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Abstract. Klebsiella became an increasingly important source of community-acquired and nosocomial infections. Extensive
broad-spectrum utilization of antibiotics in hospitalized patients has contributed to both increased carriages of Klebsiella and the
development of multidrug-resistant strains. Many of these strains are extremely virulent and show a strong tendency to spread.
Bacteriophages, viruses that because bacterial lysis can serve as a useful tool for Klebsiella infection control. In this study, two
lytic phages designated as ØKPAS1 and ØKPAS2 infecting multidrug-resistant K. pneumoniae were isolated from sewage
samples collected in Assiut, Egypt. Using transmission electron microscopy, the morphology of isolated phages was characterized,
and their host range was determined. The morphological analysis revealed that both phages belong to the Podoviridae family.
ØKPAS1 has ahead of about 50 ± 5 nm in diameter and a short tail of 20 ± 2 nm in length, while ØKPAS2 has ahead of about 53
± 5 nm in diameter with a short tail of 19 ± 2 nm in length. ØKPAS1 phage showed a broader host range within genus Klebsiella
since it was able to lyse 8 out of 15 different Klebsiella cultures while ØKPAS2 was able to lyse only 5 out of 15. Both phages
could not infect bacteria from other genera such as Escherichia coli and Salmonella typhi. The isolated phage ØKPAS1 was able
to survive at a temperature up to 50 ᵒC and was infective in pH range between 4.0-9.0, while ØKPAS2 was able to survive at a
temperature up to 60 ᵒC and was stable over the pH range of 4,0 to10,0. Both phages were stable in chloroform. One-step growth
curves of ØKPAS1 and ØKPAS2 revealed that the latent period was 10 min for either phage, with burst sizes of about 120 and
245 pfu/ml for ØKPAS1 and ØKPAS2, respectively.

Abstract. Klebsiella became an increasingly important source of community-acquired and nosocomial infections. Extensive
broad-spectrum utilization of antibiotics in hospitalized patients has contributed to both increased carriages of Klebsiella and the
development of multidrug-resistant strains. Many of these strains are extremely virulent and show a strong tendency to spread.
Bacteriophages, viruses that because bacterial lysis can serve as a useful tool for Klebsiella infection control. In this study, two
lytic phages designated as ØKPAS1 and ØKPAS2 infecting multidrug-resistant K. pneumoniae were isolated from sewage
samples collected in Assiut, Egypt. Using transmission electron microscopy, the morphology of isolated phages was characterized,
and their host range was determined. The morphological analysis revealed that both phages belong to the Podoviridae family.
ØKPAS1 has ahead of about 50 ± 5 nm in diameter and a short tail of 20 ± 2 nm in length, while ØKPAS2 has ahead of about 53
± 5 nm in diameter with a short tail of 19 ± 2 nm in length. ØKPAS1 phage showed a broader host range within genus Klebsiella
since it was able to lyse 8 out of 15 different Klebsiella cultures while ØKPAS2 was able to lyse only 5 out of 15. Both phages
could not infect bacteria from other genera such as Escherichia coli and Salmonella typhi. The isolated phage ØKPAS1 was able
to survive at a temperature up to 50 ᵒC and was infective in pH range between 4.0-9.0, while ØKPAS2 was able to survive at a
temperature up to 60 ᵒC and was stable over the pH range of 4,0 to10,0. Both phages were stable in chloroform. One-step growth
curves of ØKPAS1 and ØKPAS2 revealed that the latent period was 10 min for either phage, with burst sizes of about 120 and
245 pfu/ml for ØKPAS1 and ØKPAS2, respectively.

Abstract. Klebsiella became an increasingly important source of community-acquired and nosocomial infections. Extensive
broad-spectrum utilization of antibiotics in hospitalized patients has contributed to both increased carriages of Klebsiella and the
development of multidrug-resistant strains. Many of these strains are extremely virulent and show a strong tendency to spread.
Bacteriophages, viruses that because bacterial lysis can serve as a useful tool for Klebsiella infection control. In this study, two
lytic phages designated as ØKPAS1 and ØKPAS2 infecting multidrug-resistant K. pneumoniae were isolated from sewage
samples collected in Assiut, Egypt. Using transmission electron microscopy, the morphology of isolated phages was characterized,
and their host range was determined. The morphological analysis revealed that both phages belong to the Podoviridae family.
ØKPAS1 has ahead of about 50 ± 5 nm in diameter and a short tail of 20 ± 2 nm in length, while ØKPAS2 has ahead of about 53
± 5 nm in diameter with a short tail of 19 ± 2 nm in length. ØKPAS1 phage showed a broader host range within genus Klebsiella
since it was able to lyse 8 out of 15 different Klebsiella cultures while ØKPAS2 was able to lyse only 5 out of 15. Both phages
could not infect bacteria from other genera such as Escherichia coli and Salmonella typhi. The isolated phage ØKPAS1 was able
to survive at a temperature up to 50 ᵒC and was infective in pH range between 4.0-9.0, while ØKPAS2 was able to survive at a
temperature up to 60 ᵒC and was stable over the pH range of 4,0 to10,0. Both phages were stable in chloroform. One-step growth
curves of ØKPAS1 and ØKPAS2 revealed that the latent period was 10 min for either phage, with burst sizes of about 120 and
245 pfu/ml for ØKPAS1 and ØKPAS2, respectively.

NULLAbstract
Aims: The major aims of this study are to determine the capability of sulphur
oxidizing bacterium (SOB-1) to desulphurize dibenzothiophene (DBT) and
crude oil, detection of the reaction kinetics and identify the proposed pathway
of DBT desulphurization.
Methods and Results: The isolate was genetically identified based on 16S
rRNA gene sequencing as Klebsiella oxytoca and deposited in the Genebank
database under the accession number: MT355440. The HPLC analysis of the
remaining DBT concentration revealed that, SOB-1 could desulphurize 90% of
DBT (0
25 mmol l−1) within 96 h. The maximum production of sulphate ions
from the desulphurization of DBT (0
36 mmol l−1) and crude oil
(0
4 mmol l−1) could be quantitatively detected after 48 h of incubation at
30°C. The high values of correlation coefficient (R2) obtained at all studied
concentrations; suggested that biodesulfurization kinetics of DBT follows the
first-order reaction model. The kinetics studies showed that, DBT may have an
inhibitory effect on SOB-1 when the initial concentration exceeded
0
75 mmol l−1. The GC-MS analysis exhibited four main metabolites rather
than DBT. The most important ones are 2-hydroxybiphenyl (2-HBP) and
methoxybiphenyl n(2-MBP).
Conclusions: Klebsiella oxytoca SOB-1 catalyzes the desulphurization of DBT
through 4S pathway and forms four main metabolic products. The release of
sulphate ion and formation of 2-HBP indicating the elimination of sulphur
group without altering the carbon skeleton of DBT. The bacterial strain could also catalyzes desulphurization of crude oil. The desulphurization kinetics follows the first-order reaction model.
Significance and Impact of the Study: Klebsiella oxytoca SOB-1 could be used as a promising industrial and environmental biodesulfurizing agent as it is not affecting carbon skeleton of thiophenic compounds and forming less toxic metabolic product (2-MBP).

NULLAbstract
Aims: The major aims of this study are to determine the capability of sulphur
oxidizing bacterium (SOB-1) to desulphurize dibenzothiophene (DBT) and
crude oil, detection of the reaction kinetics and identify the proposed pathway
of DBT desulphurization.
Methods and Results: The isolate was genetically identified based on 16S
rRNA gene sequencing as Klebsiella oxytoca and deposited in the Genebank
database under the accession number: MT355440. The HPLC analysis of the
remaining DBT concentration revealed that, SOB-1 could desulphurize 90% of
DBT (0
25 mmol l−1) within 96 h. The maximum production of sulphate ions
from the desulphurization of DBT (0
36 mmol l−1) and crude oil
(0
4 mmol l−1) could be quantitatively detected after 48 h of incubation at
30°C. The high values of correlation coefficient (R2) obtained at all studied
concentrations; suggested that biodesulfurization kinetics of DBT follows the
first-order reaction model. The kinetics studies showed that, DBT may have an
inhibitory effect on SOB-1 when the initial concentration exceeded
0
75 mmol l−1. The GC-MS analysis exhibited four main metabolites rather
than DBT. The most important ones are 2-hydroxybiphenyl (2-HBP) and
methoxybiphenyl n(2-MBP).
Conclusions: Klebsiella oxytoca SOB-1 catalyzes the desulphurization of DBT
through 4S pathway and forms four main metabolic products. The release of
sulphate ion and formation of 2-HBP indicating the elimination of sulphur
group without altering the carbon skeleton of DBT. The bacterial strain could also catalyzes desulphurization of crude oil. The desulphurization kinetics follows the first-order reaction model.
Significance and Impact of the Study: Klebsiella oxytoca SOB-1 could be used as a promising industrial and environmental biodesulfurizing agent as it is not affecting carbon skeleton of thiophenic compounds and forming less toxic metabolic product (2-MBP).