• Korean Journal of Microbiology
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• v.25 no.3
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• pp.184-188
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• 1987

Evidences that the mannose permease of Escherichia coli mediates the infection of N4 in early steps, were obtained as follows. First, A mutant strain of Escherichia coli which was resistant to both wild type N4 and lambda whose genome is Charon 4A containing human genomic fragments in its EcoR I site, could not use mannose efficiently. Second, N4 could not infect pel mutant strains which lack one or all of intact components of mannose permease. However, unknown alterations in N4 made it possible for the phage to infect pel mutant of E. coli. It also turned out to be clear that the receptor of N4 was different from that of lambda.

• Journal of Microbiology and Biotechnology
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• v.18 no.7
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• pp.1227-1234
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• 2008

Pseudomonas aeruginosa is an opportunistic human pathogen that produces and secretes exopolysaccharides (EPS), in which cells are embedded to form a highly organized community structure called biofilm. Here, we characterized the role of cyclic diguanylate (c-di-GMP) and EPS (PEL) overproduction in the wspF mutant phenotypes of P. aeruginosa PA14 (wrinkly appearance, hyperadherence, impaired motilities, and reduced virulence in acute infections). We confirmed that the elevated c-di-GMP level plays a key role in all the wspF mutant phenotypes listed above, as assessed by ectopic expression of a c-di-GMP-degrading phophodiesterase (PvrR) in the wspF mutant. In contrast, PEL EPS, which is overproduced in the wspF mutant, was necessary for wrinkly appearance and hyperadherence, but not for the impaired flagellar motilities and the attenuated virulence of the wspF mutant. These results suggest that c-di-GMP affects flagellar motility and virulence, independently of EPS production and surface adherence of this bacterium.

• Journal of Microbiology and Biotechnology
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• v.14 no.5
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• pp.1047-1051
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• 2004

The phytopathogenic bacterium Pectobacterium chrysanthemi secretes multiple isozymes of plant cell wall disrupting enzyme such as pectate lyase and cellulase. The cel gene, existing in tandem with the pel gene, was isolated previously [10]. The role of Cel5Z and PelL1 in P. chrysanthemi PY35 pathogenicity on potato tissues was assessed by mutagenizing cloned cel gene and pel gene in tandem and recombining them with the chromosomal alleles. Strains with the Km cassette interposon in pelL1 or a double mutant showed a delay in the appearance of symptoms, suggesting that P. chrysanthemi PY35 pectate lyase PelL1 may playa minor role in soft-rot pathogenesis.

• Microbiology and Biotechnology Letters
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• v.19 no.3
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• pp.222-227
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• 1991

Rhizobium fredii USDA193 is one of the causal organism for root nodule formation in soybean (peking). Previously we cloned the pectate lyase gene (SY1) of R. fredii USDA193. The $pel^-$ mutants (SY1$\Omega$ and SY1$\Omega$1) of SY1 were obtained using the in vitro insertional omega mutagenesis of RpelB (of Rhizobium pel) and fill-in reaction of RpelE (of Rhizobium pel) gene respectively, and we constructed two mutants (R, fredii USDA193$\Omega$ and R. fredii USDA193$\Omega$1) in pectate lyase function by marker-exchange with pe1B::$\Omega$ and R. fredii USDA193 strain (rif). The pectate lyase activity of two pel- mutant of R. fredii USDA193 was determined by spectrophotometric method. However, all pectate lyase activity of these mutants was not lost upon the mutagenesis by marker-exchange. This suggests that other pectate lyase genes may be present on the plasmid or the chromosome of R. fredii. As yet we do not have evidence linking RpelB and RpelE genes of R. fredii directly to the early nodulation process.