The agp gene encoding the ADP-glucose pyrophosphorylase involved in cyanobacterial glycogen synthesis was amplified by PCR. The resulting agp fragment was cloned in plasmid pUC118 to generate plasmid pUCA. Part of the...The agp gene encoding the ADP-glucose pyrophosphorylase involved in cyanobacterial glycogen synthesis was amplified by PCR. The resulting agp fragment was cloned in plasmid pUC118 to generate plasmid pUCA. Part of the fragment within the agp DNA was deleted and replaced by an erythromycin resistance cassette to generate plasmid pUCAE, which was used to transform the Synechocystis sp. PCC 6803 wild-type strain and a mutant with resistance to erythromycin was obtained. PCR analysis of the genomic DNA from the resulting mutant indicated that the appropriate deletion and insertion indeed had occurred. The cell growth and Chl a, glycogen content in the mutant showed difference from those in the wild-type strain. The obtained biomass as well as the Chl a content in the mutant strain was higher than that of the wild-type strain, which suggested that the photosynthesis efficiency in the agp(-) strain was higher than that in the wild-type strain. No glycogen was found in the mutant, providing evidence for the correction of the mutant in physiological level.展开更多
This work aimed to investigate the biosorption of lead by free and immobilized bacterial cell. Twenty four samples were collected from the wastewater of batteries factory in AL-Waziria district for the period from Jun...This work aimed to investigate the biosorption of lead by free and immobilized bacterial cell. Twenty four samples were collected from the wastewater of batteries factory in AL-Waziria district for the period from June to Sept. 2004, three species of bacteria have been isolated from this wastewater： Enterobacter agglomerans, E. gergoviae, and E. sakazakii. The results revealed a high variation in the ability of these bacteria for lead biosorption, the bacteria E. agglomerans （ES） was the most efficient compared to the other bacterial species. A laboratory plant with continuous flow system was designed for lead ions removal from standards aqueous solutions, as the cells were immobilized using： white sand, charcoal, agar and calcium alginate. However, the cells immobilized to calcium alginate were the most efficient in removal of lead ions （98%）. Present study also determined the optimal conditions for the biosorptJon of lead ions which were temperature 40℃ and pH 4 with one hour contiguity between the immobilized bacteria and solution. Different washing solutions were used fo~： recovering the lead ions that have been biosorbed on the bacterial walls, 0.1 M EDTA was the most efficient. Preferential biosorption by E. agglomerans （E5） to copper and cadmium was determined, result showed that the order of this preferential capability was： Cu 〉 Pb 〉 Cd. No significant differences were found in the biosorption of lead ions by alive and dead E. agglomerans （E5）. The designed lab plant containing bacterial cells binding on calcium alginate was able to uptake all lead ions from all samples of industrial wastewater of batteries factory.展开更多
In 2009, 201 samples of live bivalve mussels （Mytillus galloprovincialis） were analyzed for presence of Listeria monocytogenes. The samples were collected from three sampling points （BM l-south, BM l-north and BMl-...In 2009, 201 samples of live bivalve mussels （Mytillus galloprovincialis） were analyzed for presence of Listeria monocytogenes. The samples were collected from three sampling points （BM l-south, BM l-north and BMl-west） in Butrinti lagoon located in the south of Albania. The examination confirmed incidence of this pathogen with average value 4.5%. Based on the results, high incidence was reported in winter with 6.7% of analyzed samples. The incidence of L. monocytogenes was also reported respectively in spring of 2009 with 4.35% and in autumn with 2.3% of controlled samples. There is no big difference in values of incidence of L. monocytogenes between summer and autumn. The northern part of the lagoon was more indicated by contamination of L. monocytogenes. Examination of 67 samples of M. galloprovincialis, collected in the northern part of this lagoon, showed five cases or about 7.5% of them to be confirmed as positive. Referring to the study results, periodic controls of the sea products, particularly of live bivalve mollusks, for presence ofL. monocytogenes remains a necessary objective of food inspection in Albania.展开更多
文摘The agp gene encoding the ADP-glucose pyrophosphorylase involved in cyanobacterial glycogen synthesis was amplified by PCR. The resulting agp fragment was cloned in plasmid pUC118 to generate plasmid pUCA. Part of the fragment within the agp DNA was deleted and replaced by an erythromycin resistance cassette to generate plasmid pUCAE, which was used to transform the Synechocystis sp. PCC 6803 wild-type strain and a mutant with resistance to erythromycin was obtained. PCR analysis of the genomic DNA from the resulting mutant indicated that the appropriate deletion and insertion indeed had occurred. The cell growth and Chl a, glycogen content in the mutant showed difference from those in the wild-type strain. The obtained biomass as well as the Chl a content in the mutant strain was higher than that of the wild-type strain, which suggested that the photosynthesis efficiency in the agp(-) strain was higher than that in the wild-type strain. No glycogen was found in the mutant, providing evidence for the correction of the mutant in physiological level.
文摘This work aimed to investigate the biosorption of lead by free and immobilized bacterial cell. Twenty four samples were collected from the wastewater of batteries factory in AL-Waziria district for the period from June to Sept. 2004, three species of bacteria have been isolated from this wastewater： Enterobacter agglomerans, E. gergoviae, and E. sakazakii. The results revealed a high variation in the ability of these bacteria for lead biosorption, the bacteria E. agglomerans （ES） was the most efficient compared to the other bacterial species. A laboratory plant with continuous flow system was designed for lead ions removal from standards aqueous solutions, as the cells were immobilized using： white sand, charcoal, agar and calcium alginate. However, the cells immobilized to calcium alginate were the most efficient in removal of lead ions （98%）. Present study also determined the optimal conditions for the biosorptJon of lead ions which were temperature 40℃ and pH 4 with one hour contiguity between the immobilized bacteria and solution. Different washing solutions were used fo~： recovering the lead ions that have been biosorbed on the bacterial walls, 0.1 M EDTA was the most efficient. Preferential biosorption by E. agglomerans （E5） to copper and cadmium was determined, result showed that the order of this preferential capability was： Cu 〉 Pb 〉 Cd. No significant differences were found in the biosorption of lead ions by alive and dead E. agglomerans （E5）. The designed lab plant containing bacterial cells binding on calcium alginate was able to uptake all lead ions from all samples of industrial wastewater of batteries factory.
文摘In 2009, 201 samples of live bivalve mussels （Mytillus galloprovincialis） were analyzed for presence of Listeria monocytogenes. The samples were collected from three sampling points （BM l-south, BM l-north and BMl-west） in Butrinti lagoon located in the south of Albania. The examination confirmed incidence of this pathogen with average value 4.5%. Based on the results, high incidence was reported in winter with 6.7% of analyzed samples. The incidence of L. monocytogenes was also reported respectively in spring of 2009 with 4.35% and in autumn with 2.3% of controlled samples. There is no big difference in values of incidence of L. monocytogenes between summer and autumn. The northern part of the lagoon was more indicated by contamination of L. monocytogenes. Examination of 67 samples of M. galloprovincialis, collected in the northern part of this lagoon, showed five cases or about 7.5% of them to be confirmed as positive. Referring to the study results, periodic controls of the sea products, particularly of live bivalve mollusks, for presence ofL. monocytogenes remains a necessary objective of food inspection in Albania.
