Machine learning modeling and additive explanation techniques for glutathione production from multiple experimental growth conditions of Saccharomyces cerevisiae

Glutathione (GSH) production is of great industrial interest due to its essential properties. This study aimed to use machine learning (ML) methods to model GSHproduction under different growth conditions of Saccharomyces cerevisiae, namely cultivation time, culture volume, pressure, and magnetic field application. Different ML and regression models were evaluated for their statistics to select the most robust model. Results showed that eXtreme Gradient Boosting (XGB) was the best predictive performance model. From the best model, additive explanation techniques were used to identify the feature importance of process. According to variable analysis, the best conditions to obtain the highest GSH concentrations would be cultivation times of 72-96 h, low magnetic field intensity (3.02 mT), low pressure (0.5 kgf.cm-2), and high culture volume (3.5 L). XGB use and additive explanation techniques proved promising for determining process optimization conditions and selecting the essential process variables.

Increase of ibuprofen penetration through the skin by forming ion pairs with amino acid alkyl esters and exposure to the electromagnetic field

A method of increasing the permeability of ibuprofen through the skin using a rotating magnetic field (RMF) is presented. This study evaluated whether 50 Hz RMF modifies ibuprofen's permeability through the skin. Ibuprofen and its structural modifications in the form of ibuprofenates of isopropyl esters of L-amino acids such as L-valine, L-phenylalanine, L-proline, and L-aspartic acid were used in the research. To this end, Franz cells with skin as membrane were exposed to 50 Hz RMF with 5% ibuprofen and its derivatives in an ethanol solution for 48 h. Following the exposures, the amount of penetrated compound was analysed. Regardless of the compound tested, a significant increase in drug transport through the skin was observed. The differences in the first 30 minutes of permeation are particularly noticeable. Furthermore, it was shown that using RMF increases the permeability of ibuprofen from 4 to 244 times compared to the test without the RMF. The greatest differences were observed for unmodified ibuprofen. However, it is noteworthy that the largest amounts of the active substance were obtained with selected modifications and exposure to RMF. The RMF may be an innovative and interesting technology that increases the penetration of anti-inflammatory and anti-ache drugs through the skin.

Exposure to a rotating magnetic field as a method of increasing the skin permeability of active pharmaceutical ingredients

The paper presents a method of increasing the permeability of various active substances through the skin by means of a rotating magnetic field. The study used 50 Hz RMF and various active pharmaceutical ingredients (APIs) such as caffeine, ibuprofen, naproxen, ketoprofen, and paracetamol. Various concentrations of active substance solutions in ethanol were used in the research, corresponding to those in commercial preparations. Each experiment was conducted for 24 h. It was shown that, regardless of the active compound used, an increase in drug transport through the skin was observed with RMF exposure. Furthermore, the release profiles depended on the active substance used. Exposure to a rotating magnetic field has been shown to effectively increase the permeability of an active substance through the skin.

Current Strategies for Real-Time Enzyme Activation

Enzyme activation is a powerful means of achieving biotransformation function, aiming to intensify the reaction processes with a higher yield of product in a short time, and can be exploited for diverse applications. However, conventional activation strategies such as genetic engineering and chemical modification are generally irreversible for enzyme activity, and they also have many limitations, including complex processes and unpredictable results. Recently, near-infrared (NIR), alternating magnetic field (AMF), microwave and ultrasound irradiation, as real-time and precise activation strategies for enzyme analysis, can address many limitations due to their deep penetrability, sustainability, low invasiveness, and sustainability and have been applied in many fields, such as biomedical and industrial applications and chemical synthesis. These spatiotemporal and controllable activation strategies can transfer light, electromagnetic, or ultrasound energy to enzymes, leading to favorable conformational changes and improving the thermal stability, stereoselectivity, and kinetics of enzymes. Furthermore, the different mechanisms of activation strategies have determined the type of applicable enzymes and manipulated protocol designs that either immobilize enzymes on nanomaterials responsive to light or magnetic fields or directly influence enzymatic properties. To employ these effects to finely and efficiently activate enzyme activity, the physicochemical features of nanomaterials and parameters, including the frequency and intensity of activation methods, must be optimized. Therefore, this review offers a comprehensive overview related to emerging technologies for achieving real-time enzyme activation and summarizes their characteristics and advanced applications.

Rotating Magnetic Field-Assisted Reactor Enhances Mechanisms of Phage Adsorption on Bacterial Cell Surface

Growing interest in bacteriophage research and use, especially as an alternative treatment option for multidrug-resistant bacterial infection, requires rapid development of production methods and strengthening of bacteriophage activities. Bacteriophage adsorption to host cells initiates the process of infection. The rotating magnetic field (RMF) is a promising biotechnological method for process intensification, especially for the intensification of micromixing and mass transfer. This study evaluates the use of RMF to enhance the infection process by influencing bacteriophage adsorption rate. The RMF exposition decreased the t₅₀ and t₇₅ of bacteriophages T4 on Escherichia coli cells and vb_SauM_A phages on Staphylococcus aureus cells. The T4 phage adsorption rate increased from 3.13 × 10⁻⁹ mL × min⁻¹ to 1.64 × 10⁻⁸ mL × min⁻¹. The adsorption rate of vb_SauM_A phages exposed to RMF increased from 4.94 × 10⁻⁹ mL × min⁻¹ to 7.34 × 10⁻⁹ mL × min⁻¹. Additionally, the phage T4 zeta potential changed under RMF from −11.1 ± 0.49 mV to −7.66 ± 0.29 for unexposed and RMF-exposed bacteriophages, respectively.

Hydrodynamic review on liquid–solid magnetized fluidized bed

The magnetic field has been successfully used to intensify the liquid–solid contact performance in the fluidized bed, creating the magnetized fluidized bed (MFB). The MFBs with purely magnetizable particles and with the binary admixture of magnetizable and nonmagnetizable particles could be simply termed the pure MFB and admixture MFB, respectively. Their potential application in the chemical and biochemical industries has been thoroughly explored in the literature. However, a fundamental investigation on the hydrodynamics therein is far from sufficient, severely hindering the commercial application. For this reason, this review summarized the relevant findings, including (1) flow regime transition, (2) boundaries between two adjacent flow regimes, (3) unique features of the magnetically stabilized bed, (4) hysteresis phenomenon and bed voidage, (5) minimum fluidization velocity and terminal velocity, (6) numerical simulation and segregation of the admixture MFB, and (7) some explored applications. More importantly, the existing controversies and unsolved issues in this area were identified. Among others, the flow regime transition and unique hydrodynamic characteristics of each flow regime should be first clarified, only after which could the terminology describing all the flow regimes be unified and the results from different scholars be compared.

Studies of neutralization reaction induced by rotating magnetic field

This study reports on research results in the field of the neutralization process (weak acid–strong base) under the action of a rotating magnetic field. The main objective of this paper is to present the possibilities of this process application to obtain the mixing time. The results show that the applied magnetic field had a strong influence on the analyzed process. Enhancement of the mixing process under the action of the rotating magnetic field may be obtained using particles with magnetic properties. It is shown that the time, after which the equivalence point of the neutralization process is reached, may be considered a parameter to describe the mixing process. Based on the proposed definition of the mixing time, the dimensionless correlation for the relationship between the mixing number and the Reynolds number is presented. Furthermore, results for the realization of the neutralization process with the application of the rotating magnetic field and magnetic particles are also discussed.

Magnetized fluidized bed with binary admixture of magnetizable and nonmagnetizable particles

Magnetic fields were used to successfully improve the fluidization quality of magnetizable particles, forming the magnetized fluidized bed (MFB). Moreover, researchers found that the binary admixture of magnetizable and nonmagnetizable particles could also be used in the MFB, creating the admixture MFB. Consequently, the MFB technique is no longer restricted to the few magnetizable particles in nature and can be extended to numerous nonmagnetizable particles. Nevertheless, research on the admixture of MFB is far from sufficient, severely hindering its commercial application in the chemical and biochemical industries. To deepen our understanding in this area, this review summarizes the relevant findings, which mainly include (1) transport phenomena in the gas-solid admixture MFB with Geldart B particles; (2) elimination of the abnormal fluidization phenomena in the gas-solid admixture MFB with Geldart C particles; (3) flow regime transition of the liquid-solid admixture MFB under both the magnetization-FIRST and magnetization-LAST operation modes; and (4) application of the pure MFB in the fields of gas filtration and coal dry separation. Finally, critical comments are made on the shortcomings of the reported research with the hope that more efforts could be devoted to these aspects in the future.

Rotating magnetic field as tool for enhancing enzymes properties - laccase case study

The aim of this study was to analyse the effect of rotating magnetic field (RMF) exposition on the fungal laccase catalytic properties. The results obtained in the study revealed that RMF may positively alter the laccase activity. A significant increase in activities of 11%, 11%, and 9% were observed at 10 Hz, 40 Hz and 50 Hz, respectively. Exposure of laccase to the rotating magnetic field resulted in its increased activity at broader pH range and a slight shift in optimum pH from 4.0 to 4.5 at RMF with frequency 20 Hz. The results show that the enzyme activity, stability, and optimum pH can be significantly altered depending on the characteristic of the applied RMF. Application of rotating magnetic field opens a new way for controlling and directions of enzyme-based bioprocessing.

High-frequency, high-intensity electromagnetic field effects on Saccharomyces cerevisiae conversion yields and growth rates in a reverberant environment

Studies of the effects of electromagnetic waves on Saccharomyces cerevisiae emphasize the need to develop instrumented experimental systems ensuring a characterization of the exposition level to enable unambiguous assessment of their potential effects on living organisms. A bioreactor constituted with two separate compartments has been designed. The main element (75% of total volume) supporting all measurement and control systems (temperature, pH, agitation, and aeration) is placed outside the exposure room whereas the secondary element is exposed to irradiation. Measurements of the medium dielectric properties allow the determination of the electromagnetic field at any point inside the irradiated part of the reactor and are consistent with numerical simulations. In these conditions, the growth rate of Saccharomyces cerevisiae and the ethanol yield in aerobic conditions are not significantly modified when submitted to an electromagnetic field of 900 and 2400 MHz with an average exposition of 6.11 V.m^-1 and 3.44 V.m^-1 respectively.

On the performance of immobilized cell bioreactors utilizing a magnetic field

This review focuses on the performance of immobilized cell bioreactors utilizing a magnetic field. These reactors utilized immobilized cells on magnetic particles or beads as the solid phase. All published research papers dealing with the performance of immobilized cell bioreactors utilizing a magnetic field from the early 1960s to the present time were considered and analyzed. It was noted that many microorganisms such as Saccharomyces cerevisiae were immobilized on different supports in these reactors. These papers used the magnetic field for several purposes, mainly for the stabilization of magnetic particles to prevent their washout from the column while operating with relatively high substrate flow rates to enhance mass transfer processes. It was observed that most publications used an axial magnetic field. In addition, most of the magnetic particles were prepared by entrapment. Some comments are presented at the end of the review which show the gaps in this promising application.

Time Dependent Influence of Rotating Magnetic Field on Bacterial Cellulose

The aim of the study was to assess the influence of rotating magnetic field (RMF) on the morphology, physicochemical properties, and the water holding capacity of bacterial cellulose (BC) synthetized by Gluconacetobacter xylinus. The cultures of G. xylinus were exposed to RMF of frequency that equals 50 Hz and magnetic induction 34 mT for 3, 5, and 7 days during cultivation at 28°C in the customized RMF exposure system. It was revealed that BC exposed for 3 days to RMF exhibited the highest water retention capacity as compared to the samples exposed for 5 and 7 days. The observation was confirmed for both the control and RMF exposed BC. It was proved that the BC exposed samples showed up to 26% higher water retention capacity as compared to the control samples. These samples also required the highest temperature to release the water molecules. Such findings agreed with the observation via SEM examination which revealed that the structure of BC synthesized for 7 days was more compacted than the sample exposed to RMF for 3 days. Furthermore, the analysis of 2D correlation of Fourier transform infrared spectra demonstrated the impact of RMF exposure on the dynamics of BC microfibers crystallinity formation.