• Research in Plant Disease
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• v.10 no.1
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• pp.63-68
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• 2004

Twenty-three strains of Serratia sp., isolated from surface-sterilized rice roots collected in Chonbuk and Chungnam province, were identified and characterized. They were Gram-negative, rod shaped and red pigmented typically and their endophytism was confirmed by inoculation and reisolation of the strains in planta. Their antifungal activity against 4 rice pathogenic fungi was compared and ranged from 62.4 to 85.2％ against Rhizoctonia solani and 68.0 to 88.5％ against Pyricularia grisea. Among the 23 strains tested, strain Rsm220 showed the strongest inhibition activity against 4 pathogenic fungi. The strain was, therefore, selected as a biocontrol candidate for both the pathogens and its bacteriological characteristics and 165 rDNA sequences were analyzed. Phenotypic and biochemical characteristics of the selected Rsm220 were highly related to the type strain of S. marcescens and 165 rDNA sequencing of Rsm220 showed a homology of 98.2％ to the type strain of S. marcescens. The strain Rsm220 was identified as S. marcescens and the inhibition result of this endophytic strain indicates that it is a potential biocontrol agent for R. solani and R grisea.

• Korean Journal of Agricultural Science
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• v.40 no.3
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• pp.221-226
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• 2013

Degrees of hydrolysis by alkaline protease produced from Serratia marcescens S3-R1 is 3.95-6.30% of whey proteins during 5, 15, 30, 60, 90, 120,180, 240 min incubation at $40^{\circ}C$. Proteolytic pattern of the whey proteins showed that various low molecular weight peptides were generated during the incubation periods. The biological function of in Raw 264.7 cells treated with whey protein hydrolytic peptides, anti-inflammatory effect showed exhibit in the expression of pro-inflammatory cytokines such as TNF-${\alpha}$, IL-6, COX-2 and iNOS by PCR analysis. COX-2 and iNOS gene expression inhibited in Raw 264.7 cells on whey protein hydrolysates below 3,000 dalton. The protease from Serratia marcescens S3-R1 showed a potential in production of low molecular weight whey protein hydrolysates which could be used for industrial application.

• Journal of Microbiology and Biotechnology
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• v.17 no.1
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• pp.74-80
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• 2007

An enantioselective lipase gene (esf) for the kinetic resolution of optically active (S)-flurbiprofen was cloned from the new strain Serratia marcescens ES-2. The esf gene was composed of a 1,845-bp open reading frame encoding 614 amino acid residues with a calculated molecular mass of 64,978 Da. The lipase expressed in E. coli was purified by a three-step procedure, and it showed preferential substrate specificity toward the medium-chain-length fatty acids. The esf gene encoding the enantioselective lipase was reintroduced into the parent strain S. marcescens ES-2 for secretory overexpression. The transformant S. marcescens BESF secreted up to 217kU/ml of the enantioselective lipase, about 54-fold more than the parent strain, after supplementing 3.0% Triton X-207. The kinetic resolution of (S)-flurbiprofen was carried out even at an extremely high (R,S)-flurbiprofen ethyl ester [(R,S)-FEE] concentration of 500 mM, 130 kU of the S. marcescens ES-2 lipase per mmol of (R,S)-FEE, and 1,000 mM of succinyl ${\beta}-cyclodextrin$ as the dispenser at $37^{\circ}C$ for 12h, achieving the high enantiomeric excess and conversion yield of 98% and 48%, respectively.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.473-476
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• 2002

A lignin degradation bacteria, symbiotic bacteria was isolated from the gut of Sympetrum depressiusculum and tested for its lignin degrading activity using lignin model compounds and related aromatic compounds. The strain was identified as Serratia marcescens HY-5 based on the 165 rDNA, cellular fatty acid composition, biochemical and physiological characteristics. S. marcescens showed 40-50% lignin degrading activity in the media that contained vaillin, guaiacol and dealkaline lignin. S. marcescens showed three ligninase activities [Jaccase, lignin peroxidase(LiP) and Manganase peroxidase(MnP)]. Addition of dealkaline lignin to the basal media increased about 6fold of laccase activity. Vanillic acid or vanillin increase 1.3fold of MnP activity and p-coumaric acid increased 12fold of LiP activity which added to the basal medium.

• Applied Biological Chemistry
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• v.34 no.1
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• pp.54-60
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• 1991

Serratia marcescens CK-3, decomposing chitin which is a mar component of cell wall in phyitopathogenic fungi, was isolated from the continuous cropping rhizosphere of pepper and cucumber and its enzymatic property was examined. S. marcescens CK-3 was found tn have an tagonistic effects against, Fusarium axysporum and Rhizoctonia solani and to have complex enzyme system such as chitinase, laminarinase, and proteinase. The preferable composition of the medium for production of chitinase was fond and was as follows : colloidal chitin 1.5%, tryptone 0.5%, glucose 1.0%, peptone 0.2%, $MgSO_4{\cdot}7H_2O\;0.1%,\;K_2HPO_4\;0.1%,\;and\;NaCl\;0.1%$(w/v), pH 6.8. The maximum enzyme production was observed after culture of 72 hours at $30^{\circ}C$ using a medium containing the above chemical composition. The optimal pH and temperature for in vitro activity of chitinase from S. marcescens CK-3 were pH 7.5 and $50^{\circ}C$, respectively. The enzyme activity in-creased by metal ions such as$Ag^+$ and $Mn^{++}$.

• Korean Journal of Microbiology
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• v.37 no.3
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• pp.189-196
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• 2001

Eighty-seven microbial strains capable of growing on bisphenol A (BPA) as a sole carbon source were isolated from soils, waste waters and sludges. Among them, three bacterial strains were finally selected as potential decomposers through measuring BPA-degradation efficiency by HPLC analysis. Two of these bacterial strains were identified as Serratia marcescens 1901 and S. marcescens 1902, and another was Pseudomonas putida 1401 by 16S rDNA partial sequences and based on morphological and physiological properties. They showed higher cell growth and BPA degradation in PAV (PAS medium containing vitamin mixtures) than in PAS medium. The degradation efficiencies of these bacterial strains were within a range of 20-40% in the PAV containing 500 mg/1 or 100 mg/l of BPA fur 3 days. S. marcescens 1901 showed higher degradation efficiency at 100 mg/1 of BPA than those of other selected strains, while S. marcescens 1902 and P. putida 1401 degraded a high concentration of BPA (500 mg/l) with a degradation efficiency of 40% for 3 days. The BPA degradation using a mixed culture of three selected strains showed the similar level of dog-radation efficiency with that using a pure culture.

• Journal of Microbiology and Biotechnology
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• v.14 no.1
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• pp.48-55
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• 2004

Six strains of an obligate predatory bdellovibrio isolate that preys on Burkholderia glumae in rice paddy field water and rhizosphere soil, were identified and characterized. The numbers of Bdellovibrio cells varied from $3.2{\times}10^3$ to $9.2{\times}10^3$ plaque-forming unit/g after enrichment in cells of B. glumae. Prey range tests with six Bdellovibrio strains and 17 prey strains of rice-pathogenic, antibiosis-related, or nitrogen-fixing bacteria resulted in unique predation patterns in related prey cells. Strain BG282 had the widest prey range on 7 plant pathogenic bacteria among the 17 prey strains tested. However, no predation occurred with strains of Azospirillum brasilense, Paenibacillus polymyxa, Pseudomonas fluorescens, P. putida, and Serratia marcescens that are associated with antibiosis or nitrogen fixation in the rice ecosystem. Identification was confirmed by the presence of typical bdelloplast in the prey cells of B. glumae and by a PCR assay using B. bacteriovorus-specific primers. Furthermore, 16S rDNA sequencing of the six bdellovibrio strains showed a homology range of 97.2% to 99.2% to the type strain of B. bacteriovorus.

• Biomedical Science Letters
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• v.18 no.3
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• pp.299-306
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• 2012

Recently, the prevalence of 16S rRNA methylase conferring high-level resistance to aminoglycosides has been increasing in Gram-negative bacilli globally. We determined the prevalence and genotype of these methylase-producing bacteria, and characterized the co-resistance to ${\beta}$-lactam antibiotics and quinolone in Gram-negative clinical isolates collected in 2010 at a hospital in Korea. Among 65 amikacin-resistant isolates screened from 864 Gram-negative bacilli (GNB), 16S rRNA methylase genes were detected from 49 isolates, including Acinetobacter baumannii (43), Klebsiella pneumoniae (2), Proteus mirabilis (2) and Serratia marcescens (1), Empedobacter brevis (1). All of the 16S rRNA methylase genotype was armA and no variant sequences of amplified PCR products for armA were noted. The 16S rRNA methylase producing bacteria showed much higher resistance to aminoglycoside for Enterobacteriaceae and glucose non-fermenting (NF)-GNB and to imipenem for glucose NF-GNB, than the non-producing isolates. All of the 16S rRNA methylase producing Enterobacteriaceae had the extended-spectrum-${\beta}$-lactamase. In addition, two K. pneumoniae concurrently produced both plasmid-mediated AmpC ${\beta}$-lactamase and qnrB gene. All of the amikacin-resistant A. baumannii (43) co-harbored armA 16S rRNA methylase and $bla_{OXA-23}$ carbapenemase. In conclusion, 16S rRNA methylase producing bacteria were very prevalent among GNB in South Korea, and were commonly associated with co-resistance, including carbapenem and quinolone.

• Fisheries and Aquatic Sciences
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• v.21 no.2
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• pp.6.1-6.10
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• 2018

The intention of this study was to identify the bacterial pathogens infecting Oreochromis niloticus (Nile tilapia) and Clarias gariepinus (African catfish), and to establish the antibiotic susceptibility of fish bacteria in Uganda. A total of 288 fish samples from 40 fish farms (ponds, cages, and tanks) and 8 wild water sites were aseptically collected and bacteria isolated from the head kidney, liver, brain and spleen. The isolates were identified by their morphological characteristics, conventional biochemical tests and Analytical Profile Index test kits. Antibiotic susceptibility of selected bacteria was determined by the Kirby-Bauer disc diffusion method. The following well-known fish pathogens were identified at a farm prevalence of; Aeromonas hydrophila (43.8%), Aeromonas sobria (20.8%), Edwardsiella tarda (8.3%), Flavobacterium spp. (4.2%) and Streptococcus spp. (6.3%). Other bacteria with varying significance as fish pathogens were also identified including Plesiomonas shigelloides (25.0%), Chryseobacterium indoligenes (12.5%), Pseudomonas fluorescens (10.4%), Pseudomonas aeruginosa (4.2%), Pseudomonas stutzeri (2.1%), Vibrio cholerae (10.4%), Proteus spp. (6.3%), Citrobacter spp. (4.2%), Klebsiella spp. (4.2%) Serratia marcescens (4.2%), Burkholderia cepacia (2.1%), Comamonas testosteroni (8.3%) and Ralstonia picketti (2.1%). Aeromonas spp., Edwardsiella tarda and Streptococcus spp. were commonly isolated from diseased fish. Aeromonas spp. (n = 82) and Plesiomonas shigelloides (n = 73) were evaluated for antibiotic susceptibility. All isolates tested were susceptible to at-least ten (10) of the fourteen antibiotics evaluated. High levels of resistance were however expressed by all isolates to penicillin, oxacillin and ampicillin. This observed resistance is most probably intrinsic to those bacteria, suggesting minimal levels of acquired antibiotic resistance in fish bacteria from the study area. To our knowledge, this is the first study to establish the occurrence of several bacteria species infecting fish; and to determine antibiotic susceptibility of fish bacteria in Uganda. The current study provides baseline information for future reference and fish disease management in the country.