Phosphorus recovery by mesoporous structure material from wastewater

This study was designed to investigate the fundamental aspects of a possible removal of phosphorous from wastewater by using the mesoporous structure materials for wastewater reuse. The zirconium sulphate with mesoporous structure as a new type of ion exchangers was synthesised by hydrothermal reaction. From the results of X-ray diffraction and transmission electron microscope, it was discovered that the synthesised material had hexagonal mesoporous structure with a pore size of approximately 40-50A. Experimental results showed that the zirconium sulphate with mesoporous structure had very high sorption capacity for the phosphorus. The novel ion exchange occurred between PO4(3-) and SO4(2-), OH-. The amount of phosphate ions exchanged into the solid was as great as 3.4 mmol/g-ZS. Furthermore, it is possible to obtain a higher removal efficiency than other ion exchange media and adsorbents.

Overexpression of carnation S-adenosylmethionine decarboxylase gene generates a broad-spectrum tolerance to abiotic stresses in transgenic tobacco plants

Polyamines (PAs), such as putrescine, spermidine, and spermine, are present in all living organism and implicate in a wide range of cellular physiological processes. We have used transgenic technology in an attempt to evaluate their potential for mitigating the adverse effects of several abiotic stresses in plants. Sense construct of full-length cDNA for S-adenosylmethionine decarboxylase (SAMDC), a key enzyme in PA biosynthesis, from carnation (Dianthus caryophyllus L.) flower was introduced into tobacco (Nicotiana tabacum L.) by Agrobacterium tumefaciens-mediated transformation. Several transgenic lines overexpressing SAMDC gene under the control of cauliflower mosaic virus 35S promoter accumulated soluble total PAs by 2.2 (S16-S-4) to 3.1 (S16-S-1) times than wild-type plants. The transgenic tobacco did not show any difference in organ phenotype compared to the wild-type. The number and weight of seeds increased, and net photosynthetic rate also increased in transgenic plants. Stress-induced damage was attenuated in these transgenic plants, in the symptom of visible yellowing and chlorophyll degradation after all experienced stresses such as salt stress, cold stress, acidic stress, and abscisic acid treatment. H2O2-induced damage was attenuated by spermidine treatment. Transcripts for antioxidant enzymes (ascorbate peroxidase, manganase superoxide dismutase, and glutathione S-transferase) in transgenic plants and GUS activity transformed with SAMDC promoter::GUS fusion were induced more significantly by stress treatment, compared to control. These results that the transgenic plants with sense SAMDC cDNA are more tolerant to abiotic stresses than wild-type plants suggest that PAs may play an important role in contributing stress tolerance in plants.

A high filtration system with synthetic permeable media for wastewater reclamation

A novel filtration process with synthetic permeable media was investigated for secondary effluent reclamation. Polyurethane was chosen as the filter medium among three tested media. Compressibility and up-flow velocity were changed to determine the optimum operation for the system. An equation was introduced to express the relationship between the removal efficiency and up-flow velocity. In a pilot study, the synthetic medium filtration with compression showed very stable effluent quality without clogging trouble, though the system operated with three times higher filtration rate and much longer backwashing interval than conventional systems.

Effects of abiotic stresses on cell cycle progression in tobacco BY-2 cells

Mild stresses such as high temperature (30 degrees C) or a low H2O2 concentration induced transient cell cycle arrest at G1/S or G2/M depending on the cell cycle stage at which the stress was applied. When stresses were introduced during G0 or G1, the G1/S checkpoint was mainly used; when stresses were introduced after S phase, G2/M was the primary checkpoint. The slowing of cell cycle progression was associated with transient delays in expression of A-, B-, and D-type cyclins. The delay in expression of NtcycA13, one of the A-type cyclins, was most pronounced. The levels of expression of Ntcyc29 (a cyclin B gene) and of CycD3-1 differed most depending on the applied stress, suggesting that different cellular adjustments to mild heat and a low concentration of H2O2 are reflected in the expression of these two cyclins.

Operational strategies for an activated sludge process in conjunction with ozone oxidation for zero excess sludge production during winter season

A pilot-scale activated sludge system coupled with sludge ozonation process was operated for 112 days of a winter season without excess sludge wasting. The concept of this process is that the excess sludge produced is first disintegrated by ozone oxidation and then recirculated to a bioreactor in order to mineralize the particulate and soluble organic compounds. The basis of operation was to determine either the optimal amount of sludge in kg SS ozonated each day (SO) or the optimal ozonation frequency under the variable influent chemical oxygen demand (COD) loading and temperature conditions, since the ozone supply consumes costly energy. The optimal SO was obtained using the theoretically estimated sludge production rate (SP) and experimentally obtained ozonation frequency (n). While the SP was mainly subject to the COD loadings, sludge concentration was affected by the temperature changes in winter season. The optimal n was observed between 2.5 and 2.7 at around 15 degrees C, but it was doubled at 10 degrees C. Mixed liquor suspended solids (MLSS) concentration was leveled off at around 5000 mg/L in bioreactor at 15 degrees C, but the volatile fraction of MLSS was fixed around 0.7 indicating that there was no significant inorganic accumulation. Suspended solids (SS) and soluble COD in effluents kept always a satisfactory level of 10 and 15 mg/L with sufficient biodegradation. It was recommended to apply a dynamic SO under variable influent COD loadings and temperature conditions to the activated sludge system without excess sludge production for saving energy as well as system stabilization.

Granulation in an upflow anaerobic sequencing batch reactor treating disintegrated waste activated sludge

An upflow anaerobic reactor operated with a sequencing batch mode to enhance high rate digestion of raw and thermally disintegrated waste activated sludge with formation of granules. The gas production rate doubled when disintegrated waste activated sludge was introduced. Gradual granulation took place and the dispersed particles become coarse granulation as the operation continued. The granular sludge showed relatively higher specific methanogenic activity than the dispersed sludge. Bacterial morphology by a scanning electron microscope showed diversity of bacteria such as filamentous, rod and spherical shape in the section of granules. Filamentous bacteria, which might support the frame of a granule, were observed as long chains at the outer surface. Meanwhile, rod and spherical bacteria, which might play a role in the initial stage of granule formation, were observed from the inner surface of the granule. High rate digestion of sludge along with efficient liquid-solids separation was achieved due mainly to development of sludge granules within the upflow reactor.

Performance evaluation of physicochemical processes for biologically pre-treated livestock wastewater

The use of a combination of biological and physicochemical methods is a promising technique to reduce highly concentrated pollutants in livestock wastewater: firstly, biodegradable organic matters, nitrogen and a part of phosphorus should be removed in a biological treatment process and then residual non-biodegradable organic matters, color and phosphorus be eliminated by physicochemical methods. In this study, therefore, the integrations of chemical coagulation, activated carbon adsorption, Fenton oxidation and ozonation were evaluated to provide an appropriate post-treatment process for biologically pre-treated livestock wastewater. With applying a single method such as coagulation and Fenton oxidation, a yellowish brown color and COD still remained. According to the experimental result, the quality of treated wastewater including color was enough to be discharged after chemical coagulation followed by ozonation or Fenton oxidation process. Among these, ozonation was the most effective technology for decolorization. Neither simple biological nor physicochemical process provides an adequate treatability for the sufficient depletion of organics and decolorization when treating livestock wastewater. Considering only the removal efficiency, the integration of Fenton oxidation and ozonation would be an efficient alternative as a post-treatment.

A leader intron and 115-bp promoter region necessary for expression of the carnation S-adenosylmethionine decarboxylase gene in the pollen of transgenic tobacco

The expression of CSDC9 encoding S-adenosylmethionine decarboxylase (SAMDC) is developmentally and spatially regulated in carnation. To examine the regulation of the SAMDC gene, we analyzed the spatial expression of CSDC9 with a 5'-flanking beta-glucuronidase fusion in transgenic tobacco plants. GUS was strongly expressed in flower, pollen, stem and vein of cotyledons. Expression in both anther and stigma was under developmental control; analysis of a series of mutants with deletions of the 5'-flanking region demonstrated differential activation in petal, anther, stigma and pollen grains. All the major cis-regulatory elements required for pollen-specific transcription were located in the upstream region between -273 and -158. This region contains four putative elements related to gibberellin induction (pyrimidine boxes, TTTTTTCC and CCTTTT) and pollen-specific expression (GTGA and AGAAA). In addition, the first 5'-leader intron was necessary for tissue-specific expression.

The role of Coptidis Rhizoma extract in a renal ischemia-reperfusion model

The effect of Coptidis Rhizoma extract on ischemia-reperfusion in rats was examined. The blood levels of urea nitrogen and creatinine increased significantly more in rats subjected to 24-h reperfusion than those subjected to 6-h reperfusion following 1-h ischemia, indicating functional kidney damage was more severe after the longer reperfusion time. These parameters were reduced by oral administration of Coptidis Rhizoma extract. Greater activity was found in rats given the extract for 30 days than in rats given the extract for 10 days prior to ischemia-reperfusion. In addition, the serum malondialdehyde level was lower, while the glutathione/glutathione disulfide ratio and the activities of the antioxidation enzymes, superoxide dismutase and catalase, were higher in rats given Coptidis Rhizoma extract orally for 30 consecutive days prior to 1-h ischemia and 24-h reperfusion in comparison with control rats given water. These results indicate that Coptidis Rhizoma has a protective action against the renal dysfunction caused by the ischemia and reperfusion process. Furthermore, renal DNA of rats given Coptidis Rhizoma extract orally showed a significantly lower DNA fragmentation rate, which was dose-dependent, implying that the extract afforded the kidneys protection against oxidative stress-mediated apoptosis during the process and ameliorated renal function impairment.

A proteomic analysis identifies glutathione S-transferase isoforms whose abundance is differentially regulated by ethylene during the formation of early root epidermis in Arabidopsis seedlings

The plant hormone ethylene has been shown to play an important role in root hair development in Arabidopsis. With the aid of proteomic analysis, we identified three distinct glutathione S-transferase (GST) isoforms, AtGSTF2, AtGSTF8, and AtGSTU19, expressed early in root epidermal establishment in Arabidopsis seedlings. The AtGSTF2 protein was specifically up-regulated by ethylene. A subsequent RNA expression study revealed that the AtGSTF2 gene was highly sensitive to ethylene, whereas the transcripts for AtGSTF8 and AtGSTU19 were constitutively present in new root tissue of 4-day-old seedlings. The steady-state level of AtGSTF2 mRNA was greatly reduced in the roots of ethylene-insensitive mutants, while mutation at the CTR1 locus, which confers an ectopic root hair phenotype, resulted in a markedly elevated level of AtGSTF2 transcript in young root tissue. Although the physiological function of ethylene-induced AtGSTF2 is not yet clear, there are several possibilities for its role during early root development.

Light differentially regulates the expression of two members of the auxin-induced 1-aminocyclopropane-1-carboxylate synthase gene family in mung bean (Vigna radiata L.) seedlings

Auxin induces the expression of the two ethylene-biosynthetic genes VR-ACS6 and VR-ACS7 in etiolated mung bean hypocotyls. However, while it also enhances VR-ACS6 expression in light-grown tissues, it does not up-regulate VR-ACS7 expression in these tissues. Here we show that transfer of 3-day-old etiolated seedlings into light quickly reduced the auxin-induced expression of both genes. However, while auxin-induced VR-ACS6 expression recovered after 24 h of light, VR-ACS7 transcription continued to reduce and was almost completely absent at 36 h. Thus, light differentially modulates the expression of the auxin-inducible VR-ACS genes. In hormone-treated etiolated seedlings, VR-ACS7 was primarily induced in the rapidly elongating zones of hypocotyl and epicotyl tissues, while auxin-induced VR-ACS6 mRNA was evenly distributed throughout the whole seedling. VR-ACS7 promoter-driven beta-glucuronidase (GUS) activity in auxin-treated etiolated transgenic Arabidopsis seedlings was observed in the highly elongating zones of the hypocotyl. During de-etiolation, the GUS activity gradually declined to become confined to the uppermost region of hypocotyls. In situ mRNA localization studies showed that in etiolated mung bean hypocotyls, the auxin-dependent VR-ACS7 transcript was predominantly present in the epidermis, which is the driving site for auxin-mediated elongation. Thus, it appears that the modulation by light of auxin-induced VR-ACS7 expression may correlate closely with the elongation growth response in early seedling development.

Characterization of arginine decarboxylase from Dianthus caryophyllus

Arginine decarboxylase (ADC, EC 4.1.1.9) is a key enzyme in the biosynthesis of polyamines in higher plants, whereas ornithine decarboxylase represents the sole pathway of polyamine biosynthesis in animals. Previously, we characterized a genomic clone from Dianthus caryophyllus, in which the deduced polypeptide of ADC was 725 amino acids with a molecular mass of 78 kDa. In the present study, the ADC gene was subcloned into the pGEX4T1 expression vector in combination with glutathione S-transferase (GST). The fusion protein GST-ADC was water-soluble and thus was purified by sequential GSTrap-arginine affinity chromatography. A thrombin-mediated on-column cleavage reaction was employed to release free ADC from GST. Hiload superdex gel filtration FPLC was then used to obtain a highly purified ADC. The identity of the ADC was confirmed by immunoblot analysis, and its specific activity with respect to (14)C-arginine decarboxylation reaction was determined to be 0.9 CO(2) pkat mg(-1) protein. K(m) and V(max) of the reaction between ADC and the substrate were 0.077 +/- 0.001 mM and 6.0 +/- 0.6 pkat mg(-1) protein, respectively. ADC activity was reduced by 70% in the presence of 0.1 mM Cu(2+) or CO(2+), but was only marginally affected by Mg(2+), or Ca(2+) at the same concentration. Moreover, spermine at 1 mM significantly reduced its activity by 30%.

RETRACTED: Evidence of a pluripotent human embryonic stem cell line derived from a cloned blastocyst

Somatic cell nuclear transfer (SCNT) technology has recently been used to generate animals with a common genetic composition. In this study, we report the derivation of a pluripotent embryonic stem (ES) cell line (SCNT-hES-1) from a cloned human blastocyst. The SCNT-hES-1 cells displayed typical ES cell morphology and cell surface markers and were capable of differentiating into embryoid bodies in vitro and of forming teratomas in vivo containing cell derivatives from all three embryonic germ layers in severe combined immunodeficient mice. After continuous proliferation for more than 70 passages, SCNT-hES-1 cells maintained normal karyotypes and were genetically identical to the somatic nuclear donor cells. Although we cannot completely exclude the possibility that the cells had a parthenogenetic origin, imprinting analyses support a SCNT origin of the derived human ES cells.

Acidic and hydrogen peroxide treatment of polyaluminum chloride (PACL) sludge from water treatment

The water treatment sludge including coagulants cannot be easily removed by conventional dewatering methods. The possibility of hydrogen peroxide (H2O2) oxidation as a pretreatment to enhance the dewaterability of polyaluminum chloride (PACl) sludge from water works was investigated. H2O2 treatment alone was not effective but H2O2 treatment under acidic condition significantly reduced both the cake water content and specific resistance to filtration (SRF), indicating the enhancement of dewaterability and filterability. The filterability after acid/H2O2 treatment was comparable to polymer conditioning and even more dewatered cake than polymer conditioning was produced. By H202 combined with sulfuric acid (H2SO4), leached iron caused Fenton's reaction, which showed a potential to significantly reduce the amount of solids mass and to produce more compact cake with higher filterability.

The putative transcriptional activator MSN1 promotes chromium accumulation in Saccharomyces cerevisiae

Yeast is a good system for studying molecular mechanisms of metal tolerance. Using a mini-Tn mutagenized yeast pool, we isolated a chromate-tolerant mutant, CrT9, that displayed metal-specific tolerance since it was only tolerant to Cr(VI), not to Cr(III), Cd, As, or Fe. The Cr-tolerance of CrT9 appeared to be due to reduced Cr accumulation as it accumulated only 56% as much as WT (Y800). Using IPCR (inverse PCR), we found that the mini-Tn had been inserted at nt 741 of the transcriptional activator, MSN1. MSN1 is a multifunctional protein involved in invertase activity, iron uptake, starch degradation, pseudohyphal growth, and osmotic gene expression. We found that there was only one mini-Tn insertion in CrT9 since MSN1 and mini-Tn probes hybridized to the same DNA fragment, and the MSN1 probe detected an enlarged MSN1 mRNA. When we over-expressed MSN1 in CrT9 and WT, both accumulated larger amounts of Cr. We conclude that Cr accumulation in S. cerevisiae is promoted by the transcriptional activator MSN1.

Generation and analysis of end sequence database for T-DNA tagging lines in rice

We analyzed 6749 lines tagged by the gene trap vector pGA2707. This resulted in the isolation of 3793 genomic sequences flanking the T-DNA. Among the insertions, 1846 T-DNAs were integrated into genic regions, and 1864 were located in intergenic regions. Frequencies were also higher at the beginning and end of the coding regions and upstream near the ATG start codon. The overall GC content at the insertion sites was close to that measured from the entire rice (Oryza sativa) genome. Functional classification of these 1846 tagged genes showed a distribution similar to that observed for all the genes in the rice chromosomes. This indicates that T-DNA insertion is not biased toward a particular class of genes. There were 764, 327, and 346 T-DNA insertions in chromosomes 1, 4 and 10, respectively. Insertions were not evenly distributed; frequencies were higher at the ends of the chromosomes and lower near the centromere. At certain sites, the frequency was higher than in the surrounding regions. This sequence database will be valuable in identifying knockout mutants for elucidating gene function in rice. This resource is available to the scientific community at http://www.postech.ac.kr/life/pfg/risd.

Application of cDNA microarray technique to detection of gene expression in host cells infected with viruses

cDNA microarray technique was used to monitor changes in mRNA levels in cells after Hantaan virus (HTNV) infection. The values of the ratio of medians for HTNV and Japanese encephalitis virus (JEV) at the early stage of infection were compared and found similar, suggesting that the same or similar genes are associated with the early events of infection with either virus. The reproducibility of values of the "ratio of medians" for HTNV was examined. We found that applying cluster analysis to the gene expression data groups efficiently together genes with the same function. Therefore, in analyzing the effects of viral infection on host cells by the cDNA microarray technique, clustering data appear to be necessary for gaining biological meaning from a dump of gene expression profiles obtained from virus-infected cells.

Antisense expression of carnation cDNA encoding ACC synthase or ACC oxidase enhances polyamine content and abiotic stress tolerance in transgenic tobacco plants

The amount of polyamines (such as putrescine, spermidine, and spermine) increased under environmental stress conditions. We used transgenic technology in an attempt to evaluate their potential for mitigating the adverse effects of several abiotic stresses in plants. Because there is a metabolic competition for S-adenosylmethionine as a precursor between polyamine (PA) and ethylene biosyntheses, it was expected that the antisense-expression of ethylene biosynthetic genes could result in an increase in PA biosynthesis. Antisense constructs of cDNAs for senescence-related 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (CAS) and ACC oxidase (CAO) were isolated from carnation flowers that were introduced into tobacco by Agrobacterium-mediated transformation. Several transgenic lines showed higher PA contents than wild-type plants. The number and weight of seeds also increased. Stress-induced senescence was attenuated in these transgenic plants in terms of total chlorophyll loss and phenotypic changes after oxidative stress with hydrogen peroxide (H2O2), high salinity, acid stress (pH 3.0), and ABA treatment. These results suggest that the transgenic plants with antisense CAS and CAO cDNAs are more tolerant to abiotic stresses than wild-type plants. This shows a positive correlation between PA content and stress tolerance in plants.

Reduction of sludge by ozone treatment and production of carbon source for denitrification

The feasibility of ozone treatment of municipal sludge for sludge reduction and carbon source production has been investigated. Significant accumulation of solubilized organics and unsettlable micro-solids (UMS) was observed at relatively low ozone dosages while mineralization became dominant at higher dosages. Batch denitrification experiments showed that the solubilized organics and the UMS could be utilized as carbon sources for nitrogen removal. In terms of overall sludge reduction, 54% reduction of the total sludge mass could be achieved by ozone treatment at 0.2 g-O3/g-MLSS.

Ozonation of wastewater sludge for reduction and recycling

An ozone treatment system was introduced as an alternative method for municipal sludge treatment and disposal. A pilot-scale facility was built to investigate the feasibility of the ozonation for sludge reduction and recycle. The system consists of three main parts; advanced wastewater treatment, sludge ozone treatment and belt press dewatering. Ozonation of wastewater sludge resulted in mass reduction by mineralization as well as volume reduction by improvement of dewatering characteristics. The supernatant of the ozonated sludge, consisting of solubilized organics and micro-particles, proved to be an effective carbon source for denitrification. A simple economic assessment reveals that the ozonation process can be more economical than incineration for sludge treatment and disposal at small- and medium-sized wastewater treatment plants.

Multidrug-resistant Salmonella typhimurium and Salmonella enteritidis identified by multiplex PCR from animals

Antibiotic resistance in Salmonella enteritidis and S. typhimurium, one of most frequent etiologic pathogens of food-borne bacterial gastroenteritidis in humans, is a serious health problem worldwide. Fifteen and 22 each of S. enteritidis and S. typhimurium were isolated from animals from 1983 to 1999 in Korea and tested for their antibiotic resistance patterns and phage types. S. enteritides isolates were highly resistant to sulfonamides (86.7%) and four of them (26.6%) showed multiple antibiotic resistance. The most frequent phage type (PT) of S. enteritids was PT1 (33.3%) even though none of them had multiple antibiotic resistance. S. typhimurium isolates were highly resistant to streptomycin, sulfonamides, and tetracycline, 100%, 95.5%, and 86.4% respectively. The incidence of multiple antibiotic resistance of S. typhimurium isolates was extremely high (100%) comparing to S. enteritidis isolates (26.7%). Two of the five ACSSuT type S. typhimurium isolates, resistant to ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline, were phage type DT104. All S. typhimurium isolates were sensitive to florfenicol. For the rapid detection of multiple antibiotic resistant S. enteritidis and S. typhimurium isolates, particularly ACSSuT type S. typhimurium DT104, antibiotic resistance genes, cmlA/tetR, PSE-1, and TEM, and Salmonella spp. Specific gene, SipB/C, were amplified using four pairs of primers in hot-started multiplex polymerase chain reaction. Two Korean isolates of S. typhimurium DT104 showed TEM amplicons instead of PSE-1 for the ampicillin resistance. The multiplex PCR used in this study was useful in rapid detection of ACSSuT type S. typhimurium and identification of b-lactamase gene distribution among Salmonella isolates.

Anti-lipid peroxidative principles from the stem bark of Kalopanax pictus Nakai

Hepatic lipid peroxide contents were examined in bromobenzene-treated rats firstly after the oral administration of MeOH extract of Kalopanax pictus stem barks, its n-BuOH fraction, EtOAc fraction and an alkaline hydrolysate of the n-BuOH fraction, and secondly after the intraperitoneal administration of hederagenin monodesmosides and bisdesmosides. Two hederagenin monodesmosides, kalopanaxsaponin A (KPS-A) and sapindoside C, exhibited significant anti-lipid peroxidation effects after intraperitoneal administration at doses of 10-30 micromole/kg, whereas their bisdesmosides did not exhibit any significant activity. These results suggest that it is the hederagenin monodesmosides that are responsible for anti-lipid peroxidation in vivo. The activity of KPS-A was established by the observation of decreased aminopyrine N-demethylase activity and increased epoxide hydrolase activity.

Correlation between 99mTc-pertechnetate uptakes and expressions of human sodium iodide symporter gene in breast tumor tissues

We investigated a correlation between the expression of human sodium iodide symporter (hNIS) mRNA and the uptake of 99mTc-pertechnetate in 25 breast tumors. 99mTc-pertechnetate scintigraphy revealed positive uptake in 4 patients. The normalized mRNA expression of hNIS was higher in tumors with positive uptake on the scintigraphy (n=4, median 0.97, range 0.78-1.27) than that in negative uptake tumors (n=21, median 0.46, range 0.10-1.03, p < 0.005). 99mTc-pertechnetate uptake is correlated with the hNIS expression in the breast tumor.

Application of nucleotide sequence of RNA polymerase beta-subunit gene (rpoB) to molecular differentiation of serovars of Salmonella enterica subsp. enterica

To establish a molecular differentiation method for Salmonella enterica subsp. enterica, a hyper-variable region of RNA polymerase beta-subunit (rpoB) of S. enterica subsp. enterica (I), serotype Typhimurium, and Escherichia coli were investigated through comparison of nucleotide sequence of the region. The hyper-variable region was identified at 612-937 of the gene. After PCR amplification of the region in the 17 serotypes and two biotypes of serotype Gallinarum of S. enterica subsp. enterica (I), the nucleotide sequences of the region were determined and compared. All serotypes were distantly related to E. coli with 82.8-84.7% identities in nucleotide sequence while showing 96.6-100% identities with each other. According to the phylogenetic analysis based on the sequenced region with the neighbor-joining method, relatedness of biotype Gallinarum to serotype Enteritidis and biotype Pullorum was determined. Biotype Gallinarum was more closely related to serotype Enteritidis than biotype Pullorum. These results suggested that the 612-937 variable region of rpoB might be useful for molecular evolutionary analysis of serotypes of S. enterica subsp. enterica (I).