Browsing by Author "Benaissa, Asmaa"

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Biological Control By Plant Growth Promoting Rhizobacteria
(جامعة الوادي - University of Eloued, 2020-12-31) ben arbia, radia; Bestami Merdia . Ben Malek, Rokaia; Fellan, Kheira; Benaissa, Asmaa
Plant Growth Promoter Rhizobacteria (PGPR) is soil bacteria that can live on, in or around plant tissue and promote plant growth by many mechanisms that include a biological control of plant pathogens. Indeed, PGPRs have a protective effect through several modes of action such as antagonism, competition, production of hydrolytic enzymes and biofilm formation. Moreover, the use of PGPRs as biocontrol agents is very harmonious with the environment and therefore represents a good alternative to the use of chemicals in agriculture. This review is presented as a general bibliographical synthesis on the different aspects of PGPRs and their biocontrol potential.
Influence of leaf extracts and total flavonoids of Rhus tripartita (Ucria) Grande on phytobeneficial bacteria associated with its rhizosphere
(جامعة الوادي - University of Eloued, 2021-06-30) Benaissa, Asmaa; Dahbi Lalla, Fatma-Zohra; Tabra Oum, Elhassenea; Djellout, Nadine Chahrazade
The article deals with the antimicrobial effect of Rhus tripartita (Ucria) Grande leaf extracts and total flavonoids against twelve antagonists Plant Growth Promoting Rhizobacteria of its rhizosphere, characterized in a previous study. The aim of this study is to demonstrate that leaves through their decomposition in the soil, may affect the distribution of bacterial communities in the rhizosphere. Leaves extracts were performed with distilled water, alcohol, methanol, hexane and chloroform as solvent and diluted in concentrations of 0.001, 0.01 and 0.1 mg/mL. The extraction of total flavonoids was carried out from leaves’ methanolic extract. The antimicrobial effect of the extracts was evaluated by the agar diffusion method and the determination of the minimum inhibitory concentration was carried out on a liquid medium. Alcohol, chloroform and methanol extracts were found to be the most effective on tested strains. The maximum zone inhibition was 18 mm, and the minimum zone inhibition was 7 mm. Rt 1: Bacillus licheniformis appears to be the most sensitive to all extracts. In contrast, Rt 7: Bacillus megaterium, seems to be the less sensitive strain. On the other hand, total flavonoids had a significant effect on 25% of the strains tested, mainly Bacillus genus. With a broad antimicrobial spectrum, the Rhus tripartita leaf extracts can be considered as a control agent for the distribution of the bacterial community in the rhizosphere. Therefore, our work showed that the plant could influence the bacterial diversity of its rhizosphere through its leaves.
Microbial Soft Rot Of Cultivated Fruits And Vegetables
(جامعة الوادي - University of Eloued, 2020-12-31) saliha, bourdi; Djellout, Nadine Chahrazade; Baika, Khadidja; Bamebarek, Hafsa; Benaissa, Asmaa
The nutritional richness of fruits and vegetables makes them an ideal target for microorganisms, causing in particular soft rot. The microorganisms responsible for this pathology are generally found in the environment, and are endowed with a very important enzymological power, the main action of their pathogenicity. These enzymes, which allow the degradation of the plant cell wall, allow them to cross the protective wall of the plant, causing a liquefaction of tissues, whose environmental conditions as well as transport and storage conditions favour the development of these phytopathogens. A better understanding of spoilage microorganisms and the characteristics of spoilage should allow the development of new conservation and protection technologies and reduce the loss of vegetables due to spoilage. This review summarizes the main literature data on soft rot, and the diversity and mode of action of the main microbial causal agents.