The behavior of Cu2＋ and Zn2＋ biosorption onto raw and modified Roccella phycopsis from aqueous solutions was studied. Modification process was applied by autoclavation at 121°C for 30 min. The effcts of pH, in...The behavior of Cu2＋ and Zn2＋ biosorption onto raw and modified Roccella phycopsis from aqueous solutions was studied. Modification process was applied by autoclavation at 121°C for 30 min. The effcts of pH, initial metal concentration and biosorbent dosage were investigated. The maximum Cu2＋ biosorption was achieved at pH 5.0 and the maximum biosorption capacities of 31.5 and 37.8 mg/g were recorded for raw and modified biosorbent, respectively. In the case of Zn2＋ biosorption, maximum biosorption capacities were obtained at pH 4.0 as 29.1 and 35.3 mg/g for raw and modified biosorbent, respectively. Biosorption of Zn2＋ and Cu2＋ on all form of R. phycopsis increased much quickly with increasing initial metal concentrations from 10 to 100 mg/L. After modification process, probable changes in the surface polarity of raw and modified R. phycopsis were investigated by contact angle measurements. As expected, R. phycopsis has a polar surface and shows a highest contact angle with water, while after autoclavation water contact angle of R. phycopsis was significantly decreased from 47.5° to 34.4°.展开更多
Objective:To screen the chitosan producing ability of endolichenic fungi and its antibacterial activity.Methods:Lichen collected from mangroves was screened for endophytes and the chitosan producing ability of endolic...Objective:To screen the chitosan producing ability of endolichenic fungi and its antibacterial activity.Methods:Lichen collected from mangroves was screened for endophytes and the chitosan producing ability of endolichenic fungi by submerged fermentation was also determined.Antibacterial activity was carried out against different pathogens.Results:Totally4 different groups of fungi were isolated from the lichen Roccella montagnei.Among the four genera,Aspergillus niger(A.niger)is potential to produce chitosan(1.3 g/L)on the twelfth day of incubation.Glucose plays an important role in the pnjductivity of chitosan and the yield was maximum at 10%(1.93 g/L).Antibacterial activity revealed that Vibrio cholerae was sensitive to chitosan followed by Escherichia coli.Conclusions:In conclusion,our findings suggest that A.niger is a potential candidate to produce more chitosan than the other strains and glucose plays an important role in the production of chitosan which proves to have a good antibacterial activity.展开更多
文摘The behavior of Cu2＋ and Zn2＋ biosorption onto raw and modified Roccella phycopsis from aqueous solutions was studied. Modification process was applied by autoclavation at 121°C for 30 min. The effcts of pH, initial metal concentration and biosorbent dosage were investigated. The maximum Cu2＋ biosorption was achieved at pH 5.0 and the maximum biosorption capacities of 31.5 and 37.8 mg/g were recorded for raw and modified biosorbent, respectively. In the case of Zn2＋ biosorption, maximum biosorption capacities were obtained at pH 4.0 as 29.1 and 35.3 mg/g for raw and modified biosorbent, respectively. Biosorption of Zn2＋ and Cu2＋ on all form of R. phycopsis increased much quickly with increasing initial metal concentrations from 10 to 100 mg/L. After modification process, probable changes in the surface polarity of raw and modified R. phycopsis were investigated by contact angle measurements. As expected, R. phycopsis has a polar surface and shows a highest contact angle with water, while after autoclavation water contact angle of R. phycopsis was significantly decreased from 47.5° to 34.4°.
基金supported by Ministry of Environment and Forests.Govt.of India(grant No.22-9/2008-CS-1)
文摘Objective:To screen the chitosan producing ability of endolichenic fungi and its antibacterial activity.Methods:Lichen collected from mangroves was screened for endophytes and the chitosan producing ability of endolichenic fungi by submerged fermentation was also determined.Antibacterial activity was carried out against different pathogens.Results:Totally4 different groups of fungi were isolated from the lichen Roccella montagnei.Among the four genera,Aspergillus niger(A.niger)is potential to produce chitosan(1.3 g/L)on the twelfth day of incubation.Glucose plays an important role in the pnjductivity of chitosan and the yield was maximum at 10%(1.93 g/L).Antibacterial activity revealed that Vibrio cholerae was sensitive to chitosan followed by Escherichia coli.Conclusions:In conclusion,our findings suggest that A.niger is a potential candidate to produce more chitosan than the other strains and glucose plays an important role in the production of chitosan which proves to have a good antibacterial activity.
