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Viruthagiri Thangavelu

Bio: Viruthagiri Thangavelu is an academic researcher from Annamalai University. The author has contributed to research in topics: Fermentation & Lipase. The author has an hindex of 14, co-authored 33 publications receiving 798 citations.

Papers
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01 Jan 2010
TL;DR: In this paper, various sources of phenol, various microorganisms involved in the biodegradation including aerobe and anaerobe, effect of environmental parameters on phenol degradation and kinetic analysis of biodegradability, and various
Abstract: Aromatic compounds are widely distributed in nature and free phenols are frequently liberated as metabolic intermediates during the degradation of plant materials. In recent years the natural supply of phenolic substances has been greatly increased due to the release of industrial byproducts into the environment. Effluents from petrochemical, textile and coal industries contain phenolic compounds in very high concentration; therefore there is a necessity to remove phenolic compounds from the environment. Among various techniques available for removal of phenols, biodegradation is an environment friendly and cost effective method. This paper describes about the various sources of phenol, various microorganisms involved in the biodegradation including aerobe and anaerobe, effect of environmental parameters on phenol degradation and kinetic analysis of biodegradation, and various

138 citations

Journal ArticleDOI
TL;DR: This review deals with lipase catalyzed ester synthesis, esterification strategies, optimum conditions and their applications in food processing industries.
Abstract: Lipases are one of the most important industrial biocatalyst which catalyzes the hydrolysis of lipids. It can also reverse the reaction at minimum water activity. Because of this pliable nature, it is widely exploited to catalyze the diverse bioconversion reactions, such as hydrolysis, esterification, interesterification, alcoholysis, acidolysis and aminolysis. The property to synthesize the esters from the fatty acids and glycerol promotes its use in various ester synthesis. The esters synthesized by lipase finds applications in numerous fields such as biodiesel production, resolution of the recemic drugs, fat and lipid modification, flavour synthesis, synthesis of enantiopure pharmaceuticals and nutraceuticals. It plays a crucial role in the food processing industries since the process is unaffected by the unwanted side products. Lipase modifications such as the surfactant coating, molecular imprinting to suit for the non-aqueous ester synthesis have also been reported. This review deals with lipase catalyzed ester synthesis, esterification strategies, optimum conditions and their applications in food processing industries. Key words: Lipase, food applications, ester, esterification, synthesis

135 citations

Journal ArticleDOI
TL;DR: Main focus of this paper is to discuss the important parameters that affect the biodiesel yield, various immobilization techniques employed, mechanisms and kinetics of transesterification reaction and the recent advances in continuoustransesterification processes.
Abstract: Biodiesel, chemically defined as monoalkyl esters of long chain fatty acids, are derived from renewable feed stocks like vegetable oils and animal fats. It is produced by both batch and continuous transesterification processes in which, oil or fat is reacted with a monohydric alcohol in the presence of a catalyst. The conventional method of producing biodiesel involves acid and base catalysts to form fatty acid alkyl esters. Downstream processing costs and environmental problems associated with biodiesel production and byproducts recovery have led to the search for alternative production methods and alternative substrates. Enzymatic reactions involving lipases can be an excellent alternative to produce biodiesel through a process commonly referred to as alcoholysis, a form of transesterification reaction or through an interesterification reaction. In order to increase the cost effectiveness of the process, the enzymes are immobilized using a suitable matrix. The use of immobilized lipases and whole cells may lower the overall cost, while presenting less downstream processing problems. Main focus of this paper is to discuss the important parameters that affect the biodiesel yield, various immobilization techniques employed, mechanisms and kinetics of transesterification reaction and the recent advances in continuous transesterification processes.

75 citations

Journal ArticleDOI
TL;DR: In this article, the statistical analysis of Plackett-Burman experimental results showed that the medium components glucose, peptone, MnSO 4 ·H 2 O, NaCl and NH 4 Cl as the significant components influencing the lovastatin production.

60 citations

Journal ArticleDOI
TL;DR: The estimated values of the kinetic model parameters, α and β, for lipase production indicate that the lipaseProduction by R. arrhizus is growth-associated, and the logistic model for cell growth, the Luedeking–Piret model for lip enzyme production and a modified Luedek–Piresen model for substrate utilisation were found to accurately predict the fermentation kinetics.
Abstract: The Plackett–Burman experimental design was used to evaluate the medium components for lipase production by Rhizopus arrhizus in submerged batch fermentation. Twelve medium components with three dummy variables were studied in this experimental design. The most significant variables affecting lipase production were found to be olive oil, peptone, KH 2 PO 4 , CaCl 2 ·2H 2 O and MgSO 4 ·7H 2 O. Maximum lipase activity (3.98 U mL −1 ) and maximum cell mass concentration (5.62 g L −1 ) were obtained using the optimised medium. Unstructured kinetic models were analysed to simulate the experimental values of cell growth, lipase activity and glucose concentration. The logistic model for cell growth, the Luedeking–Piret model for lipase production and a modified Luedeking–Piret model for substrate utilisation were found to accurately predict the fermentation kinetics. The estimated values of the kinetic model parameters, α and β , for lipase production indicate that the lipase production by R. arrhizus is growth-associated.

59 citations


Cited by
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01 Feb 2009
TL;DR: This Secret History documentary follows experts as they pick through the evidence and reveal why the plague killed on such a scale, and what might be coming next.
Abstract: Secret History: Return of the Black Death Channel 4, 7-8pm In 1348 the Black Death swept through London, killing people within days of the appearance of their first symptoms. Exactly how many died, and why, has long been a mystery. This Secret History documentary follows experts as they pick through the evidence and reveal why the plague killed on such a scale. And they ask, what might be coming next?

5,234 citations

Journal ArticleDOI
TL;DR: The most important microbial lipase-producing strains for submerged and solid-state fermentations are reviewed as well as the main substrates, including the use of agroindustrial residues.
Abstract: This review paper provides an overview regarding the main aspects of microbial lipases production. The most important microbial lipase-producing strains for submerged and solid-state fermentations are reviewed as well as the main substrates, including the use of agroindustrial residues. Current process techniques (batch, repeated-batch, fed-batch, and continuous mode) are discussed and the main bioreactors configurations are also presented. Furthermore, the present review paper shows a general overview about the development of mathematical models applied to lipase production. Finally, some future perspectives on lipase production are discussed with special emphasis on lipase engineering and the use of mathematical models as a useful tool for process improvement and control.

451 citations

01 Jan 2016
TL;DR: The current data suggest that the liver of dogs contains functional LDL receptors that are susceptible to metabolic regulation and that a drug-induced increase in the activity of these receptors can contribute to a lowering of plasma levels of LDL-cholesterol.
Abstract: Liver membranes from young beagle dogs were found to possess binding sites that resemble the low density lipo- protein (LDL) receptors originally described in cultured human fibroblasts. Treatment of the dogs with colestipol (a bile acid se- questrant) and mevinolin (a cholesterol synthesis inhibitor) pro- duced a 3-fold increase in LDL binding activity. This increase cor- related with a 2-fold increase in the fractional catabolic rate for intravenously administered human or canine "LI-labeled LDL, suggesting that the increased hepatic receptors were responsible for the enhanced clearance of LDL from plasma. The hepatic lipo- protein receptors of control and drug-treated dogs resembled hu- man fibroblast LDL receptors in that they bound apoprotein E- containing lipoproteins, such as very low density lipoproteins and a subfraction of high density lipoproteins (HDL ), with 10-fold higher affinity than the apoprotein B-containing lipoprotein LDL; failed to bind canine HDL and human HDL3 which are devoid of apoproteins B and E; failed to bind methylated LDL; required cal- cium; and were destroyed by Pronase. Treatment of dogs with mevinolin not only increased the fractional catabolic rate for LDL but also reduced the synthetic rate for the lipoprotein. The current data suggest that the liver of dogs contains functional LDL recep- tors that are susceptible to metabolic regulation and that a drug- induced increase in the activity of these receptors can contribute to a lowering of plasma levels of LDL-cholesterol.

351 citations

Journal ArticleDOI
TL;DR: An overview regarding the fungal lipase production, purification, and application is discussed, and various industrial applications of lipase in pulp and paper, food, detergent, and textile industries are described.
Abstract: Lipases (triacylglycerolacyl hydrolases, EC3.1.1.3) are class of enzymes which catalyze the hydrolysis of long-chain triglycerides. In this review paper, an overview regarding the fungal lipase production, purification, and application is discussed. The review describes various industrial applications of lipase in pulp and paper, food, detergent, and textile industries. Some important lipase-producing fungal genera include Aspergillus, Penicillium, Rhizopus, Candida, etc. Current fermentation process techniques such as batch, fed-batch, and continuous mode of lipase production in submerged and solid-state fermentations are discussed in details. The purification of lipase by hydrophobic interaction chromatography is also discussed. The development of mathematical models applied to lipase production is discussed with special emphasis on lipase engineering.

342 citations

Journal ArticleDOI
TL;DR: Immobilization has made the use of microbial lipases accomplish its best performance and hence suitable for several reactions and need to enhance aroma to the immobilization processes and reduce logistical liability on the environment and user.
Abstract: Lipases are very versatile enzymes, and produced the attention of the several industrial processes. Lipase can be achieved from several sources, animal, vegetable, and microbiological. The uses of microbial lipase market is estimated to be USD 425.0 Million in 2018 and it is projected to reach USD 590.2 Million by 2023, growing at a CAGR of 6.8% from 2018. Microbial lipases (EC 3.1.1.3) catalyze the hydrolysis of long chain triglycerides. The microbial origins of lipase enzymes are logically dynamic and proficient also have an extensive range of industrial uses with the manufacturing of altered molecules. The unique lipase (triacylglycerol acyl hydrolase) enzymes catalyzed the hydrolysis, esterification and alcoholysis reactions. Immobilization has made the use of microbial lipases accomplish its best performance and hence suitable for several reactions and need to enhance aroma to the immobilization processes. Immobilized enzymes depend on the immobilization technique and the carrier type. The choice of the carrier concerns usually the biocompatibility, chemical and thermal stability, and insolubility under reaction conditions, capability of easy rejuvenation and reusability, as well as cost proficiency. Bacillus spp., Achromobacter spp., Alcaligenes spp., Arthrobacter spp., Pseudomonos spp., of bacteria and Penicillium spp., Fusarium spp., Aspergillus spp., of fungi are screened large scale for lipase production. Lipases as multipurpose biological catalyst has given a favorable vision in meeting the needs for several industries such as biodiesel, foods and drinks, leather, textile, detergents, pharmaceuticals and medicals. This review represents a discussion on microbial sources of lipases, immobilization methods increased productivity at market profitability and reduce logistical liability on the environment and user.

313 citations