Engineering Technology Research Center of Henan Province for Aquatic Animal Cultivation, Engineering Lab of Henan Province for Aquatic Animal Disease Control, College of Fisheries, Henan Normal University, Xinxiang, China.
Engineering Technology Research Center of Henan Province for Aquatic Animal Cultivation, Engineering Lab of Henan Province for Aquatic Animal Disease Control, College of Fisheries, Henan Normal University, Xinxiang, China.
Fish Shellfish Immunol. 2019 Oct;93:73-81. doi: 10.1016/j.fsi.2019.07.028. Epub 2019 Jul 11.
In the present study, we reported 18 LAB strains isolated from the intestinal contents of Cyprinus carpio, and their probiotic properties both in vitro and in vivo. The results showed that 9 of them had higher in vitro immunomodulatory properties, effectively survived under acidic (pH 2.5) and bile salt (ranging from 0.1% to 0.5%) conditions, and inhibited the growth of 4 pathogens. Among them, Lactococcus lactis Q-8, Lactococcus lactis Q-9, and Lactococcus lactis Z-2 showed the strongest adhesion abilities and inhibition of pathogen adhesion to mucin. When the fish consumed diets containing these 3 strains (5 × 10 CFU/g) for 8 weeks, the weight gain (WG) and specific growth rate (SGR) had significantly (P < 0.05) increased, especially with L. lactis Q-8, which had a WG of 231.45%, and SGR of 2.22%. Survival rate in each LAB supplementation group was also significantly higher than that in control group during the feeding period (P < 0.05). For the cytokines expression levels in serum, different expression patterns were also observed. Before the infection with Aeromonas hydrophila, L. lactis supplementation significant up-regulated protein levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-12) compared with negative (CK1) group, while these cytokines were significantly lower than those in positive (CK2) group after infection. However, whether infected or not, the expression of anti-inflammatory cytokines (IL-10, TGF-β) were significantly increased in L. lactis Q-8, L. lactis Q-9, and L. lactis Z-2 treatment groups. In conclusion, these 3 L. lactis strains screened from common carp were effective in improving growth, innate immunity and disease resistance. Based on the physiological characteristics in our study, they might be used as potential probiotics in aquaculture.
在本研究中，我们报告了从鲤鱼肠道内容物中分离出的 18 株 LAB 菌株，并对其在体外和体内的益生菌特性进行了研究。结果表明，其中 9 株具有较高的体外免疫调节特性，能够在酸性（pH2.5）和胆汁盐（0.1%至 0.5%）条件下有效存活，并抑制 4 种病原体的生长。其中，乳球菌 Q-8、乳球菌 Q-9 和乳球菌 Z-2 表现出最强的黏附能力和抑制病原体黏附黏蛋白的能力。当鱼食用含有这 3 株菌（5×10 CFU/g）的饲料 8 周时，体重增加（WG）和特定生长率（SGR）显著增加（P<0.05），特别是乳球菌 Q-8 的 WG 达到 231.45%，SGR 达到 2.22%。在喂养期间，每个 LAB 补充组的存活率也明显高于对照组（P<0.05）。对于血清中的细胞因子表达水平，也观察到不同的表达模式。在感染嗜水气单胞菌之前，与阴性（CK1）组相比，乳球菌补充剂显著上调了促炎细胞因子（TNF-α、IL-1β、IL-6、IL-12）的蛋白水平，而感染后这些细胞因子水平显著低于阳性（CK2）组。然而，无论是否感染，在乳球菌 Q-8、乳球菌 Q-9 和乳球菌 Z-2 处理组中，抗炎细胞因子（IL-10、TGF-β）的表达均显著增加。总之，从鲤鱼中筛选出的这 3 株乳球菌在提高生长、先天免疫和抗病性方面是有效的。基于我们研究中的生理特征，它们可能被用作水产养殖中的潜在益生菌。
