实验基础

In order to metabolically engineer microorganisms to produce compounds of interest, it is often desirable to integrate foreign genes into the chromosome of the host. However, the consequences of these genetic alterations are not always predictable. The use of a reporter system can often as ...

Carotenoids have received considerable attention due to their interesting industrial applications and, more importantly, their potential beneficial effects on human health. Halophiles comprise a heterogeneous group of microorganisms that need salts for optimal growth. T ...

C-Isotopologue profiling is a powerful tool to determine on a quantitative basis the biosynthetic origin of carotenoids in microorganisms. To this aim, the carotenoid-producing microorganism is grown in medium containing 13C-labeled glucose. After growth, the 13C-isotopolog ...

The carotenoids, a subfamily of the isoprenoids, are among the most widespread, ancient, diverse, and rich class of all natural products and biomolecules. Microorganisms, as well as microalgae and bacteria synthesize isoprenoids from isopentenyl diphosphate (IPP) and its isomer dim ...

Lutein extracts are in increasing demand due to their alleged role in the prevention of degenerative disorders such as age-related macular degeneration (AMD). Lutein extracts are currently obtained from plant sources, but microalgae have been demonstrated to be a competitive source l ...

Cyanobacteria produce many kinds of carotenoids for light harvesting and light protection in photosynthesis. To elucidate the biosynthetic pathways of carotenoids in Anabaena sp. PCC 7120 (also known as Nostoc sp. PCC 7120), we have produced gene-disruption mutants lacking selected ...

Ketocarotenoids are obtained by the action of the β-carotene ketolase, which catalyses the addition of a keto-group at the C4 position of carotenoids β-ion-rings. Most microalgae and higher plants do not posses the carotene ketolase activity and consequently do not synthesize ketocaro ...

Numerous carotenoid-producing Gram positive bacteria have now been identified. Their carotenoid profiles are typically complex with C30 diapocarotenoid skeletons being modified by glucosidation and esterification. In the present article the protocols necessary to ide ...

Carotenoids are natural pigments that exhibit many biological functions, such as antioxidants (i.e., promote oxidative stress resistance), membrane stabilizers, and precursors for vitamin A. The link between these biological activities and many health benefits (e.g., anticar ...

Carotenoids are important pigments produced by plants and many microorganisms, including fungi, microalgae, cyanobacteria, and bacteria. Marine actinomycetes are a group of bacteria that produce a variety of metabolites with economic potential. Here, we describe a general meth ...

Commercial interest in the use of natural pigments isolated from microorganisms has increased in recent years; hence, molecules belonging to the polyisoprenoid group (i.e., β-carotene, astaxanthin, and canthaxanthin) have been the focus of much attention. The bacterium Gordonia ja ...

Escherichia coli is a non-carotenogenic bacterium that could synthesize farnesyl pyrophosphate precursor through the isoprenoid pathway. Carotenoid production in E. coli requires heterologous expression of carotenoid synthesis genes. The carotenoid synthesis opero ...

Many carotenoid pigments are present in a small quantity in nature or low yielding from their natural sources, despite these vivid colorations. Thus, the synthesis of useful carotenoids with metabolic pathway-engineered microorganisms should offer an alternative and promising a ...

Zeaxanthin is a powerful antioxidant that is widely found in vegetables and fruits. Epidemiological evidences suggest that increasing the consumption of zeaxanthin in the diet is associated with a lower risk of age-related macular degeneration, helps prevent glaucoma and catarac ...

Methylomonas sp. strain 16a is an obligate methanotrophic bacterium that uses methane or methanol as the sole energy and carbon source. In order to engineer a stable strain to produce carotenoids, integration of genes or gene clusters in various nonessential locations in the chromosome is u ...

C30 carotenoids, which have shorter backbones than C40 carotenoids, are known to be produced in the pathogenic bacterium Staphylococcus aureus that causes opportunistic infection. The first committed enzyme in the C30 carotenoid synthetic pathway is dehydrosqualene synthase ...

Directed evolution is a well-established strategy to confer novel catalytic functions to the enzymes. Thanks to the relative ease of establishing color screening, carotenogenic enzymes can be rapidly evolved in the laboratory for novel functions. The combinatorial usages of the evo ...

Astaxanthin is a red ketocarotenoid that exhibits extraordinary health-promoting activities such as antioxidant, anti-inflammatory, antitumor, and immune booster. The recent discovery of the beneficial roles of astaxanthin against many degenerative diseases such as can ...

Astaxanthin is a natural product of immense value. Its biosynthesis has been investigated extensively and typically requires the independent activity of two proteins, a β-carotene ketolase and β-carotene hydroxylase. Rational engineering of this pathway has produced limited s ...

Dunaliella salina has become the most important microorganism for the production of β-carotene around the world. Natural carotenoids are a source of active metabolites utilized in different areas of food nutrition and pharmaceuticals, both in humans and also in animals. Identificat ...