Shrimp waste contains 20% - 60% chitin and possible to be source of chitinolytic bacteria. Chitinolytic bacteria are capable of hydrolyzing of chitin progressively to produce N-acetylglucosamine monomer which can be u...Shrimp waste contains 20% - 60% chitin and possible to be source of chitinolytic bacteria. Chitinolytic bacteria are capable of hydrolyzing of chitin progressively to produce N-acetylglucosamine monomer which can be used to overcome the shrimp waste. The objectives of this research were to identify species of bacteria with high activity of chitin degradation in shrimp waste and to analyze their potency as chitin degradation agent. The research consists of screening of chitinolytic bacteria based on chitinolytic index, activity assay of chitinase using colorimetric method, and molecular identification of bacteria based on 16S rDNA sequences. Two of eighteen isolates of chitinolytic bacteria (PBK 2 and SA 1.2 isolates) showed the highest chitinolytic index, which were 2.069 and 2.084, whereas chitinase activity was 0.213 and 0.219 U/ml respectively. Based on 16S rDNA sequences, isolate of PBK 2 was identified as Acinetobacter johnsonii 3-1, whereas SA 1.2 was identified as Bacillus amyloliquefaciens GR53 with 99.78% similarity.展开更多
A new molecularly imprinted solid-phase extraction（MISPE） monolithic cartridge was synthesized, and MISPE-DLLME（DLLME=dispersive liquid-liquid microextraction） was developed for purification of astaxanthin in shri...A new molecularly imprinted solid-phase extraction（MISPE） monolithic cartridge was synthesized, and MISPE-DLLME（DLLME=dispersive liquid-liquid microextraction） was developed for purification of astaxanthin in shrimp waste. The eluent（methanol） from MISPE was used as the dispersive solvent in subsequent DLLME for further purifying and enriching the analyte prior to high-performance liquid chromatography（HPLC） analysis. The mobile phase was methanol-acetonitrile-water-dichloromethane（85：5：5：5, volume ratio）, flow rate was 0.7 mL/min and UV wavelength was 476 nm. Under optimal conditions, good linearity was obtained in a range of 0.2--200.0 lug/mL（r2=0.9998） with a limit of detection（LOD） of 0.08 Hg/mL, and the extraction recoveries at three spiked levels ranged from 88.3%--92.5% with a relative standard deviation（RSD） less than 4.3%. Moreover, the mean contents of astaxanthin in the three batches of shrimp waste were 95.9, 85.4 and 77.2 μg/g, respectively. This method combining the advantages of MISPE and DLLME results in high selectivity and low cost, which was applied to determining the astaxanthin level in shrimp waste samples.展开更多
文摘Shrimp waste contains 20% - 60% chitin and possible to be source of chitinolytic bacteria. Chitinolytic bacteria are capable of hydrolyzing of chitin progressively to produce N-acetylglucosamine monomer which can be used to overcome the shrimp waste. The objectives of this research were to identify species of bacteria with high activity of chitin degradation in shrimp waste and to analyze their potency as chitin degradation agent. The research consists of screening of chitinolytic bacteria based on chitinolytic index, activity assay of chitinase using colorimetric method, and molecular identification of bacteria based on 16S rDNA sequences. Two of eighteen isolates of chitinolytic bacteria (PBK 2 and SA 1.2 isolates) showed the highest chitinolytic index, which were 2.069 and 2.084, whereas chitinase activity was 0.213 and 0.219 U/ml respectively. Based on 16S rDNA sequences, isolate of PBK 2 was identified as Acinetobacter johnsonii 3-1, whereas SA 1.2 was identified as Bacillus amyloliquefaciens GR53 with 99.78% similarity.
文摘A new molecularly imprinted solid-phase extraction（MISPE） monolithic cartridge was synthesized, and MISPE-DLLME（DLLME=dispersive liquid-liquid microextraction） was developed for purification of astaxanthin in shrimp waste. The eluent（methanol） from MISPE was used as the dispersive solvent in subsequent DLLME for further purifying and enriching the analyte prior to high-performance liquid chromatography（HPLC） analysis. The mobile phase was methanol-acetonitrile-water-dichloromethane（85：5：5：5, volume ratio）, flow rate was 0.7 mL/min and UV wavelength was 476 nm. Under optimal conditions, good linearity was obtained in a range of 0.2--200.0 lug/mL（r2=0.9998） with a limit of detection（LOD） of 0.08 Hg/mL, and the extraction recoveries at three spiked levels ranged from 88.3%--92.5% with a relative standard deviation（RSD） less than 4.3%. Moreover, the mean contents of astaxanthin in the three batches of shrimp waste were 95.9, 85.4 and 77.2 μg/g, respectively. This method combining the advantages of MISPE and DLLME results in high selectivity and low cost, which was applied to determining the astaxanthin level in shrimp waste samples.
