【摘要】 本研究旨在从藏猪粪便中筛选高产纤维素酶菌株，研究其酶学特性，并评估其在饲料发酵中的应用潜力。本试验采用选择性培养基和刚果红染色法筛选纤维素降解菌，结合形态学观察、生化鉴定和16S rDNA测序进行菌株鉴定，测定纤维素酶活性并优化产酶条件，评估菌株对棕榈粕的发酵效果。结果表明：1)本研究成功分离得到一株高产纤维素酶的枯草芽孢杆菌（Bacillus subtilis ）YX1，其滤纸酶活力（FPase ）和羧甲基纤维素酶（CMCase ）活力分别达到44.98 U/mL和47.86 U/mL。2)该菌株所产纤维素酶的最适反应温度为50℃，最适反应pH为5.0，在45～55℃的温度区间及pH4.0～6.0的范围内，酶活性保持稳定。Mn²⁺对酶活性具有显著促进作用（P<0.05 ），而Ba²⁺和EDTA则表现出显著抑制效应（P<0.05 ）。3)发酵条件优化结果显示，在pH 4、30℃培养12 h条件下，产酶活性最高。4)棕榈粕发酵试验表明，以5%接种量发酵48 h后，棕榈粕粗纤维含量相对降低32.67%，饲料营养价值得到显著提升（P<0.05 ）。综上，本研究成功分离并鉴定出一株高产纤维素酶的B.subtilis YX1，该菌株具有良好的热稳定性和酸碱耐受性，在农业废弃物的生物转化及畜牧业可持续发展中具有重要的应用价值。更多还原

【Abstract】 The study aimed to screen high-yield cellulase-producing bacterial strains from Tibetan pig feces, investigate their enzymatic properties, and evaluate their potential application in feed fermentation. Cellulolytic bacteria were isolated using selective culture media and the Congo red staining method. Bacterial strains were identified through morphological observation, biochemical tests, and 16S rDNA sequencing. Cellulase activity was measured, and enzyme production conditions were optimized. The fermentation effects of the strains on palm kernel meal were also evaluated. A high-yield cellulase-producing strain,of Bacillus subtilis YX1,was successfully isolated, exhibiting filter paper enzyme（FPase）and carboxymethyl cellulase（CMCase）activities of 44.98 U/mL and 47.86 U/mL, respectively. The optimal reaction temperature for the cellulase produced by this strain was 50 ℃, with an optimal pH of 5.0. Enzyme activity remained stable within a temperature range of 45 ～ 55 ℃ and pH range of 4.0 ～ 6.0. Mn²⁺ significantly enhanced enzyme activity（P<0.05）, while Ba²⁺ and EDTA exhibited significant inhibitory effects（P<0.05）. Optimization of fermentation conditions revealed that the highest enzyme activity was achieved at pH 4 and 30 ℃ after 12 hours of cultivation. Palm kernel meal fermentation experiments demonstrated that inoculation with 5% inoculum and 2 days of fermentation reduced crude fiber content by 32.67%, significantly improving the nutritional value of the feed. This study successfully isolated and identified a high-yield cellulase-producing strain, of B. subtilis YX1, which exhibits excellent thermostability and acid-base tolerance. This strain holds significant potential for application in the biotransformation of agricultural waste and the sustainable development of animal husbandry.更多还原