DBPapers
DOI: 10.5593/sgem2017/61/S25.131

STUDY OF ANTIBACTERIAL ACTIVITY OF A RANGE OF PLANT EXTRACTS AGAINST THE CAUSATIVE AGENT OF POTATO BLACKLEG DISEASE (PECTOBACTERIUM)

N. Behidj-Benyounes, S. Letifi, L. Slamani, D. Itouchene, T. Dahmane
Tuesday 12 September 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-12-6 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 61, 999-1006 pp, DOI: 10.5593/sgem2017/61/S25.131

ABSTRACT

The Pectobacterium bacteria are classified among the most economically important pathogens for growing potatoes. In recent years, an increase in diseases caused by these bacteria could be observed. The purpose of this work is the study of the antibacterial activity in vitro of five plant extracts namely grains of black cumin (Nigella sativa L.), cloves (Syzygium aromaticum), Eucalyptus camaldulensis, wild carrot (Daucus carota L.) and thyme Numidia (Thymus numidicus), against the strain Pectobacterium collected in a production parcel located in the region of Ain Defla. The strain isolated, purified and identified is called Pectobacterium carotovorum subsp. carotovorum (P.c.c). The study in vitro of antibacterial activity of Nigella sativa L. seeds and essential oil Daucus carota shows inhibition zone diameter (ID) less than 8 mm, attesting the non-sensitivity of strain against these two extracts. However, the strain studied is extremely sensitive to the extract of Thymus numidicus with an inhibition zone diameter (ID) of 20 mm. It is very sensitive to the extract of Eucalyptus camaldulensis with an inhibition zone diameter (ID) of 17 mm. Thus, it is also sensitive to the clove that is to say about 14 mm diameter of inhibition zone (ID). The minimum inhibitory concentrations (MIC), recorded for the cloves are (D4) 1/8 and (D5) 1/16 for Eucalyptus camaldulensis and Thymus numidicus. The study of the bactericidal or bacteriostatic effect confirms the bactericidal effect of the essential oil of Thymus numidicus against the bacterial strain studied through the absence of bacterial colonies for concentration 1. While for the extract of Eucalyptus camaldulensis and clove we see the resumption of bacterial growth for all concentrations used. This confirms the bacteriostatic effect.

Keywords: Plant extracts, essential oil, Pectobacterium carotovorum subsp. carotovorum (P.c.c), antibacterial effect, minimum inhibitory concentration (MIC), bactericidal, bacteriostatic