Full
Outline
To enhance the value-added utilization of chitin derived from crustacean waste, this study collected samples from the bottom of a shrimp farm in Guangxi. High-yield chitinase-producing strains were isolated through preliminary and secondary screening, followed by taxonomic identification. The optimal fermentation conditions were determined using single-factor experiments combined with orthogonal designs. Subsequently, the enzymatic properties and hydrolysis products of the chitinase produced by the selected strain were characterized. Results showed that initial screening on chitin-containing agar plates yielded nine strains capable of forming clear zones, among which strain GXUN-J3 exhibited the highest chitinase activity (297.24±10.77 U/L) and was identified as belonging to the genus Streptomyces sp. Under optimized fermentation conditions—6% (w/v) chitin, 0.25% (w/v) bean powder, an initial pH of 7.0, a fermentation temperature of 25 ℃, a liquid volume of 40 mL per 150 mL flask, and an inoculum size of 5% (v/v)—the chitinase activity reached 1026.72±18.69 U/L, representing a remarkable increase of 3.51-fold compared to the original process. Enzyme characterization revealed optimal activity at 50 ℃ and pH5.0. Among the metal ions tested, Mg2+ and Fe3+ significantly enhanced enzyme activity, whereas Fe2+, Mn2+, and Cu2+ exhibited significant inhibitory effects (P<0.05). Additionally, the chemical agents of EDTA, SDS, and methanol markedly suppressed enzymatic activity (P<0.05). Thin-layer chromatography (TLC) analysis demonstrated that the hydrolysis products primarily consisted of chitin dimer and N-acetyl-D-glucosamine, suggesting that this enzyme functions as an exo-chitinase. This study successfully established a process for producing chitinase and preparing chitin oligosaccharide using Streptomyces strain GXUN-J3, offering a promising approach for high-value utilization of crustacean waste.
136
56
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |
关闭全屏
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62662699(Operation and Technical Support)
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
