刺参“参优1号”苗种在不同pH条件下的代谢特征和适应性研究

Metabolic characteristics and adaptability of a new variety of sea cucumber “Shenyou No.1” under different pH conditions

中文关键词: 刺参“参优1号”  酸碱度适应  生长与存活  呼吸代谢  非特异性免疫酶活性

英文关键词: Sea cucumber “Shenyou No.1”  pH adaptation  Growth and survival  Respiratory metabolism  Nonspecific immune enzyme activities

中文摘要:

      为研究刺参(Apostichopus japonicus)“参优1号”苗种的适宜pH及耐受范围并解析其对水体的酸碱性适应机制，本研究测定了pH 6.5~10.0条件下该良种苗种的生长、存活、呼吸代谢以及非特异性免疫酶活性的差异。结果显示，在pH 6.5~9.5范围内，30 d实验周期内苗种的存活率均为100%，而在pH 10.0条件下苗种全部死亡。在pH 7.5~8.5范围内，苗种特定生长率(SGR)为正值，且在pH为8.0时SGR最高，达到0.541%/d，而在pH低于7.0和高于9.0时，SGR为负值，苗种为负生长。对不同pH条件下的耗氧率(RO)和排氨率(RN)的测定结果显示，随pH的变化，RO和RN均呈现以pH 8.0为波谷的“V”型变化，在pH 8.0条件下的RO和RN分别为19.07和1.34 μg/(g·h)。不同pH实验组刺参苗种的氧氮比(O/N)均在11左右，O/N随pH变化无显著差异(P>0.05)。pH的升高和降低会引起刺参体腔液中酸性磷酸酶、碱性磷酸酶、溶菌酶和超氧化物歧化酶的活性显著升高(P<0.05)，在苗种适应pH胁迫过程中，各pH组超氧化物歧化酶活性的峰值一般在第0天出现，而溶菌酶的活性峰值在第10天出现。研究表明，刺参“参优1号”可存活的pH范围为6.5~9.5，适宜生长的pH范围为7.5~8.5，pH变化会导致苗种呼吸代谢和免疫酶活性的改变。本研究结果将为刺参“参优1号”苗种的科学化推广提供依据。

英文摘要:

      To determine the optimal pH conditions and pH adaptation mechanisms of the juveniles new sea cucumber (Apostichopus japonicus) variety "Shenyou No.1", the differences in the growth, survival, respiratory metabolism, and immunoenzyme activity were analyzed under conditions of different pH (range: 6.5~10.0). The results showed that in the pH range of 6.5~9.5, the survival rate of the juveniles was 100% during the 30 days experimental period, whereas all juveniles died at pH 10.0. Within the pH range of 7.5~8.5, the juveniles showed a positive specific growth rate (SGR), and the highest SGR was 0.541%/d at pH 8.0, while the SGR was negative at the pH lower than 7.0 or higher than 9.0. The oxygen consumption rate (RO) and ammonia excretion rate (RN) were the lowest at pH 8.0, 19.07 μg/(g·h) and 1.34 μg/(g·h) for RO and RN, respectively. The oxygen-nitrogen ratios of the juveniles in different pH groups were approximately 11, and did not differ significantly with a pH change. The activities of acid phosphatase, alkaline phosphatase, lysozyme, and superoxide dismutase in the coelomic fluid of A. japonicus significantly increased at different pH values. While adapting to pH stress, the superoxide dismutase activity in each pH group generally peaked at 0 d, while the lysozyme activity peaked at 10 d. The survival pH of "Shenyou No.1" ranged between 6.5~9.5, and the optimal pH for growth ranged between 7.5~8.5. Our results show that the changes in the pH lead to changes in respiratory metabolism and immune enzyme activity in "Shenyou No.1.” These results provide the basis for the popularization of the new sea cucumber variety "Shenyou No.1".