苜蓿青贮乳酸菌的筛选及其对苜蓿青贮发酵的影响

为获得苜蓿青贮用乳酸菌,本研究从苜蓿附生乳酸菌中通过抑菌活性、酸化苜蓿粉及结构性糖代谢中间产物的性能指标筛选优良菌株,并研究其对苜蓿(Medicago sativa)青贮发酵的影响。结果表明,1)筛选到抑菌活性较高、酸化苜蓿粉及结构性糖代谢中间产物综合性能较好的菌株ZZU A341,被鉴定为植物乳杆菌(Lactobacillus plantarum);2)青贮90 d,添加该菌株的处理组pH、氨态氮含量低于添加商业菌株(YX)的处理组,显著低于自然青贮(P<0.05)。综上所述,使用该筛选方法获得的优良乳酸菌可有效改善苜蓿发酵品质。

Identification of lactic acid bacteria inoculant ZZU A341 and its effects on fermentation properties of alfalfa silage

To obtain effective lactic acid bacteria inoculants for alfalfa ensiling,alfalfa epiphytic lactic acid bacteria strains were screened based on an antibacterial activity test,acidification ability on alfalfa meal,and structural carbohydrates constituents.Their impacts on fermentation of alfalfa silage were also studied.Results indicated that strain ZZU A341 displayed high antibacterial activity as well as effective acidification of alfalfa meal and structural carbohydrate constituents.Strain ZZU A341 was identified as Lactobacillus plantarum.Silage receiving ZZU A341 demonstrated lower pH and ammoniacal nitrogen content than silage receiving the commercial inoculant YX.The pH and ammoniacal nitrogen content in silage receiving ZZU A341 were significantly lower than the naturally ensiled alfalfa.Thus,lactic acid bacteria inoculants identified through this screening system could effectively improve fermentation qualities of alfalfa silage.