Pyrrolnitrin from Rhizospheric Serratia marcescens NCIM 5696: Optimization of Process Parameters Using Statistical Tools and Seed-Applied Bioprotectants for Vigna radiata (L.) Against Fusarium oxysporum MTCC 9913
- 19 Downloads
The extensive use of chemical fungicide in the health and agriculture sectors has increased environmental concerns and promoted an extensive search for alternative bioactives from the microbial system. In the present study, two rhizospheric strains of Serratia spp. (TO-2 and TW-3) have been shown to secrete pyrrolnitrin (PRN) in the range of 11.35 to 35.97 μg ml−1 using MSG and MSD medium after 72 h under static and shake conditions, respectively, but thereafter marginally declined in 96 to 240 h. Alternative one variable assortment at a time (OVAT) for PRN secretion by TW-3 yielded 59.27 μg ml−1 using (gl−1) glycerol (20), monosodium glutamate (14), KH2PO4 (14), NH4Cl (3), Na2HPO4 (4), and MgSO4 (0.3) at pH 7, 120 rpm within 72 h. Further, the Placket–Burman Design (PBD) identified KH2PO4, glycerol, pH, and monosodium glutamate as significant variables and optimized by centered composite design. Accordingly, 3% glycerol, 1.72% KH2PO4, 1.1% monosodium glutamate, 0.4% Na2HPO4, 0.03% MgSO4, 0.05% FeSO4, and 0.01% ZnSO4 were found to enhance the yield of PRN to 96.54 μg ml−1 by TW-3 in 72 h, 120 rpm. Thus, the statistical tool employed in the present study showed a threefold hike in PRN secretion over the OVAT approach, thereby indicating the scope for more PRN production from rhizobacteria. Further, seed application of low PRN (30 μg ml−1) concentration in treatments I and II showed > 90% germination in the initial seed germination and pot assay with the Fusarium oxysporum challenge compared to the control. Also, various growth parameters calculated during 11 days of experiment were significantly increased compared to the negative control (seed + fungus) in both treatments. Thus, the application of PRN at a low concentration to seeds of Vigna radiata (L.) offered protection against the phytopathogenic F. oxysporum MTCC 9913 challenge, suggesting biocontrol activity potential for use in agriculture soils particularly salt-affected soil.
KeywordsPyrrolnitrin (PRN) OVAT Placket Burman Design (PBD) Centered composite design (CCD) Vigna radiata (L.)
The authors acknowledge the infrastructural grant through UGC-SAP-DRS (III) (University Grants Commission, New Delhi) and DST-FIST (Department of Science and Technology, New Delhi), Govt. of India, to the School of Life Sciences of this Kavayitri Bahinabai Chaudhari North Maharashtra University. Ms. Shraddha Pawar acknowledges the financial support through UGC-BSR fellowship and from University Grant Commission (UGC), New Delhi.
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflicts of interest.
- 3.Burkhead, K. D., Schisler, D. A., & Slininger, P. J. (1994). Pyrrolnitrin production by biological control agent Pseudomonas cepacia B37w in culture and in colonized wounds of potatoes. Applied and Environmental Microbiology, 60(6), 2031–2039.Google Scholar
- 8.Fernando, W. D., Nakkeeran, S., de Kievit, T., Poritsanos, N., Zhang, Y., Paulit, T. C., Li, Z., & Ramarathnam, R. (2007). March. Multiple mechanisms of biocontrol by Pseudomonas chlororaphis PA23 affect stem rot of canola caused by Sclerotinia sclerotiorum. In Proceedings of the 12 th International Rapeseed Congress p (pp. 26–30).Google Scholar
- 10.Gorman, M., & Lively, D. H. (1967). Pyrrolnitrin: a new mode of tryptophan metabolism. In Biosynthesis (pp. 433–438). Berlin: Springer.Google Scholar
- 12.Hamill, R., Elander, R., Mabe, J., & Gorman, M. (1967). Metabolism of tryptophan by Pseudomonas aureofaciens V: conversion of tryptophan to pyrrolnitrin. Antimicrobial Agents and Chemotherapy, 1967, 388–396.Google Scholar
- 13.Kader, M. A. (2005). A comparison of seed germination calculation formulae and the associated interpretation of resulting data. Journal and Proceedings. Royal Society, 138, 65–75.Google Scholar
- 14.Kang, B. R., Han, S. H., Zdor, R. E., Anderson, A. J., Spencer, M., Yang, K. Y., Kim, Y. H., Lee, M. C., Cho, B. H., & Kim, Y. C. (2007). Inhibition of seed germination and induction of systemic disease resistance by Pseudomonas chlororaphis O6 requires phenazine production regulated by the global regulator, gacS. Journal of Microbiology and Biotechnology, 17(4), 586–593.Google Scholar
- 15.Keum, Y. S., Lee, Y. J., Lee, Y. H., & Kim, J. H. (2009). Effects of nutrients on quorum signals and secondary metabolite productions of Burkholderia sp. O33. Journal of Microbiology and Biotechnology, 19(10), 1142–1149.Google Scholar
- 19.Liu, X., Bimerew, M., Ma, Y., Müller, H., Ovadis, M., Eberl, L., Berg, G., & Chernin, L. (2007). Quorum-sensing signaling is required for production of the antibiotic pyrrolnitrin in a rhizospheric biocontrol strain of Serratia plymuthica. FEMS Microbiology Letters, 270(2), 299–305.CrossRefGoogle Scholar
- 21.Pawar, S., Chaudhari, A., Prabha, R., Shukla, R., & Singh, D. P. (2019). Microbial pyrrolnitrin: natural metabolite with immense practical utility. Biomolecules, 9 (manuscript accepted).Google Scholar