MOSP - Macao Scientific Publishers

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Possible involvement of endocyst in tolerance of the resting cyst of Colpoda cucullus against HCl

Yoichiro Sogame, Akemi Kida and Tatsuomi Matsuoka*

Abstract: Tolerance of the resting cysts of protozoa against gastric acid and proteases is a strategy for surviving in the digestive tract of animals. The present study aimed to examine the protection mechanism against HCl in resting cysts of Colpoda cucullus, which were surrounded by a cyst wall, which is composed of an outermost layer (ectocyst) and several inner layers (endocyst). In addition to water, paraformaldehyde, hydrogen peroxide (H2O2) and ethanol may diffuse across the cyst wall, because the cysts hardly showed tolerance against these molecules. However, the cysts showed tolerance against HCl (0.01 to 1 M) and pepsin. The tolerance against HCl disappeared soon after the onset of excystment induction. Electron micrographs of the excysting cells showed that digestion of the endocyst began within 30 min after the onset of excystment induction. The encysting cells surrounded by the ectocyst (3 h after encystment induction) did not show tolerance against HCl, but acquired it just after a first layer of the endocyst was formed beneath the ectocyst (6 h after encystment induction). These results suggest that the tolerance of the resting cyst of C. cucullus against HCl may be acquired by preventing its diffusion across the endocyst, although the possibility that cytoplasmic molecules and the plasma membrane may acquire tolerance has not been ruled out.[...] Read More.

Keywords: Colpoda cucullus, resting cysts, tolerance, HCl, excystment.

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Domestic wastewater (DWW) influence on secondary metabolite in thyme (Thymus vulgaris L.) under field conditions

Hossein Hassanpour Darvishi and Hossein Aliabadi Farahani

Abstract: In order to study domestic wastewater influence on secondary metabolite in thyme (Thymus vulgaris L.) under field condition, this experiment was carried out in Iran. In the field, 15 lysimeters having thyme (T. vulgaris L.) were used, where 1 to 5 lysimeters were irrigated by domestic wastewater and primary drainage water was accumulated. 6 to 9 lysimeters were irrigated by primary drainage water and then, were accumulated by secondary drainage water and we have irrigation 10, 11 and 12 lysimeters by secondary drainage water. In order to compare plants characteristics, in 13, 14 and 15 lysimeters were irrigated by agronomical water. The secondary metabolite in thyme 3.4% increased under irrigation by secondary drainage water into irrigation by agronomical water. The findings may give applicable advice to medicinal and aromatic plants researchers for management and concern on water strategy and estimate of irrigation carefully for increase of quantity and quality yields in medicinal and aromatic plants farming.[...] Read More.

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Transposon mutant of Vigna radiata-nodulating Bradyrhizobium sp. impaired in both resistance to stress conditions and symbiotic performance

Neelawan Pongsilp* and Nantakorn Boonkerd

Abstract: Rhizobial strains that nodulate Vigna radiata (mungbean) were examined for their resistance to several stress conditions. One strain of mungbean rhizobia was selected to construct a collection of transposon mutants based on resistance to high temperature (40°C), alkalinity (pH 8.0) and several heavy metals. One mutant that is deficient in resistance to high temperature, alkalinity and zinc was selected to estimate the relation between resistance to stress conditions and symbiotic performance. Southern hybridization analysis showed a single transposon insertion in the mutant strain. The impaired symbiotic performance was observed in the host plants inoculated with the mutant strain as compared with the wild-type strain. This result suggested that genes involved in stress resistance affected the symbiotic ability. The 16S rDNA sequence analysis revealed that the strain is a member of Bradyrhizobium with 98% identity.[...] Read More.

Keywords: Bradyrhizobium, mutant, transposon, stress tolerance, symbiosis.

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Isolation and characterization of Rhodococcus sp.BX2 capable of degrading bensulfuron-methyl

Minghua Xiong, Chunyan Li*, Junbo Pan, Xiaosong Cheng, and Chuanwu Xi

Abstract: Bensulfuron-methyl (BSM) is a widely applicable sulfonylurea herbicides. However, BSM remains in environment for extended period of time (over 100 days) and causes a series of environmental problems. In this study, BX2, a strain presents high BSM degradation abilities, was isolated from an activated sludge sample using a continuous enrichment method and determined to be a member of the genus Rhodococcus based on its physiobiochemical characteristics and 16S rRNA gene sequence. Strain BX2 degradated 92% BSM from an initial concentration of 20 mg/L within a 7- day incubation at 35℃. The specific degradation rate increased with an increase in the initial BSM concentration and the maximum specific degradation rate obtained was 0.146 mg/(mg•d) at 140 mg/L. BSM degradation by strain BX2 can be presented by Haldane’s inhibition equation and the kinetic parameters were: vm ax = 16.75 mg/(mg•d), ks = 7809.36 mg/L and ki = 2.41 mg/L, respectively. These results indicated that the strain BX2 could be an excellent candidate for bioremediation of BSM-contaminated environments due to its high BSM-degradative ability.[...] Read More.

Keywords: Bensulfuron-methyl (BMS); Rhodococcus sp.BX2; Isolation; Biodegradation.

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Isoniazid resistance of Mycobacterium tuberculosis isolated from human patients

Taha Nazir*, Abdul Hameed, Javed Anver Qureshik and Bashir Ahmad

Abstract: Isoniazid resistant Mycobacterium tuberculosis strains are a serious threat for successful tuberculosis control programs. Therefore, present study was aimed to figure out the pattern and level of resistance of M. tuberculosis against isoniazid. A total of 172 specimens of sputum, pus and bronchial washings; 70.9% males and 29.1% females with 84.30% pulmonary and 15.69% extrapulmonary tuberculosis were collected from six different sources. The inoculums were prepared using 0.5 Mac Farland turbidity standards. Five concentrations of isoniazid were used in Lowenstein Jensen (LJ) medium that is 3, 6, 9, 12 and + 12 µg/ml for sensitivity testing. Data showed 25 (14.5%) resistant and 147 (85.5%) sensitive M. tuberculosis strains. The growth was not inhibited at first (3 µg/ml) and second (6 µg/ml) drug levels, while 36% isolates inhibited at third level (9 µg/ml), 28% at forth level (12 µg/ml) and 24% at fifth level (10 µg/ml) and 12% at higher than fifth Level (> 12 ug/ml). These incorporated drug concentrations are higher than therapeutic index and not recommended in actual clinical practice. It is thus obvious to explore some other effective chemotherapeutic agents, modify combinations or figure out more effective procedures to stop morbidity and mortality due to isoniazide resistance of M. tuberculosis.[...] Read More.

Keywords: Isoniazid, mycobacterium tuberculosis, resistance, Lowenstein Jensen medium.

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Comparative analysis on the curing effect of acridine orange (mutagen) on beta - lactamase producing Staphylococus aureus, from bovine and human origin

Onyenwe, N. E., Mbata T. I.* and Adeleke, O. E.

Abstract: The effect of the mutagen (acridine orange) on the multi-resistant antibiotics beta lactamase producing Staphylococcus aureus strain of bovine and human origin was investigated and tested individually using iodiometric (cell supervision) method for the level of beta-lactamase produced by each strain and antibiotic – sensitivity screening using single disc agar diffusion method. Analyses revealed that 80% of the isolates from bovine origin produced beta-lactamase while only 20% showed absence of the enzyme, while 68% of the human isolates produced beta-lactamase while only 32% showed absence of the enzyme sensitivity to cefotaxime, cefuroxime and ceftriaxine were observed in both strains of bovine and human origin. At high concentrations of the mutagen (250 µg/ml), zones of inhibitions were low for penicillin, amoxicillin and augmentine at reference MIC’s of 0.25 µg/ml, while the cephalosporins recorded high zones of inhibition at 0.5 and 1.0 µg/ml reference MIC’s in all the strains at 250 and 200 µg/ml of the concentration of the mutagen (acridine orange). The resistance bovine strains producing beta-lactamase resisted curing with acridine orange than the human strains of S. aureus.[...] Read More.

Keywords: Acridine orange, Staphylococcus aureus, beta-lactamase, iodometric.

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Determination of the effect of light and salt concentrations on Aphanocapsa algal population

Ifeanyi, V. O.*, B. N. Anyanwu, J. N.Ogbulie, R. N. Nwabueze, W. Ekezie and O. S. Lawal

Abstract: The research was on the determination of the effect of light and salt concentrations on Aphanocapsa algal population. Microbiological standards were observed in the isolation of Aphanocapsa sp from water sample collected from Shell Petroleum flow station. The effect of 5,000, 3500 and 2,000 lux light intensities and 10 g/L through 50 g/L salt concentrations on the growth and proliferation of Aphanocapsa sp was determined by a spectrophotometer at 340 nm. At Day 9, the algal species gave the highest optical density of 0.495 nm at 5000 lux. The optimum salinity on the algal growth was 10 g/L and this gave 1.23 nm optical density at Day 9. The control gave 0.45 nm on Day 9. This research monitored the effect various light and salt concentrations had on Aphanocapsa sp growth and the optimum light intensity and salt concentration were identified.[...] Read More.

Keywords: Algae, environmental parameters, light intensity, salt concentration, growth, population.

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Detection of ecotone environment based on satellite and field techniques (A case study; Northern Alborz, Iran)

Karim Solaimani* and Fatemeh Shokrian

Abstract: Environmental change and socio-economic pressure are expected to have significant impacts on Northern Alborz vegetation, particularly along ecotone such as the treeline. Remote sensing may be well suited to monitoring recent changes across the treeline because it captures integrated changes of all vegetation life forms over large spatial extents. This research examines treeline vegetation composition and change along the Nojmeh treeline using a high resolution, ETM+ 2000. In this paper we investigate the use of satellite data to produce a classification of a treeline ecotone in Northern Alborz Mountains which has supported the field investigation as ground truth data collected in the summers from 2008 to 2010. The maximum correlation is related to the Bands 3 and 4 of Landsat ETM+ with shrubs canopy cover that indicated in r of 0.34 and 0.37 respectively. The maximum rate of correlation in respect to the indices were recognized for the vegetation cover of moisture stress index (MSI) for forbs cover (r= 0.62). The ratio vegetation index (RVI) for grasses cover was indicated (r= 0.53). In conclusion, the results are specified that the ETM+ sensor is the significant data with the elevated competence to discrimination of ecotone using vegetation indices.[...] Read More.

Keywords: ETM+, classification, ecotone, treeline, Alborz, Iran.

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Biofilm formation ability of Paenibacillus polymyxa and Paenibacillus macerans and their inhibitory effect against tomato bacterial wilt

Bin Li, Rongrong Yu, Qiaomei Tang, Ting Su, Xiaoling Chen, Bo Zhu, Yanli Wang, Guanlin Xie and Guochang Sun*

Abstract: The potential of biofilm formation of 16 Paenibacillus strains and their inhibitory effect against bacterial wilt of tomato seedlings were examined in this study. The crystal violet assay indicated that all strains of Paenibacillus except strain MB02-1202 formed biofilm after 96 and 144 h of incubation while there was not significant difference in biofilm formation between strains of Paenibacillus polymyxa and strains of Paenibacillus macerans. However, the increase level of biofilm formation was associated with the increase of the incubation time and the initial inoculum density. In addition, all Paenibacillus strains except strain MB02-428 reduced wilt incidence in tomato seedlings inoculated with Ralstonia solanacearum while the cell numbers of R. solanacearum in rhizosphere soil was reduced by all Paenibacillus strains compared to the pathogen control. In general, most strains of Paenibacillus were able to both form biofilm and protect tomato seedlings from bacterial wilt, indicating that biofilm formation may play an important role in the biocontrol of Paenibacillus. This is first study regarding the relationship between in vitro biofilm formation ability of Paenibacillus strains and their inhibitory activity against R. solanacearum.[...] Read More.

Keywords: Biofilm, Paenibacillus, Ralstonia solanacearum, tomato.

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Copepod parasites of gills of 14 teleost fish species caught in the gulf of Annaba (Algeria)

Boualleg C., Kaouachi N., Seridi M., Ternango S. and Bensouilah M. A.

Abstract: A parasitic copepods study of Algerian teleost fish, report 25 copepod species belonging to eight families harvested from the gills of 14 fish species. The analysis of species richness according to some ecological, biological and taxonomical variables (Diet, Displacement, Way of life, Family) of the whole of hosts are reported in this study, the differences between mean specific richness (MSR) of all variables is statically significant according to Kruskal-Walis test using sigma stat software. Parasitic specificity is discussed, infestation parameters were described.[...] Read More.

Keywords: Gulf of Annaba, copepods, species richness, parasitic indices, parasitic ecology, teleost fishes.

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