3种青贮饲料中乳酸菌群落结构特征分析及优良乳酸菌的筛选

Analysis of community structure and screening of ex⁃ cellent lactic acid bacteria in three silages

摘要:

【目的】研发出适应昆明气候条件的青贮用乳酸菌制剂，促进当地草地畜牧业的高效发展。 【方法】以自然发酵 60 d 的全株玉米(Zea mays)、紫花苜蓿(Medicago sativa)和鸭茅(Dactylis glom- erata)3 种青贮饲料为试验材料筛选优良乳酸菌，经继代培养获得 83 株天然乳酸菌(Lacticacid bacte- ria，LAB)菌株。测定 83 株乳酸菌形态特征及构建系统发育树。【结果】获得的 83 株天然乳酸菌中，昆明地区青贮饲料最常见的乳酸菌是植物乳杆菌(Lactobacillus plantarum)，占 50. 6%；其次是戊糖片球菌(Pediococcus pentosaceus)和短乳杆菌(L. brevis)，各占 21. 7%。根据乳酸菌的生长活性和产酸能力， 进一步从 83 株菌株筛选出 3 株优质乳酸菌(B10、B16、C23)。【结论】生理生化特性和 16S rRNA 测序分析显示，B10、B16、C23 分别为短乳杆菌、植物乳杆菌和戊糖片球菌。3 菌株产酸速率和生长速率的高低顺序为 B16＞C23＞B10。

Abstract:

【Objective】 In order to develop lactic acid bacteria preparation suitable for climate conditions in Kun‐ ming，and promote the efficient development of local grassland animal husbandry.【Method】 Three silages，including whole plant corn，alfalfa and orchardgrass，were used as experimental materials to screen excellent lactic acid bacteria in this study，and 83 strains of natural lactic acid bacteria were obtained by subculture from them.【Result】 The mor‐ phological characteristics and the construction of phylogenetic tree of 83 lactic acid bacteria strains showed as follows： Lactobacillus plantrum was the most common lactic acid bacteria in Silages in Kunming，accounting for 50. 6%，fol‐ lowed by Pediococcus pentosaceus and Lactobacillus brevis，accounting for 21. 7% respectively. Three high quality lactic acid bacteria (B10，B16，C23) were selected from 83 strains according to their growth activity and acid produc‐ tion ability.【Conclusion】 Physiological and biochemical characteristics and 16S rRNA sequencing analysis showed that B10，B16 and C23 were L. brevis，L. plantarum and P. pentosaceus，respectively. The acid production rate and growth rate from high to low was B16＞C23＞B10.