The present study carried out in order to enhance the production of L-asparaginase by bacteria isolated from cultivated farms and saline water in Saudi Arabia and their abilities to produce L- asparaginase. Optimum conditions of the enzyme production were achieved. A total of thirteen samples collected from some areas at Saudi Arabia were isolated using M9 agar medium. Only five out 13 isolates were selected and screened according to higher yield of enzyme productivity. The strains were identified according to their morphological and cultural characteristics, phylogenetic analysis as well as 16S rRNA Gene Amplification and Sequencing. Optimization of fermentation parameters for L-asparaginase production were achieved after three days incubation periods, incubation temperature ranging from 30-40 o C, pH 9.0 and less commonly 8.0. The enzyme production was enhanced by maltose (carbon source), peptone and ammonium sulphate (nitrogen sources) and divalent iron (F+2) as a source of metal ions
The present investigation was carried out on Wadi Al-Afreet, North Western Coast of Egypt. The study area lies between Buqbuq and Sidi Barrani on the Egyptian-Libyan frontier. It is included in the semi-desert vegetation zone with an attenuated desert climate. An analysis of vegetation along environmental gradients that prevail in the study area using the importance values of 44 perennials and 1 biennial in 16 stands, followed by multivariate data analysis was presented. Altogether, 73 species belonging to 68 genera and 23 families of the flowering plants were recorded. Asteraceae had the highest contribution, followed by Chenopodiaceae and Fabaceae. Therophytes and chamaephytes were the most frequent, denoting a typical desert life-form spectrum. Phytochorological analysis revealed that 49.32% of the studied species were bioregional. Seven groups were resulted after the application of TWINSPAN, each of definite floristic composition and environmental characteristics, and could be linked to a specific habitat. Ordination technique (CCA) was used to examine the relationship between the vegetation and the studied ʺenvironmental parametersʺ. The most important environmental variables correlated with vegetational groups in Wadi Al-Afreet were very fine sand, fine sand, coarse sand, silt & clay, HCO3ˉ, Ca+², pH, Mg+², and Clˉ.
Domestic wastewater is considered a favorable environment for the survival of broad arrays of microorganisms. The current study aimed to characterize the bacteria isolated from two domestic wastewater treatment plants in Jazan, KSA. Morphological and biochemical tests were used to identify the bacterial isolates. Moreover, the antibiotic susceptibility pattern of the bacteria isolates was studied using disc diffusion method. The enteric Gram-negative Enterobacteriaceae were identified as Citrobacter freundii, Pantoea sp., Serratia liquefaciens, Serratia odorifera, Proteus vulgaris, Rahnella aquatilis, Enterobacter sp., Escherichia coli, and Enterobacter cloacae. Simultaneously, non-enteric Gram-negative bacilli were identified as Sphingomonas paucimobilis, Pseudomonas putida, Pseudomonas aeruginosa, Aeromonas sobria, Chryseomonas luteola, and Pasteurella aerogenes. Also, the Gram-positive isolates were identified as Staphylococcus xylosus, Kocuria kristinae and Staphylococcus epidermidis. At the same time, a high level of resistance against Ampicillin/Sulbactam (94.5%) was observed while the recorded percentage of resistance against trimethoprime/sulphamethoxoazole, ticarcillin, imipenen, piperacillin, colistin, cefoxitin and cefepime were 67%, 62%, 22.2%, 33.3%, 22.2%, 83.3% and 38.9% respectively. This study highlighted the existence of multiple antibiotic resistant strains in the tested sewage wastewater that could be attributed to the disproportionate use of antibiotics for human and animal diseases.
Fissidens bryoides Hedw., is recorded for the first time from Libya on the basis of collection from Zawya Al –Qadima in Beida, north-east of Libya. This record raises the number of moss taxa recorded from Libya to 106 and the number of Fissidentaceae taxa to six. Moreover, the present work adds 3 moss taxa to Beida area which raises mosses known from it to 33 taxa. A description and illustrations of the new record together with geographic distribution of all identified taxa are given. This new record is also compared with the related taxa.
Chlorella vulgaris and Chlorella salina were successively cultivated in sewage and different mixtures of water samples for 10 days to investigate the changes in growth and some physiological parameters. Optical density, dry mass, photosynthetic pigments (Chl.a, Chl.b, and Carotenoid) and organic solutes (soluble sugars, soluble proteins and total free amino acids) of both algal species were significantly decreased in response to sewage and different mixtures of water samples. The cultivation of the two investigated Chlorella in different types of water stimulated the biosynthesis of some different amino acids, whereas caused inhibition of others within the cells. On the other hand, there was marked increase in the activity of catalase (CAT), Peroxidase (POD) and ascorbate peroxidase (APX), as well as malondialdehyde (MDA) contents of C. vulgaris and C. salina cells under these treatments. The data showed that C. salina was more sensitive to sewage and different mixtures of water than C. vulgaris.
