Fermentation Research Articles

Process Simulation of Ethanol Production from Jerusalem Artichoke Stalk

Lignocellulosic biomass can serve as raw material for ethanol production. However, lignocellulosic biomass is a complex mixture of carbohydrates that need additional processes for efficient ethanol production, such as pretreatment and hydrolysis before fermented into ethanol. Therefore, this work mainly focused on the creation and simulation of a model of ethanol production from Jerusalem artichoke stalk (JAS) following experimental data and using the commercial software ASPEN Plus with and without a heat exchanger network (HEN). Alkaline hydrogen peroxide pretreatment (AHP) was the first step for this process. The optimal conditions of AHP were a mixture of 2% w/w sodium hydroxide (NaOH) and 4% v/v hydrogen peroxide (H2O2) at 10% (w/v) solid-liquid ratio and 121°C for 90 min. After treatment, 10% AHP-JAS loading was fed to enzymatic hydrolysis at 50°C and the fermentation process at 30°C. The simulation suggested that a feedstock of 60,000 kg of JAS could yield 3,482.16 kg ethanol. The purification section by the extractive distillation system had 12 stages, a distillate to feed mole ratio (D/F) of 0.13, and a reflux mole ratio (R/R) of 1.5. The purity of the ethanol product was higher than 97 wt%. After the model simulation, HEN was designed by using Aspen Energy Analyzer. After the installation of HEN in this process, the ethanol plant with HEN showed a better result, which at 16.24 percentages reduced total cost compared to the process without HEN.

Recent Progress on Fermentation and Antibacterial Applications of Surfactin

Recent Progress on Fermentation and Antibacterial Applications of Surfactin

Effect of Acetic Acid on Succinic Acid Production of Fungal Co-culture in Slurry Fermentation

The effect of initial acetic acid concentration on succinic acid production from biologically pretreated birchwood chip-soybean hull mixture using co-culture of Aspergillus niger, Phanerochaete chrysosporium, and Trichoderma reesei in a slurry batch fermentation set-up was investigated. Acetic acid was supplied in various initial concentration: 1.65 g/L, 3.75 g/L, and 5.85 g/L. Low initial acetic acid resulted in decline of succinic acid production which coincided with declining acetic acid concentration. On the other hand, both medium and high initial acetic acid sustained higher succinic acid production with nearly constant acetic acid concentration throughout the five-day slurry batch fermentation. The residual sugar concentration was also observed as this was indirectly affected by the presence of acetic acid in the mixture. The presence of acetic acid in the fermentation media plays a crucial role in the production of succinic acid from a non-conventional source, the fungal co-culture.

Embedding Aspen Custom Modeller for Bioethanol Fermentation Into the Aspen Plus Flowsheet Simulator

Commercial processes used to produce first generation biofuels are mature. In this study, a kinetic model using the equation-oriented process modelling tool Aspen Custom Modeller (ACM) was embedded into the process simulation environment of Aspen Plus and used to simulate industrial bioreactors with cell recycle for bioethanol production. To embed a native module in a process simulation environment, the legacy codes written in ACM were treated as a black box and integrated into the component-based framework. The compliance of ACM to Aspen Plus allows for proper integration of the reactor simulator developed for the fermentation process for bioethanol production using kinetic models. The aim of this research is to improve the ability to use custom kinetic models of fermentation processes, developed in equation-oriented modelling tools, within a sequential modular flowsheet simulator. The results obtained showed the accuracy of the selected kinetic model in ACM with less than 1% difference to industrial data, while a stoichiometric model showed approximately 9% difference to the industrial data. The simulation shows that ACM integrated into Aspen Plus allows for complex biological processes to be predicted accurately in terms of biomass growth, ethanol production and sugar consumption.

Effects of the Fermented Black Garlic Extract on Lipid Metabolism and Hepatoprotection in Mice

Effects of the Fermented Black Garlic Extract on Lipid Metabolism and Hepatoprotection in Mice

Flow velocities and flow profiles in a thoroughly mixed biogas fermenter

Das Durchmischen von Garsubstrat mittels mechanischer Ruhrwerke ist einer der wichtigsten Prozesse in der Biogasproduktion, jedoch mit hohen Energieeintragen und damit fur den Biogasanlagenbetreiber mit hohen Kosten verbunden. Die Optimierung von Ruhrwerken sowie des Ruhrmanagements gewinnt in den vergangenen Jahren immer mehr an Bedeutung. Zahlreiche wissenschaftliche Studien versuchen mittels Simulationen und Versuchen im Labormasstab Rheologie, Biologie und Stromungsgeschwindigkeiten im Fermenter zu untersuchen und zu beschreiben. Die Ergebnisse zeigen jedoch im Vergleich von Labor- und Praxisuntersuchungen noch erhebliche Abweichungen. Daher wurden mittels magnetisch-induktivem Messsystem die Stromungsgeschwindigkeiten an verschiedenen Stellen des Fermenters bei unterschiedlichen Trockensubstanzgehalten (TS) und Viskositaten des Garsubstrates ermittelt. Bei einem TS-Anstieg von 7,74 auf 10,75 % uber den Versuchszeitraum zeigten die Ergebnisse eine Abnahme der Stromungsgeschwindigkeiten von 8,71 bis 63,77 cm · s-1 auf 0,05 bis 37,36 cm · s-1. Bedingt durch den Anstieg des TS-Gehaltes reduzierten sich die mittleren Stromungsgeschwindigkeiten bei gleicher Ruhrwerkseinstellung um durchschnittlich 70 %. Erganzende Untersuchungen konnten belegen, dass mit einem Anstieg der dynamischen Viskositat die uber die Ruhrwerke induzierten Stromungen am Boden, aber auch an der Oberflache, so gering werden konnen, dass diese messtechnisch nicht mehr erfassbar sind. Diese Arbeit unterstutzt die These, dass es durch Reduktion der Stromungsgeschwindigkeiten zu „Totzonen“ im Fermenter kommen kann.

Role of Biotechnology in Food Processing

Biotechnology can be well-defined as the use of living bacteria and biological systems which is used to progress useful foods. It can also be definite as any industrial applications that use biotic entity, biotic organisms or their results, to make or renovate products or apply for certain use. Its time and again joins with the biomedical production and bioengineering fields, liable upon the different applications and tools operated. The applications and practices of biotechnology in food dealing out is immense and this take in the following applications such as – its consumption in fermentation of elements and also to enhance assets of the factual goods such as the taste, perfume, shelf-life, surface, quality and nutritional value of that exact food product. Biotechnology has a vital role in the creation of enzymes and the use of firm enzymes leads to the vital modifications in food. Biotechnology is used in the creation of food constituents; flavours, aroma, food essences and an array of other high valued-enhanced goods, genetically modified bacteria and crops. Food taxing and in diagnostics of food components the utilization of innovative technologies of biotechnology is done.

Descriptive sensory evaluation of gari produced from fermentation of cassava using some selected Rhizopus species

Two local varieties of cassava (Manihot esculenta crantz) pulps named “okoiyawo” and “odongbo” were fermented with pure Rhizopus oligosporus, R. nigricans and R. oryzae. The products were subsequently processed in to “gari” (a roasted fermented cassava meal), the form in which it is popularly consumed in Nigeria. The selected process variables are cassava varieties, starter culture and fermentation time (2, 4 and 6 days). Fifteen randomly selected and trained panelists in the University carried out descriptive sensory analysis which characterized color, taste, flavor, smoothness, moldability and consistency of “gari” and “eba”. The sensory evaluation of the samples showed that the creamy-white is the most dominant color. A peculiar flavor, fine, and sour “gari”, consistent and moldable “eba” was also obtained. The optimum fermentation time for sensory quality is 48 h (2 days). The samples produced from “odongbo” are of good quality than the ones produced from “okoiyawo”. The selected Rhizopus species had a significant effect on the taste, flavor, and moldability of “eba”. There were significant differences (p<0.05) in the consistencies of the “eba” samples. The highly consistent ones are “odongbo” products while the ones made from “okoiyawo” are mildly consistent. There were no significant differences (p<0.05) in the moldability of “eba” samples. Key words: Gari, Sensory evaluation, Rhizopus species.

Effect of the incorporation of graded levels of turmeric (Curcuma longa) on different qualities of stirred yoghurt

There is an increasing trend in yoghurt consumption due to the health benefits from the gut bacteria present in yoghurt. However, there is need to evaluate other inexpensive nutrient sources such as spices (turmeric) which contain a lot of phytochemicals to make yoghurt more nutritious. Fresh turmeric rhizome was sorted, washed, peeled and milled. Ethanol was added to obtain turmeric extract. The turmeric extract was added to the yoghurt before (YTBF) and after fermentation (YTAF) at different ratios of yoghurt: Turmeric (95:5, 90:10, 85:15, 80:20, 75:25 and 100:0). Proximate composition and sensory characteristics of the blends were determined using standard procedures. Results obtained show that the addition of turmeric extract to the yoghurt had significant (p < 0.05) effect on the parameters analyzed. The protein, fat, ash and carbohydrate content of YTBF samples ranged from 2.70 - 3.98, 1.56 - 1.74, 0.20 - 0.38 and 7.69 - 8.25%, respectively while that of sampled YTAF ranged from 2.64 - 3.85, 1.53 - 1.69, 0.24 - 0.54 and 7.87 - 8.26%, respectively. From the sensory scores, sample with the lowest level of turmeric extract (YTBF1) (95:5) was most preferred and compared favorably with the control sample based on colour, taste and overall acceptability. The incorporation of turmeric extract in yoghurt improved the nutrient content of the yoghurt samples. Increased levels above 10% (90:10) led to a more intense colour and spicy taste which did not appeal to the panelists. Key words: Yoghurt, turmeric, fermentation, proximate composition, sensory characteristics.

Effect of Processing on Phytochemicals and Nutrient Composition of Tiger Nut (Cyperus esculentus L)

The study investigated the effect of processing on phytochemicals and nutrient composition of tiger nut (Cyperus esclentus L). Tiger nut also is known as Earth-almond was purchased as dried tiger nut tubers, carefully selected to remove dust particles and shared into four sets. The first set was further air-dried (EAAd) for four days and blended using laboratory miller. The second, third and fourth sets were soaked in water for four days to rehydrate. After which the following processing methods were applied; blanching at 80°C for 10 minutes (EAB), soaking in water to ferment for 4 days (EAF) and dehydrated (EAD) by oven drying again after rehydration respectively. The 2nd-4th sets were then oven-dried at a temperature of 60°C for 17 hours before milling into flour. Results of proximate analysis of the processed Earth-almond showed EAF to have the highest concentration of protein (8.37 ± 0.12), carbohydrate (49.01 ± 0.17) and ash (6.20 ± 0.12). The highest lipid (7.55 ± 0.06) and crude fibre (19.50 ± 0.23) was recorded for EAD, while the highest moisture content was recorded for EAB (19.71 ± 0.35). EAF, significantly (p<0.05) improved mineral and amino acid contents; while processing generally reduced the phytochemical content when compared with the air-dried sample (EAAd).

Biological activity in hot water extract from fermented Coix lacryma-jobi L. var. mayuen Stapf. by Hericium erinaceum (Bull. : Fr.)

Biological activity in hot water extract from fermented Coix lacryma-jobi L. var. mayuen Stapf. by Hericium erinaceum (Bull. : Fr.)

Sunflower Protein Enzymatic Hydrolysates as a Medium for Vitamin B2 and B12 Biosynthesis

Lowering the costs of industrial fermentation processes is a current challenge of modern biotechnology. In this sense, has been studied the possibility to replace the conventional medium for vitamin B2 abd B12 biosynthesis with new effective medium from renuable plant-based sources. Riboflavin (vitamin B2) and cobalamin (vitamin B12) are essencial compounds in humans diets and their demand is increasing globally. Current manufacturing process of these vitamins is unsustainable because of using costly unreneable resources and generating hazardous wastes. Meat peptone is conventionally used as a nitrogen source during the fermentation process, however it is relatively expencive. Sunflower protein is a secondary product, which can be obtained from sunflower meal after oil extraction, and rich on its nutritional value. The objective of this study was to select and evaluate fermentative potential of sunflower protein and its enzymatic hydrolysates as a nitrogen source for riboflavin and cobalamin biosynthesis by evaluating the kinetic parameters of strains growth, specific substrate consumprion and formation of metabolites. The fermentation of strains was carried out using conventional mineral medium with meat peptone in 250 mL Erlenmeyer flasks, and the results obtained were compared with fermentation where sunflower protein and it’s enzymatic hydrolysates were used as a nitrogen source instead of meat peptone. It was observed that when compared with meat peptone, some strains show positive effect in growth when nitrogen source was substituted with sunflower protein enzymatic hydrolysates. This allows affirming that sunflower protein and its enzymatic hydrolysates are promising in the use as a nitrogen sourse for riboflavin and cobalamin biosynthesis. The characteristics and parameters of studied fermentation processes reveals their potential for residue products applications for obtaining products with high added value.

Innovative Production of Biosurfactant by Candida Tropicalis Ucp 1613 Through Solid-state Fermentation

Microbial surfactants are amphipathic molecules mainly produced by submerged fermentation, and capable of decreasing the surface and interfacial tension between two immiscible phases. However, their obtention by solid state fermentation (SSF) has gained attention due to the less complex equipment involved, less energy demand, low volumes of water and requirement of less solvent for extraction. Hence, the aim of this study was to evaluate the ability of Candida tropicalis UCP 1613 to produce biosurfactant through solid-state fermentation and determine its stability under different environmental conditions. A factorial design 24 was performed to determine the influence of four variables, which were inoculum size, temperature, and particle size and inductor volume on the surface tension. In addition, the stability of the biomolecule was analysed in different pH, temperature and salinity ranges. The results showed that yeast synthesized biosurfactant under all conditions tested. From the statistical analysis, it was bserved that all variables except the inductor concentration had a significant influence on the surface tension decrease. The lowest value 25.8 mN/m was detected at condition 8 (10-6 cells/mL; 31 °C; 32 mesh and 0 mL of the inductor). The biosurfactant displayed a good performance when analysing its activity in different temperature, salinity and pH ranges. The study showed the feasibility of the solid-state fermentation to obtain a biosurfactant with excellent activity produced by a yeast. At the same time this is the first report of its kind in the literature.

Evaluation of the Medium Fermentative Parameters for the Production of Biosurfactant Using the Candida Gloebosa

The environmental pollution issue related to the widespread use of synthetic surfactants in detergents since 1960s has worried both the scientific community and regulatory agencies, in view of the foaming in rivers and lakes that makes the aquatic environment visually polluted. In this context, biological surfactants have stood out over synthetics due to their biodegradability and biological origin, since they are naturally produced by the microorganisms’ metabolism. However, the production usually requires expensive fermentative media and still demands more efficient methodologies to make the process economically advantageous. To the best of our knowledge, there are no studies in the literature reporting the use of Candida gloebosa, which was collected in Antartica, for producing of biological surfactants. Faced with this, the present study aimed to evaluate some fermentative medium parameters in order to obtain ideal conditions for biosurfactant production using Candida gloebosa. For this purpose, the fermentation time (24, 48, 72 and 96 h), the concentration of residual potato frying oil (40, 60 and 90 g.L-1), the concentration of hydrated magnesium sulfate (MgSO4.7H2O) (0.1, 0.15, 0.2 and 0.3 g.L-1), and cells concentration (1 ± 0.2, 2 ± 0.3, 3 ± 0.2 e 4 ± 0.3 g.L-1) were evaluated. According to the results, all the four parameters investigated revealed similar production yields at their best condition with a biosurfactant production of about 4 g/L when were employed 72 h of fermentation time, 0.2 g.L-1 of MgSO4, 60 g.L-1 of residual potato frying oil and a cell concentration of 3 g.L-1. Finally, the obtained results were comparable to those already reported in the literature for the yeast of the same genus known as Candida lipolytica, which is used for biosurfactant production. These findings can be used as basis for future studies involving the modeling through neural networks, for instance, in order to obtain an optimized condition or even for biosurfactant production in larger scales.

Analysis of the Environmental Life Cycle of Bacterial Cellulose Production

Cellulose is one of the most abundant natural polymers on earth and is mainly produced by plants, although many bacteria, especially those belonging to the genus Gluconacetobacter, produce a very peculiar form of cellulose with mechanical and structural properties that can be exploited in numerous industrial applications. Studies about the kinetic of microorganism’s growth, helps the researchers understand more about how to obtain bacterial cellulose (BC) films, within specific measurement based on fermentation process. On the last two decades, the public and scientific interest has increased regarding the use and evolution of biodegradable plastics. Beside the fact that biodegradable plastics have the desired chemistry and physics properties that most of the synthetic plastics own, it can be obtained from renewable sources. The agroindustry residue Corn Steep Liquor (CSL) was used to replace the yeast extract and peptone as carbon and nitrogen sources aiming to minimize the cost, environmental impact and to add value to BC production. The culture medium that uses CSL to produce BC according to the life cycle analysis (LCA) showed a considerable reduction of environmental impacts. Considering a production for industrial application of the biomaterial, the reduction of production costs can also be high.Keywords: Bacterial Cellulose, Gluconacetobacter hansenii; Life Cycle Analysis, Environmental im

Effects of crude cowpea (Vigna unculata) meal supplemented with enzyme on nutrient digestibility and growth performance of broiler chickens

This study was designed to assess the digestibility of feed components and the growth performances of broilers fed on raw Cowpea based diet supplemented with fibrolytic enzyme (Naturzyme®). A control ration without Cowpea and enzyme was compared to six others rations in which raw cowpea was incorporated at 15 and 25% and supplemented with 350 and 500g enzyme/ton of feed. The experimental rations were randomly assigned to 252 twenty-one-day old Cobb500 broiler chickens in a 2x2 factorial design (two level of enzyme and two level of cowpea). At 49 days old, faeces were collected over a period of 3 days to assess the digestibility of feed components. The main results showed that the increasing rate of raw cowpea in the rations induced a linear decrease (p<0.05) in feed intake. The inclusion of 25% of cowpea in the ration irrespective of the rate of incorporation of the enzyme tends to increase the digestibility of feed component as compared to the control. Growth parameters of broilers inversely decrease with the incorporation rate of raw cowpea in the ration. The highest carcass yield (p<0.05) was recorded with 15% raw cowpea supplemented with 500g of enzyme per ton of feed. The relative weight of the gizzard increased significantly (p<0.05) with the increasing incorporation rate of raw cowpea in the diet with or without enzyme supplements. In conclusion, raw cowpea supplemented with enzyme did not substantially improve the growth performance of broilers. Other processing methods like boiled or fermented should be considered for better utilization of cowpea in broilers diet.

The small chain fatty acid butyrate antagonizes the TCR-stimulation-induced metabolic shift in murine epidermal gamma delta T cells.

The metabolic requirements change during cell proliferation and differentiation. Upon antigen-stimulation, effector T cells switch from adenosine-triphospate (ATP)-production by oxidative phosphorylation in the mitochondria to glycolysis. In the gut it was shown that short chain fatty acids (SCFA), fermentation products of the microbiota in colon, ameliorate inflammatory reactions by supporting the differentiation of regulatory T cells. SCFA are a major energy source, but they are also anabolic metabolites, histone-deacetylase-inhibitors and activators of G protein receptors. Recently, it was reported that a topical application of the SCFA butyrate promotes regulatory T cells in the skin. Here we ask if the SCFA butyrate, propionate and acetate affect the energy metabolism and inflammatory potential of dendritic epidermal T cells (DETC), the innate resident skin γδ T cell population. Using the Seahorse™ technology, we measured glycolysis and oxidative phosphorylation (OXPHOS) in a murine DETC cell line, 7-17, upon TCR-stimulation by CD3/CD28 crosslinking, with or without SCFA addition. TCR engagement resulted in a change of the ratio glycolysis/OXPHOS. A similar metabolic shift has been described for activated CD4 T cells. Addition of 5 mM SCFA, in particular butyrate, antagonized the effect. Stimulated DETC secrete cytokines, e.g. the pro-inflammatory cytokine interferon-gamma (IFNγ), and thereby regulate skin homeostasis. Addition of butyrate and propionate to the cultures at non-toxic concentrations decreased secretion of IFNγ by DETC and increased the expression of the immunoregulatory surface receptor CD69. We hypothesize that SCFA can dampen the inflammatory activity of DETC.

Effects of Isoamyl Acetate Production in Makgeolli According to Fermentation Conditions

Effects of Isoamyl Acetate Production in Makgeolli According to Fermentation Conditions

PREBIOTIC EFFECTS OF XYLANASE MODIFICATION OF ?-GLUCAN FROM OAT BRAN ON BIFIDOBACTERIUM BIFIDUM

Oat ?-glucan (BG) was isolated from oat bran, and the xylanase treatment was conducted to obtain modification of ?-glucan (MBG). The relative molecular weight (Mw) of BG and MBG was determined by gel permeation chromatography (GPC). Results demonstrated that the Mw of BG was reduced from 1.66×104 to 5.43×103. We assessed the prebiotic effect of BG and MBG on human colon Bifidobacterium bifidum?B. bifidum). Our findings suggest that the addition of BG and MBG resulted in a lower pH of the fermentation broths. Both lactic and acetic acid production increased in the fermentation broths. While BG was found to significantly promote the proliferation of B. bifidum, MBG had a greater effect on B. bifidum.

Refinery of Gamma- Aminobutyric Acid (GABA) from the Fermentation of Rice Bran Extract by Ultrafiltration

Gamma- Aminobutyric Acid (GABA) has been known as a bioactive related to the hyperglycemia, boosting the immune system, lowering blood pressure, inhabitation of development of cancer cells and assists the treatment of anxiety disorders. It has been supplied for human from germinated beans, cereal grains and tea. Recently, GABA has been also synthesized from the fermentation through the assimilation of glutamic acid by bacteria. In this paper, application of ultrafiltration (UF) for recovery of GABA from the fermentation broth of rice bran extract was investigated, with 1,000 Da of molecular weight cut off of membrane. Pretreatment of the broth by combination of centrifugation and microfiltration prior to UF improved the performance of UF process. Influence of operating pressure, in range of 2 -10 bar, was investigated and 6 bar was suitable value of operating pressure for UF of the fermentation broth. The mechanism of fouling in UF under influence of methods of pretreatment and operating pressure was also analysed, consequently, determined the flux decline model in UF. Compared to feed, content of protein in broth reduced 65 %, while, content of GABA was insignificantly changed, at 2.5 of concentration factor. Content of soluble solid, sugar and amino acid in the broth also reduced after UF process. It means that, UF process is potential technology for recovery of GABA from fermentation broth of rice bran extract.