Unspecific peroxygenases(UPOs)are glycosylated enzymes that provide an efficient method for oxyfunctionalizing a variety of substrates using only hydrogen peroxide(H2O2)as the oxygen donor.However,their poor heterolog...Unspecific peroxygenases(UPOs)are glycosylated enzymes that provide an efficient method for oxyfunctionalizing a variety of substrates using only hydrogen peroxide(H2O2)as the oxygen donor.However,their poor heterologous expression has hindered their practical application.Here,a novel UPO from Marasmius fiardii PR910(MfiUPO)was identified and heterologously expressed in Pichia pastoris.By employing a two-copy expression cassette,the protein titer reached 1.18 g L−1 in a 5 L bioreactor,marking the highest record.The glycoprotein rMfiUPO exhib-ited a smeared band in the 40 to 55 kDa range and demonstrated hydroxylation,epoxidation and alcohol oxidation.Moreover,the peroxidative activity was enhanced by 150%after exposure to 50%(v/v)acetone for 40 h.A semipreparative production of 4-OH-β-ionone on a 100 mL scale resulted in a 54.2%isolated yield with 95%purity.With its high expression level,rMfiUPO is a promising candidate as an excellent parental template for enhancing desirable traits such as increased stability and selectivity through directed evolution,thereby meeting the necessary criteria for practical application.展开更多
To screen and characterize the analgesic components from Marasmius androsaceus, the water-soluble extracts from the mycelium of M. androsaceus were isolated by ethanol precipitation followed by macroporous resin chrom...To screen and characterize the analgesic components from Marasmius androsaceus, the water-soluble extracts from the mycelium of M. androsaceus were isolated by ethanol precipitation followed by macroporous resin chromatography and activity-based fractionation. Analgesic activities were found to be associated with glycopeptides. The glycopeptide fractions were further purified by gel-permeation chromatography and two purified glycopeptides, D2H, D2L, were obtained. Next, the physicochemical properties and characteristics of these purified glycopeptides were studied. They were composed of glucose and mannose and 10 different amino acids and with molecular weights of 18,000 and 8000 Da, respectively. The glycosidic linkages in the purified glycopeptides were analysed via methylation analysis. The sugar portion of the glycopeptides was composed of 1 - 4 linked Glc as the main chain with side chains composed primarily of Man linked to the 6 position of the main chain;the non-reducing terminal was composed of Glc. The glycosidic band in the main chain was identified as being in the β-configuration by the IR absorbance at 891 cm-1.展开更多
Nutrition is an important aspect of public health because it is linked to many significant diseases and health problems. This work is part of the promotion of traditional foods from the Democratic Republic of Congo in...Nutrition is an important aspect of public health because it is linked to many significant diseases and health problems. This work is part of the promotion of traditional foods from the Democratic Republic of Congo in general and in the province of Bandundu, in particular by assessing the selenium content and the antioxidant capacity of wild edible mushrooms. Methanolic extracts from selected mushrooms were characterized for their chemical fingerprint by TLC and their in vitro antioxidant activities using ABTS, DPPH assays. Phytochemical screening revealed the presence of alkaloids, free amines, steroids and terpenes in all species. However, Auricularia delicata and Pleurotus tuberregium contain flavonoids. All extracts displayed a good radical-scavenging activity at the concentration range 1 - 300 μg/mL in the following order: Auricularia delicata > Lentinus cf cladopus > Pleurotus tuberregium > Marasmius buzungolo > Schizophillum commune. Studied mushrooms showed the interest quantity of selenium and L. cf cladodus had the highest concentration. Moderate selenium content of these wild mushrooms associated with their important antioxidant activities could provide health benefits to Bandundu’s populations in protecting against oxidative damage under different conditions including konzo.展开更多
Musk macrolides are a kind of rare flavors structurally featuring 14-16 membered rings in the flavour and fragrance industry.While various chemical synthesis routes for musk macrolides exist,there is a growing interes...Musk macrolides are a kind of rare flavors structurally featuring 14-16 membered rings in the flavour and fragrance industry.While various chemical synthesis routes for musk macrolides exist,there is a growing interest in biocatalytic approaches.In this study,a new biocatalytic approach is proposed for the synthesis of musk macrolides from fatty acids using unspecific peroxygenases(UPOs)in combination with lipase.Specifically,the UPO from Marasmius rotula(MroUPO)was utilized as an oxidation catalyst together with the choline oxidase from Arthrobacter nicotinate(AnChOx)for the in situ generation of H_(2)O_(2).The enzymatic cascade process involved the hydroxylation of fatty acids using MroUPO as a catalyst to prepare terminal hydroxylated fatty acids.Under the optimized conditions,14-hydroxy tetradecanoic acid,15-hydroxy pentadecanoic acid and 16-hydroxy hexadecanoic acid were obtained at concentrations of 11.1,18.2 and17.1 mg/L in a 50-mL reaction system,respectively.These hydroxylated fatty acids were then separated and esterified by lipase Novozymes 435 to produce the desired macrolides.Variousω-hydroxy fatty acids were successfully converted into macrolides,with the concentrations of cyclotetradecanolide,cyclopentadecanolide and cyclohexadecanolide reaching 11,29 and 23 mg/L,respectively,in a 10-mL reaction system.This new biocatalytic approach represents a promising method for synthesizing valuable natural flavour compounds.展开更多
基金funded by the National Key Research and Development Program of China(2021YFC2102700)was Supported by the Key Science and Technology Innovation Project of Hubei Province(2021BAD001)as well as the Research Program of State Key Laboratory of Biocatalysis and Enzyme Engineering。
文摘Unspecific peroxygenases(UPOs)are glycosylated enzymes that provide an efficient method for oxyfunctionalizing a variety of substrates using only hydrogen peroxide(H2O2)as the oxygen donor.However,their poor heterologous expression has hindered their practical application.Here,a novel UPO from Marasmius fiardii PR910(MfiUPO)was identified and heterologously expressed in Pichia pastoris.By employing a two-copy expression cassette,the protein titer reached 1.18 g L−1 in a 5 L bioreactor,marking the highest record.The glycoprotein rMfiUPO exhib-ited a smeared band in the 40 to 55 kDa range and demonstrated hydroxylation,epoxidation and alcohol oxidation.Moreover,the peroxidative activity was enhanced by 150%after exposure to 50%(v/v)acetone for 40 h.A semipreparative production of 4-OH-β-ionone on a 100 mL scale resulted in a 54.2%isolated yield with 95%purity.With its high expression level,rMfiUPO is a promising candidate as an excellent parental template for enhancing desirable traits such as increased stability and selectivity through directed evolution,thereby meeting the necessary criteria for practical application.
文摘To screen and characterize the analgesic components from Marasmius androsaceus, the water-soluble extracts from the mycelium of M. androsaceus were isolated by ethanol precipitation followed by macroporous resin chromatography and activity-based fractionation. Analgesic activities were found to be associated with glycopeptides. The glycopeptide fractions were further purified by gel-permeation chromatography and two purified glycopeptides, D2H, D2L, were obtained. Next, the physicochemical properties and characteristics of these purified glycopeptides were studied. They were composed of glucose and mannose and 10 different amino acids and with molecular weights of 18,000 and 8000 Da, respectively. The glycosidic linkages in the purified glycopeptides were analysed via methylation analysis. The sugar portion of the glycopeptides was composed of 1 - 4 linked Glc as the main chain with side chains composed primarily of Man linked to the 6 position of the main chain;the non-reducing terminal was composed of Glc. The glycosidic band in the main chain was identified as being in the β-configuration by the IR absorbance at 891 cm-1.
文摘Nutrition is an important aspect of public health because it is linked to many significant diseases and health problems. This work is part of the promotion of traditional foods from the Democratic Republic of Congo in general and in the province of Bandundu, in particular by assessing the selenium content and the antioxidant capacity of wild edible mushrooms. Methanolic extracts from selected mushrooms were characterized for their chemical fingerprint by TLC and their in vitro antioxidant activities using ABTS, DPPH assays. Phytochemical screening revealed the presence of alkaloids, free amines, steroids and terpenes in all species. However, Auricularia delicata and Pleurotus tuberregium contain flavonoids. All extracts displayed a good radical-scavenging activity at the concentration range 1 - 300 μg/mL in the following order: Auricularia delicata > Lentinus cf cladopus > Pleurotus tuberregium > Marasmius buzungolo > Schizophillum commune. Studied mushrooms showed the interest quantity of selenium and L. cf cladodus had the highest concentration. Moderate selenium content of these wild mushrooms associated with their important antioxidant activities could provide health benefits to Bandundu’s populations in protecting against oxidative damage under different conditions including konzo.
基金supported by the Key Realm R&D Program of Guangdong Province(2022B0202050003)National Natural Science Foundation of China(31930084,32001633)。
文摘Musk macrolides are a kind of rare flavors structurally featuring 14-16 membered rings in the flavour and fragrance industry.While various chemical synthesis routes for musk macrolides exist,there is a growing interest in biocatalytic approaches.In this study,a new biocatalytic approach is proposed for the synthesis of musk macrolides from fatty acids using unspecific peroxygenases(UPOs)in combination with lipase.Specifically,the UPO from Marasmius rotula(MroUPO)was utilized as an oxidation catalyst together with the choline oxidase from Arthrobacter nicotinate(AnChOx)for the in situ generation of H_(2)O_(2).The enzymatic cascade process involved the hydroxylation of fatty acids using MroUPO as a catalyst to prepare terminal hydroxylated fatty acids.Under the optimized conditions,14-hydroxy tetradecanoic acid,15-hydroxy pentadecanoic acid and 16-hydroxy hexadecanoic acid were obtained at concentrations of 11.1,18.2 and17.1 mg/L in a 50-mL reaction system,respectively.These hydroxylated fatty acids were then separated and esterified by lipase Novozymes 435 to produce the desired macrolides.Variousω-hydroxy fatty acids were successfully converted into macrolides,with the concentrations of cyclotetradecanolide,cyclopentadecanolide and cyclohexadecanolide reaching 11,29 and 23 mg/L,respectively,in a 10-mL reaction system.This new biocatalytic approach represents a promising method for synthesizing valuable natural flavour compounds.
