The effect of rhamnolipids （RL） on Cd^2＋ adsorption by Penicillium simplicissimum （P. simplicissimum） was studied. The maximum adsorption capacities of Cd^2＋ were obtained at pH 6.0 for the intact P. sirnpliciss...The effect of rhamnolipids （RL） on Cd^2＋ adsorption by Penicillium simplicissimum （P. simplicissimum） was studied. The maximum adsorption capacities of Cd^2＋ were obtained at pH 6.0 for the intact P. sirnplicissimurn and at pH 5.0 for the RL-pretreated P. simplicissimum, respectively. The adsorption equilibrium was reached after about 4 h. The experimental adsorption isotherms were in good agreement with the Langmuir model. The maximum adsorption capacities （qmax） for the intact P. simplicissimurn and for the RL-pretreated P. simplicissimum were 51.6 and 70.4 rag/g, respectively. The interactions between Cd^2＋ and functional groups on the cell wall surface of the P. simplicissimum were identified by SEM, EDAX and FTIR analysis. It is indicated that carboxyl, amino and hydroxyl groups play major roles in the Cd^2＋ adsorption. The results suggest that the RL-pretreated P. simplicissimum is a promising candidate for the removal of Cd^2＋ from aqueous solutions.展开更多
Penicillium simplicissimum was cultured and preserved on the potato dextrose agar(PDA)medium.PDA-RBBR(Remazal Brilliant Blue R)medium was used for the screening of the strains,which is able to produce enzymes.After th...Penicillium simplicissimum was cultured and preserved on the potato dextrose agar(PDA)medium.PDA-RBBR(Remazal Brilliant Blue R)medium was used for the screening of the strains,which is able to produce enzymes.After the mutation process in Penicillium simplicissimum induced by chemical reagent and ultraviolet radiation,a high laccase-producing strains Penicillium simplicissimum was obtained.When 5 m L diethyl sulfate(2%)was mixed along with 5 m L spore suspension for 30 min,chemical mutagenesis reached its best condition.And the optimum conditions of UV mutagenesis were that spore suspension was irradiated for 4 min under 15 W UV lamp at a distance of 30 cm.The highest activity of C_5E_4 strains was 4.80 U/g over 18%higher than the maximum laccase activity of original microorganism.Five generations of the mutant strains were cultured,and the laccase activity of the strains was measured.The result showed that C_5E_4 strains can product laccase of the five subcultures stably.展开更多
Filamentous fungi are able to accumulate significant amount of metals from their environment. The potential of fungal biomass as agents for biosorption of heavy metals from contaminated sediments is currently receivin...Filamentous fungi are able to accumulate significant amount of metals from their environment. The potential of fungal biomass as agents for biosorption of heavy metals from contaminated sediments is currently receiving attention. In the present study, a total of 41 isolates of filamentous fungi obtained from the sediment of the Langat River, Selangor, Malaysia were screened for their tolerance and uptake capability of copper （Cu） and lead （Pb）. The isolates were identified as Aspergillus niger, A. fumigatus, Trichoderma asperellum, Penicillium simplicissimurn and P. janthinellum. A. niger and P. simplicissimum, were able to survive at 1000 mg/L of Cu（Ⅱ） concentration on Potato Dextrose Agar （PDA） while for Pb, only A. niger survived at 5000 mg/L concentration. The results showed that A. niger, P. simplicissimum and T. asperellum have a better uptake capacity for Pb compared to Cu and the findings indicated promising biosorption of Cu and Pb by these filamentous fungi from aqueous solution. The present study was also determined the maximum removal of Cu（Ⅱ） and Pb（Ⅱ） that was performed by A. niger. The metal removal which occurred at Cu（Ⅱ） 200 mg/L was （20.910 ＋ 0.581） mg/g and at 250 mg/L of PbⅡ） was （54.046 ± 0.328） mg/g.展开更多
基金Project(50978087) supported by the National Natural Science Foundation of ChinaProject(CX2010B157) supported by the Hunan Provincial Innovation Foundation for Postgraduate,China
文摘The effect of rhamnolipids （RL） on Cd^2＋ adsorption by Penicillium simplicissimum （P. simplicissimum） was studied. The maximum adsorption capacities of Cd^2＋ were obtained at pH 6.0 for the intact P. sirnplicissimurn and at pH 5.0 for the RL-pretreated P. simplicissimum, respectively. The adsorption equilibrium was reached after about 4 h. The experimental adsorption isotherms were in good agreement with the Langmuir model. The maximum adsorption capacities （qmax） for the intact P. simplicissimurn and for the RL-pretreated P. simplicissimum were 51.6 and 70.4 rag/g, respectively. The interactions between Cd^2＋ and functional groups on the cell wall surface of the P. simplicissimum were identified by SEM, EDAX and FTIR analysis. It is indicated that carboxyl, amino and hydroxyl groups play major roles in the Cd^2＋ adsorption. The results suggest that the RL-pretreated P. simplicissimum is a promising candidate for the removal of Cd^2＋ from aqueous solutions.
基金Projects(51178172,51308076,51408206,51578222)supported by the National Natural Science Foundation of ChinaProject(113049A)supported by the Ministry of Education of China
文摘Penicillium simplicissimum was cultured and preserved on the potato dextrose agar(PDA)medium.PDA-RBBR(Remazal Brilliant Blue R)medium was used for the screening of the strains,which is able to produce enzymes.After the mutation process in Penicillium simplicissimum induced by chemical reagent and ultraviolet radiation,a high laccase-producing strains Penicillium simplicissimum was obtained.When 5 m L diethyl sulfate(2%)was mixed along with 5 m L spore suspension for 30 min,chemical mutagenesis reached its best condition.And the optimum conditions of UV mutagenesis were that spore suspension was irradiated for 4 min under 15 W UV lamp at a distance of 30 cm.The highest activity of C_5E_4 strains was 4.80 U/g over 18%higher than the maximum laccase activity of original microorganism.Five generations of the mutant strains were cultured,and the laccase activity of the strains was measured.The result showed that C_5E_4 strains can product laccase of the five subcultures stably.
基金UPM and the Fundamental Research Grant Scheme provided by Ministry of Higher Education under project no. 01-11-08-661FR for the financial support for some parts of this study
文摘Filamentous fungi are able to accumulate significant amount of metals from their environment. The potential of fungal biomass as agents for biosorption of heavy metals from contaminated sediments is currently receiving attention. In the present study, a total of 41 isolates of filamentous fungi obtained from the sediment of the Langat River, Selangor, Malaysia were screened for their tolerance and uptake capability of copper （Cu） and lead （Pb）. The isolates were identified as Aspergillus niger, A. fumigatus, Trichoderma asperellum, Penicillium simplicissimurn and P. janthinellum. A. niger and P. simplicissimum, were able to survive at 1000 mg/L of Cu（Ⅱ） concentration on Potato Dextrose Agar （PDA） while for Pb, only A. niger survived at 5000 mg/L concentration. The results showed that A. niger, P. simplicissimum and T. asperellum have a better uptake capacity for Pb compared to Cu and the findings indicated promising biosorption of Cu and Pb by these filamentous fungi from aqueous solution. The present study was also determined the maximum removal of Cu（Ⅱ） and Pb（Ⅱ） that was performed by A. niger. The metal removal which occurred at Cu（Ⅱ） 200 mg/L was （20.910 ＋ 0.581） mg/g and at 250 mg/L of PbⅡ） was （54.046 ± 0.328） mg/g.
