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1.
Plant Mol Biol ; 103(4-5): 443-456, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32270430

RESUMO

KEY MESSAGE: The simultaneous expression of AmRosea1 and AmDelila transcription factors from snapdragon can activate the anthocyanin pathway in orange carrots, leading to the synthesis and accumulation of anthocyanins in the taproots. Anthocyanins are phenolic compounds produced in various parts of plants. They are used as natural food dyes and are reported as beneficial antioxidants for humans. Black carrot is an important source for anthocyanins; however, the reason for the lack of anthocyanin production in the orange carrot is unknown. Anthocyanins are synthesized by a specific branch of the phenylpropanoid pathway that has previously been reported to be activated by a triad of R2R3-MYB, basic helix-loop helix (bHLH) and WD40 transcription factors (TFs). In the current study, orange carrots were turned purple by simultaneous expression of R2R3-MYB and bHLH TFs, i.e. AmRosea1 and AmDelila from snapdragon (Antirrhinum majus). Simultaneous transgenic expression of the TFs under a constitutive promoter in the orange carrot cultivar 'Danvers 126' lead to consistent upregulation of anthocyanin-related biosynthetic genes and significant accumulation of anthocyanins in leaves, stems and taproots. Highest overall content of soluble anthocyanins in the taproot among the transformants amounted to 44.38 mg g-1 dry weight. The anthocyanin profile of the transformants were significantly different from the profile in the reference black carrot 'Deep Purple'. The main anthocyanins present in the transformed taproots were cyanidin 3-xylosyl(sinapoylglucosyl)galactoside, whereas the main anthocyanin present in Deep Purple was cyanidin 3-xylosyl(feruloylglucosyl)galactoside. This study confirms the presence of the necessary biosynthetic genes in orange carrots for production of anthocyanins and demonstrates the absence of suitable R2R3-MYB and bHLH TFs for stimulating anthocyanin biosynthesis in the orange carrot.


Assuntos
Antocianinas/biossíntese , Antocianinas/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Daucus carota/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Vias Biossintéticas/genética , Cor , Daucus carota/genética , Genes de Plantas/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fenótipo , Pigmentos Biológicos/biossíntese , Pigmentos Biológicos/genética , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas , Fatores de Transcrição , Transformação Genética
2.
Chemosphere ; 242: 125261, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31896178

RESUMO

Seedling establishment consists of the former stage (i.e. skotomorphogenesis) and the latter stage (i.e. photomorphogenesis). Due to specific developmental processes in plants, the two stages may have different sensitivities to antibiotics. Tetracycline (TC), for example, is a major-use antibiotic. Radicle length, the relatively sensitive endpoint in plant skotomorphogenesis, is less sensitive than all of the indices of cotyledon colour and pigments in plant photomorphogenesis to TC stress. In conclusion, we suggest that plant photomorphogenesis may be more sensitive than plant skotomorphogenesis to stresses of antibiotics, but which needs further studies.


Assuntos
Antibacterianos/toxicidade , Brassica rapa/efeitos dos fármacos , Desenvolvimento Vegetal/efeitos dos fármacos , Plântula/efeitos dos fármacos , Poluentes do Solo/toxicidade , Tetraciclina/toxicidade , Proteínas de Arabidopsis/genética , Brassica rapa/crescimento & desenvolvimento , Brassica rapa/efeitos da radiação , Cotilédone/efeitos dos fármacos , Cotilédone/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Luz , Pigmentos Biológicos/biossíntese , Plântula/crescimento & desenvolvimento , Plântula/efeitos da radiação
3.
Appl Biochem Biotechnol ; 190(2): 391-409, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31363982

RESUMO

Microorganisms that survive in the high salt environment have been shown to be a potential source for metabolites with pharmaceutical importance. In the present study, we have investigated the effect of 5 and 10% (w/v) NaCl on growth, biochemical changes, and metabolite production in seven moderately halophilic bacteria isolated from the salterns/mangrove area of South India. Metabolite production by Bacillus VITPS3 increased by 3.18-fold in the presence of 10% (w/v) NaCl concentration. Total phenolic and flavonoid content increased in Bacillus VITPS5 (11.3-fold) and Planococcus maritimus VITP21 (5.99-fold) whereas ß-carotene content was less at higher NaCl concentrations. VITP21 and VITPS5, in response to NaCl, produced metabolites with higher (6.72- and 4.91-fold) DPPH and ABTS radical scavenging activity. UV/visible spectrophotometry of the extracts confirmed the presence of flavonoids, phenolics, and related compounds. 1H-NMR spectra indicated substantial changes in the metabolite production in response to salt concentration. Principal component analysis (PCA) revealed that VITP21 extracts exhibited the highest antioxidant activity compared with other extracts. The present study presents the first report on the comparative analysis of pigment production by moderate halophilic bacteria, in response to the effect of salt and their relation to radical scavenging property.


Assuntos
Antioxidantes/farmacologia , Bacillus/efeitos dos fármacos , Pigmentos Biológicos/biossíntese , Planococcus (Bactéria)/efeitos dos fármacos , Cloreto de Sódio/farmacologia , Bacillus/crescimento & desenvolvimento , Bacillus/metabolismo , Compostos de Bifenilo/metabolismo , Depuradores de Radicais Livres/farmacologia , Picratos/metabolismo , Planococcus (Bactéria)/crescimento & desenvolvimento , Planococcus (Bactéria)/metabolismo
4.
J Biosci Bioeng ; 129(2): 229-236, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31500988

RESUMO

Monascus pigments (MPs), the secondary metabolites produced by the fungal strains of Monascus spp., hold commercial importance in not only the food and meat industries, but also therapeutic, cosmetic, and textile industries. To reduce the cost of MPs production, the utilization of rice straw hydrolysate as a substrate in submerged fermentation was investigated. The atmospheric and room temperature plasma (ARTP) mutation system was employed to develop a mutant strain Monascus purpureus M630, with high total extracellular Monascus pigments (exMPs) production of 34.12 U/mL in submerged fermentation with glucose-based medium. The results revealed that M. purpureus M630 produces 8.61 U/mL and 20.86 U/mL of exMPs in rice straw hydrolysate alone or in combination with glucose fermentation medium, respectively. Furfural (Fur) and 5'-hydroxymethyl furfural (5'-HMF), produced during pretreatment and hydrolysis of rice straw; are generally inhibitory for microbial growth and fermentation. Our findings revealed that M. purpureus M630 develops the tolerance and adaptation mechanisms in response to 5'-HMF and Fur during growth and MPs biosynthesis in rice straw hydrolysate. In conclusion, we report that rice straw hydrolysate can serve as an efficient and low-cost substitute for the MP production through submerged fermentation by Monascus spp.


Assuntos
Monascus/metabolismo , Oryza/metabolismo , Pigmentos Biológicos/biossíntese , Análise Custo-Benefício , Fermentação , Glucose/metabolismo , Hidrólise , Pigmentos Biológicos/economia , Especificidade por Substrato
5.
Crit Rev Food Sci Nutr ; 60(3): 391-405, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-30706720

RESUMO

The versatile use of biopigments in food, feed, cosmetic, pharmaceutical and analytical industries emphasized to find different and renewable sources of biopigments. Microalgae, including cyanobacteria, are becoming a potential candidate for pigment production as these have fast-growing ability, high pigment content, highly variable and also have "Generally recognized as safe" status. These algal groups are known to produce different metabolites that include hormones, vitamins, biopolythene and biochemicals. We discuss here the potential use of microalgal biopigments in our daily life as well as in food and cosmetic industries. Pigment like carotenoids has many health benefits such as antioxidant, anti-inflammatory properties and also provide photo-protection against UV radiation. This review details the effect of various abiotic and biotic factors such as temperature, light, nutrition on maximizing the pigment content in the microalgal cell. This review also highlights the potential of microalgae, whether in present native or engineered strain including the many metabolic strategies which are used or can be used to produce a higher amount of these valuable biopigments. Additionally, future challenges in the context of pigment production have also been discussed.


Assuntos
Biotecnologia , Engenharia Genética , Engenharia Metabólica , Microalgas/genética , Microalgas/metabolismo , Pigmentos Biológicos/biossíntese , Carotenoides/metabolismo , Cianobactérias/genética , Cianobactérias/metabolismo , Microalgas/efeitos da radiação
6.
Phytopathology ; 110(2): 278-286, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31613175

RESUMO

A characteristic feature of phytopathogenic Xanthomonas bacteria is the production of yellow membrane-bound pigments called xanthomonadins. Previous studies showed that 3-hydroxybenzoic acid (3-HBA) was a xanthomonadin biosynthetic intermediate and also, that it had a signaling role. The question of whether the structural isomers 4-HBA and 2-HBA (salicylic acid) have any role in xanthomonadin biosynthesis remained unclear. In this study, we have selectively eliminated 3-HBA, 4-HBA, or the production of both by expression of the mhb, pobA, and pchAB gene clusters in the Xanthomonas campestris pv. campestris strain XC1. The resulting strains were different in pigmentation, virulence factor production, and virulence. These results suggest that both 3-HBA and 4-HBA are involved in xanthomonadin biosynthesis. When both 3-HBA and 4-HBA are present, X. campestris pv. campestris prefers 3-HBA for Xanthomonadin-A biosynthesis; the 3-HBA-derived Xanthomonadin-A was predominant over the 4-HBA-derived xanthomonadin in the wild-type strain XC1. If 3-HBA is not present, then 4-HBA is used for biosynthesis of a structurally uncharacterized Xanthomonadin-B. Salicylic acid had no effect on xanthomonadin biosynthesis. Interference with 3-HBA and 4-HBA biosynthesis also affected X. campestris pv. campestris virulence factor production and reduced virulence in cabbage and Chinese radish. These findings add to our understanding of xanthomonadin biosynthetic mechanisms and further help to elucidate the biological roles of xanthomonadins in X. campestris pv. campestris adaptation and virulence in host plants.


Assuntos
Hidroxibenzoatos , Parabenos , Pigmentos Biológicos , Xanthomonas campestris , Hidroxibenzoatos/metabolismo , Parabenos/metabolismo , Pigmentos Biológicos/biossíntese , Pigmentos Biológicos/genética , Doenças das Plantas/microbiologia , Fatores de Virulência/genética , Xanthomonas campestris/genética , Xanthomonas campestris/metabolismo , Xanthomonas campestris/patogenicidade
7.
Nat Commun ; 10(1): 5757, 2019 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-31848330

RESUMO

Tradeoffs affect resource allocation during development and result in fitness consequences that drive the evolution of life history strategies. Yet despite their importance, we know little about the mechanisms underlying life history tradeoffs. Many species of Colias butterflies exhibit an alternative life history strategy (ALHS) where females divert resources from wing pigment synthesis to reproductive and somatic development. Due to this reallocation, a wing color polymorphism is associated with the ALHS: either yellow/orange or white. Here we map the locus associated with this ALHS in Colias crocea to a transposable element insertion located downstream of the Colias homolog of BarH-1, a homeobox transcription factor. Using CRISPR/Cas9 gene editing, antibody staining, and electron microscopy we find white-specific expression of BarH-1 suppresses the formation of pigment granules in wing scales and gives rise to white wing color. Lipid and transcriptome analyses reveal physiological differences associated with the ALHS. Together, these findings characterize a mechanism for a female-limited ALHS.


Assuntos
Borboletas/fisiologia , Elementos de DNA Transponíveis/genética , Loci Gênicos , Proteínas de Homeodomínio/genética , Traços de História de Vida , Animais , Sistemas CRISPR-Cas/genética , Cor , Feminino , Edição de Genes/métodos , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Homeodomínio/metabolismo , Masculino , Pigmentação/genética , Pigmentos Biológicos/biossíntese , Reprodução/genética , Fatores Sexuais , Sequenciamento Completo do Genoma , Asas de Animais/metabolismo , Asas de Animais/ultraestrutura
8.
J Agric Food Chem ; 67(49): 13673-13683, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31617717

RESUMO

Because Monascus pigments (MPs) predominantly accumulate in the cytoplasm during submerged fermentation, many biotechnologies are applied to enhance the production of extracellular MPs (exMPs) to reduce the downstream processing costs. In this study, the genes monascus_7017 and monascus_8018, identified as ERG4 genes, were knocked out to disrupt the ergosterol biosynthetic pathway and enhance the production of exMPs in Monascus purpureus LQ-6. Double-deletion of EGR4 in M. purpureus LQ-6 reduced ergosterol concentration by 57.14% and enhanced exMP production 2.06-fold. In addition, integrated transcriptomic and proteomic analyses were performed to elucidate the transmembrane secretion mechanism of exMPs based on the relationship between ergosterol synthesis and membrane permeability, which revealed that several metabolic pathways were noticeably dynamic, including fatty acid degradation, amino acid metabolism, energy metabolism, carbohydrate metabolism, and transport. These findings therefore clarified the secretion mechanism of exMPs and provide a novel strategy for further enhancement of exMP production in submerged fermentation.


Assuntos
Membrana Celular/metabolismo , Ergosterol/biossíntese , Monascus/metabolismo , Pigmentos Biológicos/biossíntese , Vias Biossintéticas , Membrana Celular/genética , Permeabilidade da Membrana Celular , Fermentação , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Monascus/genética
9.
Bioprocess Biosyst Eng ; 42(12): 2015-2022, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31471708

RESUMO

Global energy demand is increasing every day and most is still derived from non-renewable sources. Therefore, sustainable alternatives are sought to produce biofuels, such as biodiesel. Several studies have demonstrated the potential of microalgae and cyanobacteria to produce biodiesel and pigments. These pigments, such as lutein and astaxanthin, have a high commercial value and can economically support the production of biodiesel. However, few studies have explored the potential of cyanobacteria collected in thermal water. In these microorganisms, both biomass and metabolites production can be altered by the culture form. Thus, a cosmopolitan filamentous cyanobacterium (Geitlerinema amphibium) from thermal water was collected and isolated to evaluate its potential to produce fatty acids, biodiesel, and pigments in two culture media. G. amphibium was cultured in WC (Wright's Cryptophyte) and BBM (Bold's Basal Medium) media. Thermal stress (40 °C for 48 h) was applied to the medium, which generated higher productivity of the biomass in BBM. The cyanobacterium contained higher biodiesel content in the WC medium and higher pigment content in the BBM medium. Thermal stress increased the biodiesel content by 350%, but decreased pigment content. Two pigments with high commercial value (astaxanthin and lutein) were identified. G. amphibium produced up to 2.74 mg g-1 of astaxanthin and 5.49 mg g-1 of lutein, which is seven times more lutein than Marigold, currently the main raw material used commercially. Therefore, G. amphibium has the potential to produce biodiesel, astaxanthin, and lutein concomitantly.


Assuntos
Biocombustíveis , Cianobactérias/metabolismo , Microbiologia Industrial/métodos , Pigmentos Biológicos/biossíntese , Água/química , Biomassa , Meios de Cultura , Ácidos Graxos/química , Lipídeos , Luteína/química , Microalgas , Análise de Regressão , Temperatura , Fatores de Tempo , Xantofilas/química
10.
World J Microbiol Biotechnol ; 35(9): 138, 2019 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-31451937

RESUMO

Monascus azaphilone pigments, including red, orange, and yellow, are world-famous food colorants. However, the pigments produced by different Monascus species vary in yields and compositions. The underlying mechanism is unclear. In this study, four wild-type Monascus strains, namely M. anka M7, M. purpureus M9, M. ruber C100, and M. aurantiacus M15, were selected as research objects according to the diversification of their pigments fermented in the same mediums and conditions. Twenty-three 3 kbp segments (300 bp overlap with adjacent segments) of the pigment gene cluster were amplified, sequenced, and assembled into the DNA sequences of the clusters. The DNA sequences of pigment biosynthetic gene clusters of the four strains showed 99.94% similarity according to the results of multiple alignment. The expression levels of 17 pigment biosynthetic genes of four strains were determined by using real-time quantitative PCR. The transcriptional regulation contributed more than the DNA sequence variation in Monascus pigments metabolism. Our result gives insight into the study of Monascus pigment biosynthesis.


Assuntos
Monascus/genética , Monascus/metabolismo , Pigmentos Biológicos/biossíntese , Transcrição Genética , Sequência de Aminoácidos , Sequência de Bases , Cor , DNA Fúngico/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Variação Genética , Monascus/química , Monascus/classificação , Família Multigênica , Filogenia , Pigmentos Biológicos/química
11.
Aquat Toxicol ; 215: 105281, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31446302

RESUMO

Phthalate esters are highly present in aquatic plastic litter, which can interfere with the biological processes in the wildlife. In this work, the commonly found freshwater microalga Scenedesmus sp. was exposed to environmental concentrations (0.02, 1 and 100 µg L-1) and to a higher concentration (500 µg L-1) of dibutyl phthalate (DBP), which is an environmental pollutant. The growth, pH variation, production of photosynthetic pigments, proteins and carbohydrates were evaluated. The main inhibition effect of DBP on the microalgal growth was observed in the first 48 h of the exposure (EC50: 41.88 µg L-1). A reduction in the photosynthetic pigment concentration was observed for the 0.02, 1 and 100 µg L-1 conditions indicating that the DBP downregulated the growth rate and affected the photosynthetic process. A significant increase in protein production was only observed under 500 µg L-1 DBP exposure. The extracellular carbohydrates production slightly decreased with the presence of DBP, with a stronger decrease occurring in the 500 µg L-1 condition. These results highlight the environmental risk evaluation and ecotoxicological effects of DBP on the production of biovaluable compounds by microalgae. The results also emphasize the importance of assessing the consequences of the environmental concentrations exposure as a result of the DBP dose-dependent correlation effects.


Assuntos
Dibutilftalato/toxicidade , Ecotoxicologia , Plásticos/toxicidade , Scenedesmus/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Proteínas de Algas/biossíntese , Carboidratos/biossíntese , Concentração de Íons de Hidrogênio , Fotossíntese/efeitos dos fármacos , Pigmentos Biológicos/biossíntese , Scenedesmus/crescimento & desenvolvimento
12.
Mar Drugs ; 17(7)2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31266176

RESUMO

Rare actinobacterial species are considered as potential resources of new natural products. Marisediminicola antarctica ZS314T is the only type strain of the novel actinobacterial genus Marisediminicola isolated from intertidal sediments in East Antarctica. The strain ZS314T was able to produce reddish orange pigments at low temperatures, showing characteristics of carotenoids. To understand the biosynthetic potential of this strain, the genome was completely sequenced for data mining. The complete genome had 3,352,609 base pairs (bp), much smaller than most genomes of actinomycetes. Five biosynthetic gene clusters (BGCs) were predicted in the genome, including a gene cluster responsible for the biosynthesis of C50 carotenoid, and four additional BGCs of unknown oligosaccharide, salinixanthin, alkylresorcinol derivatives, and NRPS (non-ribosomal peptide synthetase) or amino acid-derived compounds. Further experimental characterization indicated that the strain may produce C.p.450-like carotenoids, supporting the genomic data analysis. A new xanthorhodopsin gene was discovered along with the analysis of the salinixanthin biosynthetic gene cluster. Since little is known about this genus, this work improves our understanding of its biosynthetic potential and provides opportunities for further investigation of natural products and strategies for adaptation to the extreme Antarctic environment.


Assuntos
Actinobacteria/metabolismo , Produtos Biológicos/metabolismo , Vias Biossintéticas/genética , Genoma Bacteriano , Pigmentos Biológicos/biossíntese , Actinobacteria/genética , Regiões Antárticas , Mineração de Dados , Genômica/métodos , Família Multigênica , Filogenia
13.
BMC Plant Biol ; 19(1): 287, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31262258

RESUMO

BACKGROUND: The majority of apricot (Prunus armeniaca L.) cultivars display orange or yellow background skin, whereas some cultivars are particularly preferred by consumers because of their red blushed skin on the background. RESULTS: In this study, two blushed ('Jianali' and 'Hongyu') and two nonblushed ('Baixing' and 'Luntaixiaobaixing') cultivars were used to investigate the formation mechanism of blushed skin in apricots. High-performance liquid chromatography (HPLC) analysis showed that the blushed cultivars accumulated higher cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside and peonidin-3-O-rutinoside levels during fruit ripening than the nonblushed cultivars. Based on coexpression network analysis (WGCNA), a putative anthocyanin-related R2R3-MYB, PaMYB10, and seven structural genes were identified from transcriptome data. The phylogenetic analysis indicated that PaMYB10 clustered in the anthocyanin-related MYB clade. Sequence alignments revealed that PaMYB10 contained a bHLH-interaction motif ([DE]Lx2[RK]x3Lx6Lx3R) and an ANDV motif. Subcellular localization analysis showed that PaMYB10 was a nuclear protein. Real-time qRT-PCR analysis demonstrated that the transcript levels of PaMYB10 and seven genes responsible for anthocyanin synthesis were significantly higher in blushed than in nonblushed apricots, which was consistent with the accumulation of anthocyanin. In addition, bagging significantly inhibited the transcript levels of PaMYB10 and the structural genes in 'Jianali' and blocked the red coloration and anthocyanin accumulation. Transient PaMYB10 overexpression in 'Luntaixiaobaixing' fruits resulted in the red blushed skin at the maturation stage. CONCLUSIONS: Taken together, these data reveal that three anthocyanins are responsible for the blushed skin of apricots, identify PaMYB10 as a positive regulator of anthocyanin biosynthesis in apricots, and demonstrate that blush formation depends on light.


Assuntos
Antocianinas/biossíntese , Regulação da Expressão Gênica de Plantas , Pigmentos Biológicos/biossíntese , Proteínas de Plantas/genética , Prunus armeniaca/fisiologia , Fatores de Transcrição/genética , Sequência de Aminoácidos , Antocianinas/genética , Cromatografia Líquida de Alta Pressão , Cor , Frutas/genética , Frutas/fisiologia , Glucosídeos/biossíntese , Glucosídeos/genética , Filogenia , Pigmentos Biológicos/genética , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Prunus armeniaca/genética , Alinhamento de Sequência , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo
14.
Appl Microbiol Biotechnol ; 103(12): 4889-4897, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31037381

RESUMO

Conidia are asexual spores and play a crucial role in fungal dissemination. Conidial pigmentation is important for tolerance against UV radiation and contributes to survival of fungi. The molecular basis of conidial pigmentation has been studied in several fungal species. In spite of sharing the initial common step of polyketide formation, other steps for pigment biosynthesis appear to be species-dependent. In this study, we isolated an Aspergillus flavus spontaneous mutant that produced yellow conidia. The underlying genetic defect, a three-nucleotide in-frame deletion in the gene, AFLA_051390, that encodes a copper-transporting ATPase, was identified by a comparative genomics approach. This genetic association was confirmed by disruption of the wild-type gene. When yellow mutants were grown on medium supplemented with copper ions or chloride ions, green conidial color was partially and nearly completely restored, respectively. Further disruption of AFLA_045660, an orthologue of Aspergillus nidulans yA (yellow pigment) that encodes a multicopper oxidase, in wild type and a derived strain producing dark green conidia showed that it yielded mutants that produced gold conidia. The results placed formation of the gold pigment after that of the yellow pigment and before that of the dark green pigment. Using reported inhibitors of DHN-melanin (tricyclazole and phthalide) and DOPA-melanin (tropolone and kojic acid) pathways on a set of conidial color mutants, we investigated the involvement of melanin biosynthesis in A. flavus conidial pigment formation. Results imply that both pathways have no bearing on conidial pigment biosynthesis of A. flavus.


Assuntos
Aspergillus flavus/enzimologia , ATPases Transportadoras de Cobre/metabolismo , Proteínas Fúngicas/metabolismo , Pigmentos Biológicos/biossíntese , Esporos Fúngicos/enzimologia , Aspergillus flavus/genética , ATPases Transportadoras de Cobre/genética , Proteínas Fúngicas/genética , Deleção de Genes , Genômica , Melaninas/biossíntese , Mutação , Oxirredutases/metabolismo , Pigmentação/genética , Esporos Fúngicos/genética
15.
Biotechnol Lett ; 41(6-7): 813-822, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31069568

RESUMO

OBJECTIVE: To explore the secondary metabolite biosynthetic potential of Rubrivivax benzoatilyticus JA2 using a new metabolite mining strategy. RESULTS: Combination of precursor-feeding and altered growth conditions were used to mine new biomolecules. Strain JA2 utilised L-phenylalanine as sole source of nitrogen and showed pigments production only under phenylalanine-amended aerobic cultures. Stable isotope based precursor feeding studies indicated the blue pigment consists of 4-phenyl rings derived from L-phenylalanine. The purified blue pigment displayed characteristic visible-absorption and pH-dependent color variations. Precursor-feeding under altered growth conditions activated the plausible novel aromatic pigment production in strain JA2. CONCLUSION: Our approach unraveled the previously unknown pigment synthesis in strain JA2 and demonstrated the potential of mining strategy in discovering the hidden secondary metabolite repertoire in microorganisms.


Assuntos
Burkholderiales/crescimento & desenvolvimento , Burkholderiales/metabolismo , Pigmentos Biológicos/biossíntese , Aerobiose , Técnicas Bacteriológicas , Nitrogênio/metabolismo , Fenilalanina/metabolismo , Pigmentos Biológicos/química , Pigmentos Biológicos/isolamento & purificação
16.
J Dairy Sci ; 102(7): 5979-6000, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31128867

RESUMO

Some gram-negative bacteria, including Pseudomonas spp., can grow at refrigeration temperatures and cause flavor, odor, and texture defects in fluid milk. Historical and modern cases exist of gray and blue color defects in fluid milk due to Pseudomonas, and several recent reports have detailed fresh cheese spoilage associated with blue-pigment-forming Pseudomonas. Our goal was to investigate the genomes of pigmented Pseudomonas isolates responsible for historical and modern pigmented spoilage of dairy products in the United States to determine the genetic basis of pigment-forming phenotypes. We performed whole genome sequencing of 9 Pseudomonas isolates: 3 from recent incidents of gray-pigmented fluid milk (Pseudomonas fluorescens group), 1 from blue-pigmented cheese (P. fluorescens group), 2 from a historical blue milk spoilage incident (Pseudomonas putida group), and 3 with no evidence for blue or gray pigment formation (2 from P. fluorescens group and 1 from Pseudomonas chlororaphis group). All 6 isolates collected from products with a gray or blue pigment defect were confirmed to produce pigment using potato dextrose agar or pasteurized milk. A subset of 2 isolates was selected for inoculation into milk and onto the surface of a model cheese for subsequent color measurement. These isolates produced different colors on potato dextrose agar, but produced nearly identical color defects in milk and on model cheese. For the same subset of 2 isolates, the gray color defect in milk was produced only in containers with ample headspace and not in full containers, suggesting that oxygen is vital for pigment formation. This work also demonstrated that a Pseudomonas isolate from cheese can produce a pigment defect in milk, and vice versa. Comparative genomics identified an accessory locus encoding tryptophan biosynthesis genes that was present in all isolates that produced gray or blue pigment under laboratory conditions and was only previously reported in 2 P. fluorescens isolates responsible for blue mozzarella in Italy. Because this locus was found in genetically distant isolates belonging to different Pseudomonas species groups, it may have been acquired via horizontal gene transfer. These data suggest that several past and present gray- or blue-pigmented dairy spoilage events share a common genetic etiology that transcends species-level identification and merits further investigation to determine mechanistic details and modes of prevention.


Assuntos
Queijo/análise , Genoma Bacteriano/fisiologia , Leite/química , Pseudomonas fluorescens/genética , Pseudomonas putida/genética , Animais , Queijo/microbiologia , Cor , Loci Gênicos/fisiologia , Genômica , Itália , Leite/microbiologia , Fenótipo , Pigmentação , Pigmentos Biológicos/biossíntese , Pseudomonas fluorescens/metabolismo , Pseudomonas putida/metabolismo
17.
Plant Physiol Biochem ; 138: 130-139, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30870763

RESUMO

The flower color of Paeonia 'Coral Sunset' and 'Pink Hawaiian Coral' changes from coral to pink to pale yellow during flowering, which confers high ornamental value to these two cultivars. However, the molecular mechanism underlying flower color change is still unclear. In this study, flavonoids in petals of Paeonia 'Coral Sunset' and 'Pink Hawaiian Coral' at seven flowering stages were analyzed to explore the effects of the flavonoid component on changes in flower color. In addition, four cDNA libraries of 'Coral Sunset' during the critical blooming stages were constructed and the transcriptome was sequenced to investigate the molecular mechanism underlying changes to flower color. Two anthocyanins (cyanidin-3,5-di-O-glucoside and peonidin-3,5-di-O-glucoside) were detected in both cultivars. Total anthocyanin content in both cultivars accumulated continuously from stages 1-3 and then decreased sharply. Correlation analysis showed that the change in flower color from coral to pink to pale yellow is due to a significant decrease in anthocyanin content. A total of 91,583 Unigenes were obtained in 'Coral Sunset', 33,962 (37.08%) of which were annotated to major databases. Based on the enrichment analysis of differentially expressed genes, eight structural genes (CHS, F3H, F3'H, FLS, DRF, ANS, ANR and UFGT) and 13 transcription factors (five MYB, three bHLH, one WD40, one HY5, one PIF3, one COP1 and two PHY) related to flavonoid biosynthesis were screened. The qRT-PCR results were generally consistent with the high-throughput sequencing results. This research will provide a foundation to clarify the mechanisms underlying changes in flower color of herbaceous peony.


Assuntos
Antocianinas , Flores , Perfilação da Expressão Gênica , Genes de Plantas , Paeonia , Pigmentação/genética , Pigmentos Biológicos , Antocianinas/biossíntese , Antocianinas/genética , Flores/genética , Flores/metabolismo , Paeonia/genética , Paeonia/metabolismo , Pigmentos Biológicos/biossíntese , Pigmentos Biológicos/genética
18.
J Exp Biol ; 222(Pt 5)2019 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-30718374

RESUMO

Functional validation of candidate genes involved in adaptation and speciation remains challenging. Here, we exemplify the utility of a method quantifying individual mRNA transcripts in revealing the molecular basis of divergence in feather pigment synthesis during early-stage speciation in crows. Using a padlock probe assay combined with rolling circle amplification, we quantified cell-type-specific gene expression in the histological context of growing feather follicles. Expression of Tyrosinase Related Protein 1 (TYRP1), Solute Carrier Family 45 member 2 (SLC45A2) and Hematopoietic Prostaglandin D Synthase (HPGDS) was melanocyte-limited and significantly reduced in follicles from hooded crow, explaining the substantially lower eumelanin content in grey versus black feathers. The central upstream Melanocyte Inducing Transcription Factor (MITF) only showed differential expression specific to melanocytes - a feature not captured by bulk RNA-seq. Overall, this study provides insight into the molecular basis of an evolutionary young transition in pigment synthesis, and demonstrates the power of histologically explicit, statistically substantiated single-cell gene expression quantification for functional genetic inference in natural populations.


Assuntos
Corvos/fisiologia , Plumas/fisiologia , Regulação da Expressão Gênica , Especiação Genética , Pigmentação/genética , Pigmentos Biológicos/genética , RNA Mensageiro/genética , Animais , Cor , Corvos/genética , Plumas/crescimento & desenvolvimento , Melanócitos/metabolismo , Pigmentos Biológicos/biossíntese
19.
J Ind Microbiol Biotechnol ; 46(1): 101-111, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30377866

RESUMO

The interest in and demand for natural dyes has increased significantly in recent years; however, very few natural blue dyes are commercially available, because blue colored compounds in nature are relatively rare. In this study, a blue pigment-producing bacteria from Lake Chungará (Atacama Desert, Chile) was isolated, and its blue pigment was purified and chemically characterized. The pigment-producing strain was identified as Pseudarthrobacter sp. by 16S rRNA gene sequencing. The pigment was separated from the filtered culture medium by column chromatography/solid-phase extraction using different resins (ionic exchange, C-18, size exclusion). The strain produced up to 2.5 g L-1 of blue pigment, which was very soluble in water, partially soluble in methanol and insoluble in other organic solvents. The pigment was analyzed and characterized by analytical HPLC, UV-Vis, FT-IR, and H-NMR, and purified by semi-preparative HPLC. The pigment was non-toxic to brine shrimp (LD50 > 2.3 g L-1) and was stable at pH 6-10 at temperatures below 60 °C. HPLC analysis shows that the pigment is composed of four major blue fractions. The physicochemical properties and structural analysis demonstrate that this pigment belongs to the indochrome isomers, whose properties have yet to have been characterized. The high solubility in water, good stability in neutral and basic pH, and negligible toxicity of the blue pigment make it a good candidate suitable for several industrial and possibly some food applications.


Assuntos
Micrococcaceae/química , Pigmentos Biológicos/biossíntese , Animais , Artemia , Chile , Cromatografia Líquida de Alta Pressão , Cor , Meios de Cultura , Clima Desértico , Espectroscopia de Ressonância Magnética , Micrococcaceae/classificação , Micrococcaceae/isolamento & purificação , Pigmentos Biológicos/isolamento & purificação , RNA Ribossômico 16S/genética , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Testes de Toxicidade Aguda
20.
Benef Microbes ; 10(7): 759-771, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31965848

RESUMO

Bacillus species are becoming increasingly relevant for use as probiotics or feed additives where their heat stability can ensure survival in the food matrix or enable long-term storage at ambient temperature. Some Bacillus species are pigmented and in this study, we have examined two strains, one Bacillus pumilus (pigmented red) and the other Bacillus megaterium (pigmented yellow) for their safety for potential use in humans as dietary supplements. In addition, we have set out to determine if they might confer any potential health benefits. Both strains produce C30 carotenoids while the B. pumilus strain also produced large quantities of riboflavin equivalent to genetically modified Bacillus strains and most probably contributing to this strain's pigmentation. Riboflavin's and carotenoids are antioxidants, and we have evaluated the ability of vegetative cells and/or spores to influence populations of Faecalibacterium prausnitzii in the colon of mice. While both strains increased levels of F. prausnitzii, spores of the B. pumilus strain produced a significant increase in F. prausnitzii levels. If found to be reproducible in humans such an effect might, potentially, confer health benefits particularly for those suffering from inflammatory bowel disease.


Assuntos
Antioxidantes/metabolismo , Bacillus/metabolismo , Suplementos Nutricionais/análise , Trato Gastrointestinal/microbiologia , Pigmentos Biológicos/biossíntese , Probióticos , Animais , Antibacterianos/farmacologia , Bacillus/classificação , Carotenoides/metabolismo , Fezes/microbiologia , Feminino , Humanos , Camundongos , Riboflavina/biossíntese , Esporos Bacterianos/metabolismo
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