cDNAs of barley α amylase and A.niger glucoamylase were cloned in one E.coli yeast shuttle plasmid resulting in the construction of expression secretion vector pMAG15. pMAG15 was transformed into S.cerevisiae GRF18 b...cDNAs of barley α amylase and A.niger glucoamylase were cloned in one E.coli yeast shuttle plasmid resulting in the construction of expression secretion vector pMAG15. pMAG15 was transformed into S.cerevisiae GRF18 by protoplast transformation. The barley α amylase and A.niger glucoamylase were efficiently expressed under the control of promoter and terminator of yeast PGK gene and their own signal sequence. Over 99% of the enzyme activity expressed was secreted to the medium. The recombinant yeast strain, S.cerevisiae GRF18(pMAG15), hydrolyzes 99% of the starch in YPS medium containing 15% starch in 47 h. The glucose produced can be used for the production of ethanol.展开更多
A laboratory experiment was conducted to demonstrate the importance of improving the efficiency of six isolates of Aspergillus niger fungi.Four isolates were exposed to UV-rays radiation at a distance of 30 cm,a wavel...A laboratory experiment was conducted to demonstrate the importance of improving the efficiency of six isolates of Aspergillus niger fungi.Four isolates were exposed to UV-rays radiation at a distance of 30 cm,a wavelength of 254–255 nm during M15,M30,and M45 minutes.Exposure periods,both of wild(no UV-rays exposure)and no A.niger(C)as controls,all six isolates were identified molecularly by polymerase chain reaction technique extracted DNA of A.niger was analyzed to ensure gene completion through multiple sequence alignment by bioinformatic programs to study the improvement of dissolving efficiency of mutant and wild A.niger.They were incubated after the addition of superphosphate fertilizer(47%P2O5)at 90 mg P kg–1 applied to soil with controls(no A.niger or no superphosphate)for I,II,III,and IV weeks of incubation periods at 28±1°C.In addition,the DNA extraction and purification by NanoDrop of Thermo Scientific-200 A280/A260 ratio was 2.01 and confirmed that the sequences of nitrogenous bases by the method of multiple sequence alignment(MSA)as compared to the reference sequence of A.niger recorded in the gene bank under the accession number LC632396.Results proved that the M30 minutes exposure UV-rays radiation period was the superior dose when mutant Aspergillus niger obtained the highest amount of dissolved phosphate,reducing soil-pH with maximum biomass of A.niger during the M30 isolate during the third week(III).展开更多
The combination of radio frequency(RF)heating and natamycin has been demonstrated to exert a synergistic fungicidal effect on Aspergillus niger spores in shiitake mushrooms.However,the underlying synergistic fungi-cid...The combination of radio frequency(RF)heating and natamycin has been demonstrated to exert a synergistic fungicidal effect on Aspergillus niger spores in shiitake mushrooms.However,the underlying synergistic fungi-cidal mechanism remains unclear.This study investigated the synergistic fungicidal mechanism of RF heating combined with natamycin against A.niger spores in shiitake mushrooms at cellular and molecular levels.Results indicated that the combined treatment improved membrane permeability and facilitated intracellular substance leakage,with an increase in OD260 value(0.530±0.039)and OD280 value(0.562±0.007),while a decrease in the ATP concentration(0.22±0.03μmol/L).Additionally,the mitochondrial function of spores was damaged,and the fluorescence intensity of reactive oxygen species content increased to 36.2±0.34 AU.A total of 1391 differentially expressed genes and 288 differentially expressed proteins were identified after the combined treatment.The primary mechanism of the combined treatment was the significant inhibition of intracellular ATP synthesis,oxidoreductase activity,transcription,and translation processes at both the transcript and protein levels.Furthermore,the combined treatment exacerbated damage to the cell membrane by intensifying dis-ruptions in membrane transport functions.These alterations in gene and protein expression triggered diverse cellular dysfunctions,ultimately resulting in a synergistic fungicidal effect on A.niger spores.This study provides theoretical support for controlling fungal contamination in agricultural products via the combined application of RF heating and natamycin.展开更多
Biogenic synthesis of inorganic nanoparticles has been emerging as an important branch of nanobiotechnology.Biogenic silver nanoparticles(AgNPs)are proved to be potential antimicrobial agents against an array of patho...Biogenic synthesis of inorganic nanoparticles has been emerging as an important branch of nanobiotechnology.Biogenic silver nanoparticles(AgNPs)are proved to be potential antimicrobial agents against an array of pathogens.Aqueous extract of shade dried leaves of Conyza ambigua was used for the synthesis of AgNPs.The UV-VIS absorption spectroscopy,SEM,XRD were carried out to assess the formation AgNPs.SEM image divulges that AgNPs are quite polydispersed,the size ranging from 56 nm.The above AgNPs were effective against A.niger,A.flavus and Sclerotium rolfsii.This study move towards biogenic synthesis of AgNPs using dried biomass appears to be cost effective,eco-friendly to that of conventional methods of nanoparticles synthesis.展开更多
文摘cDNAs of barley α amylase and A.niger glucoamylase were cloned in one E.coli yeast shuttle plasmid resulting in the construction of expression secretion vector pMAG15. pMAG15 was transformed into S.cerevisiae GRF18 by protoplast transformation. The barley α amylase and A.niger glucoamylase were efficiently expressed under the control of promoter and terminator of yeast PGK gene and their own signal sequence. Over 99% of the enzyme activity expressed was secreted to the medium. The recombinant yeast strain, S.cerevisiae GRF18(pMAG15), hydrolyzes 99% of the starch in YPS medium containing 15% starch in 47 h. The glucose produced can be used for the production of ethanol.
文摘A laboratory experiment was conducted to demonstrate the importance of improving the efficiency of six isolates of Aspergillus niger fungi.Four isolates were exposed to UV-rays radiation at a distance of 30 cm,a wavelength of 254–255 nm during M15,M30,and M45 minutes.Exposure periods,both of wild(no UV-rays exposure)and no A.niger(C)as controls,all six isolates were identified molecularly by polymerase chain reaction technique extracted DNA of A.niger was analyzed to ensure gene completion through multiple sequence alignment by bioinformatic programs to study the improvement of dissolving efficiency of mutant and wild A.niger.They were incubated after the addition of superphosphate fertilizer(47%P2O5)at 90 mg P kg–1 applied to soil with controls(no A.niger or no superphosphate)for I,II,III,and IV weeks of incubation periods at 28±1°C.In addition,the DNA extraction and purification by NanoDrop of Thermo Scientific-200 A280/A260 ratio was 2.01 and confirmed that the sequences of nitrogenous bases by the method of multiple sequence alignment(MSA)as compared to the reference sequence of A.niger recorded in the gene bank under the accession number LC632396.Results proved that the M30 minutes exposure UV-rays radiation period was the superior dose when mutant Aspergillus niger obtained the highest amount of dissolved phosphate,reducing soil-pH with maximum biomass of A.niger during the M30 isolate during the third week(III).
基金support of the Natural Science Foundation of Jiangsu Province(BK20220523)the National Natural Science Foundation of China(32302279).
文摘The combination of radio frequency(RF)heating and natamycin has been demonstrated to exert a synergistic fungicidal effect on Aspergillus niger spores in shiitake mushrooms.However,the underlying synergistic fungi-cidal mechanism remains unclear.This study investigated the synergistic fungicidal mechanism of RF heating combined with natamycin against A.niger spores in shiitake mushrooms at cellular and molecular levels.Results indicated that the combined treatment improved membrane permeability and facilitated intracellular substance leakage,with an increase in OD260 value(0.530±0.039)and OD280 value(0.562±0.007),while a decrease in the ATP concentration(0.22±0.03μmol/L).Additionally,the mitochondrial function of spores was damaged,and the fluorescence intensity of reactive oxygen species content increased to 36.2±0.34 AU.A total of 1391 differentially expressed genes and 288 differentially expressed proteins were identified after the combined treatment.The primary mechanism of the combined treatment was the significant inhibition of intracellular ATP synthesis,oxidoreductase activity,transcription,and translation processes at both the transcript and protein levels.Furthermore,the combined treatment exacerbated damage to the cell membrane by intensifying dis-ruptions in membrane transport functions.These alterations in gene and protein expression triggered diverse cellular dysfunctions,ultimately resulting in a synergistic fungicidal effect on A.niger spores.This study provides theoretical support for controlling fungal contamination in agricultural products via the combined application of RF heating and natamycin.
文摘Biogenic synthesis of inorganic nanoparticles has been emerging as an important branch of nanobiotechnology.Biogenic silver nanoparticles(AgNPs)are proved to be potential antimicrobial agents against an array of pathogens.Aqueous extract of shade dried leaves of Conyza ambigua was used for the synthesis of AgNPs.The UV-VIS absorption spectroscopy,SEM,XRD were carried out to assess the formation AgNPs.SEM image divulges that AgNPs are quite polydispersed,the size ranging from 56 nm.The above AgNPs were effective against A.niger,A.flavus and Sclerotium rolfsii.This study move towards biogenic synthesis of AgNPs using dried biomass appears to be cost effective,eco-friendly to that of conventional methods of nanoparticles synthesis.
