A number of ion-exchange resins were tested on their capacity to adeorb citric acid,among them resin 335, D315, Amberlite IRA-35 andIRA-68 exhibited higher adsorptioncapacity We Chose resin 335 and D315 to be used for...A number of ion-exchange resins were tested on their capacity to adeorb citric acid,among them resin 335, D315, Amberlite IRA-35 andIRA-68 exhibited higher adsorptioncapacity We Chose resin 335 and D315 to be used for extraction of citric acid fromfermentation broth, followed by elution with 10% ammonia liquor decoloration with K-15 carbon and removal of ammonia with resin 732, converting citrate to free citric acidwith a concentration of 10% and on amount of readily carbonizable substance meetingthe GB 8269-87 standard.展开更多
Cellulase can evidently increase the content of glucose and has a significant effect on the production of citric acid from apple pomace by Aspergillus niger. Based on experiments, a cellulolytic enzyme named cellulase...Cellulase can evidently increase the content of glucose and has a significant effect on the production of citric acid from apple pomace by Aspergillus niger. Based on experiments, a cellulolytic enzyme named cellulase A6 was found able to produce about 170 g glucose from 1 kg dried apple pomace after 12 h reaction, with cellulase concentration of 20 U/g in the medium at 50oC, natural pH without pretreatment of alkali. Using the treated apple pomace as a liquid state substrate, Aspergillus niger-C selected out was able to produce about 256 g citric acid from 1 kg dried apple pomace at 35oC in 3 d or 30oC in 5 d with flask rotation speed of 210 r/min, and the conversion of citric acid could reach 80% based on the amount of sugar consumed.展开更多
Corncobs could serve as a substrate for citric acid production using solid state fermentation technique. The culture optimization concerning substrate concentration, culture duration, pH, temperature and substrate hyd...Corncobs could serve as a substrate for citric acid production using solid state fermentation technique. The culture optimization concerning substrate concentration, culture duration, pH, temperature and substrate hydrolysis was carried out for maximum productivity of citric acid. Under the optimized conditions, 48.4 g of citric acid was produced from 1 kg dry corncobs. Biological evaluation was carried out for citric acid such as melanin synthesis inhibitory, anti-allergy, anti-bacterial, and hyaluronic acid production activities. The results showed that citric acid has potent melanin inhibitory activity, good inhibition for β-hexosaminidase release and potent stimulatory effect for the production of hyaluronic acid. These activities (melanin synthesis inhibitory, anti-allergy and hyaluronic acid productive activities) of citric acid have been reported for the first time.展开更多
The production of citric acid using Chrysophyllum albidum an indigenous under-utilized fruit waste peel and genetically characterized strains of Aspergillus niger was carried out. The Chrysophyllum albidum peel was dr...The production of citric acid using Chrysophyllum albidum an indigenous under-utilized fruit waste peel and genetically characterized strains of Aspergillus niger was carried out. The Chrysophyllum albidum peel was dried, sieved to remove dirt, dry milled and the powder used as substrate for citric acid production. Thirteen fungal isolates were obtained from soil samples and decayed agricultural waste by spread plate technique and screened for citric acid producing capabilities on Czapek dox agar. Citric acid producing capability of the isolates revealed a wide yellow zone around the inoculated colonies. Two (F1 and F3) out of the thirteen isolates exhibited positive reactions and were identified based on their cultural, morphological and molecular characteristics. The fungal species were identified using PCR as Aspergillus niger DTO: 133-E8 and Aspergillus niger DTO: 131-H5. Their cultural/growth optimal conditions were determined through Solid State Fermentation of the substrate using two species of the test organism. The effects of fermentation period examined revealed, Aspergillus niger DTO: 133-E8 which produced the highest amount of citric acid 15.7 ± 0.08 g/l, lower reducing sugar and final pH of 2.1 and 121.5 ± 0.31 g/l respectively after 192 h of growth at 30°C. Aspergillus niger DTO: 131-H5 showed highest amount of citric acid 10.2 ± 0.22 g/l, lower reducing sugar and final pH of 2.4 and 128.5 ± 0.15 g/l respectively after 192 h of growth at 30°C. Maximum concentration of citric acid ranging between 16.3 ± 0.30 g/l and 12.6 ± 0.11 g/l with reducing sugar 125.4 ± 0.11 g/l and 127.2 ± 0.03 g/l was achieved at an initial pH of 5.5. Methanol was used to stimulate citric acid production (0% - 3% (v/v)) and was found to be effective at 2% (v/v) level with 21.2 ± 0.20 g/l of citric acid produced with residual sucrose concentration of 129.5 ± 0.44 g/l. The effect of trace element on citric acid production showed that Cu2+ and Fe2+ stimulated citric acid production;while other ions reduced citric acid production. There was a statistically significant difference (P > 0.05) between the citric acid produced with the various parameters investigated in this research. From the study, it has been found that Chrysophlum albidum is suitable for the cultivation of Aspergillus niger and has great potential for citric acid production and could be exploited to promote certain industrial applications of underutilized fruits in Nigeria. This can be an application of waste to wealth as well as a way of minimizing agro-based environmental pollution for a cleaner environment.展开更多
文摘A number of ion-exchange resins were tested on their capacity to adeorb citric acid,among them resin 335, D315, Amberlite IRA-35 andIRA-68 exhibited higher adsorptioncapacity We Chose resin 335 and D315 to be used for extraction of citric acid fromfermentation broth, followed by elution with 10% ammonia liquor decoloration with K-15 carbon and removal of ammonia with resin 732, converting citrate to free citric acidwith a concentration of 10% and on amount of readily carbonizable substance meetingthe GB 8269-87 standard.
基金Supported by Shaanxi Province抯 Key Technological Plan Foundation(No. 2000K12-G9) Shaanxi Province抯 Natural Science Foundation(No. 2000H07)
文摘Cellulase can evidently increase the content of glucose and has a significant effect on the production of citric acid from apple pomace by Aspergillus niger. Based on experiments, a cellulolytic enzyme named cellulase A6 was found able to produce about 170 g glucose from 1 kg dried apple pomace after 12 h reaction, with cellulase concentration of 20 U/g in the medium at 50oC, natural pH without pretreatment of alkali. Using the treated apple pomace as a liquid state substrate, Aspergillus niger-C selected out was able to produce about 256 g citric acid from 1 kg dried apple pomace at 35oC in 3 d or 30oC in 5 d with flask rotation speed of 210 r/min, and the conversion of citric acid could reach 80% based on the amount of sugar consumed.
文摘Corncobs could serve as a substrate for citric acid production using solid state fermentation technique. The culture optimization concerning substrate concentration, culture duration, pH, temperature and substrate hydrolysis was carried out for maximum productivity of citric acid. Under the optimized conditions, 48.4 g of citric acid was produced from 1 kg dry corncobs. Biological evaluation was carried out for citric acid such as melanin synthesis inhibitory, anti-allergy, anti-bacterial, and hyaluronic acid production activities. The results showed that citric acid has potent melanin inhibitory activity, good inhibition for β-hexosaminidase release and potent stimulatory effect for the production of hyaluronic acid. These activities (melanin synthesis inhibitory, anti-allergy and hyaluronic acid productive activities) of citric acid have been reported for the first time.
文摘The production of citric acid using Chrysophyllum albidum an indigenous under-utilized fruit waste peel and genetically characterized strains of Aspergillus niger was carried out. The Chrysophyllum albidum peel was dried, sieved to remove dirt, dry milled and the powder used as substrate for citric acid production. Thirteen fungal isolates were obtained from soil samples and decayed agricultural waste by spread plate technique and screened for citric acid producing capabilities on Czapek dox agar. Citric acid producing capability of the isolates revealed a wide yellow zone around the inoculated colonies. Two (F1 and F3) out of the thirteen isolates exhibited positive reactions and were identified based on their cultural, morphological and molecular characteristics. The fungal species were identified using PCR as Aspergillus niger DTO: 133-E8 and Aspergillus niger DTO: 131-H5. Their cultural/growth optimal conditions were determined through Solid State Fermentation of the substrate using two species of the test organism. The effects of fermentation period examined revealed, Aspergillus niger DTO: 133-E8 which produced the highest amount of citric acid 15.7 ± 0.08 g/l, lower reducing sugar and final pH of 2.1 and 121.5 ± 0.31 g/l respectively after 192 h of growth at 30°C. Aspergillus niger DTO: 131-H5 showed highest amount of citric acid 10.2 ± 0.22 g/l, lower reducing sugar and final pH of 2.4 and 128.5 ± 0.15 g/l respectively after 192 h of growth at 30°C. Maximum concentration of citric acid ranging between 16.3 ± 0.30 g/l and 12.6 ± 0.11 g/l with reducing sugar 125.4 ± 0.11 g/l and 127.2 ± 0.03 g/l was achieved at an initial pH of 5.5. Methanol was used to stimulate citric acid production (0% - 3% (v/v)) and was found to be effective at 2% (v/v) level with 21.2 ± 0.20 g/l of citric acid produced with residual sucrose concentration of 129.5 ± 0.44 g/l. The effect of trace element on citric acid production showed that Cu2+ and Fe2+ stimulated citric acid production;while other ions reduced citric acid production. There was a statistically significant difference (P > 0.05) between the citric acid produced with the various parameters investigated in this research. From the study, it has been found that Chrysophlum albidum is suitable for the cultivation of Aspergillus niger and has great potential for citric acid production and could be exploited to promote certain industrial applications of underutilized fruits in Nigeria. This can be an application of waste to wealth as well as a way of minimizing agro-based environmental pollution for a cleaner environment.
