Streptomyces sp. JAJ06 is a seawater-dependent antibiotic producer, previously isolated and characterised from an Indian coastal solar saltern. This paper reports replacement of seawater with a defined salt formulation in production medium and subsequent statistical media optimization to ensure consistent as well as improved antibiotic production by Streptomyces sp. JAJ06. This strain was observed to be proficient to produce antibiotic compound with incorporation of chemically defined sodium-chloride-based salt formulation instead of seawater into the production medium. Plackett-Burman design experiment was applied, and three media constituents, starch, KBr, and CaCO3, were recognised to have significant effect on the antibiotic production of Streptomyces JAJ06 at their individual levels. Subsequently, Response surface methodology with Box-Behnken design was employed to optimize these influencing medium constituents for the improved antibiotic production of Streptomyces sp. JAJ06. A total of 17 experiments were conducted towards the construction of a quadratic model and a second-order polynomial equation. Optimum levels of medium constituents were obtained by analysis of the model and numerical optimization method. When the strain JAJ06 was cultivated in the optimized medium, the antibiotic activity was increased to 173.3？U/mL, 26.8% increase as compared to the original (136.7？U/mL). This study found a useful way to cultivate Streptomyces sp. JAJ06 for enhanced production of antibiotic compound. 1. Introduction Streptomyces are the prime producers of bioactive compounds for biotechnology industry. Several clinically significant antibiotics as well as widely used drugs against common diseases have been derived from this unique genus affiliated with the order Actinomycetales [1]. Diverse members of this order including Streptomyces have been isolated from previously unexplored natural habitats to nourish the current microbial antibiotic searching programs [2, 3]. Streptomyces sp. JAJ06 is a Gram-positive, moderately halophilic Streptomyces strain, which has previously been isolated from hypersaline coastal solar saltern at Tuticorin, India [4]. This strain produces an antimicrobial polyketide compound which has been reported to have potent antimicrobial activity against a set of bacteria and yeast with significant minimal inhibitory concentrations [5]. Production of antibiotic compound in JAJ06 has been reported to have seawater dependence. Like many other complex medium components, seawater has nondefined composition which might affect the
References
[1]
M. H. Medema, R. Breitling, and E. Takano, “Synthetic biology in streptomyces bacteria,” Methods in Enzymology, vol. 497, pp. 485–502, 2011.
[2]
J. Hamedi, F. Mohammadipanah, and A. Ventosa, “Systematic and biotechnological aspects of halophilic and halotolerant actinomycetes,” Extremophiles, vol. 17, pp. 1–13, 2012.
[3]
P. A. Jose and S. R. D. Jebakumar, “Phylogenetic appraisal of antagonistic, slow growing actinomycetes isolated from hypersaline inland solar salterns at Sambhar salt Lake, India,” Frontiers in Microbiology, vol. 4, no. 190, 2013.
[4]
P. A. Jose and S. R. D. Jebakumar, “Phylogenetic diversity of actinomycetes cultured from coastal multipond solar saltern in Tuticorin, India,” Aquatic Biosystems, vol. 8, no. 23, 2012.
[5]
P. Arul Jose, V. Satheeja Santhi, and S. R. D. Jebakumar, “Phylogenetic-affiliation, antimicrobial potential and PKS gene sequence analysis of moderately halophilic Streptomyces sp. inhabiting an Indian saltpan,” Journal of Basic Microbiology, vol. 51, no. 4, pp. 348–356, 2011.
[6]
G. Tsueng, S. Teisan, and K. S. Lam, “Defined salt formulations for the growth of Salinispora tropica strain NPS21184 and the production of salinosporamide A (NPI-0052) and related analogs,” Applied Microbiology and Biotechnology, vol. 78, no. 5, pp. 827–832, 2008.
[7]
Y. Wang, X. Fang, F. An, G. Wang, and X. Zhang, “Improvement of antibiotic activity of Xenorhabdus bovienii by medium optimization using response surface methodology,” Microbial Cell Factories, vol. 10, article no. 98, 2011.
[8]
R. L. Greasham, “Media for microbial fermentations,” in Bioprocessing, H. J. Rehm, G. Read, A. Puhler, and P. Stagler, Eds., vol. 3 of Biotechnology, pp. 128–139, VCH, New York, NY, USA, 1983.
[9]
S. K. Singh, S. K. Singh, V. R. Tripathi, S. K. Khare, and S. K. Garg, “Comparative one-factor-at-a-time, response surface (statistical) and bench-scale bioreactor level optimization of thermoalkaline protease production from a psychrotrophic Pseudomonas putida SKG-1 isolate,” Microbial Cell Factories, vol. 10, article no. 114, 2011.
[10]
D. Singh and G. Kaur, “Optimization of different process variables for the production of an indolizidine alkaloid, swainsonine from Metarhizium anisopliae,” Journal of Basic Microbiology, vol. 52, pp. 590–597, 2012.
[11]
P. Sharma and L. Singh, “Application of response surface analysis for biodegradation of azo reactive textile dye using Aspergillus foetidus,” Journal of Basic Microbiology, vol. 52, pp. 314–323, 2012.
[12]
V. Ramakrishnan, L. C. Goveas, B. Narayan, and P. M. Halami, “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,” ISRN Biotechnology, vol. 2013, Article ID 980562, 9 pages, 2013.
[13]
K. Adinarayana, P. Ellaiah, B. Srinivasulu, R. Bhavani Devi, and G. Adinarayana, “Response surface methodological approach to optimize the nutritional parameters for neomycin production by Streptomyces marinensis under solid-state fermentation,” Process Biochemistry, vol. 38, no. 11, pp. 1565–1572, 2003.
[14]
S. Joshi, S. Yadav, A. Nerurkar, and A. J. Desai, “Statistical optimization of medium components for the production of biosurfactant by Bacillus licheniformis K51,” Journal of Microbiology and Biotechnology, vol. 17, no. 2, pp. 313–319, 2007.
[15]
Y. Qu, Q. Ma, X. Zhang, H. Zhou, X. Li, and J. Zhou, “Optimization of indigo production by a newly isolated Pseudomonas sp. QM,” Journal of Basic Microbiology, vol. 52, pp. 687–694, 2012.
[16]
P. Yu, Y. Yan, and Y.-P. Tang, “Medium optimization for endochitinase production by recombinant pichia pastoris ZJGSU02 using response surface methodology,” African Journal of Biotechnology, vol. 10, no. 1, pp. 75–84, 2011.
[17]
P. Saravanan, R. Muthuvelayudham, and T. Viruthagiri, “Enhanced production of cellulase from pineapple waste by response surface methodology,” Journal of Engineering, vol. 2013, Article ID 979547, 8 pages, 2013.
[18]
P. Kanmani, S. Karthik, J. Aravind, and K. Kumaresan, “The use of response surface methodology as a statistical tool for media optimization in lipase production from the dairy effluent isolate Fusarium solani,” ISRN Biotechnology, vol. 2013, Article ID 528708, 8 pages, 2013.
[19]
G. Tsueng and K. S. Lam, “A low-sodium-salt formulation for the fermentation of salinosporamides by Salinispora tropica strain NPS21184,” Applied Microbiology and Biotechnology, vol. 78, no. 5, pp. 821–826, 2008.
[20]
P. W. Maxwell, G. Chen, J. M. Webster, and G. B. Dunphy, “Stability and activities of antibiotics produced during infection of the insect Galleria mellonella by two isolates of Xenorhabdus nematophilus,” Applied and Environmental Microbiology, vol. 60, no. 2, pp. 715–721, 1994.
[21]
S. H. Mohamed and A. M. Galal, “Identification and antiviral activities of some halotolerant Streptomycetes isolated from Qaroon Lake,” ” International Journal of Agriculture and Biology, vol. 5, pp. 747–753, 2005.
[22]
S. V. Satheeja and S. R. D. Jebakumar, “Phylogenetic analysis and antimicrobial activities of Streptomyces isolates from mangrove sediment,” Journal of Basic Microbiology, vol. 51, no. 1, pp. 71–79, 2011.
[23]
P. A. Jose and S. R. D. Jebakumar, “Appraisal of solar saltern based diverse actinomycetes as a source of antimicrobial natural compounds,” in Proceedings of the Amrita Bioquest 2012, International Conference on Biotechnology for Innovative Applications, pp. 444–447, Elsevier, Kerala, India, August 2013.
[24]
M. A. Farid, H. A. El-Enshasy, A. I. El-Diwany, and S. A. El-Sayed, “Optimization of the cultivation medium for natamycin production by Streptomyces natalensis,” Journal of Basic Microbiology, vol. 40, pp. 157–166, 2000.
[25]
M. E. Rateb, Z. Yu, Y. Yan et al., “Medium optimization of Streptomyces sp. 17944 for tirandamycin B production and isolation and structural elucidation of tirandamycins H, I and J,” The Journal of Antibiotics, 2013.
[26]
J. M. Chaston, G. Suen, S. L. Tucker et al., “The entomopathogenic bacterial endosymbionts Xenorhabdus and Photorhabdus: convergent lifestyles from divergent genomes,” PloS one, vol. 6, no. 11, p. e27909, 2011.
[27]
H. Chen, M. Wu, Z. Chen, M. Wang, J. Lin, and L. Yang, “Enhancing production of a 24-membered ring macrolide compound by a marine bacterium using response surface methodology,” Journal of Zhejiang University SCIENCE B, vol. 14, pp. 346–354, 2013.
[28]
S. Raytapadar and A. K. Paul, “Production of an antifungal antibiotic by Streptomyces aburaviensis 1DA-28,” Microbiological Research, vol. 155, no. 4, pp. 315–323, 2001.
[29]
Z. Guo, L. Shen, Z. Ji, and W. Wu, “Enhanced production of a novel cyclic hexapeptide antibiotic (NW-G01) by streptomyces alboflavus 313 using response surface methodology,” International Journal of Molecular Sciences, vol. 13, no. 4, pp. 5230–5241, 2012.
