Fermentation Yield Research Articles

Understanding the Fermentation Potentiality For Gibberellic Acid (GA3) Production Using Fungi.

Gibberellins represent an important group of potent phytohormones, growth-promoting, closely related diterpenoid acids biologically derived from tetracyclic diterpenoid hydrocarbon. Among these, gibberellic acid (GA3) has received the greatest attention. GA3 is a highly valued plant growth regulator which has various applications in agriculture. It is extensively used for beneficial effects including stem elongation, elimination of dormancy, sex expression, seed germination, flowering, and fruit senescence. Along with plants, many microbes are also producing GA3 as their secondary metabolite, and among these, fungi are reported to produce a higher amount of GA3. Fermentation technology based on submerged fermentation and solid-state fermentation for the production of GA3 has been used with its merits and demerits using Fusarium moniliforme fungus in the industry. Several mathematical models and optimization tools were also designed for enhancing the fermentative yield by researchers. The detailed analysis is essential to understand all the fermentation aspects, various unit parameters, process operation approaches, reduction in cost, and assessment of the possible uses of these models in the production of GA3 for higher yield. Recently, exclusive research is executed to lower down the production cost of GA3 approaching various strategies.

Modeling and Optimization of Processes for Craft Beer Production: Malt Mixture Modeling and Mashing Optimization for Lager Beer Production

Beer ranks third in terms of consumption worldwide, and its technology is constantly being improved and perfected. The boom in craft brewing has led to the production of thousands of new types of beer, but most often without scientific justification of the technological decisions made. This paper discusses the approaches to the modeling of the composition of the malt mixture and the mode of lager beer production. A special cubic simplex-lattice design with two replications was used to model the mixture with three malt types: Pilsner, Caramel Pils and Caramel Munich type 2. Models for the main brewing characteristics, i.e., wort extract and color, as well as models for the biological parameters of the mash, i.e., phenolic compound content and antioxidant potential, were developed using different methods. Multi-objective optimization was carried out and a specific mixture was developed for the production of lager beer. The influence of acidulated malt, lactic acid and CaCl2 additions on the extract yield and malt mash filtration time were established through one-factor experiments. The extract and fermentable sugar yield during individual pauses in the mashing mode was studied with a view to its optimization.

Preparation of a novel polymer microspheres and application in solid phase extraction combined with hollow fiber membrane system for capturing lactic acid from simulated fermentation broth

To separate the fermentation products in real time and improve the fermentation yield, a novel poly-4-vinylpyridine-vinylbenzeneboronic acid polymer microspheres (p4VP-VPBA) with bifunctional groups was prepared by suspension polymerization. The spherical p4VP-VPBA was 5–20 μm and thermally stable below 355.4 °C. The elemental contents of N and O were 1.36% and 5.72%, respectively, and the content of boronic acid was 0.1357 mmol/g. Its adsorption performance to lactic acid was satisfactory. Under pH 4 and 20 °C, the maximum static adsorption of p4VP-VPBA was up to 185.31 mg/g in 3 h. Its selectivity on lactic acid to glucose was 70.05 at pH 2, 7.71 at pH 4, and only 0.81 at pH 10, which indicated a good selectivity to lactic acid at low pH fitting to fermentation process. Furthermore, a p4VP-VPBA-combined with hollow fiber membrane (HFM) separation system was proposed and the removal rate of 5 mg/mL lactic acid was maintained at about 90% after 5 consecutive cycles. These data showed a huge potential for future real-time capturing lactic acid from fermentation, which also was a reference for other fermentation inhibited by product concentration.

Syngas Fermentation: Cleaning of Syngas as a Critical Stage in Fermentation Performance

The fermentation of syngas is an attractive technology that can be integrated with gasification of lignocellulosic biomass. The coupling of these two technologies allows for treating a great variety of raw materials. Lignin usually hinders microbial fermentations; thus, the thermal decomposition of the whole material into small molecules allows for the production of fuels and other types of molecules using syngas as substrate, a process performed at mild conditions. Syngas contains mainly hydrogen, carbon monoxide, and carbon dioxide in varying proportions. These gases have a low volumetric energy density, resulting in a more interesting conversion into higher energy density molecules. Syngas can be transformed by microorganisms, thus avoiding the use of expensive catalysts, which may be subject to poisoning. However, the fermentation is not free of suffering from inhibitory problems. The presence of trace components in syngas may cause a decrease in fermentation yields or cause a complete cessation of bacteria growth. The presence of tar and hydrogen cyanide are just examples of this fermentation’s challenges. Syngas cleaning impairs significant restrictions in technology deployment. The technology may seem promising, but it is still far from large-scale application due to several aspects that still need to find a practical solution.

Rapid and effective molten oxalic acid dihydrate pretreatment to enhance enzymatic saccharification for biohydrogen production by efficient coextraction of lignin and hemicellulose in wheat straw

Biohydrogen production from lignocellulose presents an enduring challenge due to the tough, rigid, and complex structure that endows the lignocellulose with high resistance to biodegradation. In the present work, a rapid and effective pretreatment method employing molten oxalic acid dihydrate (OAD) was proposed to enhance enzymatic saccharification for biohydrogen production through efficient coextraction of wheat straw. The molten OAD pretreatment at 110 °C achieves a 95 % cellulose retention, 95 % hemicellulose removal, and 81.3 % delignification within 5 min. Furthermore, an 85 % enzymolysis conversion rate and 114.04 mL/g total solids (TS) fermentative hydrogen yield can be obtained. The OAD pretreatment enhanced the feasibility of biomass refining and paves the way for a novel, fast and high-efficiency pretreatment method for advancing the productivity stage toward biohydrogen production from lignocellulosic biomass.

Structure modification of an antibiotic: by engineering the fusaricidin bio-synthetase A in Paenibacillus polymyxa.

Fusaricidin, a lipopeptide antibiotic, is specifically produced by Paenibacillus polymyxa strains, which could strongly inhibit Fusarium species fungi. Fusaricidin bio-synthetase A (FusA) is composed of six modules and is essential for synthesizing the peptide moiety of fusaricidin. In this study, we confirmed the FusA of Paenibacillus polymyxa strain WLY78 involved in producing Fusaricidin LI-F07a. We constructed six engineered strains by deletion of each module within FusA from the genome of strain WLY78. One of the engineered strains is able to produce a novel compound that exhibits better antifungal activity than that of fusaricidin LI-F07a. This new compound, known as fusaricidin [ΔAla6] LI-F07a, has a molecular weight of 858. Our findings reveal that it exhibits a remarkable 1-fold increase in antifungal activity compared to previous fusaricidin, and the fermentation yield reaches ~55 mg/L. This research holds promising implications for plant protection against infections caused by Fusarium and Botrytis pathogen infection.

Creating Polyploid Escherichia Coli and Its Application in Efficient L-Threonine Production.

Prokaryotic genomes are generally organized in haploid. In synthetic biological research, efficient chassis cells must be constructed to produce bio-based products. Here, the essential division of the ftsZ gene to create functional polyploid E. coli is regulated. The artificial polyploid E. coli containing 2-4 chromosomes is confirmed through PCR amplification, terminator localization, and flow cytometry. The polyploid E. coli exhibitsa larger cell size, and its low pH tolerance and acetate resistance are stronger than those of haploid E. coli. Transcriptome analysis showsthat the genes of the cell's main functional pathways are significantly upregulated in the polyploid E. coli. These advantages of the polyploid E. coli results in the highest reported L-threonine yield (160.3gL-1 ) in fed-batch fermentation to date. In summary, an easy and convenient method for constructing polyploid E. coli and demonstrated its application in L-threonine production is developed. This work provides a new approach for creating an excellent host strain for biochemical production and studying the evolution of prokaryotes and their chromosome functions.

Aureane-type sesquiterpene tetraketides as a novel class of immunomodulators with interleukin-17A inhibitory activity.

Interleukin (IL)-17A, a pro-inflammatory cytokine, is a fundamental function in the onset and advancement of multiple immune diseases. To uncover the primary compounds with IL-17A inhibitory activity, a large-scale screening of the library of traditional Chinese medicine constituents and microbial secondary metabolites was conducted using splenic cells from IL-17A-GFP reporter mice cultured under Th17-priming conditions. Our results indicated that some aureane-type sesquiterpene tetraketides isolated from a wetland mud-derived fungus, Myrothecium gramineum, showed remarkable IL-17A inhibitory activity. Nine new aureane-type sesquiterpene tetraketides, myrogramins A-I (1, 4-11), and two known ones (2 and 3) were isolated and identified from the strain. Compounds 1, 3, 4, 10, and 11 exhibited significant IL-17A inhibitory activity. Among them, compound 3, with a high fermentation yield dose-dependently inhibited the generation of IL-17A and suppressed glycolysis in splenic cells under Th17-priming conditions. Strikingly, compound 3 suppressed immunopathology in both IL-17A-mediated animal models of experimental autoimmune encephalomyelitis and pulmonary hypertension. Our results revealed that aureane-type sesquiterpene tetraketides are a novel class of immunomodulators with IL-17A inhibitory activity, and hold great promise applications in treating IL-17A-mediated immune diseases.

Lactic Acid Production from Steam-Exploded Sugarcane Bagasse Using Bacillus coagulans DSM2314

This work aimed at producing lactic acid (LA) from sugarcane bagasse after steam explosion at 195 °C for 7.5 and 15 min. Enzymatic hydrolysis was carried out with Cellic CTec3 and Cellic HTec3 (Novozymes), whereas fermentation was performed with Bacillus coagulans DSM2314. Water washing of pretreated solids before enzymatic hydrolysis improved both hydrolysis and fermentation yields. The presence of xylo-oligosaccharides (XOS) in substrate hydrolysates reduced hydrolysis efficiency, but their effect on fermentation was negligible. The presence of fermentation inhibitors in C5 streams was circumvented by adsorption on activated carbon powder with no detectable sugar losses. High carbohydrates-to-LA conversions (Yp/s) of 0.88 g·g−1 were obtained from enzymatic hydrolysates of water-washed steam-exploded materials that were produced at 195 °C, in 7.5 min, and the use of centrifuged-but-never-washed pretreated solids decreased Yp/s by 16%. However, when the detoxified C5 stream was added at a 10% ratio, Yp/s was raised to 0.93 g·g−1 for an LA productivity of 2.55 g·L−1·h−1. Doubling the pretreatment time caused a decrease in Yp/s to 0.78 g·g−1, but LA productivity was the highest (3.20 g·L−1·h−1). For pretreatment at 195 °C for 7.5 min, the elimination of water washing seemed feasible, but the use of longer pretreatment times made it mandatory to eliminate fermentation inhibitors.

Unveiling the Aromas and Sensory Evaluation of Hakko Sobacha: A New Functional Non-Dairy Probiotic Fermented Drink.

At the dawn of a food transition encouraging the consumption of healthy and sustainable non-dairy probiotic products, the development of a fermented functional drink based on Sobacha is considered. Sobacha is an infusion of roasted buckwheat seeds widely consumed in Asian countries for its health benefits. As fermentation improves the nutritional and organoleptic status of grains, the mixed fermentation process involved in the development of kombucha beverages (fermented sweet tea) is conducted by inoculating a symbiotic culture of bacteria and yeasts into the transposable matrix (Sobacha instead of tea). Sobacha, a healthy pseudo-cereal matrix with promising aromas, could be fermented to potentially develop an innovative drink, named "Hakko Sobacha". This neologism would reveal the fermented character of the infusion, Hakko meaning fermented in Japanese. Considering the beverage characterization, the kinetics of the volatile organic compound syntheses were determined using stir-bar sorptive extraction followed by gas chromatography coupled to mass spectrometry analysis. Odor-active compounds were theoretically calculated to estimate the flavor composition. Finally, sensory analyses highlighted the appreciation and preferences of the consumer towards the beverages. The fermentative yield differences observed between the two buckwheat concentration modalities tested seemed to be correlated with the sugar and nutrient levels available from the starch (buckwheat) matrix. Having characterized Hakko Sobacha, this study proposed the possibility of developing new beverages by monitoring the fermentative process. This should enable improved control and enhancement of their sensorial properties, which could in turn lead to greater customer acceptability.

Bioethanol production from alkali-pretreated rice straw: effects on fermentation yield, structural characterization, and ethanol analysis.

Current ethanol production technology has a dire need for efficient conversion of lignocellulosic biomass to fermentable sugars. The conversion requires pretreatment of the biomass, one of the most expensive steps, and thus it is quite necessary to identify the most cost-effective and high-efficiency conversion method. In this study, rice straw (RS) biomass was pretreated using 4% NaOH alkali, soaked for 4 h, and autoclaved for 30min. The structural and morphological changes were examined using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) analysis in both native and alkali-treated RS. The FTIR analysis revealed that native RS contains a considerable amount of lignin that was removed after the pretreatment process. The XRD pattern of the RS revealed an increasing crystallite size of the pretreated lignocellulosic biomass. The study of SEM clearly showed the distorted structure and surface porosity after the pretreatment process. Enzymatic hydrolysis efficiency was checked by comparing the commercial enzymes and microbial hydrolysis extracted from a fungal isolate. The best-reducing sugar yield obtained was 0.62g/L, achieved at optimized conditions from the commercial enzymes. Fermentation efficiency was checked using the yeast isolate Saccharomyces cerevisiae in both the native and pretreated substrate, and the highest ethanol concentration (21.45%) was achieved using 20% w/v biomass loading, enzyme loading (2:1:1), and fermentation for a week at 30°C and pH 4.5. This concentration was higher than that of the untreated RS (3.67%). The ethanol thus produced was further checked for analysis by the 1H and 13C nuclear magnetic resonance (NMR) methods.

Steam Explosion of Eucalyptus grandis Sawdust for Ethanol Production within a Biorefinery Approach

In this work, Eucalyptus grandis sawdust was subjected to steam explosion as the first step in cellulosic ethanol production within a biorefinery approach. The effect of the moisture content in the eucalypt sawdust (8 and 50%) and pretreatment process variables, such as temperature and residence time, were evaluated along with the influence of the water washing of steam-exploded solids on enzymatic hydrolysis and C6 fermentation yields. All other process streams were characterized to evaluate the recovery yield of valuable co-products. A recovery of nearly 100% glucans in the solid fraction and 60% xylans in the liquid fraction, mainly as partially acetylated oligomers, was obtained. The best enzymatic hydrolysis efficiencies (66–67%) were achieved after pretreatment at 205 °C for 10 min. The washing of pretreated sawdust with water improved the hydrolysis efficiencies and ethanol production yields by 10% compared to the unwashed pretreated solids under the same experimental condition. The highest ethanol yields were achieved after pretreatment of the sawdust with an 8% moisture content at 205 °C for 10 min, enzymatic hydrolysis at 13 wt% total solids with 25 FPU/g glucans, and fermentation with S. cerevisiae PE-2. In this case, 227 L ethanol and 40 kg total xylose (including xylo-oligomers) were obtained per ton of dry eucalypt sawdust.

Revealing the roles of carbonized humic acid in biohydrogen production

For low yield in dark fermentation (DF), in this study, the carbonized humic acid (CHA) was produced and added to DF for enhancing biohydrogen (bioH2) yield at mesophilic condition. The highest bioH2 yield was 151.08 mL/g glucose with the addition of CHA at 80 mg/L, which was 35.27% and 16.53% higher than those of 0 mg/L CHA and 80 mg/L mineral humic acid (MHA) groups, respectively. Electrons preferentially conducted via the butyrate pathway due to CHA amendments, which corresponded to the prediction of relevant functional genes. Furthermore, CHA possessed distinctive advantages over MHA, which acted as an electron shuttle to facilitate electron transfer, released metal ions as an essential signal mediator and favored the reduction of ferredoxin, obtaining more H2. The use of CHA in the field of H2-DF depicted the high-value utilization and industrial chain extension of MHA.

Enhanced fermentable sugar production in lignocellulosic biorefinery by exploring a novel corn stover and configuring high-solid pretreatment conditions

This study aimed to produce enhanced fermentable sugars from a novel stover system through the bioprocessing of its soluble sugars and insoluble carbohydrates. The pretreatment conditions were optimized for this high sugar-containing stover (HSS) to control inhibitor formation and obtain enhanced fermentable sugar concentrations. The optimum temperature, acid loading, and reaction time for the pretreatment were 155 °C, 0.5%, and 30 min, respectively, providing up to 97.15% sugar yield and 76.51 g/L total sugars at 10% solid-load. Sugar concentration further increased to 126.9 g/L at 20% solid-load, generating 3.89 g/L acetate, 0.92 g/L 5-hydroxymethyl furfural, 0.82 g/L furfural, and 3.75 g/L total phenolics as inhibitors. To determine the effects of soluble sugars in HSS on fermentable sugar yield and inhibitor formation, sugar-removed HSS was further studied under the optimum conditions. Although prior removal of sugars exhibited a reduction in inhibitor generation, it also decreased total fermentable sugar production to 115.45 g/L.

Optimization of Fermentable Sugars Production from Stale Bread using Response Surface Methodology

Background: Bread is the major waste product worldwide. It contains a considerable amount of starch, which is easily converted into sugars using enzymes. The aim of this study was to produce fermentable sugars from stale bread using barley malt as substitute of commercial enzymes. Methods: Response surface methodology based on Box-Behnken design was applied to optimize the parameters of enzymatic hydrolysis such as malt content (1.25, 2.5 and 3.75%), hydrolysis temperature (55, 62.5 and 70°C) and hydrolysis time (1, 1.5 and 2 h) to maximize fermentable sugars yield. Result: This study showed that malt content and hydrolysis temperature had a significant effect on fermentable sugars yield that increased with the increase in these two parameters. In contrast, hydrolysis time had no significant effect on fermentable sugars yield. The optimal parameters were 2.75% for malt content, 64.41°C for hydrolysis temperature and 1.31 h for hydrolysis time. At these optimal conditions, the fermentable sugars yield was at maximum reaching 63.21%. The results of this study suggested that barley malt could potentially be used to substitute commercial enzymes.

Myrtle (Eugenia gracillima Kiaersk.) as a fermented alcoholic beverage alternative to wine: Preliminary study

Myrtle (Eugenia gracillima Kiaersk.) is an underexploited fruit rich in bioactive compounds. It can be consumed fresh or processed into diverse products. This preliminary study aimed to develop myrtle-based fermented alcoholic beverages and evaluate the effects of different concentrations of total soluble solids (TSS), in which B1 (15 °Bx) and B2 (20 °Bx). Fermentation kinetics, fermentation yield, alcohol yield, productivity, physicochemical, phytochemical and color properties were determined. In addition, color degradation kinetics and correlation analyze (significant phytochemical and color parameters) were performed. A second-order polynomial model provided a good fit to fermentation data (R2 > 0.95). Fermentation of myrtle must with a lower TSS content resulted in higher fermentation yield (60.00%) and provided a beverage whose physicochemical parameters were within regulatory limits. Myrtle beverages were excellent sources of phenolic compounds (3478.66–3783.04 mg gallic acid equivalents 100 g−1). The beverage with higher TSS had a significantly stronger color (p ≤ 0.05). Color degradation kinetics were described by first-order (B1) and zero-order (B2) models, which revealed that redness (a*) was the most sensitive color parameter. There was a significant negative correlation (p ≤ 0.05) of most color parameters with phenolic compounds values, indicating that darker colored formulations have higher content of these phytochemical compounds. Industrial production of alcoholic fermentation of myrtle beverages is feasible and may represent an interesting income source for small-scale producers.

Advanced downstream processing of bioethanol from syngas fermentation

Syngas fermentation is used industrially to produce diluted bioethanol (about 1–6 wt%). This research study proposes a novel downstream process that recovers bioethanol in an energy-efficient and cost-effective manner, improves fermentation yield by recycling all fermentation broth components (microbes, acetate and water), and is designed for full-scale industrial-level application. Therefore, vacuum distillation at fermentation temperature was conceptually studied as an initial ethanol recovery step, leading to a bottom stream that may be recycled. Advanced separation and purification techniques were designed to recover 99.5% of initially present ethanol as high-purity product (99.8 wt%). Mechanical vapor recompression and heat integration methods were used to maximize sustainability and eco-efficiency of the proposed recovery process. Implementation of these techniques on a process using 6 wt% ethanol feed stream decreased the total annual costs by 54.2% (from 0.175 to 0.080 $/kgEtOH), reduced the primary energy requirement by 66.1% (from 2.82 to 0.96 kWthh/kgEtOH), lowered the CO2 emission by up to 82.6% (from 0.414 to 0.072 kgCO2/kgEtOH), and reduced the fresh water usage by 62.6% (from 0.242 to 0.091 m3W/kgEtOH). Sensitivity analysis for ethanol concentrations ranging from 6 to 1 wt% showed that the recovery costs and energy use increased to 0.336 $/kgEtOH and 1.78 kWthh/kgEtOH respectively. Since ethanol recovery performs better but fermentation will perform worse at higher ethanol concentration in fermentation broth, there is a trade-off concentration for the overall process. The current analysis is an important step toward determining this trade-off.

The Effect of Iron Oxide Nanoparticles on the Menaquinone-7 Isomer Composition and Synthesis of the Biologically Significant All-Trans Isomer.

Menaquinone-7 (MK-7) is the most therapeutically valuable K vitamin owing to its excellent bioavailability. MK-7 occurs as geometric isomers, and only all-trans MK-7 is bioactive. The fermentation-based synthesis of MK-7 entails various challenges, primarily the low fermentation yield and numerous downstream processing steps. This raises the cost of production and translates to an expensive final product that is not widely accessible. Iron oxide nanoparticles (IONPs) can potentially overcome these obstacles due to their ability to enhance fermentation productivity and enable process intensification. Nevertheless, utilisation of IONPs in this regard is only beneficial if the biologically active isomer is achieved in the greatest proportion, the investigation of which constituted the objective of this study. IONPs (Fe3O4) with an average size of 11 nm were synthesised and characterised using different analytical techniques, and their effect on isomer production and bacterial growth was assessed. The optimum IONP concentration (300 μg/mL) improved the process output and resulted in a 1.6-fold increase in the all-trans isomer yield compared to the control. This investigation was the first to evaluate the role of IONPs in the synthesis of MK-7 isomers, and its outcomes will assist the development of an efficient fermentation system that favours the production of bioactive MK-7.

Single batch co-production of Pseudomonad polyhydroxybutyrate and rhamnolipids on wasted cooking oil under salinity stress

Abstract Polyhydroxyalkanoates (PHAs) are emerging biodegradable bioplastics, and rhamnolipids are sustainable biosurfactants; both are considered as alternatives to synthetic petroleum-based plastics and surfactants, respectively. Herein, the effects of three distinct nitrogen sources on PHAs and rhamnolipid yields during the fermentation process have been undertaken. The study focuses on the optimum co-production of PHAs and rhamnolipid using a Pseudomonas aeruginosa strain grown on wasted soybean oil (WSO) with different nitrogen sources in the minimal salts’ media under salinity stress with shake flask conditions. The yields of PHAs and rhamnolipids were observed to be 2.20 g L−1 and 1.02 g L−1, respectively, with carbamide as the sole nitrogen and WSO (2 %, w/v) as the sole carbon source. The fermentative yields of both PHAs (2.37 g L−1) and rhamnolipids (1.24 g L−1) roughly increased up to 8 % under salinity stress. The products were characterized using advanced analytical techniques. The chemical structure of rhamnolipid with this strain had previously been elucidated, whereas the PHA produced was identified as a poly(hydroxybutyrate).

Effects on microstructures of decayed wood particles in spent mushroom substrates on the enzymatic saccharification and fermentation properties

Although spent mushroom substrates (SMSs) are considered to be candidate bioenergy feedstocks, there are large variations in the components and structural characteristics of SMSs. To elucidate the most important characteristics of SMSs for bioenergy production, we examined nine SMSs for their ethanol, hydrogen, and methane fermentation capacities, and analyzed their major components and microstructures. Although the lignin content was similar (25 % to 27 %) in six of the nine SMSs, their ethanol productivities varied (0.05–0.14 g/g holocellulose). The microstructure of the SMSs also varied greatly; fibrous to smooth surface. It was suggested that ethanol productivity was strongly influenced the microstructure other than lignin content. Of note, the SMS of Ganoderma sinense exhibiting fibrous surface showed ethanol and hydrogen fermentation yields (98 and 103 %) that were equivalent to those of Avicel, and approximately 70 % methane fermentation capacity, thus the SMS of G. sinese is considered to be a good candidate bioenergy feedstock.