Optimization of culture conditions by response surface methodology and unstructured kinetic modeling for bioactive metabolite production by Nocardiopsis litoralis VSM-8.

Muvva Vijayalakshmi,R Satish Babu,V S Rama Krishna Ganduri,Sudhakar Poda,Ushakiranmayi Managamuri

doi:10.1007/s13205-016-0535-2

Abstract

Response surface methodology-based central composite design on five variables incubation time, pH, temperature, sucrose concentration, and soya peptone concentration was employed for optimization of the production of bioactive compounds by Nocardiopsis litoralis strain VSM 8. The main quadratic effects and interactions of the five variables on the production of bioactive metabolites were investigated. A second-order polynomial model produced a satisfied fit for experimental data with regard to the production of the bioactive metabolites. Regression analysis showed that high R 2 values of all the five responses are significant and adjusted R 2 values showed good agreement with the experimental and predicted values. The present model was used to evaluate the direct interaction and quadratic effects to optimize the physico-chemical parameters for the production of bioactive metabolites that inhibit the pathogenic microorganisms measured in terms of zones of inhibition (responses). Mathematical kinetic model development and estimation of kinetic parameters also showed good approximation in terms of model fitting and regression analysis.

Highlights

Microorganisms dwelling in extreme environments are prolific producers of several bioactive compounds that have evolved due to adaptation of the extreme environmental conditions in terms of metabolic biochemistry
Response surface methodology-based central composite design on five variables incubation time, pH, temperature, sucrose concentration, and soya peptone concentration was employed for optimization of the production of bioactive compounds by Nocardiopsis litoralis strain VSM 8
Influence of different physico-chemical parameters on bioactive metabolite production and their effect on the response were investigated and optimized as per the model designed by Central composite design (CCD) of Response surface methodology (RSM)

Summary

Introduction

Microorganisms dwelling in extreme environments are prolific producers of several bioactive compounds that have evolved due to adaptation of the extreme environmental conditions in terms of metabolic biochemistry. RSM is a powerful statistical experimental approach used in mathematical modeling, and an ideal process for variable standardizing strategy for optimization of the target metabolite production and simultaneously evaluates the relative significance and interactive effects among different variables (Souagui et al 2015). The successful design and operation of fermentation process, in which biochemical transformation occurs in controlled conditions, need careful understanding of complex metabolic reactions. This could be supported by mathematical modeling that describes the process simpler with good representation. The objectives of this study include the statistical optimization of process parameters for bioactive metabolite production using RSM and to estimate the kinetic parameters of actinomycetes fermentation using N. litoralis strain VSM 8 (KT901293)

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Results

Discussion

Conclusion