Corynebacterium glutamicum is one of the well-studied industrial strain that is used for the production of nucleotides and amino acids. Recently, it has also been studied as a possible producer of ...organic acids such as succinic acid, based on its ability to produce organic acids under an oxygen deprivation condition. In this study, we conducted the optimization of medium components for improved succinate production from C. glutamicum under an oxygen deprivation condition by Plackett-Burman design and applied a response surface methodology. A Plackett-Burman design for ten factors such as glucose, ammonium sulfate, magnesium sulfate, potassium phosphate (K2HPO4 and KH2PO4), iron sulfate, manganese sulfate, biotin, thiamine, and sodium bicarbonate was applied to evaluate the effects on succinate production. Glucose, ammonium sulfate, magnesium sulfate, and dipotassium phosphate were found to have significant influence on succinate production, and the optimal concentrations of these four factors were sequentially investigated by the response surface methodology using a Box-Behnken design. The optimal medium components obtained for achieving maximum concentration of succinic acid were as follows: glucose 10 g/l, magnesium sulfate 0.5 g/l, dipotassium phosphate (K2HPO4) 0.75 g/l, potassium dihydrogen phosphate (KH2PO4) 0.5 g/l, iron sulfate 6 mg/l, manganese sulfate 4.2 mg/l, biotin 0.2 mg/l, thiamine 0.2 mg/l, and sodium bicarbonate 100 mM. The parameters that differed from a normal BT medium were glucose changed from 40 g/l to 10 g/l, dipotassium phosphate (K2HPO4) 0.5 g/l changed to 0.75 g/l, and ammonium sulfate ((NH4)2SO4) 7 g/l changed to 0 g/l. Under these conditions, the final succinic acid concentration was 16.3 mM, which is about 1.46 fold higher than the original medium (11.1 mM) at 24 h. This work showed the improvement of succinate production by a simple change of media components deduced from sequential optimization.
Bacillus thuringiensis, an entomopathogenic bacterium belonging to the B. cereus group harbors numerous extra-chromosomal DNA molecules whose sizes range from 2 to 250 kb. In this study, we used a ...plasmid capture system (PCS) to clone three small plasmids from R thuringiensis subsp. kurstaki K1 which were not found in B. thuringiensis subsp. kurstaki HD-1, and determined the complete nucleotide sequence of plasmid pK1S-1 (5.5 kb). Of the six putative open reading frames (ORF2-ORF7) in pK1S-1, ORF2 (MobK1) showed approximately 90% aa identity with the Mob-proteins of pGI2 and pTX14-2, which are rolling circle replicating group Ⅶ (RCR group Ⅶ) plasmids from B. thuringiensis. In addition, a putative origin of transfer (oriT) showed 95.8% identity with those of pGI2 and pTX14-2. ORF3 (RepK1) showed relatively low aa identity (17.8 similar to 25.2%) with the Rep protein coded by RCR plasmids, however. The putative double-strand origin of replication (dso) and single-strand origin of replication (sso) of pK1S-1 exhibited approximately 70% and 64% identities with those of pGI2 and pTX14-2. ORF6 and 7 showed greater than 50% similarities with alkaline serine protease, which belongs to the subtilase family. The other 2 ORFs were identified as hypothetical proteins. To determine the replicon of pK1S-1, seven subclones were contructed in the B. thuringiensis ori-negative pHT1K vector and were electroporated into a plasmid cured B. thuringiensis strain. The 1.6 kb region that included the putative ORF3 (Rep1K), dso and ORF4, exhibited replication ability. These findings identified pK1S-1 as a new RCR group Ⅶ plasmid, and determined its replication region.
Characterization of Imcrop, a Mutator-like MITE family in the rice genome Mo, Y.J., Seoul National University, Seoul, Republic of Korea; Kim, K.Y., National Institute of Crop Science, RDA, Iksan, Republic of Korea; Shin, W.C., National Institute of Crop Science, RDA, Iksan, Republic of Korea ...
Genes & genomics,
04/2012, Letnik:
34, Številka:
2
Journal Article
Recenzirano
Sequence comparisons of ammonium transporter 1-2 genes (OsAMT1-2) in different rice accessions revealed a MITE insertion in the upstream region of the gene. The 391-bp MITE, classified as a Mutator ...superfamily member and named Imcrop, included terminal inverted repeat (TIR) and 9-bp target site duplication (TSD) sequences. We identified 151 Imcrop elements dispersed on 12 chromosomes of the japonica reference genome. Of these, 12.6% were found in genic regions and 33.1% were located within 1.5 kb of annotated rice genes. We constructed comparative insertion maps with 111 and 102 intact Imcrop elements in the japonica and indica reference genomes, respectively. The Imcrop elements showed relatively even distribution across all chromosomes although their frequency was higher on chromosomes 1, 3, and 4 in both genomes. Seventy seven Imcrop elements were detected in both subspecies, whereas 34 and 25 insertions were found only in the japonica or indica genome, respectively. We compared insertion polymorphisms of 19 Imcrop elements found inside genes in 48 Korean rice cultivars, consisting of 42 japonica and six Tongil-types (indica-japonica cross). Thirteen insertions were common to all cultivars indicating these elements were present before indica-japonica divergence. The six other elements showed insertion polymorphisms among accessions, showing their recent insertion history or no critical positive effect of their insertion on the rice genome.
In a 30-1 bioreactor culture, whole differentiation occurred from 48 h, and then proceeded rapidly. As swollen hyphal fragments and arthrospores increased, cephalosporin C (CPC) production increased ...exponentially to 1.85 g/l-¹ at 72 h. To explain the morphological changes of Cephalosporilum acremonium M25 more quantitatively, specific differentiation rates and fractal analysis were employed. Specific differentiation rates of morphological factors varied greatly during the period of culture time from 48 h to 72 h, when CPC production increased significantly.
Transgenic tobacco (Nicotiana tabacum L. var. SR1) plants that over-express the Escherichia coli trehalose-6-phosphate synthase (TPS) gene (otsA) synthesized small amounts of trehalose (less than400 ...㎍ g-¹ leaf) while non-transformants produced no detectable trehalose. Some transgenic plants expressing a high level of otsA exhibited stunted growth and morphologically altered leaves. We tested F₂ homozygous plants devoid of phenotypic changes to determine their physiological responses to dehydration and salinity stresses. All transgenic plants maintained better leaf turgidity under a limited water supply or after treatment with polyethylene glycol (PEG).
Poly-γ-glutamic acid (PGA) is an unusual anionic polypeptide and has great potential as an environmentally and industrially significant biodegradable material. A new γ-PGA producer, Bacillus ...mesentericus MJM1, with high production capacity was isolated from Korean domestic Chungkuckjang bean paste. It produced γ-PGA at the level of 10 g/l in suitable media. The viscosities of 5% initially extracted mucin and purified γ-PGA solutions were 660 cps and 600 cps, respectively. The produced γ-PGA polymer consisted of 2,000 glutamic acid residues with even proportion of L and D types with molecular mass of about 200-300 kDa.
It is well established that zinc plays an important role in bone metabolism and mineralization. The role of zinc in bone formation is well documented in animal models, but not much reported in cell ...models. In the present study, we evaluated zinc deficiency effects on osteoblastic cell proliferation, alkaline phosphatase activity and expression, and extracellular matrix bone nodule formation and bone-related gene expression in osteoblastic MC3T3-E1 cells. To deplete cellular zinc, chelexed-FBS and interpermeable zinc chelator TPEN were used. MC3T3-E1 cells were cultured in zinc concentration-dependent (0-15 μM ZnCl₂) and time-dependent (0-20 days) manners.
The effect of reactive oxygen species (ROS) on the formation of N∨ε-(carboxymethly)lysine (CML). one of the endproducts in the Maillard reaction of protein (or glycation), was investigated. Glyoxal, ...a main precursor of CML formation, was produced from both glucose and fructose during their autoxidation. The transition metal ion showed to involve in the formation of glyoxal by the metal catalyzed oxidation, suggesting that ROS accelerated the reducing sugar autoxidation. The stimulative effect of ROS on the autoxidation was more prominent in glucose than in fructose.
Physicochemical Properties and Antioxidant Activity of Korean Cactus (Opuntia humifusa) Cladodes Jun, H.I., Chonbuk National University, Jeonju, Republic of Korea; Cha, M.N., CJ Cheiljedang Foods R and D Center, Seoul, Republic of Korea; Yang, E.I., Chonbuk National University, Jeonju, Republic of Korea ...
Journal of the Korean Society for Horticultural Science,
20/Jun , Letnik:
54, Številka:
3
Journal Article
Physicochemical properties and antioxidant activity of Korean native cactus (Opuntia humifusa) cladodes (KCC) were investigated to evaluate the possibility for its application in new health ...functional foods. The KCC showed a high amount of crude ash (201.2 g·kg -1 DW), characterizing Ca (1,967.8 mg·100 g -1 DW), Mg (1,411.2 mg·100 g -1 DW), K (1,269.6 mg·100 g -1 DW), and P (1,110 mg·100 g -1 DW) as the major minerals, as well as a high total dietary fiber (503.3 g·kg -1 DW) including soluble dietary fiber (233.2 g·kg -1 DW). The water holding capacity (WHC), oil holding capacity (OHC), and swelling power of KCC were 20.6 g·g -1 , 2.6 g·g -1 , and 16.8 mL·g -1 , respectively. The viscosity of a 100 g·L -1 KCC suspension showed a non-Newtonian flow behavior with shear thixotropy and time dependency. The ethyl acetate fraction from an 80% ethanol extract of KCC showed the highest antioxidant activity as well as the highest total phenolic (112.8 g·kg -1 fraction) and flavonoid (89.7 g·kg -1 fraction) contents compared to other fractions. The most abundant phenolic compound within the ethyl acetate fraction was taxifolin (13.97 g·kg -1 fraction). The results suggest that KCC could be used as potential sources of Ca and dietary fiber as well as a natural antioxidant. It might be possible to manufacture functional food products using the unique physical properties of KCC.
The Fingerprinting of Huangjinju Powder for Injection on Chinese Patent Medicine by XRD Fourier Pan, Y.L. (Beijing University of Chinese Medicine, Beijing, P. R. of China.); Zhang, G.J. (Beijing University of Chinese Medicine, Beijing, P. R. of China.), E-mail: guijunzhang@163.com; Gong, N.B. (Institute of Materia Medica of Chinese Academy of Medical Sciences, Beijing, P. R. of China) ...
Hanʼguk Yakyong Changmul Hakhoe chi,
(Apr 2006), Letnik:
14, Številka:
2
Journal Article
Recenzirano
The purpose is to study the identification method of Huangjinju powder for injection and the medicinal materials by the fingerprint of X-ray Diffraction Fourier (XRDF). We used the same method on ...both the studying of Huangjinju and the medicinal materials. Then we selected a few components alignment to compare. We analyzed the data by setting up the deviation d(A) as ±0.05 to calculate the rate of special mark on the sample (Px) and on the patent (P).
