P. Ponmurugan

Department of Biotechnology, K.S.Rangasamy College of Technology,

Tiruchengode - 637 215, Namakkal District, Tamil Nadu, India.

E-mail : drponmurugan@gmail.com

Abstract

Following the collection of 257 soil samples, 123 strains of silicon solubilizing bacteria (SSB) were identified by the use of silicon basal media. These strains were then refined, screened, and their antifungal activity was assessed. Of them, 24 isolates grew quickly, 48 slowly, and the remaining 51 strains could only develop slowly to moderately. Physiological, biochemical, and morphological characteristics identified Bacillus nucilaginosus as the parent organism of all isolated cultures. Additionally, the SSB01 strain was chosen based on its in vitro performance when tested for antagonistic potential against root pathogens like Poria hypolateritia and Fomes noxius, leaf pathogens like Pestalotiopsis theae and Cercosporella theae, and tea stem pathogens like Phomopsis theae and Tunstallia aculeata. The growth pattern, mycelial coloration, exopolysaccharide synthesis, and diffusible pigment of Bacillus nucilaginosus were all observed and recorded.  The enzymes lipase, chitinase, gelatinase, cellulase, and amylase, which are helpful in eliminating tea pathogens in vivo, were produced by each isolate.

Introduction

Numerous microorganisms can be found in tea soil, and the majority of them are good for plant growth (Baby et al., 2002). Silicon solubilizing bacteria (SSB) are a significant group of soil microorganisms that produce a wide range of secondary metabolites, many of which have antibacterial or antifungal characteristics (Al-Falih, 2003). Finding a productive soil bacterium that could dissolve silicate could allow other vital nutrients to be released into the soil (Muralikannan, 1996). One of the key mechanisms for the biological inhibition of several phytopathogens is induced systemic resistance (ISR) by SSB (Sommer et al., 2006; Sacala, 2009). Vijayapriya and Muthukkaruppan (2010) investigated the effectiveness of SSB in enhancing the ISR of rice plants against Pyricularia oryzae, the most devastating phytopathogen in terms of biotechnological application on plant growth and biocontrol activities.

Fungicides are mostly used to combat tea illnesses. A few tea diseases have been shown to be effectively controlled by soaking the soil with systemic fungicides (Ponmurugan and Baby, 2005; Chandramouli and Baby, 2002). Fungicide-soaked soil has a negative impact on helpful microorganisms. Chemical control is also costly and unpredictable. An effective substitute for treatment of stem and root problems is biological control. Tested against a range of tea illnesses, the antagonistic microorganisms, namely bacterial (Bacillus and Pseudomonas spp.) and fungal (Trichoderma and Gliocladium spp.) were found to be effective (Chandramouli and Baby, 2002; Premkumar and Baby, 2005; Ponmurugan and Baby, 2005). Similar to this, antagonistic microorganisms such as actinomycetes (Streptomyces spp.) secrete chemicals that regulate growth and antibiotics, respectively, which help to arrest the growth of pathogens and improve plant metabolism.

Conclusions

The majority of B. nucilaginosus strains identified in this investigation were demonstrated to be potential antagonists against tea pathogens, indicating that the synthesis of secondary metabolites may be able to regulate tea pathogens. After creating the carrier-based bioformulation, field tests should be started to verify the strains' effectiveness against tea illnesses in vivo.

References

[1] Al-Falih, A.M. 2003. Effect Of Silicon Compounds On Oligotrophic Soil Bacteria. Saudi. J. Biol. Sci. 10: 131-136.

[2] Augustine, S.K. Bhavsar, S.P. Baserisalehi, M. Kapadnis, B.P. 2004. Isolation, characterization and optimization of antifungal activity of an actinomycete of soil origin. Indian J. Expri. Biol. 42: 928-932.

[3] Baby, U.I. Tensingh Baliah, N. Ponmurugan, P. Premkumar, R. 2002. Population level of certain beneficial microorganisms in tea soils. UPASI Tea Res. Found. Newsletter 12 (1): 3.

[4] Bauer, A. Kirby, A.W. Sherries, J.C. Trunk, M. 1996. Antibiotic susceptibility by standard disc method. J. Clinical Pathol. 45: 493.

[5] Bunt, J.S. Rovira, A.D. 1955. Microbiological studies of some sub Antarctic soils. J. Soil Sci. 6: 119-128.

[6] Chandramouli, M.R. Baby, U.I. 2002. Control of thorny stem blight disease of tea with fungicides and biocontrol agents. pp. 531-534. In: Proceedings of Plantation Crops and Development in the new Millennium, (Eds.) P.Rethinum, H.H.Khan, V.M.Reddy, P.K.Mandal and K.Suresh, Coconut Development Board Publication, Kochi, Kerala,  

[7] Demain, A.L. Fang, A. 1995. Emerging concepts of secondary metabolism in actinomycetes. Actinomycetologica 9: 98-99.

[8] Dennis, C. Webster, J. 1971. Antagonistic properties of species groups of Trichoderma. II. Production of volatile antibiotics. Trans. Br. Mycol. Soc.  57: 41-48.

[9] Dubey, R.C. Maheshwari, D.K. 2002. Practical Microbiology. S.Chand and Company, New Delhi, 397p.

[10] Fguira, L. Fotso, S. Ben Ameur-Mehdi, R. Mellouli, L. Laatsch, H. 2005. Purification and structure elucidation of antifungal and antibacterial activities of newly isolated Streptomyces sp. Res. Microbiol. 156: 341-347.

[11] Goodfellow, M. Lacey, J. Todd, C. 1987. Numerical classification of thermophilic Streptomyces. J. Gen. Microbiol. 133: 3135-3149.

[12] Huang, H.C. Hoes, J.A. 1976. Penetration and infection of Sclerotina sclerotiorum by Coniothyrium minitans. Can. J. Bot. 54: 406-410.

[13] Keiser, T. Bibb, M.J. Buttner, M.J. Chater, F.K. Hopwood, D.A. 2000. General introduction to actinomycetes biology. pp 1-21.In: Practical Streptomyces Genetics. The John Innes Foundation, England.

[14] Muralikannan, N. 1996. Biodissolution of silicate, phosphate and potassium by silicate solubilizing bacteria in rice ecosystem M.Sc. (Ag.). Thesis, submitted to Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India, p.115.

[15] Ponmurugan, P. Baby, U.I. 2005. Management of Phomopsis canker of tea with fungicides and biocontrol agents. J. Plantn. Crops 33: 175-178.

[16] Ponmurugan, P. Gopi, C. Maripandi, A. 2007. Studies on Actinomycetes diversity in southern Indian tea soils for antifungal activity. J. Plantn. Crops 35: 28-32.

[17] Ponmurugan, P. Elango, V. Marimuthu, S. Chaudhuri, T.C. Saravanan, D. Gnanamangai, B.M. Karunambika, K.M. 2011. Evaluation of actinomycetes isolated from southern Indian tea plantations for the biological control of tea pathogens. J. Plantn. Crops 39: 239-243.

[18] Premkumar, R. Baby, U.I. 2005. Recommendations on the control of root and stem diseases of tea. pp.15-16. In: Hand book of tea culture, UPASI Tea Research Institute, Valparai, Tamil Nadu.

[19] Ramesh, S. Rajesh, M. Mathivanan, N. 2009. Characterization of a thermostable alkaline protease produced by marine Streptomyces fungicidicus MML1614. Bioprocess Biosyst. Eng. doi: 10.1007/s00449-009-0305-1

[20] Sacala, E. 2009. Role of silicon in plant resistance to water stress. J. Elementol. 14: 619-630.

[21] Sanglier, J.J. Haag, H. Huck, T.A. Fehr, T. 1993. Novel bioactive compounds from actinomycetes. A short review. Res. Microbiol. 144: 633-642.

[22] Sommer, M. Fuzyakov, D. Breuer, J. 2006. Silicon pools and fluxes in soils and landscapes-a review. J. Plant Nutr. Soil Sci. 169: 310-329.

[23] Vijayapriya, M. Muthukkaruppan, S.M. 2010. Isolation and screening of silicate solubilizing bacteria and its biocontrol nature against Pyricularia oryzae. Inter. J. Recent Sci. Res. 4: 87-91.

[24] Williams, S.T. Wilkins. S. 1994. Bergey’s Manual of Determinative Bacteriology, 9th edition, Williams and Wilkins, Baltimore, Cambridge University Press, UK.

[25] Zahner, H. Weber, W. Siebers, J. Schroder, K. Zeeck, A. 1989. Streptomyces. Arch. Microbiol. 124: 111-116.