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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Microbiology and Biotechnology
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Journal DOI :
The Korean Society for Applied Microbiology and Biotechnology
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Volume & Issues
Volume 23, Issue 12 - Dec 2013
Volume 23, Issue 11 - Nov 2013
Volume 23, Issue 10 - Oct 2013
Volume 23, Issue 9 - Sep 2013
Volume 23, Issue 8 - Aug 2013
Volume 23, Issue 7 - Jul 2013
Volume 23, Issue 6 - Jun 2013
Volume 23, Issue 5 - May 2013
Volume 23, Issue 4 - Apr 2013
Volume 23, Issue 3 - Mar 2013
Volume 23, Issue 2 - Feb 2013
Volume 23, Issue 1 - Jan 2013
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Pichia pastoris: A Recombinant Microfactory for Antibodies and Human Membrane Proteins
Goncalves, A.M. ; Pedro, A.Q. ; Maia, C. ; Sousa, F. ; Queiroz, J.A. ; Passarinha, L.A. ;
Journal of Microbiology and Biotechnology, volume 23, issue 5, 2013, Pages 587~601
DOI : 10.4014/jmb.1210.10063
During the last few decades, it has become evident that the compatibility of the yeast biochemical environment with the ability to process and translate the RNA transcript, along with its capacity to modify a translated protein, are relevant requirements for selecting this host cell for protein expression in several pharmaceutical and clinical applications. In particular, Pichia pastoris is used as an industrial host for recombinant protein and metabolite production, showing a powerful capacity to meet required biomolecular target production levels in high-throughput assays for functional genomics and drug screening. In addition, there is a great advantage to using P. pastoris for protein secretion, even at high molecular weights, since the recovery and purification steps are simplified owing to relatively low levels of endogenous proteins in the extracellular medium. Clearly, no single microexpression system can provide all of the desired properties for human protein production. Moreover, chemical and physical bioprocess parameters, including culture medium formulation, temperature, pH, agitation, aeration rates, induction, and feeding strategies, can highly influence product yield and quality. In order to benefit from the currently available wide range of biosynthesis strategies using P. pastoris, this mini review focuses on the developments and technological fermentation achievements, providing both a comparative and an overall integration analysis. The main aim is to highlight the relevance and versatility of the P. pastoris biosystem to the design of more cost-effective microfactories to meet the increasing demands for recombinant membrane proteins and clinical antibodies for several therapeutic applications.
Biogeographical Distribution and Diversity of Bacterial Communities in Surface Sediments of the South China Sea
Li, Tao ; Wang, Peng ;
Journal of Microbiology and Biotechnology, volume 23, issue 5, 2013, Pages 602~613
DOI : 10.4014/jmb.1209.09040
This paper aims at an investigation of the features of bacterial communities in surface sediments of the South China Sea (SCS). In particular, biogeographical distribution patterns and the phylogenetic diversity of bacteria found in sediments collected from a coral reef platform, a continental slope, and a deep-sea basin were determined. Bacterial diversity was measured by an observation of 16S rRNA genes, and 18 phylogenetic groups were identified in the bacterial clone library. Planctomycetes, Deltaproteobacteria, candidate division OP11, and Alphaproteobacteria made up the majority of the bacteria in the samples, with their mean bacterial clones being 16%, 15%, 12%, and 9%, respectively. By comparison, the bacterial communities found in the SCS surface sediments were significantly different from other previously observed deep-sea bacterial communities. This research also emphasizes the fact that geographical factors have an impact on the biogeographical distribution patterns of bacterial communities. For instance, canonical correspondence analyses illustrated that the percentage of sand weight and water depth are important factors affecting the bacterial community composition. Therefore, this study highlights the importance of adequately determining the relationship between geographical factors and the distribution of bacteria in the world's seas and oceans.
Monitoring the Ecology of Bacillus During Daqu Incubation, a Fermentation Starter, Using Culture-Dependent and Culture-Independent Methods
Yan, Zheng ; Zheng, Xiao-Wei ; Han, Bei-Zhong ; Han, Jian-Shu ; Nout, M.J. Robert ; Chen, Jing-Yu ;
Journal of Microbiology and Biotechnology, volume 23, issue 5, 2013, Pages 614~622
DOI : 10.4014/jmb.1211.11065
Daqu, a traditional fermentation starter, has been used to produce attractively flavored foods such as vinegar and Chinese liquor for thousands of years. Although Bacillus spp. are one of the dominant microorganisms in Daqu, more precise information is needed to reveal why and how Bacillus became dominant in Daqu, and next, to assess the impact of Bacillus sp. on Daqu and its derived products. We combined culture-dependent and culture-independent methods to study the ecology of Bacillus during Daqu incubation. Throughout the incubation, 67 presumptive Bacillus spp. isolates were obtained, 52 of which were confirmed by 16S rDNA sequencing. The identified organisms belonged to 8 Bacillus species: B. licheniformis, B. subtilis, B. amyloliquefaciens, B. cereus, B. circulans, B. megaterium, B. pumilus, and B. anthracis. A primer set specific for Bacillus and related genera was used in a selective PCR study, followed by a nested DGGE PCR targeting the V9 region of the 16S rDNA. Species identified from the PCR-DGGE fingerprints were related to B. licheniformis, B. subtilis, B. amyloliquefaciens, B. pumilus, B. benzoevorans, and B. foraminis. The predominant species was found to be B. licheniformis. Certain B. licheniformis strains exhibited potent antimicrobial activities. The greatest species diversity occurred at the Liangmei stage of Daqu incubation. To date, we lack sufficient knowledge of Bacillus distribution in Daqu. Elucidating the ecology of Bacillus during Daqu incubation would enable the impact of Bacillus on Daqu to be accessed, and the quality and stabilization of Daqu-derived products to be optimized.
Characterization of Gibberellin Biosynthetic Gene Cluster from Fusarium proliferatum
Rim, Soon-Ok ; You, Young-Hyun ; Yoon, Hyeokjun ; Kim, Ye-Eun ; Lee, Jin-Hyung ; Kang, Myung Suk ; Kim, Changmu ; Seu, Young-Bae ; Kim, Jong-Guk ;
Journal of Microbiology and Biotechnology, volume 23, issue 5, 2013, Pages 623~629
DOI : 10.4014/jmb.1212.12029
Gibberellins (GAs) are a group of phytohormones that control many developmental processes in higher plants. We report the cloning and expression pattern of gibberellin biosynthesis genes from a new GA-producing fungus, Fusarium proliferatum (strain KGL0401). These genes sequences are deposited in the National Center for Biotechnology Information (NCBI) under accession numbers EF119831, EF119832, DQ313173, DQ313174, DQ313175, DQ313176, and DQ313177. The expression level of these genes was maximal at a 0.5 M : 0.17 M carbon : nitrogen ratio, and minimal at a 0.25 M : 0.47 M carbon : nitrogen ratio.
Development of a New Duplex Real-Time Polymerase Chain Reaction Assay for Detection of Dicer in G. gallus
Ji, Xiaolin ; Wang, Qi ; Gao, Yulong ; Wang, Yongqiang ; Qin, Liting ; Qi, Xiaole ; Gao, Honglei ; Wang, Xiaomei ;
Journal of Microbiology and Biotechnology, volume 23, issue 5, 2013, Pages 630~636
DOI : 10.4014/jmb.1211.11083
Recently, there has been a growing body of evidence showing that cellular microRNAs (miRNAs) are involved in virus-host interactions. Numerous studies have focused on analyses of the expression profiles of cellular miRNAs, but the expression patterns of Dicer, which is responsible for the generation of miRNAs, have only rarely been explored in Gallus gallus. We developed a duplex real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay for the relative quantification of the mRNAs of Dicer and
-actin in G. gallus. To apply this method, the expression of Dicer in avian cells after infection with avian leukosis virus subgroup J (ALV-J) was detected using our established duplex real-time RT-PCR. The duplex real-time RT-PCR assay is sufficiently sensitive, specific, accurate, reproducible, and cost-effective for the detection of Dicer in G. gallus. Furthermore, this study, for the first time, demonstrated that ALV-J can induce differential expression of Dicer mRNA in the ALV-J-infected cells.
1-Deoxynojirimycin Isolated from a Bacillus subtilis Stimulates Adiponectin and GLUT4 Expressions in 3T3-L1 Adipocytes
Lee, Seung-Min ; Do, Hyun Ju ; Shin, Min-Jeong ; Seong, Su-Il ; Hwang, Kyo Yeol ; Lee, Jae Yeon ; Kwon, Ohsuk ; Jin, Taewon ; Chung, Ji Hyung ;
Journal of Microbiology and Biotechnology, volume 23, issue 5, 2013, Pages 637~643
DOI : 10.4014/jmb.1209.09043
We have demonstrated that 1-deoxynojirimycin (DNJ) isolated from Bacillus subtilis MORI could enhance the levels of adiponectin and its receptors in differentiated 3T3-L1 adipocytes, which has been shown to be effective in lowering blood glucose levels and enhancing insulin sensitivity. DNJ was not toxic to differentiated 3T3-L1 adipocytes for up to a concentration of
. In terms of expression levels of adiponectin and its receptors (AdipoR1 and AdipoR2), DNJ in concentrations as low as
elevated both mRNA and protein levels of adiponectin and transcript levels of AdipoR1 and AdipoR2. In addition, DNJ increased phosphorylation of 5' adenosine monophosphate-activated protein kinase (AMPK) in a statistically significant manner. Finally, treatment with DNJ resulted in increased mRNA expression of glucose transporter 4 (GLUT4), which encodes for a glucose transporter, along with a significant increase in glucose uptake into the adipocytes based on results of a 2-deoxy-D-[
] glucose uptake assay. Our findings indicate that DNJ may greatly facilitate glucose uptake into adipose tissues by increasing the action of adiponectin via its up-regulated expression as well as its receptor genes. In addition, the glucose-lowering effects of DNJ may be achieved by an increased abundance of GLUT4 protein in the plasma membrane, as a consequence of the increased transcript levels of the GLUT4 gene and the activation of AMPK.
Microbiological Features and Bioactivity of a Fermented Manure Product (Preparation 500) Used in Biodynamic Agriculture
Giannattasio, Matteo ; Vendramin, Elena ; Fornasier, Flavio ; Alberghini, Sara ; Zanardo, Marina ; Stellin, Fabio ; Concheri, Giuseppe ; Stevanato, Piergiorgio ; Ertani, Andrea ; Nardi, Serenella ; Rizzi, Valeria ; Piffanelli, Pietro ; Spaccini, Riccardo ; Mazzei, Pierluigi ; Piccolo, Alessandro ; Squartini, Andrea ;
Journal of Microbiology and Biotechnology, volume 23, issue 5, 2013, Pages 644~651
DOI : 10.4014/jmb.1212.12004
The fermented manure derivative known as Preparation 500 is traditionally used as a field spray in biodynamic agriculture for maintaining and increasing soil fertility. This work aimed at characterizing the product from a microbiological standpoint and at assaying its bioactive properties. The approach involved molecular taxonomical characterization of the culturable microbial community; ARISA fingerprints of the total bacteria and fungal communities; chemical elemental macronutrient analysis via a combustion analyzer; activity assays for six key enzymes; bioassays for bacterial quorum sensing and chitolipooligosaccharide production; and plant hormone-like activity. The material was found to harbor a bacterial community of
CFU/g dw dominated by Gram-positives with minor instances of Actinobacteria and Gammaproteobacteria. ARISA showed a coherence of bacterial assemblages in different preparation lots of the same year in spite of geographic origin. Enzymatic activities showed elevated values of
-glucosidase, alkaline phosphatase, chitinase, and esterase. The preparation had no quorum sensing-detectable signal, and no rhizobial nod gene-inducing properties, but displayed a strong auxin-like effect on plants. Enzymatic analyses indicated a bioactive potential in the fertility and nutrient cycling contexts. The IAA activity and microbial degradation products qualify for a possible activity as soil biostimulants. Quantitative details and possible modes of action are discussed.
p-Terphenyls from Fungus Paxillus curtisii Chelate Irons: A Proposed Role of p-Terphenyls in Fungus
Lee, In-Kyoung ; Ki, Dae-Won ; Kim, Seong-Eun ; Lee, Myeong-Seok ; Song, Ja-Gyeong ; Yun, Bong-Sik ;
Journal of Microbiology and Biotechnology, volume 23, issue 5, 2013, Pages 652~655
DOI : 10.4014/jmb.1210.10034
Diverse p-terphenyl compounds, named curtisians, have been isolated from the fungus Paxillus curtisii, and degradation of wood by this fungus is thought to be progressed by iron chelation of p-terphenyl curtisians. In this study, the iron chelation ability of p-terphenyls has been proved by chrome azurol S (CAS) assay, reducing power, and UV-visible spectroscopic analyses. The catechol moiety of p-terphenyl is an essential factor for the potent iron chelation ability, and thus deacylated curtisian with a tetrahydroxyl moiety in the central ring of p-terphenyl is more effective than acylated curtisians.
Nutritional Studies on Production of Antibacterial Activity by the Zebra Mussel Antagonist, Pseudomonas fluorescens CL0145A
Polanski-Cordovano, Grace ; Romano, Lea ; Marotta, Lauren L.C. ; Jacob, Serena ; Hoo, Jennifer Soo ; Tartaglia, Elena ; Asokan, Deepa ; Kar, Simkie ; Demain, Arnold L. ;
Journal of Microbiology and Biotechnology, volume 23, issue 5, 2013, Pages 656~660
DOI : 10.4014/jmb.1211.11035
Pseudomonas fluorescens strain CL0145A was discovered at the New York State Museum Field Research Laboratory as an effective agent against the environmentally destructive zebra mussel, which has contaminated US waters. Dried cells of the microbe are being commercialized as an environmentally friendly solution to the problem. We found that antibiotic activity against the Gram-positive bacterium Bacillus subtilis is produced and excreted by this strain. We have carried out studies to optimize production of the antibiotic. Studies were begun in a complex corn meal medium. Activity was found in both cells and culture supernates and was maximal after one day of fermentation. Static fermentation conditions were found to be superior to shaken culture. Production of extracellular antibiotic in complex medium was found to be dependent on the content of sucrose and enzyme-hydrolyzed casein. Indeed, production was greater in sucrose plus enzyme-hydrolyzed casein than in the complex medium. Of a large number of carbon sources studied as improvements over sucrose, the best was glycerol. An examination of nitrogen sources showed that production was improved by replacement of enzyme-hydrolyzed casein with soy hydrolysates. Production in the simple glycerol-Hy-Soy medium was not improved by addition of an inorganic salt mixture or by complex nitrogen sources, with the exception of malt extract. In an attempt to keep the medium more defined, we studied the effect of amino acids and vitamins as replacements for malt extract. Of 21 amino acids and 7 vitamins, we found tryptophan, glutamine, biotin, and riboflavin to be stimulatory. The final medium contained glycerol, Hy-Soy, tryptophan, glutamine, biotin, and riboflavin.
Isolation and Biochemical Characterization of Bacillus pumilus Lipases from the Antarctic
Arifin, Arild Ranlym ; Kim, Soon-Ja ; Yim, Joung Han ; Suwanto, Antonius ; Kim, Hyung Kwoun ;
Journal of Microbiology and Biotechnology, volume 23, issue 5, 2013, Pages 661~667
DOI : 10.4014/jmb.1212.12040
Lipase-producing bacterial strains were isolated from Antarctic soil samples using the tricaprylin agar plate method. Seven strains with relatively strong lipase activities were selected. All of them turned out to be Bacillus pumilus strains by the 16S rRNA gene sequence analysis. Their corresponding lipase genes were cloned, sequenced, and compared. Finally, three different Bacillus pumilus lipases (BPL1, BPL2, and BPL3) were chosen. Their amino acid sequence identities were in the range of 92-98% with the previous Bacillus pumilus lipases. Their optimum temperatures and pHs were measured to be
and pH 9. Lipase BPL1 and lipase BPL2 were stable up to
, whereas lipase BPL3 was stable up to
. Lipase BPL2 was stable within a pH range of 6-10, whereas lipase BPL1 and lipase BPL3 were stable within a pH range of 5-11, showing strong alkaline tolerance. All these lipases exhibited high hydrolytic activity toward p-nitrophenyl caprylate (
). In addition, lipase BPL1 showed high hydrolytic activity toward tributyrin, whereas lipase BPL2 and lipase BPL3 hydrolyzed tricaprylin and castor oil preferentially. These results demonstrated that the three Antarctic Bacillus lipases were alkaliphilic and had a substrate preference toward short- and medium-chain triglycerides. These Antarctic Bacillus lipases might be used in detergent and food industries.
Effect of Gene Amplifications in Porphyrin Pathway on Heme Biosynthesis in a Recombinant Escherichia coli
Lee, Min Ju ; Kim, Hye-Jung ; Lee, Joo-Young ; Kwon, An Sung ; Jun, Soo Youn ; Kang, Sang Hyeon ; Kim, Pil ;
Journal of Microbiology and Biotechnology, volume 23, issue 5, 2013, Pages 668~673
DOI : 10.4014/jmb.1302.02022
A recombinant E. coli co-expressing ALA synthase (hemA), NADP-dependent malic enzyme (maeB), and dicarboxylic acid transporter (dctA) was reported to synthesize porphyrin derivatives including iron-containing heme. To enhance the synthesis of bacterial heme, five genes of the porphyrin biosynthetic pathway [pantothenate kinase (coaA), ALA dehydratase (hemB), 1-hydroxymethylbilane synthase (hemC), uroporphyrinogen III synthase (hemD), and uroporphyrinogen III decarboxylase (hemE)] were amplified in the recombinant E. coli co-expressing hemA-maeB-dctA. Pantothenate kinase expression enabled the recombinant E. coli to accumulate intracellular CoA. Intracellular ALA was the most enhanced by uroporphyrinogen III synthase expression, porphobilinogen was the most enhanced by ALA dehydratase expression, uroporphyrin and coproporphyrin were the most enhanced by 1-hydroxymethylbilane synthase expression. The strain co-expressing coaA, hemA, maeB, and dctA produced heme of
-DCW, which was twice as much from the strain without coaA expression. Further pathway gene amplifications for the porphyrin derivatives are discussed based on the results.
Genetic Transformation of the Yeast Dekkera/Brettanomyces bruxellensis with Non-Homologous DNA
Miklenic, Marina ; Stafa, Anamarija ; Bajic, Ana ; Zunar, Bojan ; Lisnic, Berislav ; Svetec, Ivan-Kresimir ;
Journal of Microbiology and Biotechnology, volume 23, issue 5, 2013, Pages 674~680
DOI : 10.4014/jmb.1211.11047
Yeast Dekkera/Brettanomyces bruxellensis is probably the most common contaminant in wineries and ethanol production processes. The considerable economic losses caused by this yeast, but also its ability to produce and tolerate high ethanol concentrations, make it an attractive subject for research with potential for industrial applications. Unfortunately, efforts to understand the biology of D. bruxellensis and facilitate its broader use in industry are hampered by the lack of adequate procedures for delivery of exogenous DNA into this organism. Here we describe the development of transformation protocols (spheroplast transformation, LiAc/PEG method, and electroporation) and report the first genetic transformation of yeast D. bruxellensis. A linear heterologous DNA fragment carrying the kanMX4 sequence was used for transformation, which allowed transformants to be selected on plates containing geneticin. We found the spheroplast transformation method using 1M sorbitol as osmotic stabilizer to be inappropriate because sorbitol strikingly decreases the plating efficiency of both D. bruxellensis spheroplast and intact cells. However, we managed to modify the LiAc/PEG transformation method and electroporation to accommodate D. bruxellensis transformation, achieving efficiencies of 0.6-16 and 10-20 transformants/
DNA, respectively. The stability of the transformants ranged from 93.6% to 100%. All putative transformants were analyzed by Southern blot using the kanMX4 sequence as a hybridization probe, which confirmed that the transforming DNA fragment had integrated into the genome. The results of the molecular analysis were consistent with the expected illegitimate integration of a heterologous transforming fragment.
Exopolysaccharide Produced by Pediococcus acidilactici M76 Isolated from the Korean Traditional Rice Wine, Makgeolli
Song, Young-Ran ; Jeong, Do-Youn ; Cha, Youn-Soo ; Baik, Sang-Ho ;
Journal of Microbiology and Biotechnology, volume 23, issue 5, 2013, Pages 681~688
DOI : 10.4014/jmb.1301.01032
This work is aimed to increase knowledge of the functional exopolysaccharide (EPS) from lactic acid bacteria (LAB) in makgeolli, a Korean fermented rice wine. Among LAB strains isolated from makgeolli, strain M76 was selected as a functional strain producing a bioactive EPS, based on its antioxidative activity on the DPPH radical. The 16S rRNA gene sequencing analysis showed a high sequence similarity (99.0%) with P. acidilactici, but had different biochemical properties with the already known P. acidilactici type strains in the aspect of carbohydrates utilization. The obtained P. acidilactici M76 produced a soluble EPS above 2 g/l. One-step chromatography using gel filtration after ethanol precipitation from the supernatant of P. acidilactici M76 was enough to obtain purified EPS with a single peak, showing a molecular mass of approximately 67 kDa. Componential and structural analyses of EPS by TLC, HPLC, and FT-IR indicated that the EPS is a glucan, consisting of glucose units. The purified EPS had antioxidant activity on the DPPH radical of 45.8% at a concentration of 1 mg/ml. The purified EPS also showed proliferative effect on the pancreatic RIN-m5F cell line and remarkable protection activity on alloxan-induced cytotoxicity. This potent antioxidant and antidiabetic EPS by LAB in makgeolli may contribute to understanding the functionality of makgeolli.
Effect of Culture Conditions and Signal Peptide on Production of Human Recombinant N-Acetylgalactosamine-6-Sulfate Sulfatase in Escherichia coli BL21
Hernandez, Alejandra ; Velasquez, Olga ; Leonardi, Felice ; Soto, Carlos ; Rodriguez, Alexander ; Lizaraso, Lina ; Mosquera, Angela ; Bohorquez, Jorge ; Coronado, Alejandra ; Espejo, Angela ; Sierra, Rocio ; Sanchez, Oscar F. ; Almeciga-Diaz, Carlos J. ; Barrera, Luis A. ;
Journal of Microbiology and Biotechnology, volume 23, issue 5, 2013, Pages 689~698
DOI : 10.4014/jmb.1211.11044
The production and characterization of an active recombinant N-acetylgalactosamine-6-sulfate sulfatase (GALNS) in Escherichia coli BL21(DE3) has been previously reported. In this study, the effect of the signal peptide (SP), inducer concentration, process scale, and operational mode (batch and semi-continuous) on GALNS production were evaluated. When native SP was presented, higher enzyme activity levels were observed in both soluble and inclusion bodies fractions, and its removal had a significant impact on enzyme activation. At shake scale, the optimal IPTG concentrations were 0.5 and 1.5 mM for the strains with and without SP, respectively, whereas at bench scale, the highest enzyme activities were observed with 1.5 mM IPTG for both strains. Noteworthy, enzyme activity in the culture media was only detected when SP was presented and the culture was carried out under semi-continuous mode. We showed for the first time that the mechanism that in prokaryotes recognizes the SP to mediate sulfatase activation can also recognize a eukaryotic SP, favoring the activation of the enzyme, and could also favor the secretion of the recombinant protein. These results offer significant information for scaling-up the production of human sulfatases in E. coli.
Effect of Mild-Thiol Reducing Agents and
-Sialyltransferase Expression on Secretion and Sialylation of Recombinant EPO in CHO Cells
Chang, Kern Hee ; Jeong, Yeon Tae ; Kwak, Chan Yeong ; Choi, One ; Kim, Jung Hoe ;
Journal of Microbiology and Biotechnology, volume 23, issue 5, 2013, Pages 699~706
DOI : 10.4014/jmb.1303.03046
We have previously reported that N-acetylcysteine (NAC) not only delayed apoptosis but also enhanced the production of recombinant erythropoietin (EPO) in Chinese hamster ovary (CHO) cell culture. To investigate the production enhancement mechanism, the effects of similar thiol-reducing agents were studied. Intriguingly, all mild reducing agents examined including mercaptoethanesulfonic acid (MESNA), thiolactic acid (TLA), and thioglycolate (TG) were shown to block apoptosis and increase EPO production. A pulse-chase study of EPO secretion revealed that all four thiol-reducing agents increased the EPO secretion rate; among them TLA showed the highest rate. In terms of product quality, the sialic acid content of the glycoprotein is one of the most important factors. It was reported that a number of glycoproteins produced by CHO cells often have incomplete sialylation, particularly under high-producing conditions. Human
-ST) was introduced into EPO-producing CHO cells in order to compensate for the reduced sialylation during supplementation with NAC. When
-ST was expressed in the presence of NAC, reduced sialylation was restored and an even more sialylated EPO was produced. Thus, our study is significant in that it offers increased EPO production while still allowing the prevention of decreased sialylation of EPO.
Biomineralization of Calcium Carbonate Polymorphs by the Bacterial Strains Isolated from Calcareous Sites
Dhami, Navdeep Kaur ; Reddy, M. Sudhakara ; Mukherjee, Abhijit ;
Journal of Microbiology and Biotechnology, volume 23, issue 5, 2013, Pages 707~714
DOI : 10.4014/jmb.1212.11087
Microbially induced calcium carbonate precipitation (MICCP) is a naturally occurring biological process that has various applications in remediation and restoration of a range of building materials. In the present investigation, five ureolytic bacterial isolates capable of inducing calcium carbonate precipitation were isolated from calcareous soils on the basis of production of urease, carbonic anhydrase, extrapolymeric substances, and biofilm. Bacterial isolates were identified as Bacillus megaterium, B. cereus, B. thuringiensis, B. subtilis, and Lysinibacillus fusiformis based on 16S rRNA analysis. The calcium carbonate polymorphs produced by various bacterial isolates were analyzed by scanning electron microscopy, confocal laser scanning microscopy, X ray diffraction, and Fourier transmission infra red spectroscopy. A strain-specific precipitation of calcium carbonate forms was observed from different bacterial isolates. Based on the type of polymorph precipitated, the technology of MICCP can be applied for remediation of various building materials.
Biodegradation Capacity Utilization as a New Index for Evaluating Biodegradation Rate of Methane
Kim, Tae Gwan ; Yi, Taewoo ; Yun, Jeonghee ; Ryu, Hee Wook ; Cho, Kyung-Suk ;
Journal of Microbiology and Biotechnology, volume 23, issue 5, 2013, Pages 715~718
DOI : 10.4014/jmb.1211.11018
Density of catalytic organisms can determine the biodegradation capacity and specific biodegradation rate (SBR). A new index, biodegradation capacity utilization (BCU, %), was developed for estimating the extent of actual biodegradation of a gas compound over the full capacity. Three methanotrophic cultures were serially diluted (1-1/25), and methane SBR and BCU were measured. Consistently, biomass reduction increased the SBR and decreased the BCU. Linearity (p < 0.05, r > 0.97) between the BCU and cell density indicated the reflection of biodegradation capacity by BCU. Therefore, BCU is indicative of whether the density of catalytic organisms is pertinent for SBR evaluation of low-soluble gaseous compounds.
Selective Inhibition of Ammonia Oxidation and Nitrite Oxidation Linked to
Emission with Activated Sludge and Enriched Nitrifiers
Ali, Toor Umair ; Kim, Minwook ; Kim, Dong-Jin ;
Journal of Microbiology and Biotechnology, volume 23, issue 5, 2013, Pages 719~723
DOI : 10.4014/jmb.1302.02017
Nitrification in wastewater treatment emits a significant amount of nitrous oxide (
), which is one of the major greenhouse gases. However, the actual mechanism or metabolic pathway is still largely unknown. Selective nitrification inhibitors were used to determine the nitrification steps responsible for
emission with activated sludge and enriched nitrifiers. Allylthiourea (86
) completely inhibited ammonia oxidation and
emission both in activated sludge and enriched nitrifiers. Sodium azide (24
) selectively inhibited nitrite oxidation and it led to more
emission than the control experiment both in activated sludge and enriched nitrifiers. The inhibition tests showed that
emission was mainly related to the activity of ammonia oxidizers in aerobic condition, and the inhibition of ammonia monooxygenase completely blocked
emission. On the other hand,
emission increased significantly as the nitrogen flux from nitrite to nitrate was blocked by the selective inhibition of nitrite oxidation.
Immunomodulatory and Anti-Allergic Effects of Orally Administered Lactobacillus Species in Ovalbumin-Sensitized Mice
Lee, Jeongmin ; Bang, Jieun ; Woo, Hee-Jong ;
Journal of Microbiology and Biotechnology, volume 23, issue 5, 2013, Pages 724~730
DOI : 10.4014/jmb.1211.11079
We investigated the effects of orally administered probiotic bacteria (Lactobacillus species) as allergic immune modulators in ovalbumin (OVA)-sensitized mice. BALB/c mice were intraperitoneally injected with OVA twice at a 2-week interval for allergy sensitization. The mice were then orally administered Lactobacillus casei YIT9029 (L1), L. casei HY7201 (L2), L. brevis HY7401 (L3), or L. plantarum HY20301 (L4) every 2 days for 3 weeks. Total IgE levels significantly decreased in sera of L3-administered mice but increased in the other groups. OVA-specific IgE levels decreased slightly in sera of mice administered L1, L3, and L4 but increased significantly in L2-administered mice. In passive cutaneous anaphylaxis (PCA) using sera from administered mice, only the L3-administered group showed reaction inhibition. High expression of TLR-2 with interferon (IFN)-
stimulation on peripheral blood mononuclear cells occurred in L3- or L4-administered mice. Th1 cytokines, including IFN-
and interleukin (IL)-12, increased in splenocytes of L3-administered mice; however, IL-4 decreased in L1- and L4-administered groups; IL-5 decreased in all experimental groups. IL-6 decreased in the L3-administered group; and IL-10 decreased in L1-, L2-, and L3-administered groups. L3 induced antiallergic effects by increasing Th1 cytokines, decreasing Th2 cytokines, and inhibiting the PCA reaction, whereas L2 administration increased allergic effects.
Repression of Type-1 Fimbriae in Shiga Toxin-Producing Escherichia coli O91:H21 Isolated from Asymptomatic Human Carriers in Korea
Kim, Jung-Beom ; Oh, Kyung-Hwan ; Park, Mi-Sun ; Cho, Seung-Hak ;
Journal of Microbiology and Biotechnology, volume 23, issue 5, 2013, Pages 731~737
DOI : 10.4014/jmb.1211.11080
Seventy-four Shiga toxin-producing Escherichia coli (STEC) isolates belonging to the serotype O91:H21 were isolated from 1,643 asymptomatic human carriers in a STEC outbreak at Gwangju in Korea. Although the isolates did not cause any symptoms, all of them produced Shiga toxins 1 (Stx1) and 2 (Stx2). In order to determine why these strains cause no symptoms, we explored the differences in virulence potential between the asymptomatic STEC O91:H21 isolates and symptomatic STEC O91:H21 strains (ATCC 51435 and ATCC 51434). The asymptomatic STEC O91:H21 isolates showed strongly reduced cytopathic effects compared with the symptomatic strains when intact bacterial cells were used as an inoculant. Moreover, we found a reduced adherence phenotype when testing asymptomatic strains on HeLa cells. Real-time quantitative PCR results suggest that transcriptional repression of the genes encoding type-1 fimbriae occurs in the asymptomatic isolates but not in the symptomatic strains.