Genetic algorithm-based medium optimization for enhanced production of fluorescent pseudomonad R81 and siderophore

Fluorescent pseudomonad R81, a root-colonizing bacterium, is a potential bio-inoculant due to its plant growth promoting characteristics. It produces hydroxamate-type siderophore which is involved in disease suppression in plants. Genetic algorithm (GA) methodology was applied for the optimization of siderophore and cell mass production simultaneously in shake flask experiments. A total of 10 medium components were optimized within 80 experiments. A high siderophore concentration of 1.9 g/L and cell mass concentration of 2.8 g/L was achieved in the optimized medium. The application of GA was well suited for determination of optimum concentration levels of the medium constituents for a bi-objective function. GA was able to increase the siderophore concentration by 2.8-fold when compared to RSM-based optimization. Further, the batch fermentation of the GA-optimized medium in 14 L bioreactor without pH control produced 2.2 g/L siderophore in 36 h, the highest reported so far. GA was also successfully used to estimate the kinetic parameters of the mathematical models of the batch fermentation.

[1]  Xuehong Zhang,et al.  Medium factor optimization and fermentation kinetics for phenazine‐1‐carboxylic acid production by Pseudomonas sp. M18G , 2008, Biotechnology and bioengineering.

[2]  K. Schleifer,et al.  The mesophilic hydrogen-oxidizing (knallgas) bacteria. , 1992 .

[3]  J. Leong.  Siderophores: Their Biochemistry and Possible Role in the Biocontrol of Plant Pathogens , 1986 .

[4]  B. Duffy,et al.  Environmental Factors Modulating Antibiotic and Siderophore Biosynthesis by Pseudomonas fluorescensBiocontrol Strains , 1999, Applied and Environmental Microbiology.

[5]  Goldberg,et al.  Genetic algorithms , 1993, Robust Control Systems with Genetic Algorithms.

[6]  Dirk Weuster-Botz,et al.  Genetic algorithm for multi-objective experimental optimization , 2006, Bioprocess and biosystems engineering.

[7]  Gildo Almeida da Silva,et al.  Production of yellow-green fluorescent pigment by Pseudomonas fluorescens , 2006 .

[8]  Alok K. Sharma,et al.  Growth promoting influence of siderophore-producing Pseudomonas strains GRP3A and PRS9 in maize (Zea mays L.) under iron limiting conditions. , 2003, Microbiological research.

[9]  J. Kloepper,et al.  Enhanced plant growth by siderophores produced by plant growth-promoting rhizobacteria , 1980, Nature.

[10]  Kalyanmoy Deb,et al.  Multi-objective optimization using evolutionary algorithms , 2001, Wiley-Interscience series in systems and optimization.

[11]  D Weuster-Botz,et al.  Experimental design for fermentation media development: statistical design or global random search? , 2000, Journal of bioscience and bioengineering.

[12]  B. Johri,et al.  Diacetylphloroglucinol-producing pseudomonads do not influence AM fungi in wheat rhizosphere , 2004 .

[13]  B. Ahmed,et al.  Effect of iron and growth inhibitors on siderophores production by Pseudomonas fluorescens , 2005 .

[14]  J. Talavage,et al.  Optimization of stochastic simulation models , 1980 .

[15]  V. Sahai,et al.  Optimization of xylanase production by Melanocarpus albomyces IIS68 in solid state fermentation using response surface methodology. , 2001, Journal of bioscience and bioengineering.

[16]  A. Demain,et al.  An improved colorimetric assay for polyols. , 1977, Analytical biochemistry.

[17]  B. N. Johri,et al.  Plant growth stage, fertiliser management and bio-inoculation of arbuscular mycorrhizal fungi and plant growth promoting rhizobacteria affect the rhizobacterial community structure in rain-fed wheat fields , 2006 .

[18]  P. Villa,et al.  Evaluation of the siderophores production by Pseudomonas aeruginosa PSS. , 2002, Revista latinoamericana de microbiologia.

[19]  Christine M. Anderson-Cook.  Practical Genetic Algorithms (2nd ed.) , 2005 .

[20]  C. Wandrey,et al.  Medium Optimization by Genetic Algorithm for Continuous Production of Formate Dehydrogenase , 1995 .

[21]  Randy L. Haupt,et al.  Practical Genetic Algorithms , 1998 .

[22]  B. A. Eagles,et al.  THE MINERAL REQUIREMENTS FOR FLUORESCIN PRODUCTION , 1948 .

[23]  G. Snow.  Mycobactin. A growth factor for Mycobacterium johnei. Part II. Degradation, and identification of fragments , 1954 .

[24]  J. M. Meyer,et al.  The Fluorescent Pigment of Pseudomonas fluorescens : Biosynthesis, Purification and Physicochemical Properties , 1978 .

[25]  J. Buyer,et al.  Current ReviewSiderophores in Microbial Interactions on Plant Surfaces , 1991 .

[26]  Alok K. Sharma,et al.  Combat of iron-deprivation through a plant growth promoting fluorescent Pseudomonas strain GRP3A in mung bean (Vigna radiata L. Wilzeck). , 2003, Microbiological research.

[27]  L. J. Park,et al.  Application of genetic algorithms to parameter estimation of bioprocesses , 2006, Medical and Biological Engineering and Computing.

[28]  R. Luedeking,et al.  A kinetic study of the lactic acid fermentation. Batch process at controlled pH , 2000 .

[29]  P. Visca,et al.  Pseudobactin Biogenesis in the Plant Growth-Promoting Rhizobacterium Pseudomonas Strain B10: Identification and Functional Analysis of the l-Ornithine N5-Oxygenase (psbA) Gene , 2000, Journal of bacteriology.

[30]  M. Retzlaff,et al.  Optimisation of halogenase enzyme activity by application of a genetic algorithm. , 2007, Journal of biotechnology.

[31]  H Budzikiewicz,et al.  Secondary metabolites from fluorescent pseudomonads. , 1993, FEMS microbiology reviews.