Improved biocatalytic activity of steapsin lipase in supercritical carbon dioxide medium for the synthesis of benzyl butyrate: A commercially important flavour compound.

Enzymatic synthesis of flavours, fragrances and food additives compounds have great demand and market value. Benzyl butyrate is commercially important flavour and food additive compound having global use around 100 metric tons/year and widely used in various industrial sectors. However, industrial synthesis of food additive benzyl butyrate is carried out by conventional chemical process which demands for the green biobased sustainable synthetic process. The present work reports steapsin catalyzed synthesis of benzyl butyrate for the first time in supercritical carbon dioxide (Sc-CO2) reaction medium. All reaction variables are optimized in details to obtain competent conversion of 99% in Sc-CO2 reaction medium. The developed steapsin catalyzed synthesis in Sc-CO2 medium offered almost four-fold higher conversion to benzyl butyrate than organic (conventional) solvent. The steapsin biocatalyst was effectually recycled up to five reaction cycles in Sc-CO2 medium. Moreover, the developed steapsin catalyzed protocol in Sc-CO2 medium was extended to synthesize different ten industrially significant flavour fragrance compounds that offers 99% conversion and three to five-folds higher conversion than organic medium. Thus, the present steapsin catalyzed protocol offered improved synthesis of various commercially significant flavour compounds in Sc-CO2. medium.

Investigation of effect of ultrasound on immobilized C. rugosa lipase: Synthesis of biomass based furfuryl derivative and green metrics evaluation study.

The present work deals with the synthesis of lab-made carboxymethyl cellulose (CMC) and chitosan (CHI) based co-polymer cross-linked with glutaraldehyde (GLU) which is used as immobilization matrix for the immobilization of Candida rugosa (CRL) lipase (CMC:CHI:GLU:CRL). This immobilized biocatalyst was subjected to characterization such as lipase-activity, kinetic-parameters, water-content, surface-texture, stability and half-life time etc. Effect of various ultrasound parameters (power, frequency, duty cycle, exposure time) on lipase activity is also tested which indicated that, developed biocatalyst has significant activity-stability and half-life-time in ultrasonicated medium. Further, this biocatalyst was applied to synthesize biomass-derived furfuryl derivative which offering excellent conversion of 99 % of bio-based furfuryl ester. The synthetic protocol is optimized in detail (with twelve reaction parameters) under ultrasonicated medium. Recyclability study offered 68 % conversion of the furfuryl ester after sixth reuse. Moreover, the developed protocol is well extended to synthesize various commercially important compounds. Besides this, we investigated thermodynamic parameters (ΔG*, ΔH*, ΔS*) which demonstrating more feasibility of biocatalytic synthesis in ultrasonicated medium than conventional medium. Finally, green metrics evaluation parameters (E-factor, carbon-efficiency and mass-intensity) are studied which indicating efficient synergetic role of immobilized CMC:CHI:GLU:CRL lipase biocatalysis and ultrasonication in green and sustainable synthesis.

Vaccine development against coronavirus (2003 to present): An overview, recent advances, current scenario, opportunities and challenges.

BACKGROUND AND AIM: The pandemic COVID-19 occurring due to novel emerging coronavirus-2019 (SARS-CoV-2) is severely affecting the worldwide public health, culture, economy and human social behaviour. Till date, there is no approved medicine/treatment to cure COVID-19, whereas, vaccine development efforts are going on high priority. This review aimed to provide an overview of prior art, recent advances, vaccine designing strategies, current scenario, opportunities and challenges related to development of coronavirus vaccine. METHOD: A literature survey was conducted using Scopus, PubMed and Google Scholar with the search key as: coronavirus vaccine, SARS vaccine, MERS vaccine and COVID-19 vaccine. Articles related to above search query were retrieved, sorted, analyzed and developed into an easy-to-understand review. RESULTS: The genome phylogenetic analysis suggested that genomic sequence of SARS-CoV-2 is almost 80% similar to that of SARS-CoV, further both these viruses bind to same host cell receptor ACE-2. Hence it is expected that, previously available literature data about coronavirus vaccine designing may play crucial role in development of rapid vaccine against COVID-19. In view of this, the present review discuss (i) existing information (from 2003 to present) about the type of vaccine, antigen, immunogenic response, animal model, route of administration, adjuvants and current scenario for designing of coronavirus vaccine (ii) potential factors and challenges related to rapid development of COVID-19 vaccine. CONCLUSION: In conclusion, we discuss possible clues/ target sites for designing of vaccine against SARS-CoV-2 virus based on prior-art.

Enhanced biocatalytic activity of immobilized steapsin lipase in supercritical carbon dioxide for production of biodiesel using waste cooking oil.

The present work reports covalent immobilization of steapsin lipase (SL) on Immobead-350 support matrix (IMB) to make a robust biocatalytic system to work under supercritical carbon dioxide condition (Sc-CO2). The developed biocatalyst (IMB:SL) was characterized in details and utilized to convert waste cooking sunflower oil (WCSO) into value-added energy chemical (biodiesel) in Sc-CO2. All reaction process parameters were optimized in detail which offered 86.33% yield of biodiesel from WCSO. The developed Sc-CO2 protocol is compared with the solvent-free conventional synthesis, which indicates almost twofold higher yield of biodiesel in Sc-CO2 media as compared to solvent-free condition. To extend the scope, we have tested fresh and waste cooking oils (WCO) from various sources, offering 81-94% yield of biodiesel. The biocatalyst activity was investigated in various parameters of supercritical condition to know the biocatalyst stability in Sc-CO2. Besides this, IMB:SL biocatalyst was effectively reused up to five recycle.

Immobilization of Rhizomucor miehei lipase on a polymeric film for synthesis of important fatty acid esters: kinetics and application studies.

The present work deals with the designing of biocompatible hybrid blend of cellulosic copolymers made of hydroxypropyl methylcellulose (HMC) and chitosan (CHI) for immobilization of Rhizomucor miehei lipase (RML), in order to construct the robust biocatalytic system to synthesize industrially important dodecanoate compounds (fatty acid esters). The present biocatalyst HMC:CHI:RML was characterized in detail by various physical and biochemical methods and subsequently applied for the synthesis of fatty acid esters. The protocol was optimized in detail with kinetic parameters which provides excellent % conversion, and further we have synthesized fifteen industrially important compounds which have wide potential for commercial applications. The immobilized lipase HMC:CHI:RML offered four- to eightfold higher conversion and biocatalytic activity as compared to crude lipase. Besides this, recyclability study was also performed to assess economic and industrial viability.

Investigation of deactivation thermodynamics of lipase immobilized on polymeric carrier.

In the present work, we have investigated biochemical thermo-kinetic stability of lipases immobilized on a biocompatible polymeric material. Immobilization of lipase Candida rugosa (CRL) was carried out on biocompatible blend of poly vinyl alcohol (PVA) and chitosan (CHY) support via entrapment and glutardehyde (Glu) cross-linking method to produce PVA:CHY:CRL and PVA:CHY:Glu:CRL as robust biocatalyst. These immobilized lipases were characterized by various physico-biochemical characterization techniques. Later on, thermal and solvent stability of polymer immobilized lipase was determined in term of half-life time (t 0.5), D values, enthalpy (ΔH°), entropy (ΔS°), and free energy (ΔG°) of deactivation at different temperatures and in various solvents. The thermodynamic deactivation stability trend was found as: cross-linked lipase CRL > entrapped lipase CRL > free lipase CRL. Moreover, kinetic parameters, such as K m, V max, and catalytic efficiency, were also determined to understand the kinetic features. The polymer immobilized enzyme was reused to investigate the economic viability of the developed biocatalyst.

Kinetic modeling and docking study of immobilized lipase catalyzed synthesis of furfuryl acetate.

The present work deals with the kinetic modeling and docking study for the furfuryl acetate synthesis using immobilized Burkholderia cepacia (BCL) lipase. Initially various lipases were immobilized on hydroxypropyl methyl cellulose (HPMC) and poly vinyl alcohol (PVA) base hybrid polymer matrix. After screening of various immobilized biocatalysts, HPMC:PVA:BCL was found to be a robust biocatalyst. Various reaction conditions were optimized using response surface methodology (RSM) based on a four-factor-three-level Box-Behnken design. The optimal conditions were obtained at molar ratio of 1:2 of furfuryl alcohol to acyl donor, temperature 50°C with catalyst loading of 30mg in 3mL of non-aqueous media toluene. Under these conditions 99.98% yield was obtained in 3h. The Arrhenius plot showed that the activation energy for furfuryl acetate synthesis was 10.68kcal/mol. The kinetics of reaction was studied close to optimized conditions which obey order bi-bi model. Molecular docking study was carried out to understand the active site of BCL which is responsible for the reaction. It was observed that the reaction proceeds via acylation of the active serine of BCL and demonstrating strong hydrogen bond between the substrate and histidine site. The catalyst recyclability study was carried up to five cycles.

Enhanced biocatalytic activity of immobilized Pseudomonas cepacia lipase under sonicated condition.

The present work reports the use of biocatalyst and ultrasound for greener synthesis of cinnamyl propionate. The lipase Pseudomonas cepacia was immobilized on a copolymer of hydroxypropyl methyl cellulose and polyvinyl alcohol. This biocatalyst was u sed for ultrasound-assisted synthesis of cinnamyl propionate with the detailed optimization of various reaction parameters. Besides this, protocol was extended to synthesize various industrially important propionate esters. In addition to this, different enzyme-kinetic parameters such as r max and K m(vinyl propionate), K m(cinnamyl alcohol) and K i(cinnamyl alcohol) were studied which presented ordered bi-bi mechanism with an inhibition by cinnamyl alcohol. The developed biocatalyst demonstrated enhancement in catalytic activity and recyclability up to five recycles. Moreover, the biocatalyst was tested to investigate the effects of sonication via various characterization techniques such as scanning electron microscopy, thermogravimetry, and water content analysis.

Factors governing dissolution process of lignocellulosic biomass in ionic liquid: current status, overview and challenges.

The utilisation of non-feed lignocellulosic biomass as a source of renewable bio-energy and synthesis of fine chemical products is necessary for the sustainable development. The methods for the dissolution of lignocellulosic biomass in conventional solvents are complex and tedious due to the complex chemical ultra-structure of biomass. In view of this, recent developments for the use of ionic liquid solvent (IL) has received great attention, as ILs can solubilise such complex biomass and thus provides industrial scale-up potential. In this review, we have discussed the state-of-art for the dissolution of lignocellulosic material in representative ILs. Furthermore, various process parameters and their influence for biomass dissolution were reviewed. In addition to this, overview of challenges and opportunities related to this interesting area is presented.

Solvent Stability Study with Thermodynamic Analysis and Superior Biocatalytic Activity of Burkholderia cepacia Lipase Immobilized on Biocompatible Hybrid Matrix of Poly(vinyl alcohol) and Hypromellose.

In the present study, we have synthesized a biocompatible hybrid carrier of hypromellose (HY) and poly(vinyl alcohol) (PVA) for immobilization of Burkholderia cepacia lipase (BCL). The immobilized biocatalyst HY:PVA:BCL was subjected to determination of half-life time (τ) and deactivation rate constant (K(D)) in various organic solvents. Biocatalyst showed higher τ-value in a nonpolar solvent like cyclohexane (822 h) as compared to that of a polar solvent such as acetone (347 h), which signifies better compatibility of biocatalyst in the nonpolar solvents. Furthermore, the K(D)-value was found to be less in cyclohexane (0.843 × 10(-3)) as compared to acetone (1.997 × 10(-3)), indicating better stability in the nonpolar solvents. Immobilized-BCL (35 mg) was sufficient to achieve 99% conversion of phenethyl butyrate (natural constituent of essential oils and has wide industrial applications) using phenethyl alcohol (2 mmol) and vinyl butyrate (6 mmol) at 44 °C in 3 h. The activation energy (E(a)) was found to be lower for immobilized-BCL than crude-BCL, indicating better catalytic efficiency of immobilized lipase BCL. The immobilized-BCL reported 6-fold superior biocatalytic activity and 8 times recyclability as compared to crude-BCL. Improved catalytic activity of immobilized enzyme in nonpolar media was also supported by thermodynamic activation parameters such as enthalpy (ΔH(⧧)), entropy (ΔS(⧧)) and Gibb's free energy (ΔG(⧧)) study, which showed that phenethyl butyrate synthesis catalyzed by immobilized-BCL was feasible as compared to crude-BCL. The present work explains a thermodynamic investigation and superior biocatalytic activity for phenethyl butyrate synthesis using biocompatible immobilized HY:PVA:BCL in nonaqueous media for the first time.

Application of lipase immobilized on the biocompatible ternary blend polymer matrix for synthesis of citronellyl acetate in non-aqueous media: kinetic modelling study.

This work reports the use of new support for immobilization of lipase Burkholderia cepacia (BCL) matrix made up of polylactic acid (PLA), chitosan (CH), and polyvinyl alcohol (PVA). Initially lipase from various microbial sources and immobilization support composition was screened to obtain a robust biocatalyst. Among various biocatalysts preparation, the PLA:PVA:CH:BCL (1:6:1:2) was worked as a robust biocatalyst for the citronellyl acetate synthesis. Various reaction parameters were studied in detail to obtain the suitable reaction conditions for model citronellyl acetate synthesis reaction. Various kinetic parameters such as r(max), K(i(citronellol)), K(m(citronellol)), K(m(vinyl acetate)) were determined using non-linear regression analysis for the ternary complex as well as bi-bi ping-pong mechanism. The experimental results and kinetic study showed that citronellyl acetate synthesis catalyzed by immobilized lipase BCL followed the ternary complex mechanism with inhibition by alcohol (citronellol). The energy of activation for citronellyl acetate synthesis was found to be lower for immobilized lipase (8.9 kcal/mol) than aggregated lipase (14.8 kcal/mol) enzyme. The developed biocatalyst showed four to fivefold higher catalytic activity and excellent recyclability (up to six cycles) than the aggregated lipase.