Search Results (628)

Microbial coal gasification technology is a new, efficient, and clean method for coal resource mining; however, its commercial application remains limited by gasification efficiency and cost. To examine the impact of biomass on microbial coal gasification processes, improve gas production efficiency, and identify economically viable nutrient supplements with broad availability, this study employed culture medium (CM), sawdust (SD), and blue-green algae (BA) as nutritional additives. An anaerobic fermentation experiment with three-stage nutrient supplementation was conducted using a fed-batch reactor. The comparison of gas and liquid compositions within reactors throughout the reaction process demonstrated that key nutrient supplementation could reactivate methane production in reactors in which gas generation had ceased. Gas composition analysis revealed that under identical conditions, BA supplementation achieved the highest methane yield (24.49 ± 1.31 mL/g), followed by SD (1.56 ± 0.1 mL), representing 24.13-fold and 1.53-fold increases, respectively, compared with the yield in CM control group. Analysis of 16S rRNA sequencing indicated that nutrient supplementation induced microbial community differentiation, with dominant bacterial genera (Herbinix, Proteiniborus) shifting according to the organic composition of the liquid environment. A positive feedback relationship between microbial life activities and functional performance further confirmed the dominance of these superior strains. This study advances the understanding of substrate degradation characteristics in microbial coal degradation systems and provides theoretical support for the clean and efficient coal exploitation. Full article

This study investigates the efficient biogenic production of hydrogen via the thermophilic bacterium Thermotoga neapolitana, focusing on optimising process configurations to maximise yield and productivity. To determine optimal conditions, a 1 L anaerobic bioreactor with online gas analytics was designed and tested for batch, fed-batch and continuous fermentation. A maximum hydrogen production rate of 96.1 ± 1.7 Nml·L⁻¹·h⁻¹ was observed in the continuous reactor. The optimal dilution rate was 0.07 h⁻¹. Each dilution rate was kept for ≥56 h fermentation time and resulted in yields of 2.7–3.0 mol_H2·mol_glucose⁻¹. A consistently high cell viability (97%) was also observed across various dilution rates. A detailed carbon balance indicates acetate as the main by-product, closely linked to the hydrogen production pathway. Compared to fed batch and batch, the hydrogen production rate could be increased and remain constant over a longer time. In this way the continuous reactor design showed an additional method to produce hydrogen to the established ones. Fermentative hydrogen production is particularly promising when using carbohydrate containing biomass and biowaste, as it can be considered carbon dioxide neutral. Full article

Model-based approaches provide increasingly advanced opportunities for optimizing and accelerating bioprocess development. However, to accurately capture the complexity of biotechnological processes, continuous refinement of suitable models remains essential. A crucial gap in this field has been the lack of suitable model for describing Escherichia coli growth in cultivation media containing yeast extract, while accounting for key bioprocess parameters such as biomass, substrate, acetate, and oxygen. To address this, a published mechanistic macro-kinetic model for E. coli was extended with a set of mathematical equations that describe key aspects of the uptake of yeast extract. The underlying macro-kinetic approach is based on the utilization of amino acids in E. coli, where growth is primarily influenced by two distinct classes of amino acids. Using fed-batch cultivation data from an E. coli K-12 strain supplemented with yeast extract, it was demonstrated that the proposed model extensions were essential for accurately representing the bioprocess. This approach was further validated through fitting the model on cultivation data from five different yeast extracts sourced from various manufacturers. Additionally, the model enabled reliable predictions of growth dynamics across a range of yeast extract concentrations up to 20 g L⁻¹. Further differentiation of the data into batch and fed-batch revealed that for less complex datasets, such as those obtained from a batch phase, a simplified model can be sufficient. Due to its modular structure, the developed model provides the necessary flexibility to serve as a tool for the development, optimization, and control of E. coli cultivations with and without yeast extract. Full article

Natural disasters can disrupt communication services, leading to severe consequences in emergencies. Maintaining connectivity and communication quality during crises is crucial for coordinating rescues, providing critical information, and ensuring reliable and secure service. This study proposes FedResilience, a Federated Learning (FL) system for classifying Long-Term Evolution (LTE) network coverage in both normal operation and natural disaster scenarios. A three-tier architecture is implemented: (i) edge nodes, (ii) a central aggregation server, and (iii) a batch processing interface. Five FL aggregation methods (FedAvg, FedProx, FedAdam, FedYogi, and FedAdagrad) were evaluated under normal conditions and disaster simulations. The results show that FedAdam outperforms the other methods under normal conditions, achieving an F1 score of 0.7271 and a Global System Adherence ($S{A}_{\mathrm{global}}$) of 91.51%. In disaster scenarios, FedProx was superior, with an F1 score of 0.7946 and $S{A}_{\mathrm{global}}$ of 61.73%. The innovation in this study is the introduction of the System Adherence (SA) metric to evaluate the predictive fidelity of the model. The system demonstrated robustness against Non-Independent and Identically Distributed (non-IID) data distributions and the ability to handle significant class imbalances. FedResilience serves as a tool for companies to implement automated corrective actions, contributing to the predictive maintenance of LTE networks through FL while preserving data privacy. Full article

The logistic modeling of diauxic growth and biphasic antibacterial activity (AA) production was enhanced for four lactic acid bacteria (Lactococcus lactis CECT 539, Pediococcus acidilactici NRRL B-5627, Lactobacillus casei CECT 4043, and Enterococcus faecium CECT 410) during realkalized fed-batch fermentations. The improved growth model, also validated for describing the diauxic growth of Mos breed roosters and foals, overcomes a key limitation of the bi-logistic model, which assumes the existence of two distinct populations growing from the start of the culture, each following a different growth profile. In contrast, the improved logistic growth model developed in this study accounts for a single population growing at two rates, offering a fit to the experimental data comparable to that of the commonly used bi-logistic model. The enhanced model for product synthesis accurately describes biphasic AA production, assuming that antibacterial products are synthesized as growth-associated metabolites, depending on the final pH reached in the cultures at each sampling time. Additionally, it is easier to apply than the unmodified or modified differential forms of the Luedeking–Piret model. This study demonstrated, for the first time, the applicability of these two models in describing the diauxic growth and biphasic AA synthesis of LAB. Full article

Organic-waste-derived volatile fatty acids (VFAs) are promising substrates for fungal biomass cultivation, offering a nutrient-rich medium capable of meeting microbial growth requirements. However, the growth and biomass productivity are highly influenced by the VFAs’ composition and mode of operation. This study investigated the cultivation of Aspergillus oryzae fungal biomass using agro-industrial-derived VFA effluent, employing repeated-batch and fed-batch (stepwise and continuous-feeding) cultivation modes to evaluate fungal growth and biomass composition. The highest dry biomass yield of 0.41 dry biomass/gVFAs_fed (g/g) was achieved in fed-batch mode with continuous feeding, where the biomass exhibited pellet morphology, facilitating ease of harvesting. The crude protein content varied according to the cultivation strategy, reaching 45–53% in continuous-feeding fed-batch mode, while it was 34–42% in stepwise fed-batch mode. Additionally, the fungal biomass contained significant levels of essential macronutrients and trace elements, including Mg, Ca, K, Mn, and Fe, which are crucial if the biomass is intended to be used in animal feed formulations. This study highlights the effects of cultivation modes on biomass composition and the potential of VFA-derived fungal biomass as a sustainable feed ingredient. Full article

There is an increasing industrial demand for sustainable resources for lipid-based biofuels and platform chemical production. A promising, CO₂-efficient resource is autotrophically cultivated microalgae, either for direct single-cell oil (SCO) production or as a biomass substrate for fermentative SCO production via organisms like yeasts. Regarding the latter, chemical biomass hydrolysis typically results in high sugar yield and high salt concentrations due to the required neutralization prior to fermentation. In contrast, enzymatic hydrolysis is often lacking in mass efficiency. In this study, the enzymatic hydrolysis of both nutrient-replete and lipid-rich autotrophic Microchloropsis salina biomass was optimized, testing different pre-treatments and enzyme activities. Hereby, the protease treatment to weaken the cell wall integrity and the dosing of the Cellic CTec3 was identified to have the highest effect on hydrolysis efficiency. Sugar yields of 63% (nutrient-replete) and almost 100% (lipid-rich) could be achieved. The process was successfully scaled-up in mini bioreactors at a 250 mL scale. The resulting hydrolysate of the lipid-rich biomass was tested as a substrate of the oleaginous yeast Cutaneotrichosporon oleaginosus in a consumption-based acetic acid fed-batch setup. It outperformed both the model substrate and the glucose control, demonstrating the high potential of the hydrolysate as feedstock for yeast oil production. The presented sequential and circular SCO-producing value chain highlights the potential for mass- and space–time-efficient biofuel production, combining the autotrophic cultivation of oleaginous algae with decoupled yeast oil fermentation for the first time. Full article

Surfactants demonstrate considerable potential in enzymatic saccharification at high solids loading (ESHSL). In this paper, the effects of the non-ionic surfactant Tween 80 on enzymatic saccharification of Avicel and steam-exploded poplar (SEP) at high solid loading were studied. The results showed that under the fed-batch conditions of 15.0% solid loading, 20 FPU/g glucan, and 1.0% Tween 80, the maximum enzymatic saccharification rate of Avicel and SEP achieved was 65.4% (128.2 g/L glucose) and 86.4% (93.9 g/L glucose), respectively. Moreover, Tween 80 improved the rheological properties of ESHSL slurry of SEP, especially for the fed-batch model, reducing the complex viscosity, shear stress, and storage modulus. Furthermore, cellulase adsorption assays, SDS-PAGE, Rose Bengal staining, and Zeta potential analysis demonstrated that Tween 80 reduced non-productive adsorption of cellulase (particularly β-glucosidase) on lignin through hydrophobic interactions. All these findings contribute to establishing a foundation for subsequent investigative efforts within the discipline. Full article

The sustainable production of natural pigments is gaining attention as industries seek alternatives to synthetic additives. This study explored agro-industrial biowastes as feedstocks for carotenoid biosynthesis by Rhodotorula mucilaginosa (natural isolate from Jerusalem artichoke), aiming to identify an optimal substrate that combines high productivity with economic and environmental feasibility. Thirteen biowastes, including grape pomace, crude glycerol, chicken feathers, sugar beet juice, and pea protein isolate, were systematically evaluated for their impact on yeast growth and pigment accumulation. Carotenoid yields ranged from 21.4 to 187.2 mg/100 g dry weight, with the highest volumetric productivity achieved in pea protein isolate (14.98 mg/L), untreated white grape pomace (14.09 mg/L), and crude glycerol (13.87 mg/L). To assess scalability, a simplified techno-economic and sustainability analysis was applied, revealing that although pea protein isolate offered the best yields, its high market cost limited industrial feasibility. In contrast, untreated grape pomace and crude glycerol emerged as low-cost, abundant alternatives with strong circular bioeconomy potential. Fed-batch bioreactor validation using untreated grape pomace confirmed its suitability, achieving a 43% improvement in carotenoid productivity (20.1 mg/L) compared to shake-flask trials. These results position untreated grape pomace as the optimal substrate–strategy combination for sustainable carotenoid production linking agro-waste valorization with high-value bioproduct generation. This study provides both experimental evidence and economic rationale for integrating winery residues into industrial pigment production chains, advancing yeast biotechnology toward more circular and resource-efficient models. Full article

Background/Objectives: Hepatitis B virus (HBV) infection poses a major global health challenge, with current therapies like nucleos(t)ide analogs and pegylated interferon alpha offering limited functional cure rates due to persistent HBsAg-driven immune tolerance. This study aimed to develop a targeted immunoadsorption system using a high-affinity humanized anti-HBsAg monoclonal antibody for efficient HBsAg and viral particle clearance, providing a novel approach to overcome therapeutic bottlenecks in chronic hepatitis B (CHB). Methods: A murine anti-HBsAg monoclonal antibody was humanized via complementarity-determining region grafting, resulting in HmAb-12 (equilibrium dissociation constant, K_D = 0.36 nM). A stable Chinese Hamster Ovary K1 (CHO-K1) cell line was established for high-yield expression (fed-batch yield: 8.31 g/L). The antibody was covalently coupled to agarose microspheres (coupling efficiency > 95%) to prepare the immunoadsorbent. Efficacy was evaluated through in vitro dynamic circulation assays with artificial sera and preclinical trials using an integrated blood purification system in two CHB participants. Clearance rates for HBsAg and HBV DNA were quantified, with safety assessed via blood component monitoring. Results: In vitro, a single treatment cycle achieved HBsAg clearance rates of 70.14% (high antigen load, >10⁵ IU/mL) and 92.10% (low antigen load, ~3000 IU/mL). Preclinically, one treatment session resulted in acute HBsAg reductions of 78.30% and 74.31% in participants with high and moderate antigen loads, respectively, alongside HBV DNA decreases of 65.66% and 73.55%. Minimal fluctuations in total protein and albumin levels (<15%) confirmed favorable safety profiles, with no serious adverse events observed. Conclusions: Preliminary findings from this study indicate that the HBsAg-specific immunoadsorption system can achieve efficient HBV antigen clearance with an initial favorable safety profile in a small cohort. These results support its further investigation as a potential therapeutic strategy for functional cure in CHB. Future work will focus on validating these findings in larger studies and exploring the system’s combinatory potential with existing blood purification platforms. Full article

The development of efficient strategies for optimizing and controlling nonlinear bioprocesses remains a significant challenge due to their complex dynamics and sensitivity to operating conditions. This work addresses the problem by proposing a two-step methodology applied to a laboratory-scale fed-batch bioethanol process. The first step employs a dynamic optimization approach based on Fourier parameterization and orthonormal polynomials, which generates smooth and continuous substrate-feed profiles using only three parameters instead of the ten required by piecewise approaches. The second step introduces a controller formulated through basic linear algebra operations, which ensures accurate trajectory tracking of the optimized state variables. Simulation results demonstrate a $3.65\%$ increase in ethanol concentration at the end of the process, together with an accumulated tracking error of only $0.0189$ under nominal conditions. In addition, the closed-loop strategy outperforms open-loop implementation when the initial conditions deviate from their nominal values. These findings highlight that the proposed methodology reduces mathematical complexity and computational effort while producing continuous control profiles suitable for practical application. The combination of optimization and algebraic control thus provides a promising alternative for improving the efficiency of bioethanol-production processes. Full article

To achieve the large-scale, low-cost preparation of acetaldehyde lyase (ALS), elastin-like polypeptides (ELPs) as non-chromatographic purification tags were employed to develop an ELP-ALS fusion protein in Escherichia coli. Induction expression results demonstrated that the ELPs tag efficiently improved the soluble expression of the ALS enzyme. Through two rounds of inverse transition cycling (ITC), highly pure ELP-ALS was obtained with an enzyme recovery rate of 85.77%, outperforming Ni²⁺-affinity chromatography (66.80%). The comparative analysis of enzymatic properties revealed that ELP fusion markedly improved the stability and substrate tolerance of the ALS enzyme. Kinetic parameter analysis under identical conditions showed that ELP-ALS possessed a V_max of 15.25 U/mg and a k_cat/K_m of 73.05 s⁻¹·M⁻¹, representing 1.86-fold and 2.97-fold improvements over His-ALS, respectively. Fed-batch reaction using ELP-ALS and acetaldehyde as biocatalyst and substrate, respectively, yielded 95.92 g/L acetoin with 49.32% increase compared to His-ALS (64.24 g/L). These results demonstrated the application potential of ELP-ALS as a promising biocatalyst for acetoin production from acetaldehyde due to its lower preparation cost, higher biocatalytic efficiency, better stability, and substrate tolerance. Full article

Direct-fed microbials (DFM) have emerged as a promising dietary strategy for enteric methane abatement. However, it is unclear whether in vitro studies trialing DFM should use ruminal fluid previously adapted to the DFM of interest or if the DFM can be directly added to an unadapted inoculum. Ten lactating, multiparous, rumen cannulated Holstein-Friesian cows were randomly allocated to one of two groups: 1) adapted, basal diet plus 4 g/d of a blend of Bacillus subtilis and Bacillus licheniformis (1.6 × 10⁹ CFU/g each), delivered via the rumen canula; and 2) naive, basal diet only. Ruminal fluid from both groups was incubated in an in vitro 24-h batch culture system with two rates of Bacillus spp. and three feed substrates (hay, pasture, cereal grain), resulting in 12 treatments. Methane production was 16% greater, and total volatile fatty acid concentration was 7% greater in incubations using adapted ruminal fluid compared to those using naive ruminal fluid; however, neither parameter was affected when Bacillus spp. was added to the batch incubation system. Future in vitro studies evaluating DFM should consider including a period of in vivo adaptation to mimic their potential impact under in vivo feeding conditions. Full article

Valorization of ricotta cheese exhausted whey (RCEW), a dairy by-product generated in large quantities worldwide, is essential to mitigate its environmental impact and unlock its economic potential. This study explores the use of RCEW as a substrate for polyhydroxyalkanoate (PHA) production by Azohydromonas lata DSM 1123. The substrate was characterized by low protein and fat contents and a relevant lactose concentration (3.81%, w/v). Due to A. lata’s inability to directly metabolize lactose, β-galactosidase supplementation was necessary. Mineral supplementation of pasteurized RCEW significantly improved both microbial biomass and PHA synthesis, achieving up to 25.94% intracellular PHA content, whereas pre-adaptation trials failed to enhance strain performance. Moderate nitrogen limitation in the substrate (C/N ratio 44) favored PHA synthesis (0.55 g/L) and 32.74% intracellular accumulation. Thermal treatments decreased initial microbial contamination, hence a balanced mixture of pasteurized–sterilized (75:25) substrate was used to modulate RCEW protein content without the inclusion of additional technological or chemical processing steps and without lactose loss or dilution. Bioreactor trials using optimized RCEW pre-treatment conditions led to a further increase in biomass (2.36 g/L) and PHA production (0.88 g/L), especially under fed-batch conditions. The extracted polymer was confirmed to be polyhydroxybutyrate (PHB), with high thermal stability and a molecular weight of 5.9 KDa. Full article

Hydrophobins are small, surface-active protein biosurfactants secreted by filamentous fungi with potential applications in industries such as pharmaceuticals, sanitation, and biomaterials. Additionally, hydrophobins are known to stabilize enzymatic processing of biomass for improved catalytic efficiency. In this study, Pichia pastoris was used to recombinantly express hydrophobin HFBI from Trichoderma reesei, a well-characterized fungal system used industrially for bioethanol production. Iterative optimization was performed on both the induction and purification of HFBI, ultimately producing yields of 86.6 mg/L HFBI and elution concentrations of 48 μM HFBI determined pure by SDS-PAGE, over a five-day methanol-fed batch shake flask induction regiment followed by a single unit operation multimodal cation exchange purification. This final purified material represents an improvement over prior approaches to enable a wider range of potential applications for biosurfactants. Full article