Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 70
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Bioresour Technol ; 395: 130370, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38266787

RESUMO

Molasses is a by-product from sugarcane processing industries that contains some useful natural compounds. This paper proposes a method to produce sucralose, a non-caloric sweetener, from sugarcane molasses. In the first step, sugarcane molasses was converted to dried molasses powder using the low-temperature spray drying process in order to preserve natural compounds. Response surface methodology and artificial neural network were used to determine the experimental condition for maximal bioactive compounds content and antioxidant activity. Dried molasses powder could be produced with maximal values of sucrose yield, total phenolic content, total flavonoid content and antioxidant activity. In the final step, sucralose was derived from dried molasses powder. The yield of molasses-derived sucralose obtained from the proposed method was 0.628±0.01 g/g dried molasses powder with the purity of 99.95±0.02 %. The proposed method paves the way to convert sugarcane molasses to a non-caloric sweetener for applications in food and pharmaceutical industries.


Assuntos
Melaço , Saccharum , Antioxidantes , Edulcorantes , Pós , Indústria Farmacêutica
2.
Bioresour Technol ; 393: 130101, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38013036

RESUMO

Ergothioneine (EGT) is a high-value natural antioxidant that cannot be synthesized by the human body. This study showed that Rhodotorula mucilaginosa DL-X01 can use untreated molasses and fish bone meal enzymatic hydrolysate as the substrates to synthesize EGT. By optimizing the growth conditions, the EGT yield reached 29.39 mg/L when molasses and fish bone meal (FBM) were added at 60 g/L and 400 g/L respectively. Finally, the EGT yield was increased to 216.25 mg/L by fed-batch fermentation in a 5 L bioreactor. Compared with the fermentation by yeast extract peptone dextrose medium, the feedstock cost of EGT production was reduced by 330.91 % by using molasses and FBM as substrates. These results showed that R. mucilaginosa DL-X01 can produce high-value EGT using two cheap processing by-products, molasses and FBM, which is of great significance for environmental protection and sustainable development.


Assuntos
Ergotioneína , Minerais , Rhodotorula , Animais , Humanos , Melaço , Análise Custo-Benefício , Fermentação , Produtos Biológicos
3.
Molecules ; 28(19)2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37836653

RESUMO

Among the family of sugarcane spirits, those made from juice are diverse and often produced in a traditional way. They must be distinguished from other sugarcane spirits, which are more widely produced and made from other sugarcane derivatives, such as molasses. These alcoholic beverages contribute significantly to the socio-economic development of many countries. However, despite ancestral know-how, there is a lack of contemporary data required to characterize some sugarcane juice spirits (SCJSs) and to overcome the current and future threats that producers will have to face. While preserving their authenticity and specificity, SCJS producers expect to improve and ensure sufficient yield and a superior quality product. Even if the scientific knowledge on these spirits is not comparable, the available data could help identify the critical points to be improved in the making process. This review aims to present the main SCJSs encountered worldwide, defining their specific features through some important aspects with, notably, references to the complex notion of terroir. To continue, we discuss the main steps of the SCJS process from harvesting to aging. Finally, we expose an inventory of SCJS's chemical compositions and of their sensory description that define the specific organoleptic properties of these spirits.


Assuntos
Saccharum , Saccharum/química , Bebidas Alcoólicas/análise , Melaço
4.
Vet Med Sci ; 9(5): 2269-2277, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37595292

RESUMO

BACKGROUND: In Ethiopia, locally available feed resources are commendable in livestock production to make the sector sustainable and productive. OBJECTIVES: This on-farm evaluation was conducted to evaluate the effect of urea-molasses-treated highland bamboo (Yushania alpina) leaves (UMTHBL) in lactating crossbred dairy cows' nutrient utilization, body performance, milk yield and quality and economic performance. METHODS: On-farm feeding trial was conducted using 12 lactating cows with initial body weight (328.08 ± 0.98 kg), initial milk yield (3.14 ± 0.78 L) of uniform parity (2) and stage of lactation (early) using a Randomized Complete Block Design. Three dietary treatments, namely, 6 h grazing (control) + concentrate (T1), control + UMTHBL ad lib (T2), control + untreated BL adlib (T3) with three replications were used. Analysis of variance was employed for the feeding trial data analysis. RESULTS: The UMTHBL increased more dry matter and nutrients intake than untreated. A significant difference (p < 0.05) was recorded between UMTHBL feeding (T2) and T1 and T3 in terms of increased milk yield. The highest (6.26 L) and the lowest (3.27 L) mean milk yield per day were recorded for cows fed UMTHBL and the control group, respectively. Urea-molasses treatment improved the crude protein (CP) and reduced fibres content than untreated. Treatment effects were not-significant (p > 0.05) for milk compositions. Similar to milk yield, dairy cows in T2 consumed more CP which is also reflected in higher body weight and economic benefit. CONCLUSION: It can be concluded that employing treatment technology for highland bamboo leaves could support the crossbred dairy cows' production in smallholder farmers.


Assuntos
Lactação , Leite , Feminino , Gravidez , Bovinos , Animais , Fazendas , Etiópia , Melaço , Peso Corporal , Nutrientes , Folhas de Planta , Suplementos Nutricionais
5.
Int J Biol Macromol ; 242(Pt 1): 124721, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37150380

RESUMO

This study presented for the first time the PHA-lipid interactions by circular dichroism (CD) spectroscopy, besides a sustainable PHA production strategy using a cost-effective microbial isolate. About 48 bacterial isolates were selected from multifarious Egyptian sites and screened for PHAs production. The Fe(AZU-A6) was the most potent isolate, and identified genetically as Priestia filamentosa AZU-A6, while the intracellular PHA granules were visualized by TEM. Sugarcane molasses (SCM) was used an inexpensive carbon source and the production conditions were optimized through a Factor-By-Factor strategy and a Plackett-Burman statistical model. The highest production (6.84 g L-1) was achieved at 8.0 % SCM, pH 8.0, 35 °C, 250 rpm, and 0.5 g L-1 ammonium chloride after 72 h. The complementary physicochemical techniques (e.g., FTIR, NMR, GC-MS, DSC, and TGA) have ascertained the structural identity as poly-3-hydroxybutyrate (P3HB) with a characteristic melting temperature of 174.5 °C. The circular dichroism analysis investigated the existence of interactions between the PHB and the different lipids, particularly 1,2-dimyristoyl-sn-glycero-3-phosphocholine. The ATR technique for the lipid-PHB films suggested that both the hydrophobic and electrostatic forces control the lipid-PHB interactions that might induce changes in the structuration of PHB.


Assuntos
Poli-Hidroxialcanoatos , Saccharum , Melaço , Poliésteres
6.
FEMS Microbiol Lett ; 3702023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-37073119

RESUMO

As a first step for the use of probiotics in a formula for cattle, it is required to have available low-cost culture medium(s) and efficient production conditions for the growth of probiotic bacteria and high production of cell biomass. De Man-Rogosa-Sharpe medium, used frequently for lactic acid bacteria (LAB) contains adequate ingredients for their growth but is very expensive for industrial application. The nutrients required for LAB growth are strain-dependent. In this work, traditional culture media were evaluated omitting and/or modifying ingredients in their composition, as carbon or nitrogen source, on the basis of their low-cost industrial waste, to select those supporting the most efficient growth. The results showed that the formulation of culture media containing fructose (0.5%) and molasses (1.0%) was better for the growth and production of cell biomass for all the strains assayed, except Lactobacillus gasseri CRL1421 growing in 1.5% corn syrup. FM902 yeast extract at concentrations between 1.5% and 2.5% was the most adequate for most of the strains. The LAB grown in the designed media maintained the beneficial properties for which they selected. The use of the culture media designed to produce biomass decrease production costs, which is an important step for the feasible industrial production of probiotic pharmaceuticals.


Assuntos
Lactobacillales , Probióticos , Bovinos , Animais , Biomassa , Melaço , Meios de Cultura , Fermentação
7.
Int J Mol Sci ; 24(6)2023 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-36982832

RESUMO

A large-scale application of sophorolipids (SLs) was blocked by their high production cost. One feasible way to reduce the cost of SL production is to develop cheap feedstocks as the substrates for SL fermentation. In the present work, cottonseed molasses (CM), a waste from raffinose production, was used as the hydrophilic substrate;, and cottonseed oil (CO) was used as a hydrophobic substrate for SL production by Starmerella bombicola CGMCC 1576. The primary optimization of carbon sources, nitrogen source and inorganic salts, produced 57.6 ± 2.3 g/L of total SLs and 24.0 ± 1.2 g/L of lactonic SLs on CM and CO, almost equal to the titer of SLs produced from glucose and oleic. A response surface method was applied to optimize the fermentation medium for growth and SL production of S. bombicola. The production of total SLs reached 58.4 ± 3.4 g/L, and lactonic SLs were elevated to more than 25.0 ± 1.9 g/L. HPLC-MS analysis showed that the compositions of SLs produced by S. bombicola on CM and CO were very similar to those on glucose and oleic acid. These results suggested that cottonseed molasses and cottonseed oil can be used as renewable cheap substrates for the reduced-cost production of SLs.


Assuntos
Óleo de Sementes de Algodão , Saccharomycetales , Melaço , Glicolipídeos/química , Ácido Oleico
8.
Mar Biotechnol (NY) ; 25(1): 192-203, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36635576

RESUMO

The polysaccharide WL gum is produced by the marine microorganism Sphingomonas sp. WG and presents great commercial utility potential in many industries especially in oil industries. However, the high fermentation cost limits its wide application. Therefore, an efficient production system at a lower cost was established using beet molasses to partially replace the commonly used carbon sources. Four different molasses were screened and their composition was investigated. One-factor design and RSM statistical analysis were employed to optimize the WL gum fermentation medium. The effects of molasses on the rheological properties and gene expression of WL gum were also investigated. The results showed that the pretreated beet molasses generated both high broth viscosity and WL gum production (12.94 Pa·s and 11.16 g/L). Heavy metal ions and ash were found to be the key factors in unpretreated and pretreated molasses affecting WL production. The cost-efficient production medium contained (g/L): sucrose 61.79, molasses 9.95, yeast extract 1.23, K2HPO4 1, MgSO4 0.1, ZnSO4 0.1 and the WL gum production reached 40.25 ± 1.15 g/L. The WL gum product WL-molasses showed the higher apparent viscosity, and viscous modulus and elastic modulus than WL-sucrose and WL-mix, which might be related to its highest molecular mass. The higher expressional level of genes such as pgm, ugp, ugd, rmlA, welS, and welG in WL gum synthesis in the mixed carbon source medium caused the high production and broth viscosity. This work provided a cost-efficient method for WL gum production.


Assuntos
Sphingomonas , Sphingomonas/genética , Sphingomonas/metabolismo , Sacarose/metabolismo , Melaço , Carbono/metabolismo , Fermentação , Meios de Cultura
9.
Appl Biochem Biotechnol ; 195(5): 2863-2881, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36435897

RESUMO

The competitiveness of bacterial cellulose (BC) production with plant cellulose can be achieved by production on cost-effective media. It was found that the bacterial cell number ratio of BC to culture medium increases over time so that from the fourth day, the entrapped cell number in the cellulose network exceeds the suspended cells. Optimization based on 23-full factorial showed that inoculum development at 50 rpm and the main culture process under static conditions significantly increases BC production. A cost-effective culture medium containing molasses (ML) and corn steep liquor (CSL) was developed based on the same C/N ratio to HS medium, with 7.24 g/l cellulose at C/N ratio 12.6 is competitive with maximum production 8.7 g/L in HS medium. The BC production cost was reduced about 94% using the proposed cheap and locally available medium containing ML and CSL, while BC mechanical properties increased by about 50%.


Assuntos
Celulose , Gluconacetobacter xylinus , Meios de Cultura , Bactérias , Melaço , Zea mays
10.
Artigo em Inglês | MEDLINE | ID: mdl-36554363

RESUMO

Coal dust pollution poses a serious public health threat. This study aimed to investigate the feasibility of creating a coal dust suppressant using molasses, a byproduct of the sugar industry. We studied the effects of a molasses solution of varying concentrations (i.e., ranging from 0% (pure water) to 40%) on the moisture, bonding, and wind erosion properties of coal dust. Overall, the effectiveness of the molasses increased with their concentration, and it manifested itself in the following way: (1) the molasses improved the anti-evaporation ability of wet coal dust. For example, the evaporation mass of the coal dust wetted using a molasses solution decreased by 82.8%; (2) molasses effectively agglutinated coal dust; (3) molasses can effectively decrease the surface tension and increase the viscosity of the wetting solution. The surface tension of the molasses solution reached 41.37 mN/m and the viscosity increased to 6.79 mPa·s; (4) molasses can significantly suppress the wind erosion of deposited coal dust, with its wind erosion mass decreasing 99.1%; finally, (5) the effectiveness of molasses at suppressing coal dust was discussed at a molecular level. This study highlights the feasibility of a low-cost and environment-friendly dust suppressant in coal mines.


Assuntos
Minas de Carvão , Carvão Mineral , Carvão Mineral/análise , Melaço , Poeira/análise , Poluição Ambiental , Minerais
11.
Environ Sci Pollut Res Int ; 28(45): 64374-64393, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34304359

RESUMO

In this article, sugarcane molasses and agave juice were compared as potential feedstocks for producing bioethanol in Mexico in terms of their environmental impact and economic factors. Life cycle assessment (LCA) using SimaPro was carried out to calculate environmental impacts by using a cradle-to-gate approach. A preliminary economic analysis was performed to determine the economic feasibility of the studied options. Also, capital goods costs were obtained using the Aspen Plus economy package. Moreover, a sensitivity analysis was involved to compare the environmental and economic viability of producing bioethanol from sugarcane molasses and agave juice. LCA results revealed that cultivation and fermentation were the most harmful stages when producing bioethanol from sugarcane molasses and agave juice, respectively. Furthermore, when it was derived from agave juice rather than sugarcane molasses, it had more environmental benefits. This was ascribed to the lower consumption rate of fertilizers, pesticides, and emissions given off from the former. Regarding financial aspects, the preliminary analysis showed that producing bioethanol was not economically viable when grid energy alone was used. However, if power from the grid is partially replaced with renewable energy, producing bioethanol becomes economically feasible, and sugarcane molasses is the most suitable feedstock.


Assuntos
Agave , Saccharum , Fermentação , Melaço , Energia Renovável
12.
Bioresour Technol ; 333: 125187, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33930671

RESUMO

Food waste (FW) is difficult to manage during thermal treatment. In this study hydrothermal carbonization (HTC) of FW was carried out at increasing temperatures and retention times using the approach of reaction severities (logR0 = 5.31-7.09). The hydrochar sample with the best-obtained energy yield was further pelletized using molasses as a binder at different ratios (5%, 10%, 20% and 30%). A conceptual framework was proposed using the circular economy concept. As severity increases, hydrochar yield declines while its fuel properties improve. Decarboxylation and dehydration allow functional groups to become impaired, including C-O and -OH. Carbon microspheres were observed on the hydrochar surface due to extensive FW carbonization. The pellets with 30% molasses as binder showed the highest mass density (1683.24 kg/m3), while the energy density for it was 37.54 GJ/m3. Food waste management will generate local employment and new business prospects by integrating HTC and pelletization.


Assuntos
Eliminação de Resíduos , Gerenciamento de Resíduos , Carbono , Alimentos , Melaço , Temperatura
13.
Braz. arch. biol. technol ; 64(spe): e21200658, 2021. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1285569

RESUMO

Abstract Food supplements have been increasingly investigated. Probiotics have several benefits for human and animal health and selenium (Se) is widely recommended against oxidative stress. In this context, the aim of this study was to develop a low-cost bioprocess to produce a functional food product comprising both probiotic and Se accumulation. Yeast cells of Saccharomyces boulardii CCT 4308 were cultivated using sugarcane molasses as substrate. Optimization studies were performed to evaluate the best medium composition for biomass production and Se-accumulation in batch and fed-batch systems. Optimized conditions were defined with a medium composed of 150 g L-1 sugarcane molasses and 12 g L-1 yeast extract, with feeding of 100 g L-1 sugarcane molasses and 100 μg mL-1 of Se incorporation after 4 h and 10 h of fermentation, respectively, during 48 h in STR (stirred tank reactor). Best biomass production reached 14.52 g L-1 with 3.20 mg Se g-1 biomass at 12 h. Process optimization led to 4.82-fold increase in biomass production compared to initial condition. A final Se-enriched S. boulardii CCT 4308 biomass was obtained, which is comparable to commercial products. An alternative probiotic yeast biomass was efficiently produced as a new food-form of Se supplement in a sustainable process using an inexpensive agro-industrial residue.


Assuntos
Selênio , Melaço , Biomassa , Probióticos , Saccharomyces boulardii
14.
Bioresour Technol ; 290: 121750, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31325842

RESUMO

Production of androstenedione (AD) and 9α-hydroxyandrostenedione (9α-OH-AD) by recombinant mycobacteria using untreated cane molasses and hydrolysate of mycobacterial cells (HMC) was investigated for the first time. B-vitamins feeding experiment and reverse transcription-PCR analysis showed that propionyl-CoA carboxylase (PCC) plays an important role in the phytosterol biotransformation of mycobacteria. The respective AD and 9α-OH-AD conversion ratios were increased by 2.91 and 1.48 times through coexpression of PCC and NADH dehydrogenase. The highest conversion ratios of AD and 9α-OH-AD obtained by using a co-feeding strategy of cane molasses and HMC reached 96.38% and 95.04%, respectively, and the total costs of carbon and nitrogen sources for the culture medium were reduced by 29.89% and 49.49%, respectively. Taking the results together, untreated cane molasses and HMC can be used for the economical production of steroidal pharmaceutical precursors by mycobacteria. This study offers an economical and green strategy for steroidal pharmaceutical precursor production.


Assuntos
Melaço , Mycobacterium , Androstenodiona , Bengala , Nitrogênio
15.
Biomolecules ; 9(8)2019 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-31357463

RESUMO

Modelling has recently become a key tool to promote the bioethanol industry and to optimise the fermentation process to be easily integrated into the industrial sector. In this context, this study aims at investigating the applicability of two mathematical models (Andrews and Monod) for molasses fermentation. The kinetics parameters for Monod and Andrews were estimated from experimental data using Matlab and OriginLab software. The models were simulated and compared with another set of experimental data that was not used for parameters' estimation. The results of modelling showed that µmax = 0.179 1/h and Ks = 11.37 g.L-1 for the Monod model, whereas µmax = 0.508 1/h, Ks = 47.53 g.L-1 and Ki = 181.01 g.L-1 for the Andrews model, which are too close to the values reported in previous studies. The validation of both models showed that the Monod model is more suitable for batch fermentation modelling at a low concentration, where the highest R squared was observed at S0 = 75 g.L-1 with an R squared equal to 0.99956, 0.99954, and 0.99859 for the biomass, substrate, and product concentrations, respectively. In contrast, the Andrews model was more accurate at a high initial substrate concentration and the model data showed a good agreement compared to the experimental data of batch fermentation at S0 = 225 g.L-1, which was reflected in a high R squared with values 0.99795, 0.99903, and 0.99962 for the biomass, substrate, and product concentrations respectively.


Assuntos
Etanol/metabolismo , Melaço/microbiologia , Técnicas de Cultura Celular por Lotes , Fermentação , Modelos Biológicos
16.
Bioresour Technol ; 279: 398-403, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30744925

RESUMO

Ensiling of sugarcane trash (SCT) and sugarcane stalks (SCS) was studied to assess the effects of molasses (MOL) and lactic acid bacteria (LAB) inoculant on methane potential. The experiment was run for 70 days and monitoring parameters were analyzed at days 0, 5, 15 and 70. Biochemical methane potential (BMP) tests performed with fresh and ensiled material at day 70 showed an increase in methane potential by 24.0%, 23.4%, 1.7% and 71.1% for SCSctr, SCTctr, SCTmol and SCTmol + lab, respectively. Such improved performance is explained by the formation of organic acids (mostly acetate and lactate) which were able to decrease the pH of the silages from 5.7-5.9 to 3.8-4.2 for all SCT treatments and from 5.9 up to 3.4 for SCS treatment. Thus, the ensiling process provided similar effects to a pre-treatment at low acid concentrations, which in turn improved the digestibility of the cellulosic biomass for methane production.


Assuntos
Biomassa , Fermentação , Metano/biossíntese , Saccharum/metabolismo , Anaerobiose , Resíduos de Alimentos , Melaço , Silagem/microbiologia
17.
Microbiologyopen ; 8(6): e00755, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30350356

RESUMO

Twenty-six different bacterial strains were isolated from samples taken from different locations Dammam, Saudi Arabia, for screening of their polyhydroxyalkanoate (PHA) production capability. The initial screening was conducted by staining with Sudan Black B and Nile Red, followed by examination under fluorescence and electron microscopes to characterize PHA granule formation. The PHA-producing bacterial isolates were identified using 16S rRNA gene analyses; the most potent bacterial strain was identified as Pseudomonas sp. strain-P(16). The PHA production capability of this strain in the presence of different low-cost carbon sources, such as rice bran, dates, and soy molasses, was analyzed. PHA production in the presence of rice bran, dates, and soy molasses was 90.9%, 82.6%, and 91.6%, respectively.


Assuntos
Biopolímeros/biossíntese , Poli-Hidroxialcanoatos/biossíntese , Pseudomonas/metabolismo , Biopolímeros/economia , Microbiologia Industrial/economia , Microbiologia Industrial/métodos , Melaço/análise , Melaço/microbiologia , Poli-Hidroxialcanoatos/economia , Pseudomonas/genética , Pseudomonas/isolamento & purificação , Resíduos/análise , Resíduos/economia
18.
Bioresour Technol ; 275: 430-433, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30579775

RESUMO

In the present investigation, several residues from agro-forestry industries such as rice straw acid hydrolysate, corn cob acid hydrolysate, tomato juice, cane molasses and orange pulp were evaluated as the economical source for the production of bacterial cellulose. The bacterial cellulose attained the significant yield of 7.8 g/L using tomato juice, followed by 3.6 g/L using cane molasses and 2.8 g/L using orange pulp after 7 days of incubation. Furthermore, the optimum pH and temperature of fermentation for maximum production of bacterial cellulose was 4.5 and 30 ±â€¯1 °C. The identified bacterium Acetobacter pasteurianus RSV-4 has been deposited at repository under the accession number MTCC 25117. The produced bacterial cellulose was characterized through FTIR, SEM, TGA and DSC and found to be of very good quality. The bacterial cellulose produced by identified strain on these various agro-waste residues could be a cost effective technology for commercial its production.


Assuntos
Acetobacter/metabolismo , Celulose/isolamento & purificação , Celulose/economia , Fermentação , Melaço
19.
Microb Cell Fact ; 17(1): 190, 2018 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-30501633

RESUMO

BACKGROUND: Efficient microbial production of chemicals is often hindered by the cytotoxicity of the products or by the pathogenicity of the host strains. Hence 2,3-butanediol, an important drop-in chemical, is an interesting alternative target molecule for microbial synthesis since it is non-cytotoxic. Metabolic engineering of non-pathogenic and industrially relevant microorganisms, such as Escherichia coli, have already yielded in promising 2,3-butanediol titers showing the potential of microbial synthesis of 2,3-butanediol. However, current microbial 2,3-butanediol production processes often rely on yeast extract as expensive additive, rendering these processes infeasible for industrial production. RESULTS: The aim of this study was to develop an efficient 2,3-butanediol production process with E. coli operating on the premise of using cost-effective medium without complex supplements, considering second generation feedstocks. Different gene donors and promoter fine-tuning allowed for construction of a potent E. coli strain for the production of 2,3-butanediol as important drop-in chemical. Pulsed fed-batch cultivations of E. coli W using microaerobic conditions showed high diol productivity of 4.5 g l-1 h-1. Optimizing oxygen supply and elimination of acetoin and by-product formation improved the 2,3-butanediol titer to 68 g l-1, 76% of the theoretical maximum yield, however, at the expense of productivity. Sugar beet molasses was tested as a potential substrate for industrial production of chemicals. Pulsed fed-batch cultivations produced 56 g l-1 2,3-butanediol, underlining the great potential of E. coli W as production organism for high value-added chemicals. CONCLUSION: A potent 2,3-butanediol producing E. coli strain was generated by considering promoter fine-tuning to balance cell fitness and production capacity. For the first time, 2,3-butanediol production was achieved with promising titer, rate and yield and no acetoin formation from glucose in pulsed fed-batch cultivations using chemically defined medium without complex hydrolysates. Furthermore, versatility of E. coli W as production host was demonstrated by efficiently converting sucrose from sugar beet molasses into 2,3-butanediol.


Assuntos
Beta vulgaris/química , Butileno Glicóis/química , Escherichia coli/metabolismo , Glucose/metabolismo , Engenharia Metabólica/métodos , Melaço/análise
20.
Bioresour Technol ; 250: 1-9, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29153644

RESUMO

Propionic acid (PA) is a specialty chemical; its calcium salt is widely used as food preservative. Soy molasses (SM), a low-value byproduct from soybean refinery, contains sucrose and raffinose-family oligosaccharides (RFO), which are difficult to digest for most animals and industrial microorganisms. The feasibility of using SM for PA production by P. acidipropionici, which has genes encoding enzymes necessary for RFO hydrolysis, was studied. With corn steep liquor as the nitrogen source, stable long-term PA production from SM was demonstrated in sequential batch fermentations, achieving PA productivity of >0.8 g/L h and yield of 0.42 g/g sugar at pH 6.5. Economic analysis showed that calcium propionate as the main component (63.5%) in the product could be produced at US $1.55/kg for a 3000-MT plant with a capital investment of US $10.82 million. At $3.0/kg for the product, the process offers attractive 40% return of investment and is promising for commercial application.


Assuntos
Fermentação , Propionibacterium , Cinética , Melaço , Propionatos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA