In this study, the bacterium Bacillus licheniformis has been isolated from oil reservoir; the ability of this bacterium to produce a biosurfactant was detected. Surface properties of the produced biosurfactant were confirmed by determining the emulsification power as well as surface and interfacial tension. The crude biosurfactant has been extracted from supernatant culture growth, and the yield of crude biosurfactant was about 1 g/l. Also, chemical structure of the produced biosurfactant was confirmed using FTIR analysis. Results revealed that, the emulsification power has been increased up to 96% and the surface tension decreased from 72 of distilled water to 36 mN/m after 72 h of incubation. The potential application of this bacterial species in microbial-enhanced oil recovery (MEOR) was investigated. The percent of oil recovery was 16.6% upon application in a sand pack column designed to stimulate an oil recovery. It also showed antimicrobial activity against the growth of different strains of SRB (sulfate reducing bacteria). Results revealed that a complete inhibition of SRB growth using 1.0% crude biosurfactant is achieved after 3 h. ª 2015 Production and hosting by Elsevier B.V. on behalf of Egyptian Petroleum Research Institute. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

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ACTERIAL and fungal contamination in the air and settled dust .... were studied in old and new book libraries located in the National Research Center (NRC), Dokki, Giza, Egypt. The investigated libraries differ in age, design, size, ventilation type, and a number of occupants in relation to microclimatic parameters and particulate matter (PM) load. Airborne microorganisms were collected using an Andersen two stage impactor sampler. Indoor airborne bacteria and fungi ranged from 0-1060.4 CFU/m 3 and 11.8-315.6 CFU/m 3 , respectively. Outdoor airborne bacteria and fungi ranged within 11.7-2514.7 CFU/m 3 and 0-713.7 CFU/m 3 , respectively. Bacteria and fungi associated surface settled. The dust ranged from 0.4-10x10 6 CFU/gm and 0-73x10 4 CFU/gm, respectively. Fine microbial fraction (particles ≤ 8 μm in size) constituted 2-24.94% and 68.35-94.15% of the total airborne bacterial and fungal concentrations, respectively. Indoor/outdoor (I/O) ratios of airborne microorganisms were less than 1 at both libraries, indicating no indoor microbial sources. Gram positive cocci (14.3-47%) and bacilli (52.9-85.7%) were the dominant bacterial isolates in the air state, while bacilli represented 100% of the total isolates in the surface settled dust. Bacillus pseudomycoides and B. subtilis dominated indoors while B. subtilis and Staphylococcus outdoors. Aspergillus and Penicillium, were the common fungal species in both libraries under investigation. Many of the isolated fungal taxa had enzymatic activities (lipase, protease and cellulase), with A. flavus, Curvularia pallescens, Fusarium oxysporium, P. notatum and Trichoderma viride presented all enzymatic activities. Complex correlations and no-clear patterns were found between the airborne microorganisms and the environmental factors.

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he study is aimed to isolate and identify a potential entomopathogenic fungus from fields infested with spider mites and evaluate them as a bio-rationale agent against Tetranychus urticae Koch., which is an important agricultural pest that infests horticultural crops in both field and greenhouses. Macroscopic and microscopic characteristics showed that the obtained entomogenous isolate was Purpureocillium lilacinum (formerly, Paecilomyces lilacinus). P. Lilacinum demonstrated mortality rates on adult females of T. urticae of 71.19 and 77.97% with conidial concentrations of and 1.6 , respectively, 10 days after application. Median lethal concentration of P. lilacinum was 2.85 10 6 conidia/ml. Enzymatic activity of P. lilacinum was evaluated. In this context, chitinolytic activity of P. lilacinum was relatively weak, since the clear halo obtained was only 4.43 mm in diameter. The activity of chitinase enzyme insignificantly increased over the incubation period of 10 days. In contrast, proteolytic activity of P. lilacinum was high and showed a clear zone (25.8 mm) around the colony after 10 days. So, it is concluded that P. lilacinum has a potential biological control against T. urticae. Finally, evaluation of the ethyl acetate extract of P. lilacinum showed acaricidal potency since it exhibited LC 50 values of 10.49 mg/ml for eggs and 30.75 mg/ml for adults. So, it is concluded that P. lilacinum has a potential biological control against T. urticae.