• Journal of Microbiology and Biotechnology
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• v.27 no.8
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• pp.1379-1385
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• 2017

The content of taxol in the bark of yews is very low, and this is not affordable from the environmental point of view. Thus, it is a necessity to look for alternative sources of taxol production to solve its supply. Currently, a large portion of the taxol in the market comes from chemical semi-synthesis, but the semi-synthetic precursors such as baccatin III and 10-deacetyl-baccatin III are extracted from needles and twigs of yew trees. Taxol-producing fungi as a renewable resource is a very promising way to increase the scale of taxol production. Our group has obtained a taxol-producing endophytic fungus, Aspergillus niger subsp. taxi HD86-9, to examine if A. niger can produce the taxanes. Six compounds from the fermentation broth of strain HD86-9 were isolated and identified by $^1H$ NMR, $^{13}C$ NMR, and ESI-MS. The results showed that the six compounds included four taxane diterpenoids (taxol, cephalomannine, baccatin III, and 10-deacetyl-baccatin III) and two non-taxane compounds (${\beta}-sitosterol$ and flavonoid isovitexin). The study verified that the taxanes can be produced by the A. niger, which is very important to taxol production via chemical semi-synthesis. Additionally, the finding is potentially very significant to solve the taxol semi-synthetic precursors extracted from needles and twigs of yew trees, and the precursor production can be easily increased through the culture condition optimization, genetic breeding, and metabolic engineering of the A. niger.

• Journal of Microbiology and Biotechnology
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• v.33 no.4
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• pp.543-551
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• 2023

In this study, five endophytic fungi belonging to the Aspergillus and Alternaria genera were isolated from Lagopsis supina. The antimicrobial activity of all fungal fermented extracts against Staphylococcus and Fusarium graminearum was tested using the cup-plate method. Among them, Aspergillus ochraceus XZC-1 showed the best activity and was subsequently selected for large-scale fermentation and bioactivity-directed separation of the secondary metabolites. Four compounds, including 2-methoxy-6-methyl-1,4-benzoquinone (1), 3,5-dihydroxytoluene (2), oleic acid (3), and penicillic acid (4) were discovered. Here, compounds 1 and 4 displayed anti-fungal activity against F. graminearum, F. oxysporum, F. moniliforme, F. stratum, Botrytis cinerea, Magnaporthe oryzae, and Verticillium dahlia with diverse MIC values (128-512 ㎍/ml), which were close to that of the positive control antifungal, actidione (64-128 ㎍/ml). Additionally, compounds 1 and 4 also exhibited moderate antibacterial activity against S. aureus, Listeria monocytogenes, Escherichia coli, and Salmonella enterica, with low MIC values (8-64 ㎍/ml). Moreover, compounds 1 and 4 displayed selective cytotoxicity against cancer cell lines as compared with the normal fibroblast cells. Therefore, this study proposes that the endophytic fungi from L. supina can potentially produce bioactive molecules to be used as lead compounds in drugs or agricultural antibiotics.

• KSBB Journal
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• v.25 no.2
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• pp.155-166
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• 2010

Studies on the production of cell-wall bound innerpolysaccharides (IPS) (soluble ${\beta}$-D-glucan) have been performed by use of suspended myelial cultures of Inonotus obliquus. This product has promising potentials as an effective antidiabetic as well as an immunostimulating agents. As a first step to enhanced production of IPS, Intensive strain improvement programs were carried out by obtaining a large amounts of protoplasts for the isolation of single cell colonies. Rapid and large screening of high-yielding producers was possible because about fivefold higher amount of protoplasts ($2.3{\times}10^6$ protoplasts/mL) could be recovered with relatively high regeneration rates of $10^{-2}{\sim}10^{-3}$ by applying a modified filtration method, as compared to the previously used trapping method. A basic protocol necessary for UV-mutation of the protoplasts was also developed, resulting in several overproducing variants with good fermentation properties. Since the amount of IPS extracted from the mycelial cell walls of I. obliquus turned out to be almost constant per g DCW, increase in cell mass was considered the most important factor for the enhancement in IPS production. Therefore, attempts were made to screen mutant cells showing rapid mycelial growth rate in the final suspended cultures. Notably, the mutant strains showing an active cellgrowth in the preceding solid growth cultures were observed to produce higher amount of IPS in the suspended fermentations as well. A striking mutant, OBLQ756-15-5 strain, obtained from the survivors of a harsh UV-treated condition (97% death rate) was found to stably produce as high cell mass as 22 g DCW/L in the final fermentations. Currently, this strain is being tested for development of a scaled-up fermentation process for mass production of IPS.

• Journal of Dairy Science and Biotechnology
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• v.35 no.1
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• pp.1-7
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• 2017

Made using a natural mixed starter of lactic acid bacteria and yeast, Koumiss is a slightly alcoholic fermented mare's milk beverage, and a traditional drink of the nomadic populations of Central Asia. Cichorium intybus L. (chicory) is a sedative with potential cardioactive properties, and its oligosaccharides are beneficial in maintaining healthy gastrointestinal flora. Hence, in this study, we have generated a functional Koumiss containing two different concentrations of chicory. After fermentation of the Koumiss premix, the TA increased to 0.85~0.88%, and the pH decreased to ~4.3. The addition of either concentration of chicory had no significant effect on pH and TA. However, the taste, flavor, color, texture, and overall acceptability decreased in proportion to the added amount of chicory. This study has provided the first data on Koumiss supplemented with chicory. The results could be useful in developing high-quality Koumiss with functional activity using chicory, and allowing large-scale industrial production. Further studies are needed to determine if chicory root extract is beneficial for lifestyle-related diseases.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.5
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• pp.363-369
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• 1989

In this study, the biochemical characterization of strong proteolytic bacteria and their extracellular pretense isolated from fermented fish paste were experimented for the purpose of industrial large scale-production by accelerated fermentation. The results obtained were as follows: Among 4 strains isolated from fermented fish paste, B. subtilis p-4 and B. licheniformis p-5, which grow well at $40^{\circ}C$, pH 7.0 and $1\%$ of salt contents, were the best proteolytic bacteria and were shown $0.48hr^{-1}$, $0.49hr^{-1}$ of specific growth rate in TPY medium, respectively. Maximum enzyme activity of B. subtilis p-4 was 335n mole-Tyr/min.ml after 30 hrs and that of B. licheniformis p-5 was 300n mole-Tyr/min.ml after 28 hrs of shaking culture. Purified pretense produced by B. subtilis p-4 and B. licheniformis p-5 showed maximum activity at $50^{\circ}C$, pH 7.0 and molecular weight were estimated to be 18,000, 30,000 by sephadex G-100 gel filtration, respectively. These were supposed to be a kind of metal chelator sensitive neutral pretense from the result of high sensitivity against EDTA, o-phe-nanthroline and metal ions such as $Cu^{2+},\;Ni^{2+},\;Zn{2+}$.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.533-536
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• 2019

Recombinant baculoviruses are widely used to express heterologous genes in cultured insect cells. Recombinant baculoviruses can serve as gene-transfer vectors for expression of recombinant proteins in a wide range of mammalian cell types. Baculovirus system has significant benefits in view of safety, large-scale, and high level of gene expression. In this study, baculoviral vectors which were reconstructed from pOPINEneo-3C-GFP vector, were recombined with cytomegalovirus (CMV) promoter, green fluorescent protein (GFP), and p53 with NcoI and XhoI. These recombinant vectors were infected with various cells and cell lines. The baculovirus vector thus developed was analyzed by comparing the metastasis and expression of the recombinant genes with conventional vectors. These results suggest that the baculovirus vector has higher efficiency in metastasis and expression than the control vector. This work was supported by a grant from Mid-Career Researcher Program(NRF-2016R1A2B4016552) through the National Research Foundation of Korea(NRF) funded by the Ministry of Science, ICT & Future Planning(MSIP).

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.1
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• pp.1-8
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• 2022

With the spread of COVID-19 worldwide, non-face-to-face services have grown rapidly, but at the same time, the problem of plastic waste is getting worse. Accordingly, eco-friendly policies such as carbon neutrality and sustainable circular economy are being promoted worldwide. Due to the high demand for eco-friendly products, the packaging industry is trying to develop eco-friendly packaging materials using PLA and PBAT and create new business models. On the other hand, Ulva australis occurs in large quantities in the southern seas of Korea and off the coast of Jeju Island, causing marine environmental problems. In this study, lactic acid was produced through dilute acid pretreatment, enzymatic saccharification, and fermentation processes to utilize Ulva australis as a new alternative energy raw material. In general, seaweeds vary in carbohydrate content and sugar composition depending on the species, harvest location, and time. Seaweed is mainly composed of polysaccharides such as cellulose, alginate, mannan, and xylan, but does not contain lignin. It is difficult to expect high extraction yield of the complex polysaccharide constituting Ulva australis with only one process. However, the fusion process of dilute acid and enzymatic saccharification presented in this study can extract most of the sugars contained in Ulva australis. Therefore, the fusion process is considered to be able to expect high lactic acid production yield when a commercial-scale production process is established.