It has been reported that supplying a carbon source and probiotics improves water quality and animals in aquaculture systems. Most studies used molasses as a carbon source, which is a mixture of carbohydrate, fat, and protein. In the present study, sucrose and probiotics (Bacillus licheniformis; hereafter referred to by only the genus name “Bacillus”) were added in the culture media of 5‐d‐old postlarvae of whiteleg shrimp Litopenaeus vannamei and then cultured for 20 d. The results showed that compared with the control concentrations of NH₄⁺‐N, NO₂⁻‐N, and NO₃⁻‐N, values were lower in treatments with sucrose and Bacillus, suggesting that water quality was improved and material circulation was promoted. Values of dissolved oxygen decreased, probably due to oxygen consumption during microbial growth and oxidation processes. Body length growth rate of whiteleg shrimp was significantly higher in treatments with sucrose and Bacillus compared with the control, which might result from an increased energy uptake from ingesting microorganisms. In comparison to the control, treatments with sucrose and Bacillus greatly influenced bacterial community structure. Among them, the proportion of Actinobacteria increased and that of Proteobacteria decreased. Actinomycetes can degrade organic compounds and produce a wide variety of antibiotics, vitamins, and enzymes, inhibiting growth of some pathogenic microorganisms. Proteobacteria includes many pathogenic bacteria. Changes in these two phyla suggest that the immunity of whiteleg shrimp might be enhanced in response to treatments. These results indicate that microorganism composition might be important to biofloc systems. Further investigations in this area would help guide aquaculture production.

中文翻译：

---

蔗糖和益生菌的添加对南美白对虾南美白对虾后期幼虫性能，水质和微生物群落的影响

据报道，提供碳源和益生菌可以改善水产养殖系统中的水质和动物。大多数研究使用糖蜜作为碳源，碳源是碳水化合物，脂肪和蛋白质的混合物。在本研究中，将蔗糖和益生菌（地衣芽孢杆菌（Bacillus licheniformis），以下简称为“芽孢杆菌”（Bacillus））添加到白腿虾南美白对虾的五岁后幼虫的培养基中，然后培养20 d。结果表明，与对照浓度的NH ₄ ⁺ -N，NO ₂ ^-- N和NO ₃ ^-- N相比，蔗糖和芽孢杆菌处理的值较低，表明水质得到改善，物质循环得到了促进。溶解氧值降低，可能是由于微生物生长和氧化过程中的氧消耗所致。用蔗糖和芽孢杆菌处理的白腿虾的体长生长速率明显高于对照，这可能是由于摄入微生物吸收的能量增加所致。与对照相比，用蔗糖和芽孢杆菌治疗极大地影响了细菌群落结构。其中，放线菌的比例增加，而变形杆菌的比例降低。放线菌可以降解有机化合物并产生多种抗生素，维生素和酶，从而抑制某些病原微生物的生长。变形细菌包括许多致病细菌。这两个门的变化表明白腿虾的免疫力可能会因治疗而增强。这些结果表明微生物组成可能对生物絮凝系统很重要。在这一领域的进一步调查将有助于指导水产养殖生产。