多肽菌素在长牡蛎人工育苗生产中的应用

多肽菌素作为一类具有抗菌活性的生物短肽,是一种可以替代抗生素的生物肽。为了推广多肽菌素在水产养殖中的应用,本研究以长牡蛎(Crassostreagigas)人工育苗为基础,以添加2×10_(–6) mol/L青霉素钠为对照组,以添加5个不同浓度(2×10_(–6)、4×10_(–6)、6×10_(–6)、8×10_(–6)、10×10_(–6) mol/L)多肽菌素为实验组,研究多肽菌素在长牡蛎人工育苗生产中的应用。结果显示:(1)在长牡蛎种贝培育方面,培育前8天各组差异不显著(P 0.05),培育后期添加6×10_(–6) mol/L多肽菌素组存活率均最高,对照组最低,且培育至32天时该实验组均显著高于其他组(P0.05)。(2)在长牡蛎幼虫培育方面,幼虫壳高日增长量在添加6×10_(–6) mol/L多肽菌素组中最大,为11.57μm/d,而对照组仅为9.61μm/d;幼虫存活率方面对照组始终最低,而添加6×10_(–6) mol/L与8×10_(–6) mol/L多肽菌素组均保持较高存活率,显著高于对照组(P 0.05)。(3)在长牡蛎幼虫附着变态方面,添加6×10_(–6) mol/L多肽菌素组附着率最高、附着时间最短,且均与对照组差异显著(P0.05)。(4)在长牡蛎稚贝培育方面,稚贝壳长日增长量实验组均高于对照组,且随添加浓度的上升,日增长量也随之增加;稚贝存活率在添加6×10_(–6) mol/L多肽菌素组达到最高,与对照组差异显著(P0.05)。结果表明,使用多肽菌素与使用青霉素钠相比,多肽菌素显著提高了整个牡蛎培育过程中的存活率、生长速度、及附着变态率,这也为多肽菌素在贝类育苗生产中的推广提供了基础依据。

Application of polypeptide fungicin in the artificial seedling production of Pacific oyster (Crassostrea gigas)

Polypeptide fungicin is a type of biopeptide that possesses antibacterial activity and can replace antibiotics. To promote the application of polypeptide fungicin in aquaculture, this study aimed to determine its application in the artificial seedling production of Pacific oysters (Crassostrea gigas). This study is based on the artificial seedling production of Crassostrea gigas; penicillin sodium was employed (2×10^-6 mol/L) as the control group, and five different concentrations of polypeptide fungicin (2×10^-6, 4×10^-6, 6×10^-6, 8×10^-6, and 10×10^-6 mol/L) were employed as the experimental group. The results of this study are summarized as follows. First, there was no significant difference between each group 8 days before cultivation of the Crassostrea gigas scallop (P>0.05). The experimental group with 6×10^-6 mol/L polypeptide fungicin at the later stage of cultivation had the highest survival rate, whereas the control group had the lowest survival rate. The survival rate of the experimental group with 6×10^-6 mol/L polypeptide fungicin was significantly higher than that of the other groups at 32 days of cultivation (P<0.05). Second, in terms of Crassostrea gigas larvae, the increase in larval shell height in the experimental group with 6×10^-6 mol/L polypeptide fungicin was 11.57 microns per day, whereas that in the control group was only 9.61 microns per day. The control group had the lowest larval survival rate; a significantly higher survival rate was maintained in the experimental group with 6×10^-6 and 8×10^-6 mol/L polypeptide fungicin than in the control group (P<0.05). Third, in terms of the attachment metamorphosis of Crassostrea gigas larvae, the attachment rate of the experimental group with 6×10^-6 mol/L polypeptide fungicin was the highest along with the shortest attachment time, which were significantly different from the control group (P<0.05). Fourth, in the cultivation of the juvenile Crassostrea gigas(oysters), the daily growth amount of juveniles in the experimental group was higher than that in the control group. In addition, the increase in concentration of polypeptide fungicin led to an increase in the daily growth amount. The survival rate of juveniles was highest in the experimental group with 6×10^-6 mol/L polypeptide fungicin, which was significantly different from the control group (P<0.05). The results showed that compared with the use of penicillin sodium, the use of polypeptide fungicin considerably improved the survival rate, growth rate, and adhesion conversion rate during the entire oyster cultivation process. In addition, it improved the efficiency of artificial oyster seedlings, which provides a basis for the promotion of polypeptide fungicin in the production of shellfish seedlings.