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.

Immobilization of Lecitase (Phospholipase A1) in gelatin hydrogel and its stability is studied with a view to utilizing the immobilized enzyme for degumming rice bran oil. Excellent retention of enzyme activity ([80%) is observed in hydrogel containing 43.5% gelatin crosslinked with glutaraldehyde. Compared to the free enzyme which has a broad pH-activity profile (6.5-8.0), the activity of the immobilized enzyme is strongly dependent on pH and has a pH-optimum of pH 7.5. The optimum temperature of enzyme activity increases from 37 to 50°C. Compared to the free enzyme which loses all its activity in 72 h at 50°C, the immobilized enzyme retains its activity in full. The immobilized enzyme has been used efficiently in a spinning basket bioreactor for the degumming of rice bran oil with 6 recycles without loss of enzyme activity. The phosphorus content of the oil decreases from 400 ppm to 50-70 ppm in each cycle. After charcoal treatment and dewaxing, a second enzymatic treatment brings down the phosphorus content to \5 ppm.

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Blends of natural polysaccharide sodium alginate (5%) with gelatin (3%) cross-linked with glutaraldehyde provide beads with excellent compressive strength (8 x 10(4) Pa) and regular structure on treatment with calcium chloride. Lipases from porcine pancreas, Pseudomonas cepacia, and Candida rugosa were immobilized in such a blend with excellent efficiency. The immobilized enzymes were stable and were reused several times without significant loss of enzyme activity both in aqueous and reverse micellar media. The beads were functionalized with succinic anhydride to obtain beads with extra carboxylic acid groups. These functionalized beads were then successfully used for 7.4-fold purification of crude porcine pancreatic lipase in a simple operation of protein binding at pH 5 and release at pH 8.5.

Microbial nitrilases are biocatalysts of interest and the enzyme produced using various inducers exhibits altered substrate specificity, which is of great interest in bioprocess development. The aim of the present study is to investigate the nitrilase-producing Alcaligenes faecalis MTCC 10757 (IICT-A3) for its ability to transform various nitriles in the presence of different inducers after optimization of various parameters for maximum enzyme production and activity. The production of A. faecalis MTCC 10757 (IICT-A3) nitrilase was optimum with glucose (1.0%), acrylonitrile (0.1%) at pH 7.0. The nitrilase activity of A. faecalis MTCC 10757 (IICT-A3) was optimum at 35 °C, pH 8.0 and the enzyme was stable up to 6 h at 50 °C. The nitrilase enzyme produced using different inducers was investigated for substrate specificity. The enzyme hydrolyzed aliphatic, heterocyclic and aromatic nitriles with different substitutions. Acrylonitrile was the most preferred substrate (~40 U) as well as inducer. Benzonitrile was hydrolyzed with almost twofold higher relative activity than acrylonitrile when it was used as an inducer. The versatile nitrilase-producing A. faecalis MTCC 10757 (IICT-A3) exhibits efficient conversion of both aliphatic and aromatic nitriles. The aromatic nitriles, which show not much or no affinity towards nitrilase from A. faecalis, are hydrolyzed effectively with this nitrilase-producing organism. Studies are in progress to exploit this organism for synthesis of industrially important compounds.

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Conversion of furfuryl alcohol to 4-hydroxy-2-cyclo­pentenone was studied in a microreactor channel of 0.5 mm diameter and 1.5 m length. Addition of 1 M N-methylpyrrolidinone as a cosolvent significantly reduces the polymeric material normally formed during the reaction in purely aqueous solution. The reaction follows pseudo-first-order kinetics at constant pressure (200 bar) with the values of ΔH ⧧ = 18 ± 2 kcal/mol and ΔS ⧧ = −38 ± 3 cal/mol/K. At 240 °C, 200 bar pressure, and residence time of 1.5 min, the product is obtained with 98% conversion and is isolated as a stable O-phenylacetyl derivative in 80% yield. This racemic mixture was resolved into enantiomerically pure forms by kinetic resolution with penicillin G acylase (E.C.3.5.1.11) immobilized on epoxy-activated polymer in 90–92% theoretical yield and >99% ee.