Chemical composition and bioactive compounds of garlic (Allium sativum L.) as affected by pre- and post-harvest conditions: A review

Lipases are the industrially important biocatalysts, which are envisioned to have tremendous applications in the manufacture of a wide range of products. Their unique properties such as better stability, selectivity and substrate specificity position them as the most expansively used industrial enzymes. The research on production and applications of lipases is ever growing and there exists a need to have a latest review on the research findings of lipases. The present review aims at giving the latest and broadest overall picture of research and development on lipases by including the current studies and progressions not only in the diverse industrial application fields of lipases, but also with regard to its structure, classification and sources. Also, a special emphasis has been made on the aspects such as process optimization, modeling, and design that are very critical for further scale-up and industrial implementation. The detailed tabulations provided in each section, which are prepared by the exhaustive review of current literature covering the various aspects of lipase including its production and applications along with example case studies, will serve as the comprehensive source of current advancements in lipase research. This review will be very useful for the researchers from both industry as well as academia in promoting lipolysis as the most promising approaches to intensified, greener and sustainable processes. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:5-28, 2018.

Recent advances on sources and industrial applications of lipases

It is now plausible to dock libraries of 10 million molecules against targets over several days or weeks. When the molecules screened are commercially available, they may be rapidly tested to find new leads. Although docking retains important liabilities (it cannot calculate affinities accurately nor even reliably rank order high-scoring molecules), it can often can distinguish likely from unlikely ligands, often with hit rates above 10%. Here we summarize the improvements in libraries, target quality, and methods that have supported these advances, and the open access resources that make docking accessible. Recent docking screens for new ligands are sketched, as are the binding, crystallographic, and in vivo assays that support them. Like any technique, controls are crucial, and key experimental ones are reviewed. With such controls, docking campaigns can find ligands with new chemotypes, often revealing the new biology that may be docking’s greatest impact over the next few years.

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Docking Screens for Novel Ligands Conferring New Biology.

YMR313c/TGL3 Encodes a Novel Triacylglycerol Lipase Located in Lipid Particles of Saccharomyces cerevisiae

In the past two decades, 7 coronaviruses have infected the human population, with two major outbreaks caused by SARS-CoV and MERS-CoV in the year 2002 and 2012, respectively. Currently, the entire world is facing a pandemic of another coronavirus, SARS-CoV-2, with a high fatality rate. The spike glycoprotein of SARS-CoV-2 mediates entry of virus into the host cell and is one of the most important antigenic determinants, making it a potential candidate for a vaccine. In this study, we have computationally designed a multi-epitope vaccine using spike glycoprotein of SARS-CoV-2. The overall quality of the candidate vaccine was validated in silico and Molecular Dynamics Simulation confirmed the stability of the designed vaccine. Docking studies revealed stable interactions of the vaccine with Toll-Like Receptors and MHC Receptors. The in silico cloning and codon optimization supported the proficient expression of the designed vaccine in E. coli expression system. The efficiency of the candidate vaccine to trigger an effective immune response was assessed by an in silico immune simulation. The computational analyses suggest that the designed multi-epitope vaccine is structurally stable which can induce specific immune responses and thus, can be a potential vaccine candidate against SARS-CoV-2.

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A candidate multi-epitope vaccine against SARS-CoV-2.

blaVEB-1 is an integron-located extended-spectrum β-lactamase gene initially detected in Escherichia coli and Pseudomonas aeruginosa strains from south-east Asia. Several recent studies have reported that VEB-1-positive strains are highly resistant to ceftazidime, cefotaxime and aztreonam antibiotics. One strategy to overcome resistance involves administering antibiotics together with β-lactamase inhibitors during the treatment of infectious diseases. During this study, four VEB-1 β-lactamase inhibitors were identified using computer-aided drug design. The SWISS-MODEL tool was utilized to generate three dimensional structures of VEB-1 β-lactamase, and the 3D model VEB-1 was verified using PROCHECK, ERRAT and VERIFY 3D programs. Virtual screening was performed by docking inhibitors obtained from the ZINC Database to the active site of the VEB-1 protein using AutoDock Vina software. Homology modeling studies were performed to obtain a three-dimensional structure of VEB-1 β-lactamase. The generated model was validated, and virtual screening of a large chemical ligand library with docking simulations was performed using AutoDock software with the ZINC database. On the basis of the dock-score, four molecules were subjected to ADME/TOX analysis, with ZINC4085364 emerging as the most potent inhibitor of the VEB-1 β-lactamase.

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Homology modeling and virtual screening approaches to identify potent inhibitors of VEB-1 β-lactamase

Lipases play an important role in lipid metabolism and are produced by a variety of species. All lipases are members of the a/â hydrolase fold super-family. Also, lipases share a conserved active site signature, the Gly-Xaa-Ser-Xaa-Gly motif. To obtain an overview of this industrially and very important class of enzymes and their characteristics, we collected and classified bacterial lipases sequences available from protein databases. Here we proposed an updated and revised classification of family I bacterial "true" lipases based mainly on a comparison of their amino acid sequences and some fundamental physicochemical and biological properties. The result of this work has identified 11 subfamilies of “true” lipases. This work will therefore contribute to a faster identification and to an easier characterization and classification of novel bacterial lipolytic enzymes. Key words : Lipases, phylogenetic analysis, lipolytic enzymes.

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Classification of EC 3.1.1.3 bacterial true lipases using phylogenetic analysis

El efecto sobre el crecimiento de Salmonella hadar fue investigado utilizando un medio liquido esteril fresco (Pronadisa, Hispanlab) conteniendo el extracto acuoso de ajo (EAA) en diferentes concentraciones (0, 11, 12 y 13 mg/ml) El extracto de ajo anadido con estas concentraciones tuvo un efecto bacteriostatico sobre Salmonella hadar La prueba serovar revelo un patron de inhibicion caracterizado por: (i) una fase de inhibicion transitoria cuya duracion fue proporcional a la concentracion de EAA, (ii) una reanudacion de la fase de crecimiento, la cual mostro una tasa mas baja de crecimiento que controles sin inhibicion, y (iii) una ingreso en fase estacionaria con una menor densidad de cultivo La concentracion minima inhibitoria (CMI) y la concentracion minima bactericida (CMB) fueron muy cercanas, la CMI de ajo fue de 12 mg/ml y la CMB fue de 14 mg/ml Las actividades enzimaticas seguidas con el sistema API-ZYM, mostraron cambios significativos durante la fase de inhibicion Estos cambios bioquimicos representan una respuesta adaptativa al estres del ajo Algunas actividades enzimaticas celulares desaparecieron, mientras que otras fueron inducidas o mantenidas despues de la adicion de EAA Las imagenes de MET de las muestras tratadas con la concentracion del bacteriostatico EAA (12 mg/ml) revelaron la ruptura de las paredes celulares y la disposicion no homogenea de materiales citoplasmaticos dentro de las bacterias tratadas

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Morphological and Biochemical Changes of Salmonella hadar Exposed to Aqueous Garlic Extract

There has been a consistent increase in the search for alternative and efficient compound for food conservation, aiming a partial or total replacement of antimicrobial chemical additives. Garlic offers a promising alternative for food safety and bioconservation. Filter sterilized, aqueous garlic extract was tested for ability to inhibit the growth of some isolated Salmonella serovars. The aqueous garlic extract (A. G. E., 57.1% (w/v), containing 324 µg/ml allicin) inhibited the growth and killed most of the tested Salmonella serovars. The effect of bacteriostatic concentration of A. G. E. on the growth of the different tested serovars, revealed a pattern of inhibition characterized by: (i) a transitory inhibition phase whose duration was proportional to A. G. E concentration (ii) a resumed growth phase which showed a lower rate of growth than in uninhibited controls and (iii) an entry into stationary phase at a lower culture density. The minimal inhibitory concentration and minimum bactericidal concentrations were very close; garlic MIC range 10 - 12.5 mg/ml; MBC range 13 - 15 mg/ml. Garlic extract could be stored at 4°C because no detectable loss of antibacterial activity at this temperature over several days was observed. However, excessive warming, or longer periods at higher temperatures should be avoided. Among enzymatic activities followed with the API-ZYM system, significant changes during the inhibition phase were detected. These biochemical changes represent an adaptative response towards the garlic stress.

	 

	Key words: Allium sativum, allicin, garlic, antimicrobial, Salmonella.

Inhibitory effect of aqueous garlic extract (Allium sativum) on some isolated Salmonella serovars.

Triacylglycerol lipases have been thoroughly characterized in mammals and microorganisms. By contrast, very little is known about plant lipases. In this investigation, a homology model of Arabidopsis thaliana lipase (NP_179126) was constructed using a human gastric lipase (PDB ID: 1HLG), as a template for model building. This model was then assessed for stereochemical quality and side chain environment. Natural substrates: tributyrin, trioctanoin and triolen were docked into the model to investigate ligand-substrate interaction.

https://journals.sagepub.com/doi/pdf/10.4137/EBO.S7122

Hatem Belguith

Papers

Homology modeling and virtual screening approaches to identify potent inhibitors of VEB-1 β-lactamase

Classification of EC 3.1.1.3 bacterial true lipases using phylogenetic analysis

Morphological and Biochemical Changes of Salmonella hadar Exposed to Aqueous Garlic Extract

Inhibitory effect of aqueous garlic extract (Allium sativum) on some isolated Salmonella serovars.

Three-Dimensional Structure of Arabidopsis thaliana Lipase Predicted by Homology Modeling Method.