本文選題：甘薯酸漿 + 高通量測(cè)序��； 參考：《沈陽農(nóng)業(yè)大學(xué)》2017年碩士論文

【摘要】：甘薯酸漿是粉絲或淀粉生產(chǎn)中天然形成的副產(chǎn)物,是一種微生物絮凝劑。在淀粉生產(chǎn)的過程中加入酸漿,可以加速淀粉與蛋白質(zhì)的分離。但傳統(tǒng)的酸漿法生產(chǎn)淀粉多數(shù)靠經(jīng)驗(yàn),經(jīng)常會(huì)受到一些條件影響。所以,酸漿質(zhì)量極不穩(wěn)定,在一定程度上影響了淀粉生產(chǎn)的產(chǎn)量和質(zhì)量。因此,了解影響酸漿發(fā)酵的因素,掌握自然發(fā)酵甘薯酸漿中的微生物菌群結(jié)構(gòu),對(duì)提高酸漿質(zhì)量,開發(fā)微生物絮凝劑,減少酸漿的使用量,解決環(huán)境污染問題具有有重要的意義。本試驗(yàn)以自然發(fā)酵甘薯酸漿為研究對(duì)象,采用高通量測(cè)序法對(duì)不同發(fā)酵時(shí)期的酸漿樣品進(jìn)行細(xì)菌類群動(dòng)態(tài)規(guī)律分析,解析各細(xì)菌類群與酸漿絮凝性的關(guān)系。結(jié)果表明:自然發(fā)酵甘薯酸漿主要以厚壁菌門Firmicutes(92.6%)、變形菌門Proteobacteria(3.6%)和藍(lán)藻細(xì)菌門Cyanabacteria(3.4%)為主。其中厚壁菌門主要以乳桿菌屬Lactobaillus(55.3%)、明串珠菌屬Leuconostoc(23.8%)、芽孢桿菌屬Bacillis(2.9%)為主。變形菌門主要以假單胞菌屬Pseudomonas(2.0%)為主。因此,乳桿菌屬是自然發(fā)酵甘薯酸漿中優(yōu)勢(shì)菌,明串珠菌屬為次優(yōu)勢(shì)菌。隨著發(fā)酵時(shí)間的延長,乳桿菌屬含量先減少后增加,在發(fā)酵中期最低。而明串珠菌屬含量先增加后減少,在發(fā)酵中期最高,且在發(fā)酵中期時(shí)自然發(fā)酵甘薯酸漿絮凝率最高,因此明串珠菌屬為自然發(fā)酵甘薯酸漿中的絮凝作用菌。根據(jù)對(duì)甘薯酸漿自然發(fā)酵過程中的細(xì)菌類群動(dòng)態(tài)規(guī)律解析結(jié)果,分離并鑒定酸漿中具有絮凝性的細(xì)菌類群,并驗(yàn)證其功能。結(jié)果表明:從自然發(fā)酵甘薯酸漿中共分離出55株疑似乳酸菌,革蘭氏染色均為陽性、過氧化氫酶反應(yīng)均為陰性,初步鑒定均為乳酸菌。經(jīng)16SrDNA鑒定,均為明串珠菌屬。共包括3種明串珠菌屬,分別為:Leuconostoc mesenteroides(76.36%)、Leuconostocpseudomesenteroides(20%)、Leuconostoc sp.(3.64%)。酸漿發(fā)酵整個(gè)過程的優(yōu)勢(shì)菌株為Leuconstoc mesenteroides,絮凝率最高時(shí)優(yōu)勢(shì)菌株為Leuconostoc mesenteroides。
[Abstract]:Sweet potato acid pulp is a kind of microbial flocculant, which is a natural by-product in the production of vermicelli or starch.The separation of starch and protein can be accelerated by adding acid pulp in the process of starch production.However, most of the traditional acid sizing process starch production depends on experience, often affected by some conditions.Therefore, the quality of acid pulp is very unstable, which to some extent affects the yield and quality of starch production.Therefore, we should understand the factors that affect the fermentation of sour pulp, master the structure of microbial flora in naturally fermented sweet potato and acid pulp, improve the quality of acid pulp, develop microbial flocculant, and reduce the amount of acid pulp.It is of great significance to solve the problem of environmental pollution.In this experiment, the natural fermented sweet potato acid pulp was used as the research object. The dynamic laws of bacterial groups in different fermentation stages were analyzed by high-throughput sequencing method, and the relationship between the bacterial groups and the flocculability of acid pulp was analyzed.The results showed that the natural fermented sweet potato pulp was mainly composed of phylum firmicutes92.6g, Proteobacteria Proteobacteria 3.6B) and Cyanabacteria cyanabacteria 3.4.Among them, Lactobacillus Lactobacillus 55.3, Leuconostoctus 23.8m and Bacillis2.9.The phylum of Proteus was mainly Pseudomonas 2.0).Therefore, Lactobacillus is the dominant bacteria in natural fermentation sweet potato pulp, and Streptococcus spp is secondary dominant.With the increase of fermentation time, the content of Lactobacillus decreased first and then increased, and was the lowest in the middle stage of fermentation.However, the content of Streptomyces increased first and then decreased, and reached the highest in the middle stage of fermentation, and the flocculation rate of natural fermented sweet potato and acid pulp was the highest.Based on the analysis of the dynamic laws of bacterial groups during the natural fermentation of sweet potato acid pulp, the flocculating bacteria groups in sweet potato pulp were isolated and identified, and their functions were verified.The results showed that 55 strains of suspected lactic acid bacteria were isolated from naturally fermented sweet potato pulp. Gram staining was positive, catalase reaction was negative, and all were identified as lactic acid bacteria.All of them were identified as Streptococcus by 16SrDNA.There are three species of Leuconostoc mesenteroides76.36 in the genus Leuconostoc, Leuconostock-pseudomes enteroides20 and Leuconostoc sp.Leuconstoc mesenteroides was the dominant strain in the whole fermentation process, and the dominant strain was Leuconostoc mesenteroides when the flocculation rate was the highest.
【學(xué)位授予單位】：沈陽農(nóng)業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TS201.3;TQ920.1
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本文編號(hào)：1773252