本文關(guān)鍵詞： 糞臭素 大豆低聚糖 盲腸菌群 體外發(fā)酵 肉仔雞　出處：《沈陽農(nóng)業(yè)大學》2017年碩士論文　論文類型：學位論文

【摘要】：糞臭素是微生物降解L-色氨酸(L-try)的代謝產(chǎn)物,是引起雞排泄物產(chǎn)生惡臭的主要物質(zhì)之一。大豆低聚糖(SBO)是以大豆及其加工副產(chǎn)品為原料生產(chǎn)的,含有一定量的水蘇糖(STA)、棉子糖(RAF)和蔗糖(SUC)等低聚糖的產(chǎn)品。本試驗旨在研究SBO及其功能組分對體外條件下肉仔雞糞臭素產(chǎn)量的影響,并探索其微生物學機制。試驗采用單因素完全隨機試驗設計,以42日齡肉仔雞盲腸內(nèi)容物為菌源,分別設SUC、STA、RAF、SBO和對照組,每組3個重復。體外發(fā)酵液的體積為200mL,L-try的添加量為250 μmol/L,各處理組在對照組的基礎上添加等量的SBO、SUC、RAF、STA粉末,每個處理組都有不加L-try,但其他成分都相同的空白對照,以便對吲哚和糞臭素的含量進行校正。利用ANKOMRFS體外產(chǎn)氣系統(tǒng),39℃C厭氧培養(yǎng)24h,記錄累積產(chǎn)氣量,測定發(fā)酵體系中吲哚、糞臭素及有機酸的濃度、pH值及菌群結(jié)構(gòu)和主要菌群數(shù)量。試驗結(jié)果表明:(1)糞臭素及發(fā)酵參數(shù):①發(fā)酵至24h,SUC、STA、SBO組累積產(chǎn)氣量極顯著高于對照組和RAF組(P0.01),對照組產(chǎn)氣量最低;②SBO、SUC和STA組發(fā)酵液吲哚濃度分別比對照組降低了98.15%、97.72%和94.17%(P0.01);③SBO、SUC、STA和RAF組發(fā)酵液中糞臭素濃度分別比對照組降低了79.04%、71.88%、70.28%和62.42%(P0.05);④SUC、STA和SBO組L-try降解率極顯著低于RAF和對照組(P0.01);⑤SBO及其功能組分對發(fā)酵液乙酸濃度影響不顯著(P0.05),對乳酸濃度和pH值有極顯著的影響(P0.01)。SUC組乳酸濃度極顯著高于其余各組(P0.01),其中,比對照組高出75.44%。對照組的pH值最高(7.46),極顯著高于RAF之外的其余各試驗組(P0.01)。(2)發(fā)酵液菌群結(jié)構(gòu):采用PCR-DGGE技術(shù)研究了發(fā)酵液菌群結(jié)構(gòu)差異,表明,各組菌群多樣性指數(shù)差異不顯著(P0.05);SBO組菌群均勻度顯著低于對照組(P0.05);各試驗組菌群豐富度顯著高于對照組(P0.05);SBO、STA、RAF組發(fā)酵液的相似性均高于對照組;試驗組有3條特異性條帶,相似菌分別為布勞特氏菌屬(Blautia producta)、副擬桿菌屬(Parabacteroides distasonis)、路氏乳桿菌屬(Lactobacillus reuteri)細菌的增值,說明添加低聚糖能夠通過促進以上細菌的增長而降低吲哚、糞臭素的產(chǎn)生。(3)發(fā)酵液菌群數(shù)量:采用熒光定量PCR(qPCR)技術(shù)測定了發(fā)酵液主要菌群數(shù)量。表明,總菌數(shù)量由高至低依次為:SBO組STA組SUC組RAF組對照組;大腸桿菌數(shù)量由高至低依次為:SBO組STA組SUC組RAF組對照組;雙歧桿菌的數(shù)量由高到低依次為:對照組SBO組SUC組STA組RAF組。各組總菌、大腸桿菌和雙歧桿菌的數(shù)量無顯著差異(P0.05);乳酸菌數(shù)量由高到低依次為:SUC組STA組SBO組RAF組對照組,其中SUC、STA和SBO組乳酸菌數(shù)量顯著高于對照組(P0.05)。發(fā)酵液吲哚濃度與總細菌數(shù)量之間為顯著的負相關(guān)(P0.05),吲哚和糞臭素濃度與乳酸菌數(shù)量之間為顯著的負相關(guān)(P0.05)。綜上,在肉仔雞盲腸菌群發(fā)酵液中添加SUC、STA和SBO顯著降低了糞臭素和吲哚的濃度,影響體外發(fā)酵參數(shù),并通過提高發(fā)酵液菌群豐富度和增加乳酸菌的數(shù)量,降低糞臭素的濃度。降低糞臭素效果優(yōu)劣依次為:SBOSUCSTA。
[Abstract]:Skatole is microbial degradation of L- tryptophan (L-try) metabolite is caused by chicken excreta odor. One of the main material of soybean oligosaccharides (SBO) in soybean and its processed products for the production of raw materials, stachyose contain a certain amount of (STA), raffinose and sucrose (SUC (RAF) etc.) oligosaccharide products. This experiment was conducted to study the function of SBO and the influence of components on odor pigment production conditions in vitro broiler manure, and explore its microbiological mechanisms. Using a single factor completely randomized design, with 42 day old broiler caecum content as the bacteria source, respectively SUC, STA, RAF. SBO and control group, each with 3 replicates. The in vitro fermentation liquid volume is 200mL, the content of L-try was 250 mol/L, each treatment group added SBO, on the basis of the control group SUC, RAF, STA powder, each treatment group has no L-try, but other components of the same blank for According to the content of indole and skatole was corrected by ANKOMRFS. In vitro gas production system, 39 C C 24h anaerobic culture, record the cumulative biogas fermentation system, determination of indole, skatole and organic acid concentration, pH value and flora structure and main microflora. Test results show that: (1) scatol the fermentation and fermentation parameters: 1 to 24h, SUC, STA, SBO group, the cumulative gas production was significantly higher than the control group and RAF group (P0.01), the control group of SBO, the minimum gas production; SUC group and STA fermentation liquid indole concentrations were lower than the control group 98.15%, 97.72% and 94.17% (P0.01); SBO SUC, STA, and RAF group in the fermentation liquid of skatole concentrations were lower than the control group 79.04%, 71.88%, 70.28% and 62.42% (P0.05); the SUC, STA and SBO group, the degradation rate of L-try was significantly lower than that in RAF and control group (P0.01); the SBO and the functional components of the fermentation broth of acetic acid concentration was not significant (P0.05), milk 閰告祿搴﹀拰pH鍊兼湁鏋佹樉钁楃殑褰卞搷(P0.01).SUC緇勪鉤閰告祿搴︽瀬鏄捐憲楂樹簬鍏朵綑鍚勭粍(P0.01),鍏朵腑,姣斿鐓х粍楂樺嚭75.44%.瀵圭収緇勭殑pH鍊兼渶楂，

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