微生物诱导子对霉素PT95菌株菌核生物量和类胡萝卜素产率的影响

菌核是许多丝状真菌形成的一种休眠体。我们从土壤中分离到一株经鉴定属于Ｐｅｎｉｃｉｌｌｉｕｍｔｈｏｍｉｉｓｅｒｉｅｓ的ＰＴ95青霉菌株 ,该菌株能在固态培养基上形成大量坚硬的砂粒状的菌核 (直径约 30 0 μｍ)。ＰＴ95菌株的菌核与众不同之处在于可以积累以β 胡萝卜素为主的类胡萝卜素[1 ] 。菌核的形成 ,除了遗传因素外 ,还受多种因素影响 ,例如生长环境中的温度、水势 (Ｗａｔｅｒｐｏｔｅｎｔｉａｌ)、有机物成分等[2～ 4] 。Ｈａｗｋｅｒ[5] 认为对真菌的营养生长 (Ｖｅｇｅｔａｔｉｖｅｇｒｏｗｔｈ)有利的物质也对菌核生长有…     

Elicitor-enhanced syringin production in suspension cultures of Saussurea medusa

Syringin production and related secondary metabolism enzyme activities in suspension cultures of Saussurea medusa treated with different elicitors (yeast extract, chitosan and Ag⁺) were investigated. All elicitors enhanced syringin production, and the optimal feeding protocol was the combined addition of 1.5% (v/v) yeast extract, 0.2 g l⁻¹ chitosan and 75 μM Ag⁺ at the 15th day of the cell culture. The highest syringin production reached 741.9 mg l⁻¹, which was 3.6−fold that of the control. The glucose−6-phosphate dehydrogenase (EC 1.1.1.49), phenylalanine ammonia lyase (EC 4.3.1.5) and peroxidase (EC 1.11.1.7) activities increased significantly after elicitor treatment. The maximum enzyme activities were obtained when the treatment time was 6 h.     

Production and optimization of carotenoid-enriched dried distiller’s grains with solubles by <Emphasis Type="Italic">Phaffia rhodozyma</Emphasis> and <Emphasis Type="Italic">Sporobolomyces roseus</Emphasis> fermentation of whole stillage

Whole stillage—a co-product of grain-based ethanol—is used as an animal feed in the form of dried distiller’s grain with solubles (DDGS). Since animals cannot synthesize carotenoids and animal feed is generally poor in carotenoids, about 30–120 ppm of total carotenoids are added to animal feed to improve animal health, enhance meat color and quality, and increase vitamin A levels in milk and meat. The main objective of this study was to produce carotenoid (astaxanthin and β-carotene)-enriched DDGS by submerged fermentation of whole stillage. Mono- and mixed cultures of red yeasts, Phaffia rhodozyma (ATCC 24202) and Sporobolomyces roseus (ATCC 28988), were used to produce astaxanthin and β-carotene. Media optimization was carried out in shake flasks using response surface methodology (RSM). Macro ingredients, namely whole stillage, corn steep liquor and glycerol, were fitted to a second-degree polynomial in RSM. Under optimized conditions, astaxanthin and β-carotene yields in mixed culture and P. rhodozyma monoculture were 5 and 278, 97, and 275 μg/g, respectively, while S. roseus produced 278 μg/g of β-carotene. Since the carotenoid yields are almost twice the quantity used in animal feed, the carotenoid-enriched DDGS has potential application as “value-added animal feed or feed blends.”     

Dynamic Changes of Photosynthetic Pigments in Soybean Callus under High Irradiance

Dynamic changes of neoxanthin (NEO), violaxanthin (VIO), anteraxanthin (ANT), zeaxanthin (ZEA), chlorophyll (Chl) a, Chl b, α-carotene, β-carotene, and their behaviour under increasing duration of high irradiance (HI) were investigated in the soybean hypocotyl callus culture. The calli were induced on solid (1.1 % agar) MS medium (pH 5.8) supplemented with 4.52 μM 2,4-D, 2.32 μM kinetin, and 3 % sucrose. After 30 d of culture, the green calli were irradiated with “white light” (133W m⁻²) for 0, 3.5, and 24 h. HPLC profiles were separated on a C₁₈ column. With increasing duration of HI, the content of total carotenoids (Cars) increased, but the ratio of Chl a+b/Cars decreased. With lengthening the duration of HI, there was induction of ZEA. Contents of ANT, α-carotene, and β-carotene remained nearly constant, but ratio of ZEA/Chl a+b increased with lengthening the HI duration. This revised version was published online in August 2006 with corrections to the Cover Date.     

Torularhodin and torulene are the major contributors to the carotenoid pool of marine Rhodosporidium babjevae (Golubev)

A carotenoid-producing yeast strain, isolated from the sub-arctic, marine copepod Calanus finmarchicus, was identified as Rhodosporidium babjevae (Golubev) according to morphological and biochemical characteristics and phylogenetic inference from the small-subunit ribosomal RNA gene sequence. The total carotenoids content varied with cultivation conditions in the range 66–117 μg per g dry weight. The carotenoid pool, here determined for the first time, was dominated by torularhodin and torulene, which collectively constituted 75–91% of total carotenoids under various regimes of growth. β-Carotene varied in the range 5–23%. A high-peptone/low-yeast extract (weight ratio 38:1) marine growth medium favoured the production of torularhodin, the carotenoid at highest oxidation level, with an average of 63% of total carotenoids. In standard yeast medium (YM; ratio 1.7:1), torularhodin averaged 44%, with increased proportions of the carotenes, torulene and β-carotene. The anticipated metabolic precursor γ-carotene (β,ψ-carotene) constituted a minor fraction (≤8%) under all conditions of growth.     

Influence of inocula and grains on sclerotia biomass and carotenoid yield of<Emphasis Type="Italic"> Penicillium</Emphasis> sp. PT95 during solid-state fermentation

Various inocula and grains were evaluated for carotenoid production by solid-state fermentation using Penicillium sp. PT95. Millet medium was more effective in both sclerotia growth and carotenoid production than other grain media. An inoculum in the form of sclerotia yielded higher sclerotia biomass compared to either a spore inoculum or a mycelial pellet inoculum. Adding wheat bran to grain medium favored the formation of sclerotia. However, neither the inoculum type nor addition of wheat bran resulted in a significant change in the carotenoid content of sclerotia. Among grain media supplemented with wheat bran (wheat bran:grain =1:4 w/w, dry basis), a medium consisting of rice and wheat bran gave the highest sclerotia biomass (15.10 g/100 g grain), a medium consisting of buckwheat and wheat bran gave the highest content of carotenoid in sclerotia (0.826 mg/g dry sclerotia), and a medium consisting of millet and wheat bran gave the highest carotenoid yield (11.457 mg/100 g grain).     

Sclerotia growth and carotenoid production of Penicillium sp PT95 during solid state fermentation of corn meal

Using corn meal as fermentation substrate, the effect of some factors, fermentation time and supplementation of saccharide and nitrogen sources as well as vegetable oil, on the sclerotia growth and carotenoid production of Penicillium sp PT95 during solid state fermentation were studied. When PT95 strain was grown on the amended medium by supplementing of 3g NaNO3, 10g maltose and 2.5g soybean oil per liter of salt solution to basal medium for 20 days, the dry sclerotia weight and carotenoid yield reached 9.70 g and 5260 g / 100 g of substrate, respectively. Without supplementation only 5.36g dry sclerotia and 2149g carotenoid / 100 g of substrate was attained. © Rapid Science Ltd. 1998     

The leaves of the common box,Buxus sempervirens (Buxaceae), become red as the level of a red carotenoid,anhydroeschscholtzxanthin, increases

Carotenoids from the leaves of the common box,Buxus sempervirens (Buxaceae), which turn red in late autumn to winter, were analyzed by reversed-phase HPLC. A novel carotenoid, monoanhydroeschscholtzxanthin (3), was isolated from the red-colored leaves. UV-VIS, MS,¹H-NMR and CD spectral data showed that the structure of 3 was (3S)-2′, 3′, 4′, 5′-tetradehydro-4, 5′-retro-β, β-caroten-3-ol. As well as anhydroeschscholtzxanthin (2), the major red carotenoid in the leaves, eschscholtzxanthin (4) was identified. Very small amounts of yellow carotenoids (neoxanthin, violaxanthin, lutein and β-carotene), which are major components of green leaves, were present in the red-colored leaves. The amounts of chlorophylla andb in the leaves decreased markedly during coloration, even at the early stages, whereas those of the yellow carotenoids decreased gradually. In contrast, the content of 2, a red carotenoid, increased steadily during coloration. The biosynthetic pathway of 2 inB. sempervirens was deduced tentatively on the basis of the individual carotenoid contents during autumnal coloration.     

Synthesis of carotenoids by<Emphasis Type="Italic"> Rhodotorula rubra</Emphasis> GED8 co-cultured with yogurt starter cultures in whey ultrafiltrate

Two cultures, a yeast (Rhodorula rubra GED8) and a yogurt starter (Lactobacillus bulgaricus 2–11+Streptococcus thermophilus 15HA), were selected for associated growth in whey ultrafiltrate (WU) and active synthesis of carotenoids. In associated cultivation with the yogurt culture L bulgaricus 2–11+S. thermophilus 15HA under intensive aeration (1.3 l^–1min^–1 air-flow rate) in WU (45 g lactose l^–1), initial pH 5.5, 30 °C, the lactose-negative strain R. rubra GED8 synthesized large amounts of carotenoids (13.09 mg l^–1 culture fluid). The carotenoid yield was approximately two-fold higher in association with a mixed yogurt culture than in association with pure yogurt bacteria. The major carotenoid pigments comprising the total carotenoids were -carotene (50%), torulene (12.3%) and torularhodin (35.2%). Carotenoids with a high -carotene content were produced by the microbial association 36 h earlier than by Rhodotorula yeast species. No significant differences were notd in the ratio between the pigments synthesized by R. rubra GED8+L. bulgaricus 2–11, R. rubra GED8+S. thermophilus 15HA, and R.rubra GED8+yogurt culture, despite the fact that the total carotenoid concentrations were lower in the mixed cultures with pure yogurt bacteria.     

Substrate specificity of a recombinant chicken <Emphasis Type="Italic">β</Emphasis>-carotene 15,15′-monooxygenase that converts <Emphasis Type="Italic">β</Emphasis>-carotene into retinal

The recombinant β-carotene 15,15′-monooxygenase from chicken liver was purified as a single 60 kDa band by His-Trap HP and Resource Q chromatography. It had a molecular mass of 240 kDa by gel filtration indicating the native form to be tetramer. The enzyme converted β-carotene under maximal conditions (pH 8.0 and 37°C) with a k _cat of 1.65 min⁻¹ and a K _m of 26 μM and its conversion yield of β-carotene to retinal was 120% (mol mol⁻¹). The enzyme displayed catalytic efficiency and conversion yield for β-carotene, β-cryptoxanthin, β-apo-8′-carotenal, β-apo-4′-carotenal, α-carotene and γ-carotene in decreasing order but not for zeaxanthin, lutein, β-apo-12′-carotenal and lycopene, suggesting that the presence of one unsubstituted β-ionone ring in a substrate with a molecular weight greater than C₃₀ seems to be essential for enzyme activity.     

Elicitors,SA and MJ enhance carotenoids and tocopherol biosynthesis and expression of antioxidant related genes in Moringa oleifera Lam. leaves

Moringa oleifera Lam. leaves are rich source of carotenoids (provitamin A) and α-tocopherol (vitamin E), and there is a scope for their further enhancement, through elicitor mediation, thereby a great potential for addressing these vitamins deficiency. In the present study, we report the efficacy of foliar administration of biotic elicitors, carboxy-methyl chitosan and chitosan, and signaling molecules, methyl jasmonate (MJ) and salicylic acid (SA) for enhancement of major carotenoids and α-tocopherol. Highest α-tocopherol content of 49.7 mg/100 g FW was recorded upon foliar application of 0.1 mM SA after 24 h of treatment, which represented a 187.5 % increase in comparison to the untreated control. Similarly, a maximum of 52.6 mg/100 g FW lutein, and 21.8 mg/100 g FW β-carotene content were observed in leaves after 24 h of treatment with MJ, which represented a 54.0 and 20.3 % increase in comparison to the untreated control, respectively. Among the major genes of carotenoid biosynthetic pathway, the expression of lycopene β-cyclase (LCY-β) was maximum influenced after treatment with elicitors and signaling molecules, compared to phytoene synthase and phytoene desaturase, suggesting the LCY-β-mediated enhancement in the production of β-carotene in elicitor treated M. oleifera leaves. Enhanced production of α-tocopherol under respective elicitor treatment was further supported by 2.0–2.7 fold up-regulation of γ-tocopherol methyl transferase, compared to untreated control. This is the first report on elicitor-mediated enhanced production of tocopherol and carotenoids in foliage of economically important food plant.     

Carotenoids in the eyespot apparatus of the flagellate green alga Spermatozopsis similis: Adaptation to the retinal-based photoreceptor

Isolated intact eyespot apparatuses, the photoreceptive organelles involved in blue-light-mediated photoresponses of flagellate green algae, were analyzed regarding their carotenoid composition. Carotenoids from the eyespot apparatuses of Spermatozopsis similis were identified by high-performance liquid chromatography, visible-light absorption spectra, mass spectroscopy and by ¹H-nuclear magnetic resonance spectroscopy (carotenes), and compared with those of whole-cell extracts. Both extracts contained ,-carotene, ,-carotene (formerly -carotene), lycopene, lutein, zeaxanthin, violaxanthin and all-E-and 9-Z-neoxanthin. The relative carotenoid compositions, however, differed significantly. A twofold relative increase in the total carotene level was evident in the fraction enriched in eyespot apparatuses. This was mainly due to an increase in the monocyclic ,-carotene and the aliphatic lycopene, whereas the relative content of ,-carotene remained unchanged. On the other hand a relative decrease in the total xanthophyll content, especially of lutein and the epoxidic carotenoid neoxanthin, was observed in the eyespot apparatuses compared with the whole-cell extracts. The decrease of the latter resulted almost solely from a reduction of the 9-Z-rather than the all-E-isomer. The bulk of the carotenes is thought to be localized in the highly organized eyespot lipid globules, which act as a combined quarter-wave interference reflector and absorption screen for the photoreceptor in green algae. The enrichment of ,-carotene and lycopene in the eyespot apparatuses, extending the range of visible light absorption to longer wavelengths, represents an adaptation of the screen to the retinal-based photoreceptor of flagellate green algae and is one of the prerequisites for maximal directional sensitivity of the eyespot apparatus.Abbreviations ¹H-NMR nuclear magnetic resonance - IUPAC International Union of Pure and Applied Chemistry - VIS visible absorption spectra This work was supported by the Deutsche Forschungsgemeinschaft (G.K. and M.M.). M.G. was supported by a fellowship from the Norwegian Research Council of Science and Humanities.     

Elicitation of camptothecin production in cell cultures ofCamptotheca acuminata

Campothecin production was increased with elicitors, methyl jasmonate, jasmonic acid, yeast extract elicitor, and ferulic acid in suspension cultures ofCamptotheca acuminata. jasmonic acid was found to be the most efficient elicitor. Camptothecin production increased 11 times by using the optimum dosing concentration of jasmonic acid which was 50 μM. The kinetics of camptothecin accumulation in response to the treatment with jasmonic acid showed that the camptothecin accumulation reached the maximum value at 4 days after jasmonic acid dosing and then a rapid decrease in camptothecin accumulation was observed.     

Protein,fatty acid,and pigment content of <Emphasis Type="Italic">Chlorella vulgaris</Emphasis> under different light regimes

The effects of irradiance and photoperiod on growth rates, chlorophyll a, β-carotene, total protein, and fatty acid content of Chlorella vulgaris were determined. The maximum growth rate (1.13 day⁻¹) was at 100 μmol photons m⁻² s⁻¹ and 16:8-h light/dark photoperiod. Chlorophyll a and β-carotene contents significantly differed under different light regimes with chlorophyll a content lower at high irradiance and longer light duration, while β-carotene showed the inverse trend. The total protein and fatty acid content also significantly differed in different light regimes; the maximum percentage of protein (46%) was at 100 μmol photons m⁻² s⁻¹ and 16:8 h photoperiod, and minimum (33%) was at 37.5 μmol photons m⁻² s⁻¹ and 8:16 h photoperiod; the total saturated fatty acids increased, while monounsaturated and polyunsaturated fatty acids decreased with increasing irradiance and light duration.     

The biosynthetic pathway of carotenoids in the astaxanthin-producing green alga <Emphasis Type="Italic">Chlorella zofingiensis</Emphasis>

The carotenoid composition of the astaxanthin-producing green alga Chlorella zofingiensis was investigated using high-performance liquid chromatography. Astaxanthin, adonixanthin, and zeaxanthin are the major carotenoids in this alga. The pigment pattern was characterized during the accumulation period, and in response to diphenylamine (DPA), an inhibitor of carotenoid biosynthesis. An increase in zeaxanthin followed by a decrease in xanthophyll was seen after the induction of astaxanthin biosynthesis by glucose. This biphasic kinetics of zeaxanthin was parallel to the marked increase in adonixanthin (from 0 mg g⁻¹ to 0.21 mg g⁻¹) and astaxanthin (from 0.05 mg g⁻¹ to 0.35 mg g⁻¹) and decrease of β-carotene (from 0.30 mg g⁻¹ to 0.03 mg g⁻¹). More importantly, unlike the Haematococcus alga, in which there was a high β-carotene accumulation after DPA treatment, C. zofingiensis showed an accumulation of extra zeaxanthin instead of β-carotene after treatment of the cells with DPA. All these results observed in vivo studies corroborate the observations in vitro studies at the enzyme level that zeaxanthin is a substrate for the carotenoid oxygenase in C. zofingiensis. It is suggested that zeaxanthin might be an important intermediate and not an end product of the biosynthetic pathway of astaxanthin. Therefore, a new pathway for astaxanthin formation by C. zofingiensis, which is different from that of the other astaxanthin-producing microorganisms, is proposed. An understanding of the astaxanthin biosynthetic pathway may yield important information toward the optimization of astaxanthin production, especially for the improvement of astaxanthin through genetic manipulations.     

Partial quantification of pigments extracted from the zooxanthellate octocoral <Emphasis Type="Italic">Sinularia flexibilis</Emphasis> at varying irradiances

Chlorophyll-a (chl-a) and carotenoid pigments of the zooxanthellate octocoral Sinularia flexibilis were analyzed using high performance liquid chromatography following exposure to three light intensities for over 30 days. From the coral fragments located at different light intensities, a total carotenoid of >41 μg g⁻¹ dry weight, including peridinin, xanthophylls (likely diadinoxanthin + diatoxanthin), and chl-a as the most abundant pigments, with minor contents of astaxantin and β-carotene were detected. The whole content of chl-a weighed 5 μg g⁻¹ dry weight in all coral colonies. Chl-a and carotenoids contributed 11.2% and 88.2%, respectively, to all pigments detected, and together accounted for 99.4% of the total pigments present. The highest contents of carotenoids and chl-a was observed in the coral grafts placed in an irradiance of 100 μmol quanta m⁻² s⁻¹; they showed lower ratios of total carotenoids: chl-a compared to those exposed to 400 μmol quanta m⁻² s⁻¹ after >30 days of incubation. The ratios of peridinin and xanthophylls with respect to chl-a from the colonies at 400 μmol quanta m⁻² s⁻¹ were approximately double those observed at irradiances of 100 and 200 μmol quanta m⁻² s⁻¹. Partial quantification of pigments in this study showed that the carotenoids of S. flexibilis showed a decrease at irradiances above 100 μmol quanta m⁻² s⁻¹, with the exception of an increase in β-carotene at 200 μmol quanta m⁻² s⁻¹.     

Spray-drying of Dunaliella salina to produce a β-carotene rich powder

Powders of Dunaliella salina biomass were obtained by spray drying a cell concentrate under different drying regimes. A three-factor, two-level experimental design was employed to investigate the influence of inlet temperature, outlet temperature and feed solids on β-carotene recovery. The effect of microencapsulation in a polymer matrix of maltodextrin and gum arabic was also studied. All powders were stored under specific conditions to assess the stability of the native β-carotene. There was a trend indicating that lower outlet temperature yielded higher carotenoid recoveries, β-carotene recovery varying between 57% and 91%. Microencapsulated biomass yielded 100% recoveries. All non-microencapsulated powders were unstable in terms of β-carotene content in the presence of natural light and oxygen showing 90% degradation over a 7-day period. The incorporation of a microencapsulating agent had a significant increase in the storage stability. Results indicated a first-order degradation of the β-carotene in microencapsulated powders with kinetic constants of 0.06 day⁻¹ and 0.10 day⁻¹. HPLC analysis showed no effect of drying processes on isomer composition (9-cis-β-carotene and all-trans-β-carotene ratio). This behaviour was also observed during storage of the microencapsulated powders. Received 16 October 1996/ Accepted in revised form 13 November 1997