Kinetic study of the growth of Saccharothrix algeriensis DSM 44581 in batch fermenter on a semi-synthetic medium in the presence of tiglic acid and methacrylic acid

This work aimed to investigate the effect of some nutriments (tiglic acid and methacrylic acid) on the growth of Saccharothrix algeriensis DSM 44581 on chemically defined medium (semi-synthetic medium) by using controlled batch fermenters. The controlled batch fermentations were conducted in the presence of tiglic and methacrylic acids. The growth rate of S. algeriensis in all fermentations was fast during the first 10 h of fermentation. The control culture showed a partially cell lysis in comparison to cultures with organic acids. This result showing that these organic acids could be used for biomass maintaining. The formation of biomass was influenced by the addition of organic acids. The experiment in the fermentor showed some differences with results obtained in Erlenmeyers

Étude de la toxicité des extraits foliaires d’Euphorbia guyoniana Boiss. et Reut. (Euphorbiaceae) chez Schistocerca gregaria (Forskål, 1775) (Orthoptera-Acrididea)

Study of the toxicity of the crude acetone leaf extract of Euphorbia guyoniana Boiss. and Reut. (Euphorbiaceae) in Schistocerca gregaria (Forskål, 1775) (Orthoptera-Acrididea) Abstract-This study examines the effect by ingestion of leaf cabbage sprayed with crude acetone extract of Euphorbia guyoniana leaves harvested in the Algerian Sahara on some biological parameters of larvae L5 and adult of desert locusts. The ingestion of cabbage leaves soaked in acetone extract of this Saharan plant generates a 100% mortality in larvae L5 and 66,67% for adult. A significant reduction in food intake was observed in the treated population compared to the control population. It results in a loss of exceptional weight ranging from 26,93% in larvae L5 to 33,09% in adults. Difficulties and anomalies are observed in moulting 16,66% of larvae L5 fed with cabbage leaves soaked in leaf extract of E. guyoniana. Dissection of adult females of the lot processing allows the observation of body regression demonstrating the depressant action of this extract on ovocyte cycle in the desert locust

ACTIVITÉS BIOLOGIQUES DES EXTRAITS AQUEUX DE PERGULARIA TOMENTOSA L. (ASCLEPIADACEAE)

Cherif R., A. Kemassi, Z. Boual, N. Bouziane, F. Benbrahim, A. Hadjseyd, T. Gharib, A. Ould el Hadj-Khelil, M.L. Sakeur et M.D. Ould el Hadj. 2016. Biological activity of aqueous extracts of Pergularia tomentosa L. (Asclepiadaceae). Lebanese Science Journal, 17(1): 27-37. This study focuses on the allelopathic potential of the aqueous extract, obtained under reflux conditions, of Pergularia tomentosa L. (Asclepiadaceae) harvested from the north-eastern region of Algerian Sahara, through the examination of their effects on seeds germina-tion of barley (Hordeum vulgare L.). The results obtained highlighted the inhibitory effect on seed germination of treated barley. It appeared that the pure aqueous extracts and the 50% diluted solution have an excellent capability to inhibit the germination of barley seeds, which corresponds to a 100% inhibition rate, with reduced inhibition for lower concentrations. It is found that the root extract seems more phytotoxic than the foliar extract of the same plant. In addition, abnormal growth abnormalities were observed in the treated samples