Bioprocess and Biosystems Engineering最新文献

Immobilized enzyme bioreactors provide a controlled reaction environment and integrated reaction-separation processes for biocatalysis. In this study, a biocatalytic process based on resin-immobilized nitrilase and a partial-mixed recirculating bed bioreactor was developed for the synthesis of 1-cyanocyclohexaneacetic acid, a gabapentin intermediate. The resin catalyst prepared by immobilizing the regioselective nitrilase AcN-S on the activated amino resin LX-1000EPHA achieved 99.12% immobilization yield, 73.40 U/g specific activity, and 95.42% activity recovery when loaded with 10 mg/g crude enzyme. The resin catalyst (100 g/L) could convert 1 M (148.2 g/L) substrate 1-cyanocyclohexaneacetonitrile to 1-cyanocyclohexaneacetic acid within 18 h, achieving a conversion of 95.40%. At a substrate concentration of 0.5 M, > 85% conversion could still be achieved after 15 batches. In a partial-mixed recirculating bed reactor, the resin catalyst (100 g/L) could completely convert 500 mM substrate within 10 h, and achieve > 90% conversion after 20 batches, with residual activity of 93.23%. Resin activation and cross-linking treatment after immobilization were found to improve operational stability, reduce protein leakage, and ensure high immobilization yield and activity recovery. The reactor provided a low-shear environment and recirculating flow, which together improve catalyst reusability and reduce product inhibition. The constructed reaction system provides a solution for the efficient conversion of slightly soluble/insoluble substrates and the integration of reaction and separation.

The conventional physical and chemical synthesis of nanomaterials is associated with multiple disadvantages, such as high energy consumption, high cost, time consumption, and the use of toxic chemicals that are not only hazardous in the manufacturing setup but are also harmful to the environment. To overcome such limitations, phytofabrication, i.e., the use of plants for the synthesis of nanoparticles is considered preferred as it is an inexpensive, sustainable, non-toxic, eco-friendly, and green approach. The current study aims to explore and compare the biological properties of green synthesized zinc oxide and zinc sulfide nanoparticles. The materials are prepared using eco-friendly chemistry, using an aqueous herbal extract of Bergenia ciliata. The materials are then subjected to comprehensive characterization techniques and biological studies using antibacterial, antifungal, antiparasitic, anticancer, antioxidant, and biocompatibility studies. Our comprehensive evaluation reveals that green-synthesized ZnS-NPs demonstrate superior antibacterial and anticancer properties compared to ZnO-NPs. Specifically, ZnS-NPs induced significant zones of inhibition (ZOI) of 24 ± 1.2 and 22 ± 0.8 mm against B. subtilis and E. coli, respectively, with a minimum inhibitory concentration (MIC) of 1.125 mg/mL. In contrast, ZnO-NPs displayed better dispersion behavior, along with enhanced antioxidant, antiparasitic, and antidiabetic activities. Notably, ZnO-NPs significantly inhibited both amastigote and promastigote forms of Leishmania tropica (KWH23), with MICs of 112 and 135 µg/mL, respectively, highlighting their strong therapeutic potential against leishmaniasis. However, none of the samples exhibit antifungal properties as they fail to inflict any zone of inhibition against the tested fungal strains. We thus conclude that the B. ciliata synthesized green ZnS-NPs and ZnO-NPs exhibit distinct but excellent therapeutic properties and that both the synthesized materials have the potential to be further explored in in vitro and in vivo studies.

Laccases, categorized as multicopper oxidases, are recognized for their multifaceted roles in ecosystems and their utility in diverse industrial applications. Laccases from higher fungi, specifically Ascomycota and Basidiomycota, have garnered significant research interest due to their elevated redox potentials and their capacity to degrade lignin in decaying wood, alongside other industrial uses. Here, we have conducted a comprehensive and systematic analysis on fungal laccases using Web of Science, Scopus, PubMed, and ScienceDirect. The genomic distribution, phylogenetic affiliation, and structural organization of laccase-encoding genes in higher fungal species were investigated, as were the catalytic mechanisms of the corresponding enzymes. Additionally, the study explores the correlation between structural domains and redox potential, as well as the impact of post-translational modifications like glycosylation on enzyme activity. Furthermore, the recent advancements in laccase engineering, employing strategies such as rational design, directed evolution, and heterologous expression are discussed. The review also explores the scope of "artificial intelligence and machine learning" in deducing the structure-function relationships, optimizing codon usage, predicting signal peptides, enhancing enzymatic performance, and developing host-specific genetic engineering techniques is also discussed for tailoring fungal laccases to meet the demands of industrial biocatalysis for improved activity and stability.

Industrial processes play a major role in environmental pollution, particularly through the discharge of sulfate-laden wastewater containing harmful metals and organic contaminants. The generation of sustainable energy and the management of industrial wastewater are pressing global challenges that require worldwide attention. Bioelectrochemical systems (BES) represent an emerging technology capable of simultaneously addressing both challenges by harnessing the metabolic processes of electroactive microorganisms to convert the chemical energy of organic substrates into electrical energy. Sulfate-reducing bacteria (SRB) are anaerobic microorganisms that converts sulfate to sulfide, facilitating the precipitation of heavy metals and other pollutants. SRB oxidize a broad spectrum of electron donors, and their ability to work in extreme environments and to decompose complex pollutants makes them promising options for treatment of sulfate- and metal-rich industrial effluents. The present study integrates metabolic and electrochemical insights to consolidate current knowledge on SRB-based bioelectroremediation systems, emphasizing their mechanisms, influencing factors, and electrode interactions, while also exploring design strategies and performance limitations. By outlining existing challenges and highlighting future opportunities, this study provides a framework for advancing SRB-BES applications in sustainable industrial wastewater treatment.

Pseudomonas aeruginosa poses a significant threat in clinical settings, acting as a major causative agent of bacteremia, particularly in immunocompromised patients. Intrinsic resistance of this bacterium necessitates the urgent need for novel anti-Pseudomonas agents. Current therapeutic strategies are becoming increasingly inadequate, emphasizing the importance of screening studies aimed at discovering new antimicrobials that can effectively target this resilient bacterium. In this context, the exploration of herbal remedies presents a promising avenue for the development of effective antimicrobial agents. Many herbs possess bioactive compounds with documented antimicrobial properties, which could serve as potential lead substances in the quest for new treatments against P. aeruginosa. In the current study, the effect of the aqueous extract of 38 plant tissues, which have been introduced as an antimicrobial plant in the available publications, was investigated on P. aeruginosa. This study was done on a standard strain which is known as causative agent of bacteremia to find new avenues against P. aeruginosa bacteremia. Extracts from flower buds of S. aromaticum, flower of P. granatum L. var. pleniflora, and fruit of R. coriaria were found as effective against P. aeruginosa. Combination effect of these extracts was primarily evaluated by double well synergy test, and it was found that P. granatum and R. coriaria extracts may have additive or synergistic antimicrobial effect. More evaluations were performed via checkerboard assay. Fractional inhibitory concentration index (FICI) was calculated as 0.84 which fall within the additive range (0.5 < FICI ≤ 1). These results suggest that the combination of P. granatum and R. coriaria extracts can provide a promising natural mixture with enhanced antimicrobial efficacy to treat P. aeruginosa bacteremia. So, it can be concluded that mixed extract is a valuable source of natural anti-Pseudomonas compounds which can be subjected for further studies regarding toxicity and formulation.

As pressure on the environment increases and urban populations continue to sprawl across, there is shortage of water resources, hence a strong need to improve wastewater treatment technologies emphasis to support sustainable water resource management. Aerobic granular microbial reactors is one of the advanced technologies that have shown great potential in enhancing wastewater treatment performance. The use of biocarriers in wastewater treatment systems depends on the capacity to attain microbial adhesion, formidable biofilm growth, and trigger deterioration of organic and developing contaminants. The porosity and hydrophobicity of biocarriers are important features of key materials that determine microbial colonization and activity. The new trends in biocarrier development have given rise to materials providing resilient microbial communities, the removal of recalcitrant contaminants, and the overall higher efficiency. The initiatives are more scalable, less expensive, and more environmentally friendly in comparison to conventional techniques of wastewater treatment. Moreover, the integration of the engineered biocarriers make the system more resistant to the changes in hydraulic and organic loading, which provides long-term sustainability and stability of the treatment activities. Further development of biocarrier technology is relevant to meet the continuously emerging challenges in wastewater treatment aligns with the scope of resource recovery and circular bioeconomy.

The CO₂ absorption-microalgae conversion (CAMC) system is a promising technology platform for simultaneous carbon capture and bioproduct generation. This work introduces potassium argininate (ArgK), an amino acid salt with dual functionality, as a novel component to enhance the performance of this CAMC system using Chlorella sp. L166. The ArgK-enhanced process significantly improved system performance, achieving a sevenfold increase in biomass carbon accumulation rate. The final biomass concentration also increased by 396.25% compared with the control. Furthermore, the technology effectively upgraded captured carbon into key biomolecules, boosting protein content by 331.73% to 512.79 mg/L and elevating carbohydrate content to 97.57 mg/L. This performance significantly surpassed that of conventional K₂CO₃-based systems, which resulted in limited protein accumulation. These findings demonstrate the dual role of ArgK as an efficient CO₂ absorbent and biochemical modulator, offering a promising pathway to improve both biomass carbon accumulation efficiency and the economic value of algal biomass. This strategy supports the development of biocompatible, high-performance CAMC system for carbon mitigation and bioresource valorization.

Lignocellulosic biomass, a renewable raw material for producing biobased products, has attracted significant attention in biorefinery. To efficient deconstruct the complex components in lignocellulose, development of pretreatment technologies is a key research focus. Practically, use of cost-effective and easily recyclable solvent to achieve high fractionation and enzymatic hydrolysis efficiency could prompt the valorization of lignocellulose. With the excellent nucleophilicity and reactivity, amine compounds have shown remarkable advantages in lignocellulose pretreatment. Hence, this review summarizes recent amine-based pretreatment strategies to explore their key roles in lignocellulose structural deconstruction, enhancement of sugar yields, and fermentability of substrates for biobased chemical production. Firstly, the effects of amine compounds on lignin removal, cellulose crystalline structure transformation, and improvement in enzymatic hydrolysis are reviewed. Subsequently, progress in synergistic pretreatment combining amine solvents with green systems such as ionic liquids, surfactants, and mechanical assistance is summarized, demonstrating the potential of integrated approach to enhance biomass fractionation, preserve lignin structure, and increase fermentable sugar yields. Meanwhile, this review also discusses the application of solid and liquid fractions obtained from amine-based pretreatment in microbial fermentation to produce bioethanol, L-lactic acid, and biobutanol. Finally, challenges remain in by-product control and solvent recovery in amine-based pretreatment, and prospects for its development in future biorefinery are systematically provided. Overall, amine-based pretreatment offers a sustainable pathway for efficient deconstruction and valorization of lignocellulose.

This study aimed to improve methyl tertiary butyl ether (MTBE) degradation and power production in microbial fuel cells (MFCs) by employing an iron nanoparticle-coated graphite carbon electrode (Fe-GCE), co-metabolites (sodium acetate (SAC) and glucose (GLS)), and surfactants (sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB)). Fe-GCE enhanced the roughness and hydrophilicity of the electrodes, thereby promoting their electrochemical activity. This study compared the use of polyvinyl alcohol/glutaraldehyde (PVA/GA) and Nafion 117 membranes and the impact of carbon sources and surfactants on the performance of MFCs. The optimal conditions achieved 97.9% MTBE removal (10 mg/L) within 96 h by employing SAC and SDS in Nafion 117-MFC with a voltage of 335 mV in synthetic wastewater. Fe-GCE exhibited minimal antibacterial action and iron leaching (< 0.3 mg/L in 30 days), suggesting its stability during wastewater treatment. Bacterial community profiling revealed that Bacillus, Alcaligenes, Trichococcus, and Magnetospirillum were the main MTBE degraders. Statistical analysis validated substantial improvement in MTBE removal and voltage yield with the use of additives, and that PVA/GA-MFC had performance similar to Nafion 117-MFC, providing a cost-effective alternative with potential commercial success. This study provides insights into the potential use of MFCs for treating recalcitrant pollutants while producing green energy, paving the way for eco-friendly waste management strategies.

The rising global demand for sustainable energy has directed significant attention towards biohydrogen production via dark fermentation of organic wastes. Accurate yield prediction is crucial for optimizing process conditions and enhancing overall process. This study aims to develop a robust and interpretable predictive framework that integrates kinetic modeling with a hybrid Bayesian Optimization-Artificial Neural Network (BO-ANN) approach for precise biohydrogen yield prediction. The core novelty lies in representing each substrate not as a simple category, but by its quantitative kinetic parameters from the Modified Gompertz equation, providing a biologically meaningful input. A comprehensive database compiled from the literature incorporates key process variables, including temperature, pH, residence time, and substrate concentration, along with kinetic parameters from the Modified Gompertz equation characterizing each substrate. The BO algorithm was employed to optimize the ANN architecture, and 5-fold cross-validation was used to evaluate model generalization ability. The proposed hybrid model achieved outstanding predictive performance (R² = 0.9980, RMSE = 0.0117, MAE = 0.0062), confirming its accuracy and robustness. Furthermore, SHAP analysis and correlation metrics provided interpretable insights into feature contributions, particularly the relevance of kinetic descriptors. Overall, the proposed BO-ANN framework offers a scalable, interpretable, and biologically grounded tool to improve predictive accuracy and support the design of more efficient and sustainable biohydrogen production systems.