Water-Soluble Red Pigment Production by <Emphasis Type="Italic">Paecilomyces sinclairii</Emphasis> and Biological Characterization

Natural pigments have several advantages over synthetic colorants. In this study, the production of red pigment produced by Paecilomyces sinclairii in microbial fermentation was demonstrated and the pigment was purified and characterized. The red pigment was produced from submerged fungal fermentation and fractionated by medium pressure flash chromatography. After fractionation, the spectrophotometric characterization of the red pigment revealed an λ_max at 520 nm. Antimicrobial activity of the red pigment fraction was also studied against Escherichia coli O157 and Pseudomonas aeruginosa PAO1. The fraction (F2-F6) of the red pigment exhibited broad-spectrum antimicrobial activity in both bacteria. These results demonstrate the potential of this pigment in inhibiting bacterial growth and in food processing and other foodrelated applications.     

Red Pigment Formation by the Reaction of Oxidized Ascorbic Acid and Protein in a Food Model System of Low Moisture Content

Ascorbic acid-protein mixtures of low moisture content stored for 2~3 days in aerobic conditions at 60°C produced a red coloration, which was shown to have resulted from an amino-carbonyl reaction of oxidized ascorbic acid (dehydroascorbic acid, DHA) by the facts that DHA-casein or ovalbumin systems yielded a rapid red coloration in low moisture conditions as well as in an ethanol suspension. Zein showed only a weak red coloration with DHA. An apparent decrease in the free amino group, as determined by the TNBS method, was observed to be associated in parallel with the red pigment formation. The electrophoretic pattern of ovalbumin changed significantly upon incubation with DHA, together with the formation of the red pigment. The red pigment extracted from a DHA-casein system showed an absorption spectrum, TLC Rf value, and hydrolyzed products (DHA and scorbamic acid) identical to those of 2,2′-nitrilo di-2(2)-deoxy-l-ascorbic acid mono ammonium salt, produced from DHA and amino acid. Formation of the red pigment was also observed in the reaction of DHA with N_α-acetyl lysine. These results indicate that the ε-amino group of lysine in protein can be attributed to the formation of a red pigment identical with NDA.     

Optical properties of some freshwater phytoplanktonic algae

Measurements of absorption and scattering of light by pure cultures of some New Zealand freshwater phytoplankters have been made with a spectrophotometer. An integrating sphere accessory was used to capture most of the light scattered by an algal cell suspension and thus give an indication of the true absorption coefficient, with only a small correction required for residual scattering. The purpose of this study was to investigate the factors affecting the relationships of chlorophyll-a concentration to absorption and scattering by a diverse selection of algae. Qualitative differences in absorption spectra of the different phytoplankton studied here can be related to differences in pigment composition. Quantitative differences in the specific absorption coefficients (absorption coefficient divided by Chl-a concentration) at the Chl-a red peak (676 nm in vivo) are explained in terms of different extents of packaging of pigment in cells or cell aggregates in the different cultures. Qualitative differences in scattering spectra are explained in terms of optical size of the particulates comprising the pure cultures. The green and diatom cultures displayed a complex-shaped but non-trending scattering spectrum with minima (troughs) in scattering associated with maxima (peaks) in absorption. The blue-green cultures behaved as optically small particles and displayed a pattern of decreasing scattering with increasing wavelength. Quantitative differences in specific scattering coefficients (scattering coefficient divided by Chl-a concentration) were related mainly to differences in the effective ratio of surface areas to Chl-a content of scattering centres in the different cultures. Overall, however, the specific absorption and scattering coefficients at any given wavelength were less variable between cultures than expected suggesting that the common assumption that absorption and scattering by the algal component of a lake water depends only on the Chl-a concentration may be a justifiable first approximation in field studies.     

Cassane diterpenoids from the stem of Caesalpinia pulcherrima

Cassane diterpenoids: pulcherrin A, pulcherrin B, pulcherrin C, neocaesalpin P, neocaesalpin Q and neocaesalpin R, together with eight known compounds: isovouacapenol C, 6β-cinnamoyl-7β-hydroxy-vouacapen-5α-ol, pulcherrimin E, pulcherrimin C, α-cadinol, 7-hydroxycadalene, teucladiol and bonducellin were isolated from the stem of Caesalpinia pulcherrima. The chemical structures were elucidated by analysis of their spectroscopic data.     

Effect of carbon dioxide on pigment and membrane content in Synechococcus lividus

The effect of carbon dioxide on pigment and membrane content in Synechococcus lividus was studied by depriving cells of CO₂ and examining cell populations biochemically and by electron microscopy. After 120 h of CO₂ deprivation, S. lividus lost all detectable chlorophyll a and C-phycocyanin. Such bleached cultures were mustard yellow, the result of approximately 1.8 times more carotenoid per cell than green control cultures.Although cells from beached cultures appeared morphologically identical to control green cells when examined by light microscopy, electron microscopic examination revealed them to be devoid of detectable thylakoid membrane. Thylakoid membrane could not be recovered by physical isolation or revealed by freeze etching of bleached S. lividus. In addition, inclusion bodies characteristically found in S. lividus were also absent.Reintroduction of CO₂ into bleached cultures resulted in a rapid resynthesis of both chlorophyll a and C-phycocyanin. Electron microscopic examination of these regreening cultures revealed that thylakoid membrane was also rapidly resynthesized. Growth of regreened cultures did not occur until there was the synthesis of a full complement of chlorophyll a, C-phycocyanin, and thylakoid membrane.A time course study of the cytological events occurring during bleaching and regreening is presented.     

Repeated harvest of vacuole-located secondary product from in vitro grown plant cells using 1.02 MHz ultrasound

Summary Beta vulgaris L. (red beetroot) cells from a suspension culture were sonicated with continuous wave ultrasound (1.02 MHz) for periods ranging from 10 s to 60 s. In general, cells sonicated for 30 s released vacuole-located pigment into the surrounding medium, whereas cells sonicated for < 30 s and control (unsonicated) cells released no pigment. Sonicated cells were viable as determined using fluorescein diacetate: microscopic examination of a selected population of sonicated cells did not show any signs of obvious structural damage. Sonicated cell samples were subcultured to re-establish actively growing, pigment-competent cell cultures. Cells from such cultures were available for further harvests of the pigment by sonication. For sonication periods 50 s, repeated cycles of sonication and incubation allowed pigments to be harvested from cells every 7 days during a 21-day culture period. Offprint requests to: N. J. Kilby     

Dependence of the maximum temperature for growth of Saccharomyces cerevisiae on nutrient concentration

Anacystis nidulans (Synechococcus) was maintained in a medium of low phosphate concentration (0.1 mM) and grew with a normal doubling time of 5 hrs at 30°C. Such cultures ahd a normal pigment composition and alkaline phosphatase was detectable at low specific activities only.The onset of phosphate-limited growth occurred when the phosphate concentration in the medium fell to a value below 4 M (the limit of accurate determination by the assay method used) and resulted in increases in alkaline phosphatase activity, reaching a final 10 to 15 fold increase in specific activity after a period of several hours. Marked changes in the overall pigment composition occurred in this period of growth restriction. The addition of phosphate to such cultures resulted in a halt in synthesis of the enzyme and the restoration of normal pigmentation before growth resumed at the normal rate.Several organic phosphate esters could replace inorganic phosphate for growth and were also hydrolyzed by the partially purified enzyme, but growth rates were characteristically lower and the specific activity only 3 to 4 fold higher than in cultures grown in phosphate excess.Studies with the partially purified enzyme suggested that it differed in some of its properties from other alkaline phosphatases described in the literature.Abbreviations Used pNP pnitrophenol - pNPP pnitrophenylphosphate     

Microspectrophotometric characterization and localization of three visual pigments in the compound eye ofNotonecta glauca L. (Heteroptera)

Summary The absorption maxima ( _max) of the visual pigments in the ommatidia ofNotonecta glauca were found by measuring the difference spectra of single rhabdomeres after alternating illumination with two different adaptation wavelengths. All the peripheral rhabdomeres contain a pigment with an extinction maximum at 560 nm. This pigment is sensitive to red light up to wavelengths > 700 nm. In a given ommatidium in the dorsal region of the eye, the two central rhabdomeres both contain one of two pigments, either a pigment with an absorption maximum in the UV, at 345 nm, or — in neighboring rhabdoms — a pigment with an absorption maximum at 445 nm. In the ventral part of the eye only the pigment absorbing maximally in the UV was found in the central rhabdomeres. The spectral absorption properties of various types of screening-pigment granules were measured.     

Red Pigment Produced by the Reaction of Dehydro-l-ascorbic Acid with α-Amino Acid

At the initial stage of the browning reaction of dehydro-l-ascorbic acid (DHA) with α-amino acid, a kind of red pigment was produced. The pigment was isolated as very hygroscopic red powder from non-aqueous reaction system, and its characterization was made. It was revealed that it had the same structure with that of the red pigment produced by the oxidation of l-scorbamic acid, an intermediate amino-reductone expected to be produced by Strecker degradation. Formation mechanism of the pigment which was considered to be an intermediate of browning reaction of DHA with α-amino acid was also discussed.     

Pigmentation and Acriflavine Resistance in Serratia marcescens

Stable, orange, acriflavine-resistant variants were selected by treatment of a wild-type, red, acriflavine-sensitive strain of Serratia marcescens with acriflavine. Visible, ultraviolet, infrared, and nuclear magnetic resonance spectra of purified pigment from the red strain were identical to those of the pigment from the orange strain, and the orange mutant was not due to a mutation affecting the structure of the pigment, prodigiosin. The color of the red strain was not affected by variations in pH between 5.0 and 8.0, whereas the color of the orange mutant changed from pink to orange over the same pH range. This variation was mimicked by the pH-induced variation in color of prodigiosin purified from either the red, wild-type or the orange, mutant strains. Density-gradient centrifugation of cell fragments after ultrasonic disintegration resulted in characteristic pigmented bands. Biochemical characterization of these pigmented bands showed that they contained pigment and a protein component, but no lipids, polysaccharides, sugars, glucosamine, or phosphates were detected. Further fractionation of these pigmented bands by zone electrophoresis on a sucrose density gradient indicated that some pigment in S. marcescens was specifically attached to protein components.     

Interaction between Phycobilisomes from <Emphasis Type="Italic">Porphyridium cruentum</Emphasis> and Thylakoid Membranes from <Emphasis Type="Italic">Gymnodinium</Emphasis> sp. or Spinach

Thylakoid membranes were isolated from Gymnodinium sp. and spinach, whereas the phycobilisomes were isolated and purified from red alga Porphyridium cruentum. The absorption spectra of the purified phycobilisomes (PBS) showed three peaks at 548, 564, and 624 nm, respectively, and the ratio of the fluorescence intensity at the ₆₈₀ ^em to that at ₅₈₀ ^em was about 7.3. All these results demonstrated that the purified PBS remained intact. The thylakoid membranes were incubated with the purified phycobilisomes, and the thylakoid membranes, which harbored the phycobilisomes, were purified by sucrose density gradient centrifugation. Meantime, the conjugates of phycobilisome-thylakoid membranes were constructed using glutaraldehyde and further purified. Their characteristics were studied by measuring the absorption spectra and fluorescence emission spectra. The results showed that the phycobilisomes from Porphyridium cruentum can attach to the thylakoid membranes from Gymnodinium sp. and spinach without covalent cross-linking, but the excited energy transfer did not occur. The conjugate of phycobilisome-thylakoid membranes with covalent cross-linking exhibits the excited energy transfer between the phycobilisomes and the thylakoid membranes.__________From Fiziologiya Rastenii, Vol. 52, No. 3, 2005, pp. 331–337.Original English Text Copyright © 2005 by Zhu, Wang, Tseng.This article was submitted by the authors in English.     

Biofilm formation onto starch fibres by Bacillus subtilis governs its successful adaptation to chickpea milk

Beneficial biofilms may confer effective adaptation to food matrices that assist bacteria in enduring hostile environmental conditions. The matrices, for instance, dietary fibres of various food products, might serve as a natural scaffold for bacterial cells to adhere and grow as biofilms. Here, we report on a unique interaction of Bacillus subtilis cells with the resistant starch fibresof chickpea milk (CPM), herein CPM fibres, along with the production of a reddish-pink pigment. Genetic analysis identified the pigment as pulcherrimin, and also revealed the involvement of Spo0A/SinI pathway in modulating the observed phenotypes. Besides, through successful colonization of the CPM fibres, the wild-type cells of B. subtilis displayed enhanced survivability and resilience to environmental stress, such as heat and in vitro gastrointestinal treatments. In total, we infer that the biofilm formation on CPM fibres is an adaptation response of B. subtilis for strategic survival.     

Superoxide dismutase from Mycobacterium species,strain Takeo

Superoxide dismutase from Mycobacterium species, strain Takeo, has been purified to homogeneity as judged by disc gel electrophoresis and ultracentrifugation. The enzyme was found to have a molecular weight of approximately 61 500 by sedimentation equilibrium and to contain manganese by atomic absorption and electron spin resonance spectra. The amino acid composition was also determined. The enzyme was considerably stable to the treatment with sodium dodecyl sulfate; unless incubating at 80°C for 2 min, it was not completely dissociated into the subunits. The molecular weight of the subunit was found to be approximately 21 000. Antibodies against the superoxide dismutase were produced by immunization of rabbits with the enzyme, and the -globulin fraction was purified. Superoxide dismutase preparations obtained from various species of mycobacteria and nocardia cross-reacted to different degrees with these antibodies on the Ouchterlony double diffusion plates. Comparative immunological studies indicated that strain Takeo might be most closely related to Myobacterium smegmatis among species of mycobacteria and nocardia tested. The antibodies against superoxide dismutase may be used as a valuable tool for the classification of mycobacteria.     

Natural occurrence of denatured phycoerythrin during Porphyra cultivation

Dried Nori (Porphyra spp.) normally turns greenish when toasted and this color usually remains for many days when moistened with vinegar in the Japanese food Sushi. However, for some lots of toasted Nori, this color changes to an undesirable reddish-brown one within a few hours in vinegar. A clear difference was noticed by spectrophotometry between the abnormally and normally colored toasted Nori. The former exhibited absorption maxima at around 490 and 530–600 nm while these were absent in the spectrum of the latter. The responsible pigment for the abnormal coloration was purified by ammonium sulfate fractionation and preparative flat-bed isoelectric focusing. On the basis of pI, molecular weight and the visible absorption, fluorescence and circular dichroism spectra, the pigment was identified as monomeric phycoerythrin. Dried Nori contained three times as much monomer as hexamer. From field cultivation tests, dried Nori produced large amounts of monomeric phycoerythrin when the fronds on frozen nursery-nets were damaged.     

Properties of phytochrome in gymnosperms

Summary Addition of water to dry seeds of Pinus spp. increased the detectable phytochrome immediately and the level reached after 2 h in darkness was retained for at least 20 h at 20° C. The in-vivo difference spectra of phytochrome in Pinus seeds showed absorption maxima at approximately 656 nm and at 710 nm to 715 nm. An isosbestic point was observed at about 680 nm. Shifts towards longer wavebands were obtained especially with tissue containing substantial amounts of chlorophyll and are, therefore, not due to diverse types of phytochrome. Embryo tissue of Ginkgo biloba showed also a maximum in R at 655 nm but the peak in FR occurred at a longer wavelength, 725 nm. This was confirmed by determining action spectra for the phototransformations P_rP_fr.The dark reactions of phytochrome in Pinus differed from those in Ginkgo. Following a short exposure to R light, the total quantity of photoreversible pigment in Pinus seeds remained constant for several hours in darkness at room temperature. Dark reversion of P_fr occurred extremely rapidly and tP_fr 50 was only 0.3 h. In Ginkgo embryos total phytochrome in darkness following a brief exposure to R light was not completely stable. Reversion of P_fr was much slower and tP_fr 50 was slightly less than 2 h.It is concluded that, at least as regards the spectral qualities, the phytochrome in Gymnospermae differs from that of Angiospermae and is apparently also not identical in Coniferae and Ginkgoinae. Abbreviations. R = red; FR = far-red; R/FR ratio = (A) red max./(A) far-red max. of difference spectrum. The peak positions and the isosbestic point are estimated from the difference spectra and are approximate only. P_r = red-absorbing form of phytochrome, P_fr = far-red absorbing formThis work was carried out with financial support from the Netherlands Organisation for Pure Scientific Research (Z.W.O.).312th Communication.     

Identification and characterization of a brilliant yellow pigment produced by Bordetella pertussis

Culture supernatants of Bordetella pertussis are a brilliant yellow; however, the structure and biological role of the responsible pigment have not been investigated. In this study, a brilliant yellow‐colored fraction was extracted from culture supernatants of B. pertussis and analyzed by HPLC. UV–visible spectral analysis and mass spectrometry identified the brilliant yellow pigment as riboflavin. Riboflavin production was high in lag and early log phases and riboflavin was found to enhance growth of B. pertussis in low‐density cultures. Riboflavin production is not regulated by the BvgAS system. In addition, it was found that other Bordetella species, such as B. parapertussis , B. holmesii and B. bronchiseptica, also release riboflavin into their culture supernatants. This is the first report that B. pertussis secrets riboflavin to the extracellular space and that riboflavin may promote its growth. The mechanism may be associated with pathogenesis of B. pertussis .

     

An ultraviolet light induced bacteriophage inBeneckea gazogenes

An ultraviolet light induced prophage has been discovered in the red pigmented marine vibrioBeneckea gazogenes. Two spontaneously derived pigment mutants, one forming pink colonies and one lacking pigment and forming white colonies, were also irradiated. The presence of pigment was not related to phage induction; uv-induced cell lysis occurred in wildtype and mutant strains at the same dosages. Lysis was not prevented or retarded by exposure after irradiation to visible light indicating the phenomenon was not photoreactivable. Electron micrographs of the T-likeB. gazogenes phage are shown.A second beneckea was isolated from the anaerobic zone of cyanobacterial mats growing in the hypersaline environment of Laguna Mormona, Baja California. The Baja beneckea does not harbor a uv inducible prophage and is resistant to theB. gazogenes phage under all conditions tested.     

Photoregeneration of visual pigments in a moth

Summary The spectral absorbance by the visual pigments in the compound eye of the mothDeilephila elpenor was determined by microphotometry. Two visual pigments and their photoproducts were demonstrated. The photoproducts are thermostable and are reconverted to the visual pigments by light. The concentrations of the visual pigments and the photoproducts at each wavelength are determined by their absorbance coefficients at this wavelength. P 525: The experimental recordings (difference spectra and spectral absorbance changes after exposure to monochromatic lights) were completely reproduced by calculations using nomograms for vertebrate rhodopsin. The identity between experimental recordings and calculations show: One visual pigment absorbs maximally at 525 nm (P 525). The resonance spectrum of the visual pigment is identical to that for a vertebrate rhodopsin (_max at 525 nm). The photoproduct of this pigment absorbs maximally at 480 nm (M 480). It is similar to the acid metarhodopsin in cephalopods. The relative absorbance of P 525 to that of M 480 is 11.75. The quantum efficiency for photoconversion of P 525 to M 480 is nearly equal to that for reconversion of M 480 to P 525. Wavelengths exceeding about 570 nm are absorbed only by P 525, i. e. P 525 is completely converted to M 480. Shorter wavelengths are absorbed both by P 525 and M 480. At these wavelengths a photoequilibrium between the two pigments is formed. Maximal concentration of P 525 is obtained at about 450 nm. P 350: A second visual pigment absorbs maximally at about 350 nm (P 350), and its photoproduct at 450 to 460 nm. In the region of spectral overlap a photoequilibrium between the two pigments is formed.The visual pigment and the photoproduct are similar to those in the neuropteran insectAscalaphus.The work reported in this article was supported by Deutsche Forschungsgemeinschaft, Schwerpunktsprogramm Rezeptorphysiologie Ha 258-10, and SFB 114, by the Swedish Medical Research Council (grant no B 73-04X-104-02B), by Karolinska Institutet, and by a grant (to G. Höglund) from Deutscher Akademischer Austauschdienst.     

The effect of yeast <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis> red pigment on the expression of cloned human α-synuclein

Two transgenic yeast strains expressing human α-synuclein were used to study the impact of yeast red pigment exhibiting antiamyloid properties. It has been demonstrated that the endogenous red pigment produced under special conditions in strains carrying an ade1 mutation inhibits the expression of the hybrid protein α-synuclein-GFP. This was evident from the reduced mean value of GFP fluorescence and diminished number of cells accumulating cytoplasmic inclusions of α-synuclein-GFP. Exogenous forms of the purified red pigment (natural, synthetic and hydrolyzed derivatives) differ from the endogenous red pigment by their effect on α-synuclein. Exogenous red pigments increased the number of both cells expressing GFP fluorescence and those containing cytoplasmic inclusions. However, both endogenous and exogenous red pigments reduced the cloned α-synuclein toxicity and resulted in redistribution of the α-synuclein in cells. α-Synuclein content decreased in cell lysate pellets and increased in supernatants.     

Responses of strawberry plantlets cultured in vitro under superbright red and blue light-emitting diodes (LEDs)

Unrooted strawberry cv. `Akihime' shoots with three leaves obtained from standard mixotrophic cultures were cultured in the ``Culture Pack'-rockwool system with sugar-free MS medium under CO<sub>2</sub>-enriched condition. To examine the effect of superbright red and blue light-emitting diodes (LEDs) on in vitro growth of plantlets, these cultures were placed in an incubator, ``LED PACK', with either red LEDs, red LEDs1blue LEDs or blue LEDs light source. To clarify the optimum blue and red LED ratio, cultures were placed in ``LED PACK 3' under LED light source with either 100, 90, 80, or 70% red + 0, 10, 20, 30% blue, respectively, and also under standard heterotrophic conditions. To determine the effects of irradiation level, cultures were grown under 90% red LEDs + 10% blue LEDs at 45, 60 or 75 mol m^–2 s^–1 . Plantlet growth was best at 70% red + 30% blue LEDs. The optimal light intensity was 60 mol m^–2 s^–1. Growth after transfer to soil was also best after in vitro culture with plantlets produced were 70% red LEDs + 30% blue LEDs.