• Microbiology and Biotechnology Letters
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• v.37 no.1
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• pp.55-61
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• 2009

Ginseng saponins (a secondary metabolite, termed ginsenosides) are the principal bioactive ingredients of ginseng, and modification of the sugar chains may markedly change the its biological activity. One of soil bacteria having $\beta$-glucosidase (to transform ginsenoside $Rb_1$) activity was isolated from soil of a ginseng field in Daejeon. 16S rRNA gene sequence analysis revealed that the isolate belonged to the genus Cellulosimicrobium, with highest sequence similarity (99.7%) to Cellulosimicrobium funkei ATCC BAA-$886^T$. The strain, Gsoil 235, could transform ginsenoside $Rb_1$ into Rd, $Rg_3$ and 3 of un-known ginsenosides by the analyses of TLC, HPLC. By investigating its deglycosylation progress, the optimal broth for, $\beta$-glucosidase was nutrient broth (In 48 hours, almost ginsenoside $Rb_1$ could be transformed into minor ginsenosides). On the contrary, the optimal broth for growth was determined as trypic soy broth (TSB).

• Journal of Life Science
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• v.30 no.6
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• pp.522-531
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• 2020

The aim of this study was to establish the optimal medium composition for enhancing L(+)-lactic acid (LLA) production using response surface methodology (RSM). Lactobacillus paracasei SRCM201474 was selected as the LLA producer by productivity analysis from nine candidates isolated from kimchi and identified by 16S rRNA gene sequencing. Plackett-Burman design was used to assess the effect of eleven media components on LLA production, including carbon (glucose, sucrose, molasses), nitrogen (yeast extract, peptone, tryptone, beef extract), and mineral (NaCl, K₂HPO₄, MgSO₄, MnSO₄) materials. Glucose, sucrose, molasses, and peptone were subsequently chosen as promising media for further optimization studies, and a hybrid design experiment was used to establish their optimal concentrations as glucose 15.48 g/l, sucrose 16.73 g/l, molasses 39.09 g/l, and peptone 34.91 g/l. The coefficient of determination of the equation derived from RSM regression for LLA production was mathematically reliable at 0.9969. At optimum parameters, 33.38 g/l of maximum LLA increased by 193% when compared with MRS broth as unoptimized medium (17.66 g/l). Our statistical model was confirmed by subsequent validation experiments. Increasing the performance of LLA-producing microorganisms and establishing an effective LLA fermentation process can be of particular benefit for bioplastic technologies and industrial applications.

• Journal of Life Science
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• v.23 no.2
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• pp.273-281
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• 2013

The purpose of this research was to investigate the production and characterization of alkaline protease from Micrococcus sp. PS-1 newly isolated from seawater. Micrococcus sp. PS-1 was grown in Luria-Bertani (LB) medium. Its optimal temperature and pH for growth were $30^{\circ}C$ and 7.0, respectively. The effect of nitrogen sources was investigated on optimal enzyme production. A high level of alkaline protease production occurred in LB broth containing 2% skimmed milk. The protease was purified in a 3-step procedure involving ultrafiltration, acetone precipitation, and dialysis. The procedure yielded a 16.43-purification fold, with a yield of 54.25%. SDS-PAGE showed that the enzyme had molecular weights of 35.0 and 37.5 kDa. Its maximum protease activity was exhibited at pH 9.0 and $37^{\circ}C$, and its activity was stable at pH 8.0-11.0 and $25-37^{\circ}C$. The protease activity was strongly inhibited by PMSF, EDTA, and EGTA. Taken together, the results demonstrate that the protease enzyme from Micrococcus sp. PS-1 probably belongs to a subclass of alkaline metallo-serine proteases.

• Journal of Life Science
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• v.31 no.8
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• pp.761-770
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• 2021

In this study, the optimal medium composition for enhancing protease production was established by the Bacillus strain isolated from Makgeolli, a traditional fermented food, using the response surface methodology. B. amyloliquefaciens SRCM115785 was selected as the protease producer by productivity analysis and identified by 16S rRNA gene sequencing. Plackett-Burman design (PBD) was introduced to analyze the effect of each component on protease production among the 11 selected medium components. As a result, glucose, yeast extract, and beef extract were finally selected as factors for enhancing protease production. Central composite design (CCD) analysis was designed as a method to determine the optimal concentration of each component for protease production and the concentration of each medium composition for maximum protease production was predicted to glucose 6.75 g/l, yeast extract 12.42 g/l and beef extract 17.48 g/l. The suitability of the experimental model was proved using ANOVA analysis and as a result of quantitative analysis to prove this, the amount of increase was 230.47% compared to the LB medium used as a control. Through this study, the optimization of medium composition for enhancing protease production was established, and based on this, it is expected that it can be efficient use of protease as an industrial enzyme.

• Journal of Applied Biological Chemistry
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• v.60 no.1
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• pp.79-86
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• 2017

Microbes in forest are very important due to not only to enhance soil fertility but also maintain a healthy ecosystem by supplying the energy available to living organisms by producing various kinds of enzymes related to degradation of lignocellulosic biomass. In order to isolate a lignocellulosic biomass degrading bacterial strain from the Jurassic park located in Gyeongnam National University of Science and Technology, We used the Luria-Bertani-Carboxymethyl cellulose (CMC) agar trypan blue method containing 0.4 % carboxymethyl cellulose and 0.01 % trypan blue. As a result, we isolated a bacterial strain showing both activity on the CMC and xylan. To identify the isolated strain, 16S rRNA sequencing and API kit analysis were used. The isolated strain turned out to belong to Bacillus species and then named Bacillus sp. GJY. In the CMC zymogram analysis, it showed that one active band of about 28kDa in size is present. Xylan zymogram analysis also showed to have one active band of about 25kDa in size. The optimal growth temperature of Bacillus sp. GJY was $37^{\circ}C$. The maximal activities of CMCase and xylanase were 12 hour after incubation. The optimal pH and temperature for CMCase were 5.0 and $40^{\circ}C$, respectively, whereas the optimal pH and temperature for xylanase was 4.0 and $40^{\circ}C$. Both activities for CMCase and xylanase showed to be thermally stable at 40and $50^{\circ}C$, while both activities rapidly decreased at over $60^{\circ}C$.

• Journal of Life Science
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• v.32 no.11
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• pp.872-881
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• 2022

In this study, we optimized the composition of the indole-3-acetic acid (IAA) production medium using response surface methodology on Pantoea agglomerans SRCM 119864 isolated from soil. IAA-producing P. aglomerans SRCM 119864 was identified by 16S rRNA gene sequencing. There are 11 intermediate components known to affect IAA production, hence the effect of each component on IAA production was investigated using a Plackett-Burman design (PBD). Based on the PBD, sucrose, tryptone, and sodium chloride were selected as the main factors that enhanced the IAA production at optimal L-tryptophan concentration. The predicted maximum IAA production (64.34 mg/l) was obtained for a concentration of sucrose of 13.38 g/l, of tryptone of 18.34 g/l, of sodium chloride of 9.71 g/l, and of L-tryptophan of 6.25 g/l using a the hybrid design experimental model. In the experiment, the nutrient broth medium supplemented with 0.1% L-tryptophan as the basal medium produced 45.24 mg/l of IAA, whereas the optimized medium produced 65.40 mg/l of IAA, resulting in a 44.56% increase in efficiency. It was confirmed that the IAA production of the designed optimal composition medium was very similar to the predicted IAA production. The statistical significance and suitability of the experimental model were verified through analysis of variance (ANOVA). Therefore, in this study, we determined the optimal growth medium concentration for the maximum production of IAA, which can contribute to sustainable agriculture and increase crop yield.

• Journal of Mushroom
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• v.6 no.1
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• pp.20-26
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• 2008

The stromatal forms of T. fuciformis and the mycelia of Hypoxylon sp. were collected. The DNA sequence in the ITS region of the 5.8S ribosomal genes of isolated strain KG103 was very similar to that of T. fuciformis AF042409 with a homology of over 98% in the EMBL/GenBank database through BLAST searching. A second isolate, No KG201, one of the symbiotic strains for cultivating T. fuciformis also exhibited high homology with Annulohhypoxylon stygium AJ390406. Potato Dextrose Medium exhibited the best mycelial growth of 14 mm/14 days and 85 mm/14 days for T. fuciformis and its symbiotic fungi, respectively. Optimum culture conditions for the micelial growth were pH 5 at $25^{\circ}C$. For the optimization of artificial cultivation of T. fuciformis in bottle with sawdust medium, several conditions such as type of sawdust, supplements, pH, moisture content, and incubation temperature were investigated. T. fuciformis and symbiotic fungi showed fast mycelial growth on corn cob media (77 and 52%) followed by oak tree sawdust and cotton seed meal. The optimal temperature for mycelial growth of T. fuciformis and symbiotic fungi on corn cob media was $25^{\circ}C$ at 55% of moisture content.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7211-7217
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• 2015

Background: The aims of this study were to evaluate the diagnostic and prognostic roles of serum osteopontin (OPN) and single nucleotide polymorphisms (SNPs) in the OPN promoter in patients with hepatitis B-related hepatocellular carcinoma (HCC). Materials and Methods: Four groups were studied, which included 157 patients with HCC, 73 with liver cirrhosis (LC) and 97 with chronic hepatitis (CH), along with 80 healthy subjects. Serum OPN and alpha-fetoprotein (AFP) levels were measured. The SNPs -66 T/G, -156 G/${\Delta}G$ and -433 C/T within the OPN promoter were determined by direct sequencing. Results: Serum OPN levels were significantly higher in patients with HCC than in the other groups. Area under receiver operating characteristics curves in distinguishing HCC from chronic liver disease (CLD; CH and LC) were 0.782 (95% CI; 0.729-0.834) for OPN and 0.888 (95% CI; 0.850-0.927) for AFP. Using the optimal cut-off value (70 ng/mL), OPN had sensitivity and specificity of 72% and 71%, respectively. Serum OPN was superior to AFP in detecting early-stage HCC (68% vs. 46%). A combination of both markers yielded an improved sensitivity for detecting early HCC to 82%. A high OPN level was significantly correlated with advanced BCLC stage and was an independent prognostic factor for HCC. The SNPs -156 and -443 were associated with susceptibility to HCC, but were not related to overall survival. Conclusions: Serum OPN is a useful diagnostic and prognostic marker for HCC. The combined use of serum OPN and AFP improved the diagnosis of early HCC. Genetic variation in the OPN promoter is associated with the risk, but not the prognosis of HCC.

• Journal of Life Science
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• v.26 no.4
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• pp.453-459
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• 2016

Agarases are classified into α-agarase and β-agarase that produce agarooligosaccharides and neoagarooligosaccharides, respectively. Neoagarooligosaccharides have whitening effect of skin, delay of starch degradation, and inhibition of bacterial growth etc. Hence, the object of this study was to isolate a novel agarase producing marine bacterium and characterization of its β-agarase. A novel agar-degrading bacterium was isolated from seashore of Namhae at Gyeongnamprovine, Korea and purely cultured with Marine agar 2216 media. The isolated bacterium was identified as Simiduia sp. SH-4 after 16S rRNA gene sequencing. The enzymatic sample was obtained from culture media of Simiduia sp. SH-4. Enzymatic activity was highly increased from 20(30% relative activity) to 30℃ (100%) and decreased from 30 to 40℃(75%) and so more. Relative activity was 100% at pH 6 while those were about 91% and 59% at pH 5.0 and 7.0, respectively, meaning the enzyme possesses narrow optimal pH range. Hence, the enzyme exhibited the maximal activity with 120.4 units/l at pH 6.0 and 30℃ in 20 mM Tris-HCl buffer. Thin layer chromatography (TLC) analysis showed that Simiduia sp. SH-4 produces β-agarase, which hydrolyze agarose to produce biofunctional neoagarooligosaccharides such as neoagarotetraose and neoagarobiose. Hence, broad applications would be possible using Simiduia sp. SH-4 and its enzyme in the food industry, cosmetics and medical fields.

• Journal of Life Science
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• v.30 no.3
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• pp.304-312
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• 2020

Agarase can be used in the field of basic science, as well as for production of agar-derived high-functional oligosaccharides and bioenergy production using algae. In 2012, we summarized the classification, origin, production, and applications of agar. In this paper, we briefly review the literature on the recombinant expression of agarases from 2012 to the present. Agarase genes originated from 19 genera, including Agarivorans, Flammeovirga, Pseudoalteromonas, Gayadomonas, Catenovulum, Microbulbifer, Cellulophaga, Saccharophagus, Simiduia, and Vibrio. Of the 47 recombinant agarases, there were only two α-agarases, while the rest were β-agarases. All α-agarases produced agarotetraose, while β-agarases yielded many neoagarooligosaccharides ranging from neoagarobiose to neoagarododecaose. The optimum temperature ranged between 25 and 60℃, and the optimum pH ranged from 3.0 to 8.5. There were 14 agarases with an optimum temperature of 50℃ or higher, where agar is in sol state after melting. Artificial mutations, including manipulation of carbohydrate-binding modules (CBM), increased thermostability and simultaneously raised the optimum temperature and activity. Many hosts and secretion signals or riboswitches have been used for recombinant expression. In addition to gene recombination based on the amino acid sequence after agarase purification, recombinant expression of the putative agarase genes after genome sequencing and metagenome-derived agarases have been studied. This study is expected to be actively used in the application fields of agarase and agarase itself.