Bioactivity of endophytic bacteria and yeasts isolated from Thymus

Document Type : Original Research Papers


1 Plant Protection Department, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran

2 Research Center for Agriculture and Natural Resources, Hamedan, Iran


Endophytes are important resources of bioactive compounds and due to their potential in the
production of secondary metabolites, they are regarded as a potential reservoir of
biotechnological applications. In this study, the bioactivity of bacteria and yeasts endophytes
residing in Thymus sp. was evaluated. During April to October 2011, symptomless and healthy
tissues of Thymus sp. were collected. A total of 23 strains of endophytic bacteria and 6 yeasts
were isolated. The bio-effects of the endophytes were studied on Botrytis cinerea and plant
pathogenic bacteria Xanthomonas arboricola pv. juglandis and Streptomyces scabies and
human pathogens Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC. Growth
inhibition mechanisms of the endophytes against B. cinerea were evaluated and it seems that the
antimicrobial effects of bacterial endophytes are related to the production of protease enzyme,
hydrogen cyanide and volatile compounds. Bacterial strains were identified as Bacillus,
Pseudomonas and Xanthomonas of which Bacillus was the predominant isolate. For the first
time, Bacillus is reported from Thymus eriocalyx, T. lancifolius, T. fallax, T. kotschyanus and T.
vulgaris and Pseudomonas and Xanthomonas as endophytic bacteria from Thymus.


Main Subjects

1. Dalton, D.A., Kramer, S., Azios, N., Fusaro, S., Cahill, E. and Kennedy C. (2004) Endophytic nitrogen fixation in dune grasses from Oregon. Microbial. Ecol., 49,469-479.
2. Li, Ch.H., Zhao, M.W., Tang, C.M. and Li, Sh.P. (2010) Population dynamics and identification of endophytic bacteria antagonistic toward plant-pathogenic fungi in cotton root. Microbial. Ecol., 59, 344-356.
3. Berg, G. and Hallmann, J. (2006) Control of plant pathogenic fungi with bacterial endophytes. In Schulz, B., Boyle, C. and Sieber, T.N. (eds.) Microbial Root Endophytes. Springer, Germany, pp.53-68.
4. Strobel, G., Yang, X., Scars, J., Kramer, R., Sidhu, R.S. and Hess, W.M. (1996) Taxol from Pestaloptiopsis microspors, an endophytic fungus of Taxus wallichiana. Microbiology, 142, 435-440.
5. Caruse, M., Colombo, A.L., Fedeli, L., Pavesi, A., Quaroni, S., Saracchi, M. and Ventrella, G. (2000) Isolation of endophytic fungi and actinomycetes taxane producers. Ann. Microbiol., 50, 3-13.
6. Khan, R., Shahzad, S., Choudhary, M., Shakeel, I., Khan, A. and Aqeel, A. (2010) Communities of endophytic fungi in medicinal plant Withania somnifera. Pakistan J. Bot., 42, 1281-1287.
7. Naghdibadi, H. and Makkizadeh-Tafti, M. (2003) Review on Thymus vulgaris L. J. Med. Plant, 7, 1-13.
8. Asgharian Sh. (2010) Evaluation of antibacterial and antifungal activities of endophyte residing in stems and leaves of native medicinal plants in Chaharmahal province. PhD Thesis, Shahrekord University, Iran.
9. Selim, K.A., El-Beih, A.A., AbdEl-Rahman, T.M. and El-Diwany, A.I. (2011) Biodiversity and antimicrobial activity of endophytes associated with Egyptian medicinal plants. Mycosphere, 2, 669-678.
10. Lin, L., Qiao, Y.S., Ju, Z.Y., Ma, C.W., Liu, Y.H., Zhou, Y.J. and Dong, H.S. (2009) Isolation and characterization of endophytic Bacillius subtilis Jaas ed1 antagonist of eggplant Verticillium Wilt. Biosci. Biotechnol. Biochem., 73, 1489-1493.
11. Schaad, N.W., Jones, J.B. and Chun, W. (2001) Laboratory guide for the identification of plant pathogenic bacteria. 3rd eds., Phytopathological Society St. Paul, Minnesota, USA.
12. Mirzaei, S., Goltapeh E.M., Shams-Bakhsh, M. and Safaie, N. (2008) Identification of Botrytis spp. on plants grown in Iran. J. Phytopathol., 156, 21-28.
13. Jalgaonwala, R.E., Mohite, B.V. and Mahajan, R.T. (2010) Evaluation of endophytes for their antimicrobial activity from indigenous medicinal plants belonging to north Maharashtra region India. Int. J. Biol. Pharmaceut. Res. (IJBPR), 1, 136-141.
14. Karimi, E., Rouhani, H., Zafari, D., Khodakaramian, Gh. and Taghinasab, M. (2007) Biological control of vascular wilt disease of carnation caused by Fusarium oxysporum f.sp. dianthi by Bacillus and Pseudomonas strains isolated from rhizosphere of carnation. J. Sci. Technol. Agric. Natural Res, Water Soil Sci., 11, 309-320.
15. Castric, K.F. and Castric, P.E. (1983) Method for rapid detection of cyanogenic bacteria. App. Environ. Microbiol., 45, 701-702.
16. Camassola, M. and Dillon, A.J.P. (2012) Cellulase Determination: Modifications to Make the Filter Paper Assay Easy, Fast, Practical and Efficient. 1: 125. doi:10.4172/scientificreports.125
17. Fiddaman, P.J. and Rossall, S. (1993) The production of antifungal volatiles from Bacillus subtilis. J. Appl. Bacteriol., 74, 119-126.
18. Kraus, J. and Loper, J.E. (1990) Biocontrol of Pythium damping-off of cucumber by Pseudomonas fluorescens pf-5: mechanistic studies. In Keel, C., Koller, B. and Defago, G. (eds.) Plant Growth Promoting Rhizobacter. The second international workshop on plant growth promoting Rhizobacteria. Interlaken, Switzerland. pp.172-175.
19. Baghestan P. (2007) Biological control of Fusarium rot of crown and root of corn by species of fungi Trichoderma in the province Hamedan. MSc Thesis, University of Tehran, Iran.
20. Stutz, E., Defago, G. and Kern, H. (1986) Naturally occurring fluorescent Pseudomonas involved in suppression of black root rot of tobacco. Phytopathology, 76, 181-185.
21. De Siqueira, M.V., Conti, R., De Araújo, J.M. and Souza-Motta, C.M. (2011) Endophytic fungi from the medicinal plant Lippia sidoides Cham. and their antimicrobial activity. Symbiosis, 53, 89-95.
22. Czaczyk, K., Stachowiak, B., Trojanowska, K. and Gulewicz, K. (2000) Antifungal activity of Bacillus sp. isolated from compost. Folia Microbiol., 45, 552-554.
23. Liu, B., Huang, L.L., Buchenauer, H. and Kang, Z.S. (2010) Isolation and partial characterization of an antifungal protein from the endophytic Bacillus subtilis strain EDR4. Pestic. Biochem. Phys., 98, 305-311.
24. Kong, H.G., Kim, J.C., Choi, G.J., Lee, K.Y., Kim, H.J., Hwang, E.C., Moon, B.J. and Led, S.W. (2010) Production of surfactin and iturin by Bacillus licheniformis N1 responsible for plant disease control activity. J. Plant Pathol., 26, 170-177.
25. Wang, H.K., Xiao, R.F. and Qi, W. (2013) Antifungal activity of Bacillus coagulans TQ33, isolated from skimmed milk powder, against Botrytis cinerea. Food Technol. Biotechnol.51, 78-83.
26. Berde, C.V., Bhosale, P.P. and Chaphalkar, S.R. (2010) Plasmids of endophytic bacteria as vectors for transformation in plants. Int. J. Integ. Biol., 9, 113-118.