraction from wheat on bioethanol production
Biochemical Engineering Journal, 2009Co-Authors: Najmul Arifeen, Apostolis A Koutinas, Ruohang Wang, Ioannis K Kookos, Colin WebbAbstract:Abstract Wheat has been used in a novel biorefinery as the sole raw material for the production of bioethanol and some co-products (bran-rich pearlings, gluten and pure yeast cells). Minimisation in waste production has been achieved either by generating co-products from major wheat components that are not required for bioethanol fermentation or by re-generating nutrients contained initially in wheat via microbial autolysis. On-site production of enzymes required to hydrolyse wheat macromolecules has been achieved by Aspergillus awamori fermentation of pearled wheat flour. Complete gluten extraction was made feasible by providing the required amount of Free Amino Nitrogen (FAN) for bioethanol fermentations via on-site fungal autolysis. A wheat to ethanol conversion yield of 0.296 g g −1 , which constitutes 77% of the maximum theoretical conversion (0.385 g ethanol (g wheat) −1 ) calculated from the starch content in the wheat used, has been achieved including the starch requirements for enzyme production. A modified unstructured model has been proposed to describe fermentations of Saccharomyces cerevisiae on wheat-derived media for bioethanol production.
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polyhydroxybutyrate production from a novel feedstock derived from a wheat based biorefinery
Enzyme and Microbial Technology, 2007Co-Authors: Apostolis A Koutinas, Ruohang Wang, Yunji Xu, Colin WebbAbstract:Abstract A wheat-based biorefining strategy was evaluated for polyhydroxybutyrate (PHB) production by Cupriavidus necator (formerly classified as Ralstonia eutropha but currently designated Wautersia eutropha ). Wheat was bioconverted into two feedstock streams, wheat hydrolysate (WH) and fungal extract (FE) that were rich in glucose and Nitrogen, respectively. WH and FE were mixed in appropriate proportions to provide media with varying glucose (5–26 g l −1 ) and Free Amino Nitrogen (FAN) (0.1–1.2 g l −1 ) concentrations for batch shake flask fermentations. Increasing FAN concentration resulted in higher microbial growth and less PHB accumulation. The consumption of various carbon sources (carbohydrates, Amino acids, peptides) resulted in high growth yields (up to 1.07 g cells (g glucose) −1 ) as related to glucose. Specific growth rates up to 0.16 h −1 were observed. Three WH with similar glucose (200–220 g l −1 ) and varying FAN (0.3–1.48 g l −1 ) concentrations were evaluated in fed-batch shake flask fermentations for C. necator growth and PHB accumulation. The medium with the highest Nitrogen concentration (WH3) gave the highest microbial biomass concentration (29.9 g l −1 ), growth yield (0.28 g residual microbial biomass (g glucose) −1 ) and PHB yield (0.43 g (g glucose) −1 ). WH2 gave the highest PHB concentration (51.1 g l −1 ) and content (0.7 g g −1 ).
Carol Sze Ki Lin - One of the best experts on this subject based on the ideXlab platform.
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Efficient sophorolipids production using food waste
Journal of Cleaner Production, 2019Co-Authors: Guneet Kaur, Huaimin Wang, Sophie Roelants, Wim Soetaert, Carol Sze Ki LinAbstract:Abstract Recent sustainable development goals of food security, environmental protection, material and energy efficiency are the key drivers of the valorization of food waste. In the present work, the production of biosurfactant sophorolipids from several (food) waste streams was investigated, using the non-pathogenic yeast Starmerella bombicola. From a preliminary screening, restaurant food waste emerged as the most suitable feedstock compared to bakery waste, textile waste, used corn oil, animal fat and lipid fraction of hydrolyzed food waste. Restaurant food waste was subsequently used for sophorolipids production in a laboratory-scale bioreactor. Food waste obtained from a local restaurant was subjected to enzymatic hydrolysis for 16 h, yielding a hydrolysate containing about 100 g/L glucose and 2.4 g/L Free Amino Nitrogen. High SL process efficiency was achieved by fed-batch fermentation using the restaurant food waste hydrolysate as the complete batch medium, i.e. without any supplementation of additional medium components such as vitamins, salts, Nitrogen or phosphate. Controlled feeding of glucose and oleic acid to the culture was performed after the batch phase. A sophorolipids titer of 115.2 g/L was obtained in a fermentation time of 92 h resulting in an overall volumetric productivity of 1.25 g/L.h. These results achieved for sophorolipids productivity using hydrolyzed food waste are in the same order of magnitude as the reported values using traditional (complex) fermentation media. This indicates the suitability of the developed process using food waste for the advancement of waste-based bio-processes for the production of sophorolipids.
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valorisation of food waste via fungal hydrolysis and lactic acid fermentation with lactobacillus casei shirota
Bioresource Technology, 2016Co-Authors: Tsz Him Kwan, Carol Sze Ki LinAbstract:Food waste recycling via fungal hydrolysis and lactic acid (LA) fermentation has been investigated. Hydrolysates derived from mixed food waste and bakery waste were rich in glucose (80.0-100.2gL(-1)), fructose (7.6gL(-1)) and Free Amino Nitrogen (947-1081mgL(-1)). In the fermentation with Lactobacillus casei Shirota, 94.0gL(-1) and 82.6gL(-1) of LA were produced with productivity of 2.61gL(-1)h(-1) and 2.50gL(-1)h(-1) for mixed food waste and bakery waste hydrolysate, respectively. The yield was 0.94gg(-1) for both hydrolysates. Similar results were obtained using food waste powder hydrolysate, in which 90.1gL(-1) of LA was produced with a yield and productivity of 0.92gg(-1) and 2.50gL(-1)h(-1). The results demonstrate the feasibility of an efficient bioconversion of food waste to LA and a decentralized approach of food waste recycling in urban area.
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valorisation of mixed bakery waste in non sterilized fermentation for l lactic acid production by an evolved thermoanaerobacterium sp strain
Bioresource Technology, 2015Co-Authors: Xiaofeng Yang, Carol Sze Ki Lin, Muzi Zhu, Xiongliang Huang, Jufang WangAbstract:In this study, an advanced biorefinery technology that uses mixed bakery waste has been developed to produce l-lactic acid using an adaptively evolved Thermoanaerobacterium aotearoense LA1002-G40 in a non-sterilized system. Under these conditions, mixed bakery waste was directly hydrolysed by Aspergillus awamori and Aspergillus oryzae, resulting in a nutrient-rich hydrolysate containing 83.6g/L glucose, 9.5 g/L fructose and 612 mg/L Free Amino Nitrogen. T. aotearoense LA1002-G40 was evaluated and then adaptively evolved to grow in this nutrient-rich hydrolysate. Using a 5-L fermenter, the overall lactic acid production from mixed bakery waste was 0.18 g/g with a titer, productivity and yield of 78.5 g/L, 1.63 g/L/h and 0.85 g/g, respectively. This is an innovative procedure involving a complete bioconversion process for l-lactic acid produced from mixed bakery waste under non-sterilized conditions. The proposed process could be potentially applied to turn food waste into l-lactic acid in an economically feasible way.
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fatty acid feedstock preparation and lactic acid production as integrated processes in mixed restaurant food and bakery wastes treatment
Food Research International, 2015Co-Authors: Kin Yan Lau, Daniel Pleissner, Roland Schneider, Joachim Venus, Carol Sze Ki LinAbstract:Abstract In this study, fatty acid feedstock preparation and lactic acid production as integrated processes in mixed restaurant food and bakery waste treatment were investigated. The treatment included the hydrolysis of waste using extracellular fungal enzymes in submerged fermentation. By hydrolysis, 0.27 g glucose, 4.7 mg Free Amino Nitrogen (FAN) and 1.9 mg phosphate were recovered per gram dry waste material. After hydrolysis, a lipid-rich solid fraction, to be used as a source of fatty acids, remained. The nutrient-rich hydrolysate was used as medium in fed-batch cultures of the heterotrophic microalga Chlorella pyrenoidosa, which grew well at a rate of 1.4 day− 1. In order to establish a cost- and water-efficient process, hydrolysis and algae cultivation were performed in recycled culture supernatant without any negative impacts on the fungal hydrolysis and growth of C. pyrenoidosa. The extraction of lipids from algal biomass and lipid-rich solids resulted in a saturated and unsaturated fatty acid-rich feedstock. Defatted waste derived solids and algal biomass were further tested successfully as Nitrogen sources in lactic acid production using Bacillus coagulans. The outcomes of this study contribute to the establishment of a ‘green society’ by utilization of waste material in the production of chemicals, materials and fuels.
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valorisation of bakery waste for succinic acid production
Green Chemistry, 2013Co-Authors: Andrew Yan Zhu Zhang, Cho Chark Joe Leung, Wei Han, Kin Yan Lau, Mingji Li, Zheng Sun, Carol Sze Ki LinAbstract:In this paper, bakery waste, including cakes and pastries from Starbucks Hong Kong, was evaluated for the potential of succinic acid (SA) production. Through simultaneous hydrolysis and fungal autolysis, both cake and pastry hydrolysates were found to be rich in glucose (35.6 and 54.2 g L−1) and Free Amino Nitrogen (685.5 and 758.5 g L−1), whereas the protein hydrolysis yields were 23.2 and 22.5%, respectively. These cake and pastry hydrolysates, together with magnesium carbonate (10 g L−1) were subsequently used as feedstock in Actinobacillus succinogenes fermentation, and the resultant SA concentrations were 24.8 and 31.7 g L−1, respectively. A cation-exchange resin-based process (via vacuum distillation and crystallisation) was subsequently used to recover the SA crystals from fermentation broth, and a high SA crystal purity (96–97.7%) was obtained. Results of the present work successfully demonstrated the novel use of bakery waste as the generic feedstock for the sustainable production of SA as a platform chemical in food waste biorefinery.
Ruohang Wang - One of the best experts on this subject based on the ideXlab platform.
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bioconversion of rapeseed meal for the production of a generic microbial feedstock
Enzyme and Microbial Technology, 2010Co-Authors: Ruohang Wang, Apostolis A Koutinas, Shalyda Md Shaarani, Leticia Casas Godoy, Mehmet Melikoglu, Carlos Sola Vergara, Colin WebbAbstract:Abstract Rapeseed meal, a major byproduct from biodiesel production, has been used as a low-cost raw material for the production of a generic microbial feedstock through a consolidated bioconversion process. Solid state fermentation by Aspergillus oryzae led to the production of hydrolytic enzymes that could release Free Amino Nitrogen (FAN), inorganic phosphorus (IP), small amount of glucose, and possibly many other microbial nutrients from rapeseed meal. Suspending the fermented solids in water at elevated temperature resulted in further hydrolysis of the remaining meal components for the production of a feedstock containing 2061.2 mg l −1 FAN, 304 mg l h −1 IP, and 1.8 g l −1 glucose. A three-fold dilution of this feedstock provided all essential nutrients except sufficient carbon source to support the production of 6.85 g l −1 dry Saccharomyces cerevisiae cells in aerobic incubation, while consuming 80.6 g l −1 of the glucose supplement. Comparative yeast incubation confirmed the nutritional similarity between the feedstock and a mixture of commercial peptone and yeast extract.
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cereal based biorefinery development utilisation of wheat milling by products for the production of succinic acid
Journal of Biotechnology, 2009Co-Authors: Sze Ki Carol Lin, Apostolis A Koutinas, Ruohang Wang, Pilar M Dorado, Colin WebbAbstract:A novel wheat-based bioprocess for the production of a nutrient-complete feedstock for the fermentative succinic acid production by Actinobacillus succinogenes has been developed. Wheat was fractionated into bran, middlings and flour. The bran fraction, which would normally be a waste product of the wheat milling industry, was used as the sole medium in two solid-state fermentations (SSF) of Aspergillus awamori and Aspergillus oryzae that produce enzyme complexes rich in amylolytic and proteolytic enzymes, respectively. The resulting fermentation solids were then used as crude enzyme sources, by adding directly to an aqueous suspension of milled bran and middlings fractions (wheat flour milling by-products) to generate a hydrolysate containing over 95 g/L glucose, 25 g/L maltose and 300 mg/L Free Amino Nitrogen (FAN). This hydrolysate was then used as the sole medium for A. succinogenes fermentations, which led to the production of 50.6 g/L succinic acid. Supplementation of the medium with yeast extract did not significantly improve succinic acid production though increasing the inoculum concentration to 20% did result in the production of 62.1 g/L succinic acid. Results indicated that A. succinogenes cells were able to utilise glucose and maltose in the wheat hydrolysate for cell growth and succinic acid production. The proposed process could be potentially integrated into a wheat-milling process to upgrade the wheat flour milling by-products (WFMB) into succinic acid, one of the future platform chemicals of a sustainable chemical industry.
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improving wheat flour hydrolysis by an enzyme mixture from solid state fungal fermentation
Enzyme and Microbial Technology, 2009Co-Authors: Ruohang Wang, Apostolis A Koutinas, Shalyda Md Shaarani, Leticia Casas Godoy, Mehmet Melikoglu, Colin WebbAbstract:In traditional cereal-based industrial processes, component separation is often incomplete resulting in a residue of mixed macromolecules including largely starch, protein, phytic acid and many others. The development of a viable cereal-based biorefinery would involve effective bioconversion of cereal components for the production of a nutrient-complete fermentation feedstock. Simultaneous starch and protein hydrolysis represents an effective approach to the production of platform chemicals from wheat. Solid state fermentations of wheat pieces and waste bread by Aspergillus oryzae and Aspergillus awamori have been combined in this study to enhance starch and protein hydrolysis. Kinetic studies confirmed that the proteolytic enzymes from A. oryzae introduced no negative effect on the stability of the amylolytic enzymes from A. awamori under the optimal conditions for starch hydrolysis. When applied to hydrolyse wheat flour, the enzyme solution from A. awamori converted nearly all of the starch into glucose and 23% of the total Nitrogen (TN) into Free Amino Nitrogen (FAN). Under the same reaction conditions the enzyme solution from A. oryzae hydrolysed 38% of the protein but only 18.5% of the starch. A mixture of the two enzyme solutions hydrolysed 34.1% of the protein, a 1.5-fold increase from that achieved by the enzyme solution from A. awamori, while maintaining a near completion of starch hydrolysis.
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development of novel wheat biorefining effect of gluten extraction from wheat on bioethanol production
Biochemical Engineering Journal, 2009Co-Authors: Najmul Arifeen, Apostolis A Koutinas, Ruohang Wang, Ioannis K Kookos, Colin WebbAbstract:Abstract Wheat has been used in a novel biorefinery as the sole raw material for the production of bioethanol and some co-products (bran-rich pearlings, gluten and pure yeast cells). Minimisation in waste production has been achieved either by generating co-products from major wheat components that are not required for bioethanol fermentation or by re-generating nutrients contained initially in wheat via microbial autolysis. On-site production of enzymes required to hydrolyse wheat macromolecules has been achieved by Aspergillus awamori fermentation of pearled wheat flour. Complete gluten extraction was made feasible by providing the required amount of Free Amino Nitrogen (FAN) for bioethanol fermentations via on-site fungal autolysis. A wheat to ethanol conversion yield of 0.296 g g −1 , which constitutes 77% of the maximum theoretical conversion (0.385 g ethanol (g wheat) −1 ) calculated from the starch content in the wheat used, has been achieved including the starch requirements for enzyme production. A modified unstructured model has been proposed to describe fermentations of Saccharomyces cerevisiae on wheat-derived media for bioethanol production.
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polyhydroxybutyrate production from a novel feedstock derived from a wheat based biorefinery
Enzyme and Microbial Technology, 2007Co-Authors: Apostolis A Koutinas, Ruohang Wang, Yunji Xu, Colin WebbAbstract:Abstract A wheat-based biorefining strategy was evaluated for polyhydroxybutyrate (PHB) production by Cupriavidus necator (formerly classified as Ralstonia eutropha but currently designated Wautersia eutropha ). Wheat was bioconverted into two feedstock streams, wheat hydrolysate (WH) and fungal extract (FE) that were rich in glucose and Nitrogen, respectively. WH and FE were mixed in appropriate proportions to provide media with varying glucose (5–26 g l −1 ) and Free Amino Nitrogen (FAN) (0.1–1.2 g l −1 ) concentrations for batch shake flask fermentations. Increasing FAN concentration resulted in higher microbial growth and less PHB accumulation. The consumption of various carbon sources (carbohydrates, Amino acids, peptides) resulted in high growth yields (up to 1.07 g cells (g glucose) −1 ) as related to glucose. Specific growth rates up to 0.16 h −1 were observed. Three WH with similar glucose (200–220 g l −1 ) and varying FAN (0.3–1.48 g l −1 ) concentrations were evaluated in fed-batch shake flask fermentations for C. necator growth and PHB accumulation. The medium with the highest Nitrogen concentration (WH3) gave the highest microbial biomass concentration (29.9 g l −1 ), growth yield (0.28 g residual microbial biomass (g glucose) −1 ) and PHB yield (0.43 g (g glucose) −1 ). WH2 gave the highest PHB concentration (51.1 g l −1 ) and content (0.7 g g −1 ).
Sergio O Sernasaldivar - One of the best experts on this subject based on the ideXlab platform.
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functionality and characterization of kafirin rich protein extracts from different whole and decorticated sorghum genotypes
Journal of Cereal Science, 2016Co-Authors: Johanan Espinosaramirez, Sergio O SernasaldivarAbstract:Abstract The study of food-grade isolated kafirin proteins has increased recently due to the interest of their potential applications in gluten-Free products. However, functionality of extracted proteins and fractions have been poorly characterized. In this investigation, kafirins were extracted from whole or decorticated sorghum genotypes (white-regular, white-waxy, red-regular and high-tannin) with 70% aqueous ethanol with metabisulfite. Chemical composition, color parameters, functionality and molecular characterization of kafirin extracts were determined. When kafirin extracts were obtained from decorticated sorghums, higher protein purities (81.5–93.3%), lower lipid contents (1.9–12.6%), better color parameters, and higher yields were obtained compared to counterparts extracted from whole caryopses. Functional properties of the extracted kafirins showed low water solubility, Free Amino Nitrogen, and emulsifying activity, but adequate water holding and fat absorption capacities and in vitro protein digestibility. Differences in functionality were attributed to sorghum genotype. SDS-PAGE showed extraction of α1-, α2-, β-, and γ-kafirins with no contamination of other protein fractions. FTIR indicated a reduction in α-helix:β-sheet after extraction, especially in proteins obtained from decorticated sorghums. High correlations found from Pearson analysis could be used to optimize protein yield and the functionality (emulsifying activity and solubility) of the extracted proteins to be applied in gluten-Free food systems.
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effect of extrusion conditions and hydrolysis with fiber degrading enzymes on the production of c5 and c6 sugars from brewers spent grain for bioethanol production
Biofuel Research Journal, 2015Co-Authors: Erick Herediaolea, Esther Perezcarrillo, Sergio O SernasaldivarAbstract:The bioconversion of brewers’ spent grain into bioethanol was investigated in the present study using thermoplastic extrusion and the use of fiber degrading enzymes. The extrusion conditions i.e. tempering moisture, screws speed, and temperature of last zone of the barrel were taken into account in order to optimize the yield of C5 and C6 sugars during the subsequent enzymatic hydrolysis step of the fibers. The most important variable that affected the sugar yield was the extrusion temperature, followed by the screws speed. The best extrusion conditions were 20% tempering moisture, 200 rpm and 50 °C. No enzymatic and yeast inhibitors were detected in any of the enzymatically-treated fiber hydrolyzates. The fermentation resulted in 5.43 mL bioethanol per 100g of extruded brewers’ spent grain (dry weight basis). The only sugar consumed was glucose. The Free Amino Nitrogen amount quantified in the hydrolyzates was as low as >20 mg L-1, negatively affecting sugars consumption during the fermentation and consequently the ethanol yield.
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fate of Free Amino Nitrogen during liquefaction and yeast fermentation of maize and sorghums differing in endosperm texture
Food and Bioproducts Processing, 2013Co-Authors: Mayeli Peraltacontreras, Esther Perezcarrillo, Cristina Chuckhernandez, Gabriela Bandocarranza, Mariano Veragarcia, Nallely Gaxiolacuevas, Ranses Tamayolimon, Feliznando Isidro Cardenastorres, Sergio O SernasaldivarAbstract:Abstract Biofuels demands have motivated the increasing research in production technology as well as effective raw material utilization. Fusel alcohol production had been related with the Free Amino Nitrogen (FAN) content produced during hydrolyses stages and also as a stress response of Saccharomyces cerevisiae . This paper analyses the effect of grain type and endosperm texture on FAN production during starch liquefaction and yeast fermentation of maize, white and red sorghums bioconverted into ethanol. The white sorghum had a harder endosperm texture and upon milling produced a coarser granulation compared to the red counterpart. Therefore, the red sorghum produced higher amounts of FAN during liquefaction and the kinetics of these Nitrogenous compounds were metabolized faster during the first hours of yeast fermentation. The white and red sorghums yielded 13.6% and 2.7% lower ethanol compared to the maize counterpart. The white sorghum yielded the lowest amount of ethanol likely to its relatively harder endosperm texture that was less susceptible to biocatalysis and yeast fermentation.
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addition of protease during starch liquefaction affects Free Amino Nitrogen fusel alcohols and ethanol production of fermented maize and whole and decorticated sorghum mashes
Biochemical Engineering Journal, 2012Co-Authors: Esther Perezcarrillo, Sergio O Sernasaldivar, Cristina Chuckhernandez, Luisa M CortescallejasAbstract:Abstract The aim of this research was to study the effect of the dual treatment of sorghum decortication and protease addition during liquefaction with α-amylase, on the concentration of Free Amino Nitrogen (FAN), fusel alcohols and ethanol during yeast fermentation. A bifactorial experiment was designed to revise the differences among grains (maize, whole and 9.7% decorticated sorghum) and the effectiveness of protease addition during liquefaction. The decorticated sorghum was more susceptible to protein hydrolysis compared to the whole kernel sorghum due to its lower fiber content. The protease improved the levels of FAN approximately to 60% and 30% in the maize and sorghum mashes, respectively. The maize mash contained the highest amount of FAN followed by the decorticated and whole sorghum mashes. The protease treatment improved the fusel alcohol concentration in both sorghum beers and did not affect ethanol concentration in the maize mash. Both sorghum decortication and protease addition during liquefaction are therefore recommended treatments to obtain mashes with a higher FAN level. The decorticated protease-treated sorghum mashes yielded higher amounts of ethanol compared to the maize treatments and produced the maximum ethanol after only 20 h of fermentation. This research proved that a positive synergistic effect on FAN concentration, fusel alcohols and bioethanol yields can be achieved through the proposed proceeding of sorghum decortication and protease addition.
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evaluation of bioethanol production from five different varieties of sweet and forage sorghums sorghum bicolor l moench
Industrial Crops and Products, 2011Co-Authors: F J Davilagomez, Cristina Chuckhernandez, Esther Perezcarrillo, William L Rooney, Sergio O SernasaldivarAbstract:Abstract Cultivars of sweet (Rio, M81E and Della) and forage sorghums (Tato and Thor) were planted in Northeast Mexico in order to estimate optimum harvesting time, sugar production, biomass composition and ethanol yields. The juices were characterized in terms of sugar composition, Free Amino Nitrogen (FAN) and phenolics and then yeast ( Saccharomyces cerevisiae )-fermented into ethanol. The cultivars yielded different volumes of sweet juice and total sugars. They also had different optimum harvesting times. Glucose was the most abundant sugar in raw juices, followed by fructose and sucrose. FAN concentration ranged from 19 to 36 mg L −1 therefore, Nitrogen supplementation was required for adequate fermentation. After 18 h fermentation, there were no differences in efficiencies among cultivars but the sweet sorghums yielded more ethanol Ha −1 compared to the two forage sorghums (approximately 1000 L Ha −1 versus 770 L Ha −1 ). Della was the cultivar with the highest productivity with 1051 L Ha −1 ethanol produced after the first cut.
