Antimicrobial and antibiofilm activities of phenolic compounds extracted from Populus nigra and Populus alba buds (Algeria)

The interest of this work is the discovery of new antimicrobial agents of plant origin to inhibit the formation of microbial biofilms. The present research was conducted to identify and quantify the phenolic compounds extracted from Populus nigra and Populus alba buds harvested in the area of Tizi-Ouzou (Algeria), and to evaluate their antimicrobial and antibiofilm activity. High performance liquid chromatography (HPLC) was performed to identify the phenolic compounds in the ethyl acetate fraction of P. nigra and the methanolic extracts of P. nigra and P. alba. The antimicrobial activity of the crude extracts and the fractions of these two species was tested against 11 microorganisms, using the disk diffusion method, while the antibiofilm effect of certain extracts was carried out in a 96-well microplate and on a biomaterial (catheter). HPLC analysis revealed the presence of 10 bioactive compounds. The main phenolic compounds identified in the three extracts were p-coumaric acid, ellagic acid, and Kaempferol. This study was able to demonstrate that the extracts of P. nigra and P. alba buds have interesting antimicrobial properties, with diameters ranging from 6.6 to 21.3 mm. In addition, extracts of P. nigra exhibited antibiofilm effects greater than 70%. Our results provide evidence for the antimicrobial and antibiofilm potential of bud extracts from both poplar species. Thus, these results will pave the way for further research on these two plants.

[Daily attacks of three barley Hordeum vulgare L.plots by the hybrid sparrow Passer Domesticus X.P. hispaniolensis in the eastern Mitidja]

This study shows the daily distribution density of the Passer domesticus x P. hispaniolensis in three plots in Boudouaou. This investigation was conducted during two months [April, May] in 2003. This period of time corresponds to the growing up and maturation of Hordeum vulgare L. During April, the average of hybrid sparrows found in plots 1, 2 and 3 is 50.77, 36.10 and 17.24 respectively. The same trend was also observed in May. During the period of study, it is found that the number of sparrows identified in the three plots, was higher in the morning than what it was in the afternoon