• 한국미생물·생명공학회지
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• 제37권4호
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• pp.306-315
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• 2009

원유의 고갈, 반복되는 에너지 위기 및 지구온난화 문제에 기인하여 석유 대신 재생가능한 바이오매스를 사용하여 방향족 화학원료를 개발하는 연구가 광범위하게 진행되고 있다. 특히, 바이오테크놀로지를 이용한 포도당으로부터 방향족아미노산 생합성경로 중간대사체 및 그 유도체 합성기술은 벤젠유래 화합물을 포함한 많은 방향족 석유화학원료를 대체할 가능성이 있는 기술들이 개발되고 있다. 본 고는 미생물 대사공학, 생물전환, 화학공정 기술을 이용하여 hydroquinone, catechol, adipic acid, shikimic acid, gallic acid, pyrogallol, vanillin, p-hydroxycinnamic acid, p-hydroxystyrene, p-hydroxybenzoic acid, indigo, indole 3-acetic acid와 같은 방향족화합물을 어떻게 개발하고 있는지를 논하였다. 또한, 경쟁력있는 화이트바이오텍기반 방향족화합물 생산기술을 개발하기 위한 문제점 및 해결방안등을 논했다.

• Journal of Microbiology and Biotechnology
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• 제18권11호
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• pp.1773-1784
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• 2008

Effects of various industrially important carbon sources (glucose, sucrose, xylose, gluconate, and glycerol) on shikimic acid (SA) biosynthesis in Escherichia coli were investigated to gain new insight into the metabolic capability for overproducing SA. At the outset, constraints-based flux analysis using the genome-scale in silico model of E. coli was conducted to quantify the theoretical maximum SA yield. The corresponding flux distributions fueled by different carbon sources under investigation were compared with respect to theoretical yield and energy utilization, thereby identifying the indispensable pathways for achieving optimal SA production on each carbon source. Subsequently, a shikimate-kinase-deficient E. coli mutant was developed by blocking the aromatic amino acid pathway, and the production of SA on various carbon sources was experimentally examined during 51 batch culture. As a result, the highest production rate, 1.92 mmol SA/h, was obtained when glucose was utilized as a carbon source, whereas the efficient SA production from glycerol was obtained with the highest yield, 0.21 mol SA formed per mol carbon atom of carbon source consumed. The current strain can be further improved to satisfy the theoretically achievable SA production that was predicted by in silico analysis.

• Mycobiology
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• 제39권4호
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• pp.257-265
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• 2011

L-Phenylalanine is one of the essential amino acids that cannot be synthesized in mammals in adequate amounts to meet the requirements for protein synthesis. Fungi and plants are able to synthesize phenylalanine via the shikimic acid pathway. L-Phenylalanine, derived from the shikimic acid pathway, is used directly for protein synthesis in plants or metabolized through the phenylpropanoid pathway. This phenylpropanoid metabolism leads to the biosynthesis of a wide array of phenylpropanoid secondary products. The first step in this metabolic sequence involves the action of phenylalanine ammonialyase (PAL). The discovery of PAL enzyme in fungi and the detection of $^{14}CO_2$ production from $^{14}C$-ring-labeled phenylalanine and cinnamic acid demonstrated that certain fungi can degrade phenylalanine by a pathway involving an initial deamination to cinnamic acid, as happens in plants. In this review, we provide background information on PAL and a recent update on the presence of PAL genes in fungi.

• 한국미생물·생명공학회지
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• 제48권3호
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• pp.296-302
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• 2020

Rapamycin, derived from Streptomyces rapamycinicus, is an important bioactive compound having a therapeutic value in managing Parkinson's disease, rheumatoid arthritis, cancer, and AIDS. Because of its pharmaceutical activity, studies over the past decade have focused on the biosynthesis of rapamycin to enhance its yield. In this study, the effect of rapG on rapamycin production was investigated. The rapG expression vector was constructed by utilizing the integration vector pSET152 under the control of the erythromycin resistance gene (ermE^⁎), a strong constitutive promoter. The rapamycin yield of wild type (WT) and WT/rapG overexpression mutant strains, under fermentation conditions, was analyzed by high-performance liquid chromatography (HPLC). Our results revealed that overexpression of rapG increased rapamycin production by approximately 4.9-fold (211.4 mg/l) in MD1 containing 15 g/l of glycerol, compared to that of the WT strain. It was also found that Illicium verum powder (10 g/l), containing shikimic acid, enhanced rapamycin production in both WT and WT/rapG strains. Moreover, the amount of rapamycin produced by the WT/rapG strain was statistically higher than that produced by the WT strain. In conclusion, the addition 15 g/l glycerol and 15 g/l I. verum powder produced the optimal conditions for rapamycin production by WT and WT/rapG strains.

• 생약학회지
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• 제27권4호
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• pp.301-308
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• 1996

Hairy roots induced from stems of Rubia cordifolia var. pratensis were cultured in the liquid medium under a variety of auxins to find the optimal condition for the growth and production of pigments. Culture of the hairy roots on NN liquid medium containing NAA 0.5 mg/l was best for growth of hairy roots. Production of yellow anthraquinone derivatives and purpurin in hairy roots was enhanced by the culture on NN liquid medium without auxins. Effects of L-phenylalanine, L-tyrosine and juglone, synthesized via the shikimic acid pathway, on growth and production of pigments in hairy roots were studied in the present study. Concentration of exogeneous L-phenylalanine. L-tyrosine and juglone in liquid culture system of hairy root containing NAA 0.1 mg/l was decreased quickly in its early stages of the culture period. Addition of juglone to NN liquid medium containing NAA 0.1 mg/l enhanced the productivity of pigments in hairy roots.

• 한국식품과학회지
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• 제38권4호
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• pp.543-547
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• 2006

복분자 딸기의 일반성분은 수분 86.5%, 조단백 0.2%, 조지방 0.9%, 조섬유 6.6%, 회분 0.5%, $10^{\circ}Brix$정도의 당함량을 가지고 있었으며, 착즙액의 유리당은 fructose(2.99%), glucose(2.53%) 및 sucrose(0.07%)로 구성되어 있었다. Citric acid(14.57 mg/mL)와 malic acid(2.24 mg/mL)가 주요유기산 성분이었으며, shikimic, pyroglutamic, oxalic 순으로 미량 함유되어있었다. 본 실험에 이용된 3가지 균주중 Sc-24 균주가 복분자 발효에 적당한 것으로 판단되었으며, 발효시 오염방지를 위한 아황산 종류로는 $K_2S_2O_5$ 200 ppm 첨가가 양호하였다. Sc-24균주의 알코올 생산력은 $18-28^{\circ}Brix$의 당농도 범위에서 당농도에 비례적으로 증가하여 9.2-14.8%의 범위를 나타내었다. 매실즙의 첨가는 발효초기 복분자주 색상향상에 상당한 영향을 미치는 것으로 나타났으나 발효과정을 거치면서 색상 개선에 뚜렷한 영향을 볼 수는 없었다. 발효주의 유기산성분은 citric acid와 malic acid가 주요성분으로 발효과정에 의하여 상당량 감소되었고 formic acid와 acetic acid가 생성되었다. 씨를 포함하고 있지 않은 과즙 펄프나 과즙 상태로 발효시켰을 때 떫은맛이 약간 감소하였으며, 설탕의 용해처리는 외관상 주류의 품질에 영향을 미치지 않았다.

• Journal of Microbiology and Biotechnology
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• 제27권5호
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• pp.975-982
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• 2017

Curcumin, a hydrophobic polyphenol derived from the rhizome of the herb Curcuma longa, possesses diverse pharmacological properties, including anti-inflammatory, antioxidant, antiproliferative, and antiangiogenic activities. Two curcuminoids (dicinnamoylmethane and bisdemethoxycurcumin) were synthesized from glucose in Escherichia coli. PAL (phenylalanine ammonia lyase) or TAL (tyrosine ammonia lyase), along with Os4CL (p-coumaroyl-CoA ligase) and CUS (curcumin synthase) genes, were introduced into E. coli, and each strain produced dicinnamoylmethane or bisdemethoxycurcumin, respectively. In order to increase the production of curcuminoids in E. coli, the shikimic acid biosynthesis pathway, which increases the substrates for curcuminoid biosynthesis, was engineered. Using the engineered strains, the production of bisdemethoxycurcumin increased from 0.32 to 4.63 mg/l, and that of dicinnamoylmethane from 1.24 to 6.95 mg/l.

• 한국식품과학회지
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• 제37권4호
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• pp.574-578
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• 2005

복분자 발효주의 품질향상을 위하여 효모 종류 및 효소 등 처리방법을 달리하여 발효과정 중의 이화학적 특성을 검토한 결과 Saccharomyces cerevisiae KCCM 12224(Sc-24), 복분자 분리효모(Bok-3), 약주분리(Yak-7), Saccharomyces cerevisiae(Sc-24)와 약주효모(Yak-7) 혼합균주의 주발효 후 알코올 함량은 각각 11.08%, 10.62%, 10.18%, 10.26%이었으며, pectinase 첨가시 알코올 함량을 0.1-1.5% 증가시킬 수 있었다. 발효주의 유기산은 oxalic, citric, malic, shikimic, formic acid 등이었으며, 발효과정 중 citric acid와 malic acid가 큰 폭으로 감소되었다. 복분자주 발효 중 적정산도는 발효액 중의 citric acid의 함량변화에 의존적이었다. 복분자주의 색도는 발효초기에 유의적으로 감소되었으며 Sc-24, Yak-7 및 Bok-3+pectinase 처리구가 발효에 의한 색도의 변화가 비교적 낮았다. 이화학적 성분의 변화를 고려할 때 복분자주의 발효는 8-10일이 적당하였으며, Sc-24 및 Bok-3균주와 500ppm의 pectinase 첨가가 발효에 효과적이었다.

• ALGAE
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• 제35권2호
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• pp.177-187
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• 2020

Cyanobacteria have been widely reported to produce a variety of UV-absorbing mycosporine-like amino acids (MAAs). Herein, we reported production of the unusual MAA, mycosporine-glycine-alanine (MGA) in the cyanobacterium Sphaerospermopsis torques-reginae ITEP-024 using a newly developed UHPLC-DAD-MS/HRMS (ultra-high performance liquid chromatography-diode array detection-high resolution tandem mass spectrometry) method. MGA had previously been first identified in a red-algae, but S. torques-reginae strain ITEP-024 is the first cyanobacteria to be reported as an MGA producer. Herein, the chemical structure of MGA is fully elucidated from one-dimensional / two-dimensional nuclear magnetic resonance and HRMS data analyses. MAAs are unusually produced constitutively in S. torques-reginae ITEP-024, and this production was further enhanced following UV-irradiance. It has been proposed that MAA biosynthesis proceeds in cyanobacteria from the pentose phosphate pathway intermediate sedoheptulose 7-phosphate. Annotation of a gene cluster encoded in the genome sequence of S. torques-reginae ITEP-024 supports these gene products could catalyse the biosynthesis of MAAs. However, addition of glyphosate to cultures of S. torques-reginae ITEP-024 abolished constitutive and ultra-violet radiation induced production of MGA, shinorine and porphyra-334. This finding supports involvement of the shikimic acid pathway in the biosynthesis of MAAs by this species.