兰州大学机构库 >生命科学学院
青藏高原不同地区垂穗披碱草青贮饲料中乳酸菌多样性及优势菌种的发酵特性研究
Alternative TitleStudy on Biodiversity and Fermentation Characteristics of Lactic Acid Bacteria in Elymus nutans Silage Ensiled at Different Areas of the Qinghai-Tibetan Plateau
保安安
Thesis Advisor郭旭生
2016-06-07
Degree Grantor兰州大学
Place of Conferral兰州
Degree Name硕士
Keyword青藏高原 垂穗披碱草 青贮 乳酸菌 多样性 低温发酵
Abstract本研究采用真空袋法对青藏高原四个不同地区的垂穗披碱草(Elymus nutans)进行青贮,并通过PacBio Ⅱ平台对青藏高原四个地区及不同发酵阶段垂穗披碱草青贮饲料发酵体系中的微生物(细菌)多样性进行了研究;同时,对青贮饲料中的优势乳酸菌进行分离鉴定、产酸能力和耐低温能力的筛选研究;将表现优良的乳酸菌作为青贮饲料乳酸菌添加剂添加到垂穗披碱草中,研究其对青贮发酵品质的影响,以期为开发适合青藏高原地区青贮用乳酸菌添加剂提供理论依据,试验结果如下:就乳酸菌而言,通过高通量测序得知青藏高原垂穗披碱草青贮饲料中的乳酸菌主要包括6个属,28个种。从不同地区不同发酵阶段的垂穗披碱草青贮饲料中共分离得到优势乳酸菌92株,分为乳杆菌属和片球菌属,其中又包括了4个种:植物乳杆菌13株,乳酸片球菌50株,短乳杆菌28株,副干酪乳杆菌1株。通过对92株优势乳酸菌进行产酸能力和耐低温能力的筛选得到6株表现突出的乳酸菌,分别是LB-40、LB-59、PA-60、PA-69、PA-87、LP-66。将筛选得到的一株植物乳杆菌LP-66与购自美国的植物乳杆菌ALP作为青贮添加剂添加到垂穗披碱草青贮30、60天后发现相对于商品菌株,LP-66在低温条件下表现出了一定的发酵优势,可作为在青藏高原低温条件调制青贮饲料的备选菌株。
Other AbstractIn this study, the grass of Elymus nutans growing in four different regions of the Qinghai-Tibetan Plateau (Tianzhu, Guoluo, Dangxiong, Naqu) was ensiled, and we extract the total bacterial DNA of the silage at different fermentation stages (14, 30, 60, 90 days) to find microbial biodiversity of the silage by high-throughput sequencing analysis. Meanwhile, dominant lactic acid bacteria (LAB) from the silage were separated and identified; subsequently, all the separated LAB stains were tested based on their low temperature resistant ability and acid producing ability to screen strains with good fermentation performance at low temperature. Thereafter, the selected strain was applied to Elymus nutans as silage additives and fermented at 10, 15, 25℃ respectively. The study was conducted to determine the effects of the selected LAB strain on fermentation quality of ensiled Elymus nutans at different temperatures, and to thereby to provide a theoretical basis for developing appropriate lactic acid bacteria for making high quality silage on the Qinghai-Tibetan Plateau. The results are as follows:1.The biodiversity of the Elymus nutans silage of different regions and different fermentation stages showed some differences. In this study, lactic acid bacteria mainly include 6 genera: Enterococcus, Lactobacillus, Pediococcus, Leuconostoc, Weissella and Lactococcus. This 6 genera of lactic acid bacteria include: Lactobacillus plantarum, Weissella cibaria, Pediococcus pentosaceus, Enterococcus mundtii, Lactobacillus brevis, Leuconostoc mesenteroides, Lactococcus lactis,et.2.In this study, totally 92 dominant LAB strains were isolated. These 92 strains belonged to Lactobacillus and Pediococcus, and included 4 species, there were 13 stains of Lactobacillus plantarum, 50 strains of Pediococcus acidilactici, 28 strains of Lactobacillus brevis and just 1 strain of Lactobacillus paracasei. Through the screening of acid producing ability and low temperature resistance ability, 6 strains of good performance LAB strains were selected out, they are LB-40, LB-59, PA-60, PA-69, PA-87 and LP-66. LP-66 reduced the green guice’s pH value at 10 and 15℃ significantly (P<0.05), PA-87 and LP-66 showed a batter growth advantage at 15 and 25℃. PA-87 with the strongest sugar utilization ability compared with laboratory isolates and standard lactic acid bacteria. All 10 strains grown well at 10 to 50℃, and 3.5 to 9.0 pH range, but there are obvious differences on the growth ability ...
URL查看原文
Language中文
Document Type学位论文
Identifierhttp://ir.lzu.edu.cn/handle/262010/220497
Collection生命科学学院
Recommended Citation
GB/T 7714
保安安. 青藏高原不同地区垂穗披碱草青贮饲料中乳酸菌多样性及优势菌种的发酵特性研究[D]. 兰州. 兰州大学,2016.
Files in This Item:
There are no files associated with this item.
Related Services
Recommend this item
Bookmark
Usage statistics
Export to Endnote
Altmetrics Score
Google Scholar
Similar articles in Google Scholar
[保安安]'s Articles
Baidu academic
Similar articles in Baidu academic
[保安安]'s Articles
Bing Scholar
Similar articles in Bing Scholar
[保安安]'s Articles
Terms of Use
No data!
Social Bookmark/Share
No comment.
Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.