Multiresponse analysis of microbiological parameters affecting the production of pectolytic enzymes by Aspergillus niger: a statistical view
TL;DR: In order to develop a two-stage inoculum possessing the best conditions for the maximum production of all three enzymes, a multiresponse analysis was carried out using a generalized distance approach.
About: This article is published in Process Biochemistry.The article was published on 1999-10-01. It has received 63 citations till now.
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TL;DR: In this paper, a statistical experimental design was employed for the improvement of citric acid production from Madhuca indica through submerged fermentation process using mutant fungi Aspergillus niger MTCC 282.
Abstract: Statistical experimental design was employed for the improvement of citric acid production from Madhuca indica through submerged fermentation process using mutant fungi Aspergillus niger MTCC 282. Efficient production of citric acid by mutant Aspergillus niger MTCC 282 grown on a sugar rich byproduct requires the supplementation of the optimized quantities of nutrients. Optimization of chemical parameters for the production of citric acid was done by Box-Behnken design. Box-Behnken design was used to statistically compare different combinations of four different nutrients, namely Ammonium sulphate ((NH4)2SO4), Magnesium (Mg2+), Ethylene diamine tetra acetic acid (EDTA) and Potassium phosphate (KH2PO4), for the maximum production of citric acid. The optimum nutrient concentrations obtained using the Box-Behnken design were Ammonium sulphate ((NH4)2SO4) 0.2138 g/l, Magnesium (Mg2+) 0.1896 g/l, Ethylene diamine tetra acetic acid (EDTA) 0.3968 g/l and Potassium phosphate (KH2PO4)3 g/l. Under the optimum conditions, mutant Aspergillus niger MTCC 282 produced the maximum citric acid of 75 g/l of citric acid/ kg substrate at pH 4.
5 citations
TL;DR: Results demonstrated that AP can be evaluated as an additional C source to OP for PG production, which in turn both can be alternative solutions for the elimination of the waste accumulation in the food industry with economical returns.
Abstract: The potential of important agro-industrial wastes, apple pomace (AP) and orange peel (OP) as C sources, was investigated in the maximization of polygalacturonase (PG), an industrially significant enzyme, using an industrially important microorganism Aspergillus sojae Factors such as various hydrolysis forms of the C sources (hydrolysed-AP, non-hydrolysed-AP, hydrolysed-AP + OP, non-hydrolysed-AP + OP) and N sources (ammonium sulphate and urea), and incubation time (4, 6, and 8 days) were screened It was observed that maximum PG activity was achieved at a combination of non-hydrolysed-AP + OP and ammonium sulphate with eight days of incubation For the pre-optimization study, ammonium sulphate concentration and the mixing ratios of AP + OP at different total C concentrations (9, 15, 21 g l−1) were evaluated The optimum conditions for the maximum PG production (14496 U ml−1) was found as 21 g l−1 total carbohydrate concentration totally coming from OP at 15 g l−1 ammonium sulphate concentration On the
4 citations
Cites background from "Multiresponse analysis of microbiol..."
...8 and 40°C.[16] One unit of enzyme activity was defined as the amount of enzyme that catalyses the release of 1 micromole of galacturonic acid per unit...
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10 Apr 2018
TL;DR: The results display the potential of R. pusillus as a promising pectolyase producer on inexpensive substrates, opening the way for several industrial application.
Abstract: Rhizomucor pusillus DSM 1331 is recognized to produce several industrial enzymes by solid-state fermentation (SSF). In pectinases research, little work was performed on the pectolyase enzyme production or molecular level using R. pusillus. Pectinases have been exploited in various industrial applications e.g. juice clarification and wine production. This project deals with the exploration of R. pusillus as pectolyase producer, with the emphasis on pectin lyase (PNL) production under solid-state conditions. PNL catalyzes the degradation of highly esterified pectin via a β-elimination mechanism. The study conducted a rational bioprocess development using different strategies. R. pusillus exhibited the ability to produce pectolyase using submerged and solid-state fermentation systems. SSF is showed an efficient fermentation mode using agroindustrial material reaching maximum PNL activity of 100 U/g. The process was optimized at the laboratory scale and scaled-up 200X utilizing at rotating drum bioreactor (with a productivity of 20,000 U/kg/d). Strain development strategy using the genome shuffling approach was selected to enhance enzyme production. The genome shuffling system was successfully developed. AR9-fusant was obtained with significant enhancement in pectolyase production showing a PNL activity of 580 U/g, five times higher than the parental strain. Optimal biochemical properties and pectinolytic activities of enzyme complexes revealed different patterns between R. pusillus and AR9-fusant. A preliminary attempt for protein identification was performed using MALDI-TOF. For the first time, the Rppnl gene, which encodes the pectin lyase of R. pusillus was isolated.Nucleotide and deduced amino acid sequence of Rppnl gene were compared with the reported PNL sequences and significant homology was confirmed. The results display the potential of R. pusillus as a promising pectolyase producer on inexpensive substrates, opening the way for several industrial application
2 citations
Cites methods from "Multiresponse analysis of microbiol..."
...The presented mechanism modified from [9]....
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...Exo-polygalacturonase (exo-PG) activity was assayed according to the procedure provided by [9]with slight modifications, which is based on measuring the reducing sugar concentration after incubation of enzyme with the substrate....
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Dissertation•
07 Jan 2010
2 citations
Cites methods from "Multiresponse analysis of microbiol..."
...age, inoculum age and amount of inoculum were studied using RSM for production of pectolytic enzymes in submerged fermentation [80]....
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References
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TL;DR: The work described in this article is the result of a study extending over the past few years by a chemist and a statistician, which has come about mainly in answer to problems of determining optimum conditions in chemical investigations, but they believe that the methods will be of value in other fields where experimentation is sequential and the error fairly small.
Abstract: The work described is the result of a study extending over the past few years by a chemist and a statistician. Development has come about mainly in answer to problems of determining optimum conditions in chemical investigations, but we believe that the methods will be of value in other fields where experimentation is sequential and the error fairly small.
4,359 citations
2,808 citations
Book•
01 Jan 1987
TL;DR: In this paper, the authors present a methodology for estimating response surfaces that rival least squares based on the integrated mean squared error criterion analysis of multiresponse experiments with block effects mixture designs and analyses nonlinear response surface models.
Abstract: Introduction to response surface methodology matrix algebra, least squares, the analysis of variance, and principles of experimental design first-order models and designs second-order models and designs determining optimum conditions methods of estimating response surfaces that rival least squares based on the integrated mean squared error criterion analysis of multiresponse experiments response surface models with block effects mixture designs and analyses nonlinear response surface models Taguchi's robust parameter design additional topics and some directions for future research. Appendix: solutions to selected exercises.
1,480 citations
TL;DR: In this paper, the authors present a methodology for estimating response surfaces that rival least squares based on the integrated mean squared error criterion analysis of multiresponse experiments with block effects mixture designs and analyses nonlinear response surface models.
Abstract: Introduction to response surface methodology matrix algebra, least squares, the analysis of variance, and principles of experimental design first-order models and designs second-order models and designs determining optimum conditions methods of estimating response surfaces that rival least squares based on the integrated mean squared error criterion analysis of multiresponse experiments response surface models with block effects mixture designs and analyses nonlinear response surface models Taguchi's robust parameter design additional topics and some directions for future research. Appendix: solutions to selected exercises.
1,384 citations
TL;DR: In this paper, the concept of the variance function for an experimental design is introduced, and the problem of selecting practically useful designs is discussed, and in this connection, the notion of variance function is introduced.
Abstract: Suppose that a relationship $\eta = \varphi(\xi_1, \xi_2, \cdots, \xi_k)$ exists between a response $\eta$ and the levels $\xi_1, \xi_2, \cdots, \xi_k$ of $k$ quantitative variables or factors, and that nothing is assumed about the function $\varphi$ except that, within a limited region of immediate interest in the space of the variables, it can be adequately represented by a polynomial of degree $d$. A $k$-dimensional experimental design of order $d$ is a set of $N$ points in the $k$-dimensional space of the variables so chosen that, using the data generated by making one observation at each of the points, all the coefficients in the $d$th degree polynomial can be estimated. The problem of selecting practically useful designs is discussed, and in this connection the concept of the variance function for an experimental design is introduced. Reasons are advanced for preferring designs having a "spherical" or nearly "spherical" variance function. Such designs insure that the estimated response has a constant variance at all points which are the same distance from the center of the design. Designs having this property are called rotatable designs. When such arrangements are submitted to rotation about the fixed center, the variances and covariances of the estimated coefficients in the fitted series remain constant. Rotatable designs having satisfactory variance functions are given for $d = 1, 2$; and $k = 2, 3, \cdots, \infty$. Blocking arrangements are derived. The simplification in the form of the confidence region for a stationary point resulting from the use of a second order rotatable design is discussed.
1,332 citations