The use of combined essential oils (EOs) is a new technique that can improve their preservative effects while minimizing their sensory impact in foods. The aim of this study was to determine the chemical profile of three essential oils (EOs) extracted from Lavandula stoechas L. (Ls), Thymus zygis L. (Tz), and Eucalyptus camaldulensis Dehnh (Ec) and to evaluate their synergistic antibacterial activity for optimal inhibition against Bacillus subtilis, Escherichia coli, and Staphylococcus aureus using an augmented Simplex centroid mixing scheme. The essential oils were extracted by hydrodistillation and analyzed via gas chromatography–mass spectrometry. Anti-bacterial potency was evaluated by disk diffusion. Chemical analysis revealed the main compounds in Lavandula stoechas (Ls) essential oil: camphor (36.15%), followed by fenchone (16.57%) and Z-8-hydroxy linalool (8.28%). The Thymus zygis (Tz) essential oil is dominated by δ-terpineol (27.64%), δ-3-carene (15.7%), and thymol (14.17%). In contrast, the Eucalyptus camaldulensis (Ec) essential oil contains mainly 1,8-cineole (43.61%), γ-terpinene (11.71%), and α-terpineol (10.58%). The optimal mixture is the binary association of 40% E. camaldulensis EO and 60% T. zygis EO, which provides an effective inhibition diameter (ID) of 13.37 mm to inhibit S. aureus. Furthermore, the formulation of 27% and 73% EOs of E. camaldulensis and T. zygis, respectively, corresponds to the mixture required to achieve the optimum inhibition diameter (ID = 11.55 mm) against E. coli. In addition, the mixture of 29% EO of E. camaldulensis and 71% EO of T. zygis is the optimum mixture to inhibit B. subtilis, with an inhibition diameter of 12.31 mm. These findings highlight the potency of antibacterial formulations of these essential oils and suggest that they might be used as substitutes for conventional drugs to prevent the development of bacteria responsible for serious infections and food spoilage.
1 January 2022 in Journal of Ecological Engineering
In order to understand the relationship between the biological characteristics of insects and their environment, an entomological study was conducted at 5 stations (agricultural and natural) in the region of northwest Morocco (Sidi Kacem) between March 2019 and September 2020. Three sampling...
Phosphorus deficiency is a major limiting factor in horticultural production. One potential solution can be restoring soil phosphorus from mineral resources, such as solid phosphate sludge (SPS) generated from phosphate treatment processes at mining sites in agriculture. This study explores the possibility of using this sludge in nurseries to produce fruit and forest plants. We tested six mixtures of SPS with the sandy soil of the Maamora forest on ten plant species. In the second experiment, we tested the same mixtures with sea sand. In addition, one concentration of four composts based on phosphate sludge was also tested on two citrus rootstocks and carob. The first experiment’s results showed significantly higher growth with the control mixture for pomegranate, acacia, and C. volkameriana plants. The relative growth was higher at SPS concentrations of 20% to 30% for the other plant species, although there was no significant difference between treatments. The estimations of AUGPC (area under the growth progress curve) showed no significant difference in most species. In the second experiment, the relative growth in the M4 (30% of SPS + 70% of sand) mixture was higher, and the AUGCP showed a significant difference compared to the M1 control mixture. The application of solid phosphate sludge positively affects and improves the growth of fruit and forest trees in the nurseries, especially when the concentration is between 20 and 30%. For this purpose, the phosphate sludge could have great potential to be used in nurseries and create a favourable soil condition as a cultivation substrate.