Laboratory of Molecular Biology, Institute of Biological Sciences (ICB), Federal University of Rio Grande (FURG), Rio Grande, RS, Brazil.
Laboratory of Nutrition of Aquatic Organisms, Institute of Oceanography (IO), Federal, University of Rio Grande (FURG), Rio Grande, RS, Brazil.
Fish Shellfish Immunol. 2019 Oct;93:652-658. doi: 10.1016/j.fsi.2019.08.030. Epub 2019 Aug 11.
Although aquaculture is among the fastest growing food production sectors in the world, one of the bottlenecks for the continuity of its expansion is the dependence of animal protein on commercial feed formulations. Vegetable proteins are an alternative due to the low cost and high availability. However, this protein source is accompanied by a series of antinutritional and pro-inflammatory compounds, including phytate. Phytases can be added in feed for phytate degradation and increase nutrient availability. However, the use of purified phytases significantly increases the production costs. An interesting alternative is to use probiotics genetically modified as bioreactors for phytase production. In the present study, a strain of Bacillus subtilis secreting a fungal phytase was used to evaluate the effect of a feed with high content of soybean meal on zebrafish (Danio rerio). We analysed the condition factor (K) of fish, and the expression of genes related to the immune system, inflammatory response and oxidative. stress. The results obtained demonstrate that the transgenic probiotic was efficient in improving the fish condition factor, stimulating the immune system, reducing the inflammatory response and oxidative stress. Thus, probiotics acting as phytase bioreactors can be considered an interesting tool for the adaptation of commercial species to feed of lower cost.
尽管水产养殖是世界上增长最快的食品生产部门之一，但它持续扩张的一个瓶颈是动物蛋白对商业饲料配方的依赖。由于成本低、可用性高，植物蛋白是一种替代蛋白。然而，这种蛋白质来源伴随着一系列抗营养和促炎化合物，包括植酸盐。植酸酶可以添加到饲料中，以降解植酸盐并提高营养物质的可用性。然而，使用纯化的植酸酶会显著增加生产成本。一个有趣的选择是使用经过基因改造的益生菌作为植酸酶生产的生物反应器。在本研究中，使用了一株分泌真菌植酸酶的枯草芽孢杆菌来评估高豆粕含量饲料对斑马鱼（Danio rerio）的影响。我们分析了鱼的条件因子（K），以及与免疫系统、炎症反应和氧化应激相关的基因表达。结果表明，转基因益生菌能有效提高鱼的条件因子，刺激免疫系统，减少炎症反应和氧化应激。因此，作为植酸酶生物反应器的益生菌可以被认为是商业品种适应低成本饲料的一种有趣工具。
