eng
National Information and Documentation Center (NIDOC), Academy of Scientific Research and Technology
Egyptian Journal of Microbiology
0022-2704
2357-0881
2010-12-31
45
1
1
13
10.21608/ejm.2010.273
273
Original Article
Biosurfactant Producing Bacteria from Oil Contaminated Egyptian Soil
TEN PURE bacterial isolates with biosurfactant activity were obtained from autochthonous microflora of oil contaminated soil. Soil samples were selected from bus garage stations in Cairo and from different plots around oil wells of western desert of Egypt. Biosurfactant production was investigated using three parameters (hydrolyses of blood, surface tension reduction, and emulsification index techniques). The biosurfactant accumulation was coincided with growth. By means of standard bacterial identification procedures, the isolates were identified as different strains of Bacillus licheniformis. The phylogenetic relationships between these strains were determined using the RAPDPCR technique. The similarity between the strains was ranging from 78 to 100 %.
https://ejm.journals.ekb.eg/article_273_626fe12300b5282207917b0f122242c6.pdf
Biosurfactant
Emulsification
Bacillus licheniformis
RAPD-PCR
eng
National Information and Documentation Center (NIDOC), Academy of Scientific Research and Technology
Egyptian Journal of Microbiology
0022-2704
2357-0881
2010-12-31
45
1
15
29
10.21608/ejm.2010.274
274
Original Article
Mycoremediation of Monocyclic Aromatic Hydrocarbons by a Local Marine Aspergillus oryzae (Statistical Analysis of the Main and Substrate Interaction Effects)
AN AROMATIC hydrocarbon utilizing fungus was isolated from a wastewater polluted sea spot in the Mediterranean, Alexandria, Egypt. It was identified to the species level as Aspergillus oryzae. The marine fungal isolate has the ability to remove BTHX compounds (benzene, toluene, hexylbenzene, and xylene), concentrations ranged between 15 and 75 mgl-1. Up to our knowledge, it is the first description of BTHX removal by a local marine strain of A. oryzae. The removal efficiencies of these compounds varied between 58 and 85 %, within 48hr. Experiments were conducted according to the 24 fraction fractorial design to identify the main and interaction effects of individual BTHX removal efficiency. A statistical interpretation of the results revealed that the main effect of benzene was significant (P < 0.05). High F values for the 4-way interaction between different hydrocarbons with low P values suggest that the interactions between individual BTHX are the most significant factors. The negative interactions between benzene and hexylbenzene, benzene and xylene concentrations were found to be statistically significant (P < 0.05). On the other hand, there was a positive significant interaction between hexylbenzene and xylene (P < 0.05). A successful trial showed the very good applicability of the marine fungal isolate to remove 80.00, 95.64 and 89.00 % of benzene, toluene, and xylene, respectively, in the waste effluent of Alexandria Petroleum Company after 48 hr. This effluent contains very high concentrations of BTX compounds (36.38gl-1). Using the diluted effluent (50%), the removal efficiency of the BTX reached a distinct value of 97, 98 and 98% for benzene, toluene, and xylene, respectively, after 72 hr. These significant quantitative removal capacities demonstrate the potential application of marine A. oryzae for the mycoremediation of BTX compounds from waste water systems
https://ejm.journals.ekb.eg/article_274_f47f26d1a3feee352eb8047567e5386f.pdf
BTHX mixture
Marine fungi
Fungal bioremediation
Removal efficiency
Statistical analyses
eng
National Information and Documentation Center (NIDOC), Academy of Scientific Research and Technology
Egyptian Journal of Microbiology
0022-2704
2357-0881
2010-12-31
45
1
31
43
10.21608/ejm.2010.275
275
Original Article
Petroleum Hydrocarbon Utilization by Some Molecularly Identified Filamentous Marine Fungi Isolated from a Polluted Area in the Mediterranean Sea
THREE DIFFERENT newly isolated marine fungi were subjected to 18S rRNA gene partial sequence analysis. The resulting sequences showed that the isolates belong to Fusarium solani, Trichoderma viride and Aspergillus niger. The isolates have the ability to utilize some petroleum hydrocarbons such as hexane, motor oil, and diesel oil. The tested fungi could grow up to 7 days, especially on medium supported with diesel oil. Although all of the tested fungi have the ability to utilize the increased concentrations of diesel oil, Fusarium solani EH has the highest ability, growing at a concentration of 4 ml/l. Static and shaking incubation conditions of Fusarium solani EH with 7.2 mg/100ml diesel oil as a sole carbon source, showed a significant decrease in the hydrocarbon concentration (90.28% and 93.05%, respectively) within 7 days. Results of this study may provide a help in petroleum hydrocarbon spill clean-up.
https://ejm.journals.ekb.eg/article_275_61ee35fdf981289329c9e6d3a1a8a6b5.pdf
marine
fungi
18S rDNA
Diesel oil
eng
National Information and Documentation Center (NIDOC), Academy of Scientific Research and Technology
Egyptian Journal of Microbiology
0022-2704
2357-0881
2010-12-31
45
1
45
61
10.21608/ejm.2010.276
276
Original Article
Protective Strategies Induced by Azotobacter sp. Strain and its Role after Exposure to H2O2 in Improving Hibiscus sabdarriffa Performance
THE EFFECT of hydrogen peroxide (H2O2) solutions, applied to pure cultures of Azotobacter at concentrations ( 0.0, 0.05, 0.1 and 1%), was determined by measuring survival, protein content, antioxidant enzymes, H2O2 content and malondialdehyde content after 15 and 30 min. The impact of the treated bacteria to affect seed vigour of Hibiscus sabdarriffa was then evaluated. Survival of Azotobacter cells was not affected significantly at H2O2 concentrations of 0.05 % and 0.1 % after 15 min (11 % and 34 % reduction, respectively) compared to the control. With 30 min exposure, the protein content was reduced 2 fold compared to 15 min exposure time. However, for superoxide dismutase (SOD), ascorbat peroxidase (APX) and catalase (CAT), no significant differences were observed at low concentrations of H2O2, but only at the highest concentration (1%). In contrast, peroxidases (PODs) showed slightly increased activity at low concentrations and significant reduction at higher concentrations. Also, H2O2 content and malondialdehyde (MDA) content were increased in treated Azotobacter cells. The native isolates of Azotobacter sp. strain greatly increased the vigour index and germination rate of H. sabdarriffa up to 90% as compared to only 50% in the untreated control. We believe the response of Azotobacter, treated with H2O2 was probably related to the different protective effects of antioxidant enzymes in this strain. The ability of the bacterium to respond and survive at exposure to H2O2 during logarithmic growth could be important during colonization of the root surface when the cells are presumably entering into an actively growing phase
https://ejm.journals.ekb.eg/article_276_801439a652a358711ee2a61197df3e8d.pdf
Antioxidant enzymes
Azotobacter
Hibiscus sabdarriffa
Hydrogen peroxide
eng
National Information and Documentation Center (NIDOC), Academy of Scientific Research and Technology
Egyptian Journal of Microbiology
0022-2704
2357-0881
2010-12-31
45
1
63
76
10.21608/ejm.2010.277
277
Original Article
Nested PCR and Conventional Techniques for Detection of Salmonella< /i>spp. in River Nile Water, Egypt
THIS STUDY aimed to detect salmonellae group using most probable number (MPN), membrane filtration (MF) and nested PCR techniques from River Nile at Cairo segment and Rossita branch so, 74 samples were collected and analyzed to count the total viable bacteria/ml and total salmonellae. Total viable bacterial counts ranged from 1.0x102 to 1.6x108 cfu/m1 during the study. Using MPN technique salmonellae were detected in 64 samples out of 74 samples (86.4% recovery), with the MF technique, salmonellae were detected in 73 samples out of 74 samples and with PCR technique salmonellae were detected in all samples. It can be concluded that MF technique is more suitable to detect salmonellae as it allows to filter or pass the relatively larger amount of water sample rather than MPN which measure salmonellae presence in fixed amount of water while nested PCR technique is more rapid, sensitive and specific than conventional techniques (i.e., MF and MPN). Statistical analysis was done only between MF and MPN techniques due to PCR technique doesn't provide counts to be involved in statistical analysis (provide only positive and negative results). Results indicated that counts of Salmonella showed significant differences between sites using both techniques MF and MPN at Cairo segment. Wherever, no significant difference between sites at Rossita branch.
https://ejm.journals.ekb.eg/article_277_41574c38b461dbe7f6db1d440936b8c7.pdf
River Nile
Salmonella
MPN technique
MF technique
PCR technique
eng
National Information and Documentation Center (NIDOC), Academy of Scientific Research and Technology
Egyptian Journal of Microbiology
0022-2704
2357-0881
2010-12-31
45
1
77
93
10.21608/ejm.2010.278
278
Original Article
In Vitro Evaluation of Some Bacterial Isolates as Biofertilizers and Biocontrol Agents Against The Second Stage Juveniles of Meloidogyne incognita
REPRESENTATIVE soil samples were collected from the rhizosphere soils of different plant varieties grown in five Egyptian governorates. The soil samples were taken from areas where vegetable crops were moderately infected with nematodes causing galls on their root systems. The presence of plant parasitic nematodes (PPN) and free living nematodes (FLN) in the collected samples was estimated. In addition, one hundred and seventy six bacterial cultures which are well known as biofertilizers (some are able to fix nitrogen and the others solubilize either phosphate or potassium) were isolated. The isolated bacteria were screened based on their rate of growth. Thirty-five cultures of fast growing nitrogen fixing bacteria (NFB), phosphate solubilizing bacteria (PSB) and potassium solubilizing bacteria (KSB) and their cultural filtrates were tested in vitro as biocontrol agents against the second-stage juvenile (J2s) of the Meloidogyne incognita. In general, higher mortality percentages of nematodes were recorded by bacterial cultures than their comparative cultural filtrates. The highest mortality levels (100%) was recorded for cultures of NFB7, PSB2, and KSB2 at 10-1 dilution while it was 99.3, 99.0 and 97.8%, respectively, at a dilution of 10-2. NFB7 exhibited a high nitrogen fixation rate (4.2 µmole N2/ml/h), while PSB2 and KSB2 revealed effective phosphate and potassium solubilization efficiencies compared with the control treatments (1.94 fold of available phosphate and 2.0 fold of available potassium, respectively). NFB7, PSB2 and KSB2 isolates showed the highest protease, gelatinase and chitinase activities, which might be responsible for their nematicidal effect. The three bacterial isolates were identified as Paenibacillus polymyxa, Bacillus megaterium and Bacillus circulans, respectively.
https://ejm.journals.ekb.eg/article_278_78de5082a9e8e520101b4b286a00bfb9.pdf
biofertilizers
Biocontrol
Root-knot nematodes
Meloidogyne incognita.
eng
National Information and Documentation Center (NIDOC), Academy of Scientific Research and Technology
Egyptian Journal of Microbiology
0022-2704
2357-0881
2010-12-31
45
1
95
111
10.21608/ejm.2010.279
279
Original Article
Detection and Identification of Tomato Yellow Leaf Curl Virus-EG Using Molecular Technique
TOMATO Yellow Leaf Curl virus (TYLCV-Eg) was isolated from whiteflies-infected tomato (Lycopersicon esculentum cv. Castle rock) plants growing in Nubaria and El-Behera Governorate. The infected plants exhibited systemic viral symptoms in the form of severe leaf curling, leaf crinkle with marginal yellowing, stem upright, twisted and stunted. TYLCV-Eg reacted positively with polyclonal antibodies specific to TYLCV using DAS-ELISA. It was transmitted by both syringe injection and whiteflies with the transmission efficiency of about 80% and 100%, respectively. TYLCV-Eg isolate was transmitted to different species belonging to families Cucurbitaceae, Fabaceae, Solanaceae, and Chenopodiaceae. TYLCV had TIP (Thermal Inactivation Point) of 70ºC, DEP (Dilution End Point) of 10-7 and LIV (Longevity) of about 6 days. Electron micrograph of the partially purified TYLCV revealed the presence of monomer and dimmer gemini particles with dimensions of 22 nm and 20 x 30 nm to 24 x 30 nm, respectively when negatively stained with uranyl acetate. DNA from infected plants was extracted and amplified successfully by polymerase chain reaction (PCR) using degenerate oligonucleotide primers V324(+) and C889 (-) producing ~ 500 bp fragment from infected tomato plants. The viral genome was detected by specific DNA probe using dot blot hybridization technique. Comparative nucleotide sequence analysis showed a similarity of 98% between TYLCV-EG and other isolates.
https://ejm.journals.ekb.eg/article_279_386f87717ee95cdfbbd3b6ff080df20d.pdf
nucleotide sequence
TYLCV-EG
DAS-ELISA
PCR
Dot-blot hybridization
eng
National Information and Documentation Center (NIDOC), Academy of Scientific Research and Technology
Egyptian Journal of Microbiology
0022-2704
2357-0881
2010-12-31
45
1
113
129
10.21608/ejm.2010.280
280
Original Article
Prevalence of Toxigenic Fungi in Egyptian Smoke-Dried Herring Fish: I- Antifungal Activity of Basil (Ocimum basilicum L.) Essential oil
A SURVEY was carried out on malt salt agar media to isolate and evaluate mycoflora occurring in samples of smoke-dried herring fish (Clupea harengus L.) that are ready for human consumption in Egypt. Aspergillus species were the most abundant fungi followed by Penicillium species then Fusarium species. Fungal genera of Cladosporium, Epicoccum, Mucor, and Rhizopus species were also isolated. A. flavus and A. fumigatus were the most frequently isolated aspergilli. P. griseofulvum was the most species common among penicillia, and F. solani was the predominant Fusarium species. C. cladosporioides was recovered in a high incidence. Findings of mycotoxins formation by the isolated mycoflora showed that some mycotoxins (aflatoxins, cyclopiazonic acid and kojic acid) were produced by some isolates of A. flavus. Some isolates of A. niger and A. fumigatus were able to produce kojic acid. A. ochraceus isolates produced penicillic acid but were not able to produce ochratoxin A. Two isolates of A. parasiticus were aflatoxin B1-producing and one isolate of A. versicolor produced sterigmatocystin. Concerning Fusarium species, some isolates of F. oxysporum and F. solani had the ability to produce cyclosporin A and zearalenone. The antibiotic, griseofulvin, citrinin and patulin were the characteristics metabolites produced by the toxigenic isolates of Penicillium species. This study was also extended to evaluate the efficacy of different concentrations of Ocimum basilicum L. essential oil on in vitro activity against the toxigenic isolated moulds. The recorded minimum inhibitory concentration (MIC) of the essential oil was 15% (v/v) with all the tested mould strains except A. niger, A. ochraceus (the MIC value was 10%, v/v) and Penicillium species (the MIC value was 20%, v/v). This oil was found to be fungicidal at all the tested concentrations. These findings indicate the possibility to use O. basilicum essential oil as a substitute for chemical additives to control fungal growth and toxins production
https://ejm.journals.ekb.eg/article_280_c476ff25fab09c2072e53ebdcd68c20a.pdf
Mycoflora
Mycotoxins
Smoke-dried herrings
Ocimum basilicum L
essential oil
Antifungal
eng
National Information and Documentation Center (NIDOC), Academy of Scientific Research and Technology
Egyptian Journal of Microbiology
0022-2704
2357-0881
2010-05-01
45
1
131
146
10.21608/ejm.2010.281
281
Original Article
Selection of Gamma Irradiation Dose for Sterilising Eye Make up Preparations
IN THE PRESENT study, radioresistant bacterial strains isolated from the dried mixed populations of bacteria of, eye make up preparations were used. The mixed population of bacterial strains from eye shadow, eye mascara, and eye liner, survived the radiation doses of 5-14 kGy, 5-6 kGy, and 4-11 kGy, respectively. Dose survival curves of the radioresistant bacterial strains exhibited the exponential response, except Bacillus cereus which showed non exponential response towards gamma radiation. The D10 values were in the range of 0.7-1.8 kGy, 0.8-1.0 kGy and 0.7-1.4 kGy for the strains from eye shadow, eye mascara, and eye liner, respectively. The sterilization doses for the eye make up products were determined from the dose response curves. The maximum sterilization doses were found to be 16.0, 8.3 and 12.3 kGy for sterilization of the eye makeup products at the same mentioned order.
https://ejm.journals.ekb.eg/article_281_96cc4dbe16f0ae8b8abe8617e0402cfa.pdf
Eye make up preparations
Mixed population
gamma radiation
sterilization