Liu Zhikun, Guo Jiaojiao, Su Qingyang, Feng Shikun, Zhang Xindang, Zhang Yanmin, Yang Guokun, Chang Xulu, Meng Xiaolin
College of Fisheries, Henan Normal University, Xinxiang, 453007, PR China.
Probiotics Antimicrob Proteins. 2025 Sep 5. doi: 10.1007/s12602-025-10721-0.
Clostridium butyricum has gained attention as a probiotic in aquaculture due to its ability to improve growth, gut health, and immune function. However, most strains currently used are derived from non-aquatic sources, which may limit their colonization and efficacy in fish. In this study, a novel strain, C. butyricum LZK-08, was isolated from the intestine of grass carp. The strain was identified based on morphological features, 16S rRNA sequencing, and whole-genome analysis. Its probiotic properties were assessed through comprehensive in vitro assays and in vivo trials in largemouth bass. LZK-08 exhibited strong acid (pH 4.0), bile salt (0.3%), and heat (up to 80 °C) tolerance, along with high auto-aggregation (92.3%) and notable surface hydrophobicity. It produced digestive enzymes (amylase, protease, lipase) and short-chain fatty acids, particularly butyrate (523.32 μg/mL). Genomic analysis revealed a 4.71 Mb genome composed of a circular chromosome and plasmid, encoding 4,207 protein-coding genes. Key genes were enriched in carbohydrate and amino acid metabolism, stress response, and adhesion. Feeding trials in largemouth bass showed that dietary supplementation with LZK-08 significantly improved growth parameters, reduced feed conversion ratio, enhanced intestinal antioxidant enzyme and digestive enzyme activities. Histological analysis revealed improved intestinal morphology, including increased villus height and muscle thickness. 16S rRNA sequencing further showed that LZK-08 modulated gut microbiota by enriching beneficial taxa such as Lactobacillus and reducing potentially unfavorable Romboutsia. These findings indicate that C. butyricum LZK-08 is a physiologically robust, and genomically safe probiotic with strong functional attributes, demonstrating high potential for use in sustainable aquaculture.
丁酸梭菌因其具有促进生长、改善肠道健康和增强免疫功能的能力，已成为水产养殖中的一种益生菌并受到关注。然而，目前使用的大多数菌株都来源于非水生环境，这可能会限制它们在鱼类中的定殖和功效。在本研究中，从草鱼肠道中分离出了一种新型菌株——丁酸梭菌LZK-08。该菌株通过形态特征、16S rRNA测序和全基因组分析进行鉴定。通过在大口黑鲈上进行的全面体外试验和体内试验评估了其益生菌特性。LZK-08表现出对强酸（pH 4.0）、胆盐（0.3%）和高温（高达80°C）的强耐受性，以及高自凝性（92.3%）和显著的表面疏水性。它能产生消化酶（淀粉酶、蛋白酶、脂肪酶）和短链脂肪酸，尤其是丁酸（523.32μg/mL）。基因组分析显示，其基因组大小为4.71 Mb，由一条环状染色体和质粒组成，编码4207个蛋白质编码基因。关键基因在碳水化合物和氨基酸代谢、应激反应及黏附方面富集。大口黑鲈的投喂试验表明，在饲料中添加LZK-08可显著改善生长参数，降低饲料转化率，提高肠道抗氧化酶和消化酶活性。组织学分析显示肠道形态得到改善，包括绒毛高度增加和肌肉厚度增加。16S rRNA测序进一步表明，LZK-08通过富集有益菌属（如乳酸杆菌属）和减少潜在有害的罗姆布茨菌属来调节肠道微生物群。这些发现表明，丁酸梭菌LZK-08是一种生理性能强大、基因组安全且具有强大功能特性的益生菌，在可持续水产养殖中具有很高的应用潜力。
