Engineering CotA Laccase for Acidic pH Stability Using Bacillus subtilis Spore Display

( Silu Sheng ),( Han Jia ),( Sidney Topiol ),( Edgardo T. Farinas ) 한국미생물 · 생명공학회 2017 Journal of microbiology and biotechnology Vol.27 No.3

Bacillus subtilis spores can be used for protein display to engineer protein properties. This method overcomes viability and protein-folding concerns associated with traditional protein display methods. Spores remain viable under extreme conditions and the genotype/phenotype connection remains intact. In addition, the natural sporulation process eliminates protein-folding concerns that are coupled to the target protein traveling through cell membranes. Furthermore, ATP-dependent chaperones are present to assist in protein folding. CotA was optimized as a whole-cell biocatalyst immobilized in an inert matrix of the spore. In general, proteins that are immobilized have advantages in biocatalysis. For example, the protein can be easily removed from the reaction and it is more stable. The aim is to improve the pH stability using spore display. The maximum activity of CotA is between pH 4 and 5 for the substrate ABTS (ABTS = diammonium 2,2`-azino-bis(3-ethylbenzothiazoline-6-sulfonate). However, the activity dramatically decreases at pH 4. The activity is not significantly altered at pH 5. A library of approximately 3,000 clones was screened. A E498G variant was identified to have a half-life of inactivation (t_1/2) at pH 4 that was 24.8 times greater compared with wt-CotA. In a previous investigation, a CotA library was screened for organic solvent resistance and a T480A mutant was found. Consequently, T480A/E498G-CotA was constructed and the t_1/2 was 62.1 times greater than wt-CotA. Finally, E498G-CotA and T480A/E498G-CotA yielded 3.7- and 5.3-fold more product than did wt-CotA after recycling the biocatalyst seven times over 42 h.

Indirect Method for Quantification of Cellular Biomass in a Solidscontaining Medium Used as Pre-culture for Cellulase Production

F. M. Cunha,A. L. G. Bacchin,A. C. L. Horta,T. C. Zangirolami,A. C. Badino,C. S. Farinas 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.1

A process that combines the advantages of solid state fermentation (SSF) and submerged fermentation (SmF) could increase the efficiency of cellulase production required in the cellulosic ethanol industry. Due to the difficulty of measuring cellular biomass in the presence of solids, we developed a novel methodology for indirect quantification of biomass during production of the preculture for a combined fermentation process. Cultivation of Aspergillus niger was initiated as SSF using sugar cane bagasse as a solid substrate. Experiments were conducted in the absence of bagasse to determine growth kinetic parameters. Changes in glucose and biomass concentrations were measured. and the data were used for simulation employing a simple unstructured model. Parameters were estimated by applying a combination of Simulated Annealing (SA) and Levenberg-Marquardt (LM) algorithms to search for minimization of the error between model estimates and experimental data. Growth kinetics followed the Contois model, with a maximum specific growth rate (μmax) of 0.042/h, a yield coefficient for biomass formation (Yx/s) of 0.30 g/g and a death constant (kD) of 0.005/h.These parameters were used to simulate cellular growth in the solids-containing medium. The proposed model accurately described the experimental data and succeeded in simulating the cell concentration profile. The selected pre-culture conditions (24 h as SSF followed by 48 h as SmF) were applied for cellulase production using the combined fermentation process and resulted in an endoglucanase activity (1,052 ± 34 U/L) greater than that obtained using the conventional SmF procedure (824 ± 44 U/L). Besides the standardization of pre-culture conditions, this methodology could be very useful in systems where direct measurement of cell mass is not possible.

Japan's gastrodiplomacy as soft power: global washoku and national food security

Farina, Felice World Association for Triple Helix and Future Stra 2018 Journal of Contemporary Eastern Asia Vol.17 No.1

Until recently, Japanese cuisine was known only for sushi and was still considered exotic outside the archipelago. However, today the number of specialized restaurants which serve other traditional foods is constantly increasing all over the world, making Japanese gastronomy one of the most influential. Japanese government has supported the promotion of national cuisine worldwide in different ways, making washoku (Japanese traditional cuisine) one of the main elements of Japan's soft power and cultural diplomacy. In this paper, I will analyse the connection between Japan's gastrodiplomacy, defined as the use of typical food and dishes as an instrument of soft power, and Japan's food security strategy. I will argue that the strategy of promotion of washoku worldwide is not a mere act of popularization of Japanese food but it is strictly related to the issue of the low self-sufficiency rate of the country, as the main objective of the government is the raise of food export, in order to foster agricultural production and improve self-sufficiency.

Book Review: Katarzyna J. Cwiertka and Yasuhara Miho (2020) Branding Japanese food: From meibutsu to washoku University of Hawai'i Press (Honululu)

Farina, Felice World Association for Triple Helix and Future Stra 2021 Journal of Contemporary Eastern Asia Vol.20 No.1

EMG Pattern Recognition Using TFD for Future Control of In-Car Electronic Equipment

Ezreen Farina Shair,Radhi Hafizuddin Razali,Abdul Rahim Abdullah,Nurul Fauzani Jamaluddin 한국지능시스템학회 2022 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.22 No.1

Distracted drivers contribute to motor vehicle accidents. The maneuvering of in-car electronic equipment and controls, which typically requires the driver’s hands to be off the wheel and eyes off the road, are important factors that distract drivers. To minimize the interference of such distractions, a new control method is presented for detecting and decoding human muscle signals, which is known as electromyography (EMG). It is associated with various fingertips and pressures, and allows the mapping of various commands to control in-car equipment without requiring hands off the wheel. The most important step to facilitate such a scheme is to extract a highly discriminatory feature that can be used to separate and compute different EMG-based actions. The aim of this study is to accurately analyze EMG signals and classify finger movements that can be used to control in-car electronic equipment using a time–frequency distribution (TFD). The average root mean square voltage of seven participants and fourteen different finger movements are extracted as EMG features using a TFD. Four machine learning classifiers, i.e., support vector machine (SVM), decision tree, linear discriminant, and K-nearest neighbor (KNN), are used to classify pointing finger classes. The overall accuracy of the SVM precedes that of the other classifiers (89.3%), followed by decision tree (57.1%), linear discriminant (34.5%), and KNN (27.4%). The findings of this study are expected to be used in real-time applications that require both time and frequency information. Integrating the EMG signal to control in-car electronic equipment is expected to reduce the number of motor vehicle crashes globally.

Vascular compression syndromes: a pictorial review

Renato Farina,Pietro Valerio Foti,Isabella Pennisi,Tiziana Vasile,Mariangela Clemenza,Giuliana La Rosa,Luca Crimi,Marco Catalano,Francesco Vacirca,Antonio Basile 대한초음파의학회 2022 ULTRASONOGRAPHY Vol.41 No.3

Vascular compression syndromes include a group of rare vascular changes due to extrinsic compression of veins or arteries by surrounding structures. These pathologies are often underestimated due to their rarity, clinicians’ poor level of knowledge, and the non-specificity of their symptoms. The best known are Eagle syndrome, thoracic outlet syndrome, nutcracker syndrome, May-Thurner syndrome, Dunbar syndrome, and popliteal entrapment syndrome. This work summarizes the main ultrasonographic characteristics, symptoms, and treatments of choice for these syndromes. Knowledge of these conditions’ characteristic signs is essential for the differential diagnosis. Failure to diagnose these rare diseases can expose patients to serious complications and risks to their health.

The Wnt Receptor Ryk Reduces Neuronal and Cell Survival Capacity by Repressing FOXO Activity During the Early Phases of Mutant Huntingtin Pathogenicity

Tourette, Cendrine,Farina, Francesca,Vazquez-Manrique, Rafael P.,Orfila, Anne-Marie,Voisin, Jessica,Hernandez, Sonia,Offner, Nicolas,Parker, J. Alex,Menet, Sophie,Kim, Jinho,Lyu, Jungmok,Choi, Si Ho,C Public Library of Science 2014 PLoS biology Vol.12 No.6

<▼1><P>A study of Huntington's disease reveals that neurons might fail to cope with maintaining their function during the pre-symptomatic, pathogenic phases of HD, possibly due to the early repression of key longevity-promoting transcription factors by abnormal developmental signaling.</P></▼1><▼2><P>The Wnt receptor Ryk is an evolutionary-conserved protein important during neuronal differentiation through several mechanisms, including γ-secretase cleavage and nuclear translocation of its intracellular domain (Ryk-ICD). Although the Wnt pathway may be neuroprotective, the role of Ryk in neurodegenerative disease remains unknown. We found that Ryk is up-regulated in neurons expressing mutant huntingtin (HTT) in several models of Huntington's disease (HD). Further investigation in <I>Caenorhabditis elegans</I> and mouse striatal cell models of HD provided a model in which the early-stage increase of Ryk promotes neuronal dysfunction by repressing the neuroprotective activity of the longevity-promoting factor FOXO through a noncanonical mechanism that implicates the Ryk-ICD fragment and its binding to the FOXO co-factor β-catenin. The Ryk-ICD fragment suppressed neuroprotection by <I>lin-18</I>/Ryk loss-of-function in expanded-polyQ nematodes, repressed FOXO transcriptional activity, and abolished β-catenin protection of mutant htt striatal cells against cell death vulnerability. Additionally, Ryk-ICD was increased in the nucleus of mutant htt cells, and reducing γ-secretase PS1 levels compensated for the cytotoxicity of full-length Ryk in these cells. These findings reveal that the Ryk-ICD pathway may impair FOXO protective activity in mutant polyglutamine neurons, suggesting that neurons are unable to efficiently maintain function and resist disease from the earliest phases of the pathogenic process in HD.</P></▼2><▼3><P><B>Author Summary</B></P><P>Neuronal cell decline in neurodegenerative disease can be caused by inherited mutations and involves neuronal dysfunction followed by neuronal death. The ability of neurons to cope with the chronic stress induced by mutant protein expression may determine the course of their decline and eventual demise. Although the pathophysiological importance of these stress responses has been previously shown, very little is known about the signaling networks that regulate neuronal homeostasis during the early presymptomatic—but pathogenic—phases of a neurodegenerative disorder such as Huntington's disease (HD). In particular, it remains unclear whether neuronal differentiation factors regulate stress response pathways during neurodegenerative disease and how this might impact the overall capacity of neurons to cope with stress and maintain their function. Here, we show that the Wnt receptor Ryk, a protein known to be important for neurogenesis, is increased in different animal models of HD, before or during the early phases of the disease process. Interestingly, increased levels of Ryk repress activity of the FOXO proteins—a family of transcription factors that play a role in cell survival/longevity and in neuronal homeostasis and protection. Ryk represses FOXO protective activity, possibly directly, through its intracellular domain, a product of γ-secretase–mediated cleavage previously implicated in the birth of new cortical neurons. This highlights the regulation of HD neuron survival by a Ryk-dependent pathway that is distinct from canonical Wnt/Ryk signaling. From our findings, we postulate that neurons are unable to develop an efficient FOXO-mediated survival response during the very early, pathogenic phases of HD.</P></▼3>

Positive Dynamical Systems: New Applications, Old Problems

Luca Benvenuti,Lorenzo Farina 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.3

This review paper presents four relevant and very recent real-world application problems demanding developments of long-standing theoretical open problems in the field of positive systems research. Notably, the selected applications belong to very different fields of science and technology, ranging from biology and medicine to civil and electronic engineering. This clearly shows how pervasive positive systems are in mainstream research. Additionally, the theoretical issues stemming from these applications are the living proofs of how the apparently simple positivity constraint on the variables of interest makes the theory behind practical problems far from trivial, even for the linear case.

A SIMPLE TRANSFER FUNCTION TECHNTOUE FOR IMPEDANCE TUBE MEASUREMENTS

M. Garai,A. Farina,V. Scida 한국소음진동공학회 1994 한국소음진동공학회 국제학술대회논문집 Vol.1994 No.3

Homogeneous Synthesis and Characterization of Sulfonated Polyarylethersulfones Having Low Degree of Sulfonation and Highly Hydrophilic Behavior

Valentina Sabatini,Stefano Checchia,Hermes Farina,Marco Aldo Ortenzi 한국고분자학회 2016 Macromolecular Research Vol.24 No.9

In the present paper, the wettability of polyarylethersulfones (PESs) was promoted through the controlled introduction of sulfonic groups in PES polymeric chain. Homogeneous synthesis using a sulfonated comonomer introduced sulfonic groups while exerting a tight control over the degree of sulfonation (DS) and avoiding the undesired side reactions brought about by heterogeneous sulfonation reactions. A series of sulfonated polyarylethersulfones (SPESs) with very low amounts of sulfonic groups - 0.5, 0.75, and 1 meq SO3 -*g-1 of polymer - was synthesized via polycondensation using 4,4'-difluorodiphenylsulfone, 4,4'-dihydroxydiphenyl and a sulfonated comonomer, 2,5- dihydroxybenzene-1-sulfonate potassium salt. The presence of sulfonic groups was confirmed by Fourier transform infrared (FTIR) spectra; the macromolecular structure and the real DS of SPESs were determined by 1H NMR; the molecular weights were investigated by size exclusion chromatography (SEC); ion exchange capacity (IEC) values, measured by potentiometric titration, are in good agreement with the experimental DS. The polyelectrolyte effect was studied on intrinsic viscosity (IV) measurements. The effect of DS on the thermal properties of SPES membranes was studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC); wetting properties were characterized by static water contact angle (SWCA) measurements on membranes obtained via solution casting. The results showed that an increased DS results in higher glass transition temperatures (Tg) and lower water contact angles, the latter dropping from 91o to 43o as DS was raised from 0 to 1.0 meq SO3 -*g-1. This work demonstrates that homogeneous synthesis of SPES is an efficient way to prepare SPES membranes with tightly controlled DS and enhanced hydrophilic properties, in particular, an excellent hydrophilic SWCA even at very low amounts of sulfonic moieties.