• BMB Reports
• /
• 제29권4호
• /
• pp.327-334
• /
• 1996

In this study, the origin of the monovinyl chlorophyll a carboxylic biosynthetic route was investigated in barley (Hordeum vulgare L.) and com (Zea mays L.). Protoporphyrin IX accumulated in vivo or in vitro was found to be all of the divinyl form. Furthermore, the conversion of divinyl protoporphyrin IX to monovinyl protoporphyrin IX in vitro was not observed. In contrast, the biosynthesis and accumulation of monovinyl Mg-protoporphyrin IX and its methyl ester occurred in etiolated leaves and divinyl Mg-protoporphyrin IX was convertible to monovinyl Mg-protoporphyrin IX in vitro. These results suggest that the monovinyl chlorophyll ${\alpha}$ carboxylic biosynthetic route in plants may originate from the divinyl Mg-protoporphyrin IX pool.

• Plant Biotechnology Reports
• /
• 제3권4호
• /
• pp.267-275
• /
• 2009

Over the years, cyanobacteria have been regarded as ideal model systems for studying fundamental biochemical processes like oxygenic photosynthesis and carbon and nitrogen assimilation. Additionally, they have been used as human foods, sources for vitamins, proteins, fine chemicals, and bioactive compounds. Aiming to increase plant productivity as well as nutritional values, cyanobacterial genes involved in carbon metabolism, fatty acid biosynthesis, and pigment biosynthesis have been intensively exploited as alternatives to homologous gene sources. In this short review, transgenic plants with cyanobacterial genes generated over the last two decades are examined, and the future prospects for transgenic crops using cyanobacterial genes obtained from functional genomics studies of numerous cyanobacterial genomes information are discussed.

• 약학회지
• /
• 제45권6호
• /
• pp.701-707
• /
• 2001

Melanogenesis is a physiological process resulting in the synthesis of melanin pigment. We investigated the inhibitory effect of crude polysaccharide of water extract of Artemisia iwayomgi Kitamura (AI) on melanin biosystheies in B16/F10 melanoma cells. Crude polysaccharide of water extract of Artemisia iwayomgi Kitamura significantly inhibited tyrosinase activity and melanin contents with or without $\alpha$-MSH in vivo. Melanin contents and tyrosinase activity were decreased in a dose-dependent manner,These results show that crude polysaccharide of water extract of Artemisia iwayomgi Kitamura could be developed as skin whitening components of cosmetics.

• 한국균학회지
• /
• 제18권4호
• /
• pp.181-190
• /
• 1990

The growth and biochemical activities of Chlorella fusca were studied in the presence of different concentrations of either filtrates or mycelial mats of Saprolegnia ferax and Pythium graminicola. Low concentrations of both fungal filtrates exerted increase in total count, dry weight and in the biosynthesis of photosynthetic pigments, carbohydrates and nitrogen content. High concentrations showed inhibitory effect on both growth and biochemical activities of Chlorella fusca. Supplementation with different concentrations of dry mycelial mats of either fungi the culture of Chlorella showed elevation in biomass, dry weight, and biosynthesis of carbohydrates and nitrogen content especially at low concentrations. The contents of photosynthetic pigment were inhibited only at low concentrations. Neither the culture filtrate of Pythium nor Saprolegnia had cellulolytic activity, although polygalacturonase enzymes were detected, whereas chloroform-extract of both fungal filtrates showed blue spots under long wave light (366 nm).

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제8권6호
• /
• pp.322-330
• /
• 2003

The unicellular green alga Haematococcus pluvialis has recently attracted great inter-est due to its large amounts of ketocarotenoid astaxanthin, 3,3'-dihydroxy-${\beta}$,${\beta}$-carotene-4,4'-dione, widely used commercially as a source of pigment for aquaculture. In the life cycle of H. pluvialis, astaxanthin biosynthesis is associated with a remarkable morphological change from green motile vegetative cells into red immotile cyst cells as the resting stage. In recent years we have studied this morphological process from two aspects: defining conditions governing astaxanthin biosynthesis and questioning the possible function of astaxanthin in protecting algal cells against environmental stress. Astaxanthin accumulation in cysts was induced by a variety of environmental conditions of oxidative stress caused by reactive oxygen species, intense light, drought, high salinity, and high temperature. In the adaptation to stress, abscisic acid induced by reactive oxygen species, would function as a hormone in algal morphogenesis from veget ative to cyst cells. Furthermore, measurements of both in vitro and in vivo antioxidative activities of astaxanthin clearly demonstrated that tolerance to excessive reactive oxygen species is greater in astaxanthin-rich cysts than in astaxanthin-poor cysts or astaxanthin-less vegetative cells. Therefore, reactive oxygen species are involved in the regulation of both algal morph O-genesis and carotenogenesis, and the accumulated astaxanthin in cysts can function as a protective agent against oxidative stress damage. In this study, the physiological roles of astaxanthin in stress response and cell protection are reviewed.

• Applied Biological Chemistry
• /
• 제33권3호
• /
• pp.239-246
• /
• 1990

유기 용매에 추출되는 유리형의 홍국 색소를 보다 많이 얻기 위하여 Monascus anka의 균주를 자연 및 자외선 변이균주에서 선발하고 배양 조건을 탐색하였다. 균주 N3를 Lin's medium에서 진탕 배양, Nishikawa's medium에서 정치 배양 및 진탕 배양하여 균체성장과 색소생성에 소요되는 시간, 유기용매에 추출되는 색소의 양을 비교하여 보았다. Lin's medium에서의 액침 배양에서는 수용성 색소가 우세하게 생성되는 반면 Nishikawa's medium에서의 정치 배양에서는 보다 많은 유기용매 가용성의 색소를 얻을 수 있었다. 한편 탄소원으로는 자당외에 에탄올이 가장 효과적이었다. Sterol 합성저해제를 처리하였을 때는 상당한 색소 형성의 증가를 볼 수 있었다. 이차원 TLC로써 아직 보고된 바 없는 색소들이 존재함을 알 수 있었다. 이 균주의 색소중 가장 다량으로 존재하는 황색소의 하나를 분리하였고 분광학적 방법으로 ankaflavin으로 동정하였다.

• 한국미생물·생명공학회지
• /
• 제46권2호
• /
• pp.114-119
• /
• 2018

Astaxanthin is one of the major carotenoids used in pigment has a great economical value in pharmaceutical markets, feeding, nutraceutical and food industries. This study was to increase the production of astaxanthin by co-expression with transformed Escherichia coli using six genes involved in the non-mevalonate pathway. Involved in the non-mevalonate biosynthetic pathway of the strain Kocuria gwangalliensis were cloned dxs, ispC, ispD, ispE, ispF, ispG, ispH and idi genes in order to increase astaxanthin production from the transformed E. coli. And co-expression with the genes to compared the amount of astaxanthin production. This engineered E. coli, containing both the non-mevalonate pathway gene and the astaxanthin biosynthesis gene cluster, produced astaxanthin at $1,100{\mu}g/g$ DCW (dry cell weight), resulting in approximately three times the production of astaxanthin.

• Molecules and Cells
• /
• 제38권12호
• /
• pp.1105-1110
• /
• 2015

Phleichrome, a pigment produced by the phytopathogenic fungus Cladosporium phlei, is a fungal perylenequinone whose photodynamic activity has been studied intensively. To determine the biological function of phleichrome and to engineer a strain with enhanced production of phleichrome, we identified the gene responsible for the synthesis of phleichrome. Structural comparison of phleichrome with other fungal perylenequinones suggested that phleichrome is synthesized via polyketide pathway. We recently identified four different polyketide synthase (PKS) genes encompassing three major clades of fungal PKSs that differ with respect to reducing conditions for the polyketide product. Based on in silico analysis of cloned genes, we hypothesized that the non-reducing PKS gene, Cppks1, is involved in phleichrome biosynthesis. Increased accumulation of Cppks1 transcript was observed in response to supplementation with the application of synthetic inducer cyclo-(${_L}-Pro-{_L}-Phe$). In addition, heterologous expression of the Cppks1 gene in Cryphonectria parasitica resulted in the production of phleichrome. These results provide convincing evidence that the Cppks1 gene is responsible for the biosynthesis of phleichrome.

• 한국미생물·생명공학회지
• /
• 제34권1호
• /
• pp.1-6
• /
• 2006

Harmful algal blooms (HABs or red tides), caused by uncontrolled proliferation of marine phytoplankton, impose a severe environmental problem and occasionally threaten even public health. We sequenced the genome of an EPS-producing marine bacterium Hahella chejuensis that produces a red pigment with the lytic activity against red-tide dinoflagellates at parts per billion level. H. chejuensis is the first sequenced species among algicidal bacteria as well as in the order Oceanospirillales. Sequence analysis indicated a distant relationship to the Pseudomonas group. Its 7.2-megabase genome encodes basic metabolic functions and a large number of proteins involved in regulation or transport. One of the prominent features of the H. chejuensis genome is a multitude of genes of functional equivalence or of possible foreign origin. A significant proportion (${\sim}23%$) of the genome appears to be of foreign origin, i.e. genomic islands, which encode genes for biosynthesis of exopolysaccharides, toxins, polyketides or non-ribosomal peptides, iron utilization, motility, type III protein secretion and pigment production. Molecular structure of the algicidal pigment was determined to be prodigiosin by LC-ESI-MS/MS and NMR analyses. The genomics-based research on H. chejuensis opens a new possibility for controlling algal blooms by exploiting biotic interactions in the natural environment and provides a model in marine bioprospecting through genome research.

• Biomolecules & Therapeutics
• /
• 제25권2호
• /
• pp.171-176
• /
• 2017

Streptomyces avermitilis produces clinically useful drugs such as avermectins and oligomycins. Its genome contains approximately 33 cytochrome P450 genes and they seem to play important roles in the biosynthesis of many secondary metabolites. The SAV_7130 gene from S. avermitilis encodes CYP158A3. The amino acid sequence of this enzyme has high similarity with that of CYP158A2, a biflaviolin synthase from S. coelicolor A3(2). Recombinant S. avermitilis CYP158A3 was heterologously expressed and purified. It exhibited the typical P450 Soret peak at 447 nm in the reduced CO-bound form. Type I binding spectral changes were observed when CYP158A3 was titrated with myristic acid; however, no oxidative product was formed. An analog of flaviolin, 2-hydroxynaphthoquinone (2-OH NQ) displayed similar type I binding upon titration with purified CYP158A3. It underwent an enzymatic reaction forming dimerized product. A homology model of CYP158A3 was superimposed with the structure of CYP158A2, and the majority of structural elements aligned. These results suggest that CYP158A3 might be an orthologue of biflaviolin synthase, catalyzing C-C coupling reactions during pigment biosynthesis in S. avermitilis.