Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
A modeling study by response surface methodology and artificial neural network on culture parameters optimization for thermostable lipase production from a newly isolated thermophilic Geobacillus sp. strain ARM
Afshin Ebrahimpour, Raja Rahman, Diana Ean Ch'ng, Mahiran Basri, Abu Salleh
BMC Biotechnology , 2008, DOI: 10.1186/1472-6750-8-96
Abstract: Different production media were tested for lipase production by a newly isolated thermophilic Geobacillus sp. strain ARM (DSM 21496 = NCIMB 41583). The maximum production was obtained in the presence of peptone and yeast extract as organic nitrogen sources, olive oil as carbon source and lipase production inducer, sodium and calcium as metal ions, and gum arabic as emulsifier and lipase production inducer. The best models for optimization of culture parameters were achieved by multilayer full feedforward incremental back propagation network and modified response surface model using backward elimination, where the optimum condition was: growth temperature (52.3°C), medium volume (50 ml), inoculum size (1%), agitation rate (static condition), incubation period (24 h) and initial pH (5.8). The experimental lipase activity was 0.47 Uml-1 at optimum condition (4.7-fold increase), which compared well to the maximum predicted values by ANN (0.47 Uml-1) and RSM (0.476 Uml-1), whereas R2 and AAD were determined as 0.989 and 0.059% for ANN, and 0.95 and 0.078% for RSM respectively.Lipase production is the result of a synergistic combination of effective parameters interactions. These parameters are in equilibrium and the change of one parameter can be compensated by changes of other parameters to give the same results. Though both RSM and ANN models provided good quality predictions in this study, yet the ANN showed a clear superiority over RSM for both data fitting and estimation capabilities. On the other hand, ANN has the disadvantage of requiring large amounts of training data in comparison with RSM. This problem was solved by using statistical experimental design, to reduce the number of experiments.Today, lipases (EC, triacylglycerol acylhydrolases) stand amongst the most important biocatalysts. They carry out novel reactions in both aqueous and nonaqueous media. Lipases are used to hydrolyze ester bonds of a variety of nonpolar substrates at high activity, chem
Optimization of Parameters for the Production of Lipase from Pseudomonas sp. BUP6 by Solid State Fermentation  [PDF]
Panichikkal Abdul Faisal, Erandapurthukadumana Sreedharan Hareesh, Prakasan Priji, Kizhakkepowathial Nair Unni, Sreedharan Sajith, Sasidharan Sreedevi, Moolakkariyil Sarath Josh, Sailas Benjamin
Advances in Enzyme Research (AER) , 2014, DOI: 10.4236/aer.2014.24013
Abstract: Solid-state fermentation (SSF) holds tremendous potentials for the production of industrially significant enzymes. The present study describes the production of lipase by a novel rumen bacterium, Pseudomonas sp. strain BUP6 on agro-industrial residues. Pseudomonas sp. strain BUP6 showed higher lipase production when grown in Basal salt medium (BSM) supplemented with oil cakes. Initially, five different oil cakes (obtained after extracting oil from coconut, groundnut, cotton seed, gingelly or soybean) were screened to find out the most suitable substrate-cum-inducer for the production of lipase. Among them, groundnut cake supported the maximum production of lipase (107.44 U/gds). Box-Behnken Design (BBD), followed by response surface methodology (RSM) was employed to optimize the culture parameters for maximizing the production of lipase. Using the software Minitab 14, four different parameters like temperature, pH, moisture content and incubation time were selected for the statistical optimization, which resulted in 0.7 fold increase (i.e., 180.75 U/gds) in production of lipase under the optimum culture conditions (temperature 28°C, pH 5.9, moisture 33% and incubation 2 d). Thus, this study signifies the importance of SSF for the production of industrially-significant lipase using agro-industrial residues as solid support.
Statistical optimization of culture conditions by response surface methodology for synthesis of lipase with Enterobacter aerogenes
Kumari, Annapurna;Mahapatra, Paramita;Banerjee, Rintu;
Brazilian Archives of Biology and Technology , 2009, DOI: 10.1590/S1516-89132009000600005
Abstract: optimization of lipase production by enterobacter aerogenes was carried out using response surface methodology (rsm) where the statistical model was obtained by fractional factorial central composite design. the influence of various physico-chemical parameters, viz. temperature, oil concentration, inoculum volume, ph and incubation period on lipase production was examined. optimization of physico-chemical parameters resulted 1.4- fold increase in lipase activity. the optimum levels of parameters were 34°c, oil concentration 3%, inoculum volume 7%, ph 7 and incubation time 60 h for obtaining a maximum lipase activity of 27.25 u/ml.
Optimization of lipase production by Staphylococcus sp. Lp12
P Pogaku, W Fan, A Suresh, S Zhong, P Srinivas, S Ram Reddy, C Ma, P Li, K Zhou, Z Peng, M Zhu
African Journal of Biotechnology , 2010,
Abstract: A bacterial strain isolated from an oil contaminated soil, identified as Staphylococcus sp. Lp12 was screened for lipase activity on tributyrin agar and spirit blue agar medium. Maximum lipase production was observed at 48 h of growth (3.5 Eu/ml). Peptone was found to be as an ideal nitrogen source for production at a concentration of 1.0% (4.25 Eu/ml). Addition of any nitrogen source other than peptone to the medium resulted in a significant reduction of enzyme production. Lower lipase production was noted when an inorganic nitrogen source was used as the sole nitrogen source. Starch was used as a major carbon source for optimum production of lipase (4.25 Eu/ml) at a concentration of 1.5%. Of the natural oils, olive oil was able to induce more lipase (4.25 Eu/ml) rather than the oils like groundnut, coconut, castor oils. Basal medium containing tween 80 enhanced lipase production to a significant level. The pH 8 and temperature 45°C were found to be ideal pH and temperature for optimum production of lipase by this strain.
Journal of Applied Sciences in Environmental Sanitation , 2007,
Abstract: Optimization of different process parameters for lipase production by Rhizopus oryzae KG-10 and its validation using response surface methodology was carried out during the present study. Four various nutritional parameters were screened using Plackett–Burman experimental design were further optimized by Box–Behnken factorial design of response surface methodology for lipase production in submerged fermentation. Maximum lipase production of 13.33 IU were predicted in medium containing Tween 20 (1.48 mL L-1), Peptone (0.51 g L-1) at agitation (175 rpm), and pH (5.00) using response surface plots and point prediction tool of DESIGN EXPERT 7.0 (V. 7.0.10 Trail, Stat-Ease, Minneapolis, 2006) software. Exploring the fungal biodiversity for lipase producing strains and its statistical optimization is a key issue now a day, which means search for new variables and nutritional options for commercial productions for medical or commercial use from such fungal species.
The effect of olive cake types on lipase production by isolated Rhizopus sp. and process statistical optimization  [PDF]
Gholam Khayati,Hossein Ghanadzadeh Gilani,Mahshid Kazemi
Journal of BioScience and Biotechnology , 2013,
Abstract: The aim of this work was to study the production of extracellular lipase by solid-state fermentation with different olive cakes varieties including Mary, Shenghe and Yellow from isolated fungi using agro-industries waste such as rice straw, rice barn and wheat straw. The highest yields of enzyme were obtained in solid-state fermentation using rice straw as solid substrate in combination with 40% Mary olive cakes as inducer. The initial screening by using Plackett-Burman's design demonstrated that among the tested factors, lactose and ammonium sulfate of the medium significantly (p < 0.05) enhanced the lipase production. Further optimization of lipase production by isolated fungi in solid-state fermentation by applying response surface methodology was achieved, which revealed these as follows: 0.42 (% w/v) for lactose and 0.09 (% w/v) for ammonium sulfate. Also the enzyme kinetics parameters, biochemical properties, thermodynamic of thermal deactivation and deactivation rate constant of enzyme were determined.
The Use of Response Surface Methodology as a Statistical Tool for Media Optimization in Lipase Production from the Dairy Effluent Isolate Fusarium solani  [PDF]
P. Kanmani,S. Karthik,J. Aravind,K. Kumaresan
ISRN Biotechnology , 2013, DOI: 10.5402/2013/528708
Abstract: The optimization of extracellular lipase production by Fusarium isolani strain SKWF7 isolated from dairy wastewater was carried out in this study. Initially, the physicochemical factors significantly influencing enzyme production were studied by varying one-factor-at-a-time (OFAT). A mesophilic temperature of 40°C, alkaline pH of 8, and incubation period of 72 hours were found to be the optimal conditions for lipase production. Among the media components, the disaccharide sucrose acted as the best carbon source; palm oil as the best inducing lipid substrate; casein and (NH4)2SO4 as the best organic and inorganic nitrogen sources; Ca2+ ion as the best trace element. In the next phase of work, statistical optimization of medium components was performed by employing the Box-Behnken design of Response Surface Methodology (RSM). The optimum concentrations of three significant factors, namely, palm oil, (NH4)2SO4, and CaCO3 were determined by this method to be 5% (v/v), 5.5?g/L, and 0.1?g/L, respectively. RSM-guided design of experiments resulted in a maximum lipase production of 73.3?U/ml, which is a 1.7-fold increase in comparison with that obtained in the unoptimized medium. These results point towards the success of the model in developing a process for the production of lipase, an enzyme of enormous industrial significance. 1. Introduction Lipases are enzymes that belong to the class of hydrolases and are involved in catalyzing the hydrolysis of triglycerides to fatty acids and glycerol, this reaction occurs at the oil-water interface [1]. Besides, they are also capable of catalyzing the reverse reaction, that is, ester synthesis, in water-restricted environments [2]. Transesterification and resolution of racemic mixtures are also reactions that could be facilitated by lipases. Such a versatile nature has paved the way for their application in diversified industries including food, dairy, cosmetic, detergent, and pharmaceuticals [3]. The environmental applications of the enzyme are also innumerable, where they break down fat, oil, and greasy material in the wastewater [4]. These constituents could pose problems in the sewers as well as the treatment plant, impeding oxygen transfer in aerobic biological treatment systems. These are some of the underlying reasons for a sustained interest in the enzyme. Lipases can be procured from plant, animal [5–8], and microbial sources. However, microbial lipases have gained increasing attention due to their stability and high substrate specificity [9, 10]. In the microbial community, lipolytic activity is exhibited by
Optimization of extracellular thermophilic highly alkaline lipase from thermophilic Bacillus sp isolated from Hotspring of Arunachal Pradesh, India
Bora, Limpon;Bora, Minakshi;
Brazilian Journal of Microbiology , 2012, DOI: 10.1590/S1517-83822012000100004
Abstract: studies on lipase production were carried out with a bacterial strain (bacillus sp lbn 2) isolated from soil sample of hotspring of arunachal pradesh, india. the cells were cultivated in a mineral medium with maximum production at 1% groundnut oil. the optimum temperature and initial medium ph for lipase production by the organism were 50oc and 9.0 respectively. the molecular mass was found to be 33kda by sds page. the optimal ph and temperature for activity were 10 and 60oc respectively. the enzyme was found to be stable in the ph range of 8-11 with 90% retention of activity at ph 11. the enzyme retained 90% activity at 60oc and 70% of activity at 70oc for 1h. the lipase was found to be stable in acetone followed by ethanol. the present findings suggested the enzyme to be thermophilic alkaline lipase.
Immobilized Rhizopus oryzae lipase catalyzed synthesis of palm stearin and cetyl alcohol wax esters: Optimization by Response Surface Methodology
Mohamed Sellami, Imen Aissa, Fakher Frikha, Youssef Gargouri, Nabil Miled
BMC Biotechnology , 2011, DOI: 10.1186/1472-6750-11-68
Abstract: Palm stearin is a solid fraction obtained by fractionation of palm oil. Palm stearin was esterified with cetyl alcohol to produce a mixture of wax esters. A non-commercial immobilized lipase from Rhizopus oryzae was used as biocatalyst. Response surface methodology was employed to determine the effects of the temperature (30-50°C), the enzyme concentration (33.34-300 IU/mL), the alcohol/palm stearin molar ratio (3-7 mol/mol) and the substrate concentration (0.06-0.34 g/mL) on the conversion yield of palm stearin. Under optimal conditions (temperature, 30°C; enzyme concentration, 300 IU/mL; molar ratio 3 and substrate concentration 0.21 g/mL) a high conversion yield of 98.52% was reached within a reaction time of 2 h.Response surface methodology was successfully applied to determine the optimum operational conditions for synthesis of palm stearin based wax esters. This study may provide useful tools to develop economical and efficient processes for the synthesis of wax esters.Palm oil is one of the traditional fats that have been widely used throughout the world in human diet. Global palm oil production was estimated to 42 million ton during 2007/2008, accounting for 40% of the worldwide production of total dietary oils [1]. Palm oil contains a mixture of high and low melting triglycerides. By a simple dry fractionation process under a controlled temperature, palm oil can be resolved into a liquid (olein) and a solid (stearin) fraction [2]. The palm olein fraction is the mostly used in industry due to its low melting point [3]. The high melting point of palm stearin (44-56°C) poses problems in manufacturing of edible fats such as margarine and shortenings as it confers low plasticity to the end product. Many attempts have been carried out to maximise the use of palm stearin by transesterification [4-7]. Among transesterification reactions, alcoholysis of triacylglycerols to produce wax esters is relatively a simple process and rather economically important to the oil
Comparison of Lipase Production by Enterococcus faecium MTCC 5695 and Pediococcus acidilactici MTCC 11361 Using Fish Waste as Substrate: Optimization of Culture Conditions by Response Surface Methodology  [PDF]
Vrinda Ramakrishnan,Louella Concepta Goveas,Bhaskar Narayan,Prakash M. Halami
ISRN Biotechnology , 2013, DOI: 10.5402/2013/980562
Abstract: A medium using fish waste as substrate was designed for production of lipase by Enterococcus faecium MTCC 5695 and Pediococcus acidilactici MTCC 11361. Medium components and culture conditions (fish waste protein hydrolysate (FWPH) concentration, fish waste oil (FWO) concentration, pH, temperature, and fermentation time) which affect lipase production were screened using factorial (5 factors ? 2 levels) design of which FWPH concentration, FWO concentration, and fermentation time showed significance ( ). The levels of these factors were optimized further by Box-Behnken design using response surface methodology (RSM). Optimized conditions were found to be 5%?v/v FWO, 0.15?mg/mL FWPH and 24?h of fermentation time for MTCC 5695, and 4%?v/v FWO, 0.15?mg/mL FWPH and 24?h of fermentation for MTCC 11361, which were further validated. Under optimized conditions, MTCC 5695 and MTCC 11361 showed 3.15- (543.63 to 1715?U/mL) and 2.3- (214.74 to 493?U/mL) fold increase in lipase production, respectively, as compared to unoptimized conditions. 1. Introduction Lipases (triacylglycerol acylhydrolases EC are a class of serine hydrolases which catalyze the hydrolysis of triglycerides to glycerol and free fatty acids over oil-water interface [1]. In addition, lipases catalyze the hydrolysis and transesterification of other esters as well as the synthesis of esters and exhibit enantioselective properties [2]. These unique properties of lipases make them a very important enzyme of industrial significance. Lipases are used in chemical processing, dairy industries for improvement of flavour, paper industries, oleochemical industries, pharmaceuticals, synthesis of surfactants, detergent industries, leather industries, and polymer synthesis [3, 4]. Lipases are produced by plants, animals, and microbes but only microbial lipases are found to be industrially important since they are diversified in their enzymatic properties and substrate specificity [5]. Bacterial lipases that are of commercial importance are obtained from Achromobacter, Alcaligenes, Arthrobacter, Bacillus, Burkholderia, Chromobacterium, and Pseudomonas [6, 7]. Lactic Acid Bacteria (LAB) are generally considered to be weakly lipolytic, as compared to other groups of microorganisms. The lipolytic activity by LAB plays an important role in the determination of special aroma of different cheeses [8, 9]. Since they are considered as generally recognised as safe (GRAS), they are used extensively as starter cultures in food and feed industries [10]. Although there are reports on lactic acid bacterial lipase
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.