陳佳敏,張文羿,李康寧,孟和畢力格
植物乳桿菌抑制黃曲霉活性代謝物的初步研究
陳佳敏,張文羿,李康寧,孟和畢力格※
(內(nèi)蒙古農(nóng)業(yè)大學(xué)乳品生物技術(shù)與工程教育部重點(diǎn)實(shí)驗(yàn)室,農(nóng)業(yè)農(nóng)村部奶制品加工重點(diǎn)實(shí)驗(yàn)室,呼和浩特 010018)
植物乳桿菌()能夠抑制黃曲霉生長(zhǎng),但起主要抑菌作用的物質(zhì)尚未明確。該研究采用非靶向代謝組學(xué)技術(shù)比較分析了8株抑菌活性較好(S組)和8株抑菌活性較差(W組)的.發(fā)酵上清液。結(jié)果顯示,兩組.發(fā)酵上清液的代謝組存在顯著差異(<0.05)。通過數(shù)據(jù)庫比對(duì)鑒定得到咪唑乙酸、酪氨酸等30個(gè)顯著差異代謝物(<0.05),其中有機(jī)酸、脂肪酸等酸性物質(zhì)較多為22個(gè)。通過與已報(bào)道的乳酸菌產(chǎn)生的抗真菌物質(zhì)相比較,找到十八烷酸、吲哚乙酸等結(jié)構(gòu)一致或結(jié)構(gòu)類似物,表明上清液中酸性物質(zhì)起主要的抑菌作用,且其抑菌活性依賴于低 pH 值的酸性環(huán)境。在.產(chǎn)生的主要有機(jī)酸中,乳酸、乙酸、丙酸的抑菌活性良好,其抑制黃曲霉活性從大到小依次為丙酸、乙酸、乳酸。當(dāng)乙酸濃度為2.64g/L、丙酸濃度為1.76 g/L時(shí),可完全抑制濃度為106個(gè)/mL的黃曲霉孢子生長(zhǎng)。綜合表明,植物乳桿菌代謝物中有機(jī)酸和脂肪酸為主要抑菌物質(zhì),且抑菌活性隨酸性物質(zhì)濃度增大而增強(qiáng)。
農(nóng)產(chǎn)品;酸;植物乳桿菌;抗黃曲霉活性;代謝產(chǎn)物;非靶向代謝組學(xué)
黃曲霉是一種食品腐敗真菌,能夠污染小麥、水稻、玉米等主要糧食作物。同時(shí),黃曲霉菌可產(chǎn)生多種黃曲霉毒素,其中黃曲霉毒素B1在全球范圍內(nèi)分布最為廣泛,其具有強(qiáng)毒性、強(qiáng)致癌性、強(qiáng)致畸性,屬于Ⅰ類致癌物,對(duì)人畜健康存在嚴(yán)重威脅[1]。目前,全世界約10%的支氣管肺曲霉病是由黃曲霉引起[2],另外黃曲霉還可以危害人的神經(jīng)、皮膚系統(tǒng)[3]。
黃曲霉毒素可存在于食品中,過量攝入會(huì)使人畜產(chǎn)生不同程度的中毒,急性中毒可引起兒童生長(zhǎng)障礙甚至致人死亡[4]。為減少黃曲霉對(duì)食品安全的影響,當(dāng)前使用最多的是調(diào)節(jié)溫度、噴灑農(nóng)藥等物理化學(xué)方法來抑制其生長(zhǎng),但大多數(shù)方法抑制效果不佳且影響食用者健康[1]。因此,專一性好、安全高效的生物防治法越來越受到消費(fèi)者的認(rèn)可與重視[5-6]。
眾所周知,乳酸菌在食品中有著長(zhǎng)期安全使用歷史,在眾多乳酸菌中,植物乳桿菌的抑菌特性尤為引人關(guān)注[7]。先前研究指出,植物乳桿菌產(chǎn)生的天然化合物可抑制真菌生長(zhǎng),延長(zhǎng)多種食品的保質(zhì)期[8-9]。有研究將實(shí)驗(yàn)室培養(yǎng)的植物乳桿菌產(chǎn)生的多肽應(yīng)用于新鮮玉米種子,發(fā)現(xiàn)其可以顯著抑制黃曲霉及孢子的生長(zhǎng)[10]。另一項(xiàng)研究中,植物乳桿菌在30 ℃培養(yǎng)5 d后表現(xiàn)出有效的解毒活性并可降解玉米種子中的黃曲霉毒素B1[11]。此外眾多研究指出,植物乳桿菌的抑菌活性依賴于其產(chǎn)生的多種代謝物[12-13],而酸是植物乳桿菌抑菌的主要原因,其中有機(jī)酸是植物乳桿菌最主要的酸性代謝產(chǎn)物[14]。在植物乳桿菌產(chǎn)生的眾多有機(jī)酸中,乙酸是最有效的抗真菌代謝產(chǎn)物[15]。已有多位學(xué)者對(duì)植物乳桿菌發(fā)酵上清液中的有機(jī)酸成分進(jìn)行分析,發(fā)現(xiàn)上清液有機(jī)酸中乳酸、乙酸、丙酸的含量最高[16-17]。
當(dāng)前針對(duì)植物乳桿菌對(duì)黃曲霉抑制作用的研究大多集中在單菌株所產(chǎn)生的抑菌物質(zhì)上,對(duì)具有不同抑菌活性的多菌株之間差異代謝物的研究較少。因此,本試驗(yàn)基于前期研究發(fā)現(xiàn)的具有不同抑制黃曲霉活性的16株性植物乳桿菌(其中8株抑菌活性強(qiáng),8株抑菌活性弱),利用超高效液相色譜-四級(jí)桿飛行時(shí)間質(zhì)譜技術(shù)結(jié)合主成分分析(Principal Components Analysis,PCA)和正交偏最小二乘法-判別分析(Orthogonal Partial Least Square-Discriminate Analysis,OPLS-DA)研究具有不同抑菌活性菌株之間的差異代謝物,從代謝角度分析其抑菌作用的組分,以期尋找確切抑制黃曲霉的小分子代謝物,為開發(fā)天然防腐劑提供依據(jù)。同時(shí),本研究基于實(shí)驗(yàn)室前期定量測(cè)定的植物乳桿菌發(fā)酵上清液中乳酸、乙酸和丙酸的含量,在黃曲霉孢子數(shù)相同的情況下,分別用1、2、3倍濃度的標(biāo)準(zhǔn)品對(duì)其抑制黃曲霉活性進(jìn)行驗(yàn)證,為植物乳桿菌的實(shí)際應(yīng)用奠定一定基礎(chǔ)。
本試驗(yàn)所用的16株植物乳桿菌均由乳品生物技術(shù)與工程教育部重點(diǎn)實(shí)驗(yàn)室乳酸菌菌種資源庫提供。本次抑菌試驗(yàn)所采用的黃曲霉菌株編號(hào)為CICC2219,由中國工業(yè)微生物菌種保藏管理中心提供。
甲酸(色譜級(jí))、乙腈(色譜級(jí))、氨水(色譜級(jí)),Sigema公司;乳酸標(biāo)準(zhǔn)品(色譜純)、乙酸標(biāo)準(zhǔn)品(色譜純)、丙酸(色譜純),Sigma-Aldrich公司。
ACQUITY UPLC-Xevo G2 QTOF MS超高效液相色譜-四極桿飛行時(shí)間質(zhì)譜儀,Waters公司;Milli-Q純水儀,Millipore公司;旋轉(zhuǎn)蒸發(fā)氮?dú)獍l(fā)生器,Peak公司;電熱恒溫培養(yǎng)箱,上海一恒科技有限公司;高速控溫離心機(jī),Eppendorf公司。
1.3.1 植物乳桿菌菌株的活化、活菌數(shù)檢測(cè)及無菌上清液的制備
菌株活化及活菌數(shù)檢測(cè):將16株保藏好的植物乳桿菌分別按1%接種量接種于5 mL MRS瓊脂液體培養(yǎng)基中,在37 ℃恒溫培養(yǎng)箱中進(jìn)行24 h培養(yǎng)活化,然后,在MRS液體培養(yǎng)基中連續(xù)傳代兩次,接種量為1%,培養(yǎng)條件均為37 ℃,培養(yǎng)12 h使其恢復(fù)菌株活力。將恢復(fù)活力的菌株在37 ℃下培養(yǎng),生長(zhǎng)至對(duì)數(shù)期,倍比稀釋后,采用MRS固體培養(yǎng)基平板傾注法進(jìn)行活菌數(shù)檢測(cè)。
無菌上清液(Cell Free Supernatants,CFS)制備:將活菌數(shù)為5×106cfu/mL的植物乳桿菌菌株接種到MRS液體培養(yǎng)基,37 ℃恒溫靜置培養(yǎng)24 h,8 000×離心5 min,隨后,將離心得到的上清液用0.22m濾膜過濾。
1.3.2 黃曲霉培養(yǎng)條件及孢子懸液的制備
將黃曲霉CICC2219作為指示菌,劃線接種于馬鈴薯葡萄糖瓊脂(Potato Dextrose Agar,PDA)斜面培養(yǎng)基上,30 ℃培養(yǎng)3~4 d至孢子形成。將已滅菌的PBS緩沖液倒入長(zhǎng)好孢子的試管中,輕微振蕩,使孢子脫落,用5層無菌紗布過濾去除菌絲體得到孢子懸液。采用梯度稀釋法測(cè)定孢子數(shù),將孢子濃度調(diào)整為106個(gè)/mL備用。
1.3.3 植物乳桿菌抑制黃曲霉活性測(cè)定
采用雙層平板點(diǎn)接法測(cè)定植物乳桿菌抑制真菌活性,將16株已恢復(fù)菌株活力的植物乳桿菌分別接種于MRS液體培養(yǎng)基中,37 ℃培養(yǎng)12 h。在直徑約為90 mm的培養(yǎng)皿中,加入已滅菌融化的MRS,制成MRS固體培養(yǎng)基,待水氣消失后,使用微量移液器將5L活菌數(shù)相同的植物乳桿菌菌液點(diǎn)接于固體培養(yǎng)基上,37 ℃培養(yǎng)24 h至圓形菌斑形成。將0.15 mL黃曲霉孢子懸液與15 mL熔化的PDA培養(yǎng)基充分混合,傾注在MRS培養(yǎng)基上,30 ℃培養(yǎng)3 d,量取抑菌圈直徑。依據(jù)抑菌圈直徑,將植物乳桿菌劃分為Strong組(S組)與Weak組(W組)。抑菌圈直徑>6 mm,為抑菌活性較強(qiáng)(+);直徑<6 mm,為抑菌活性較弱(-)[17]。
抑菌圈直徑=抑菌圈外徑-植物乳桿菌菌斑直徑
1.3.4 發(fā)酵上清液抑菌活性的測(cè)定
將發(fā)酵上清液按10%添加量加入PDA培養(yǎng)基中,混勻后倒入培養(yǎng)皿,待培養(yǎng)基冷凝后,在培養(yǎng)皿中心位置點(diǎn)接5L黃曲霉孢子懸浮液,30 ℃培養(yǎng)3 d后觀察黃曲霉菌落直徑,驗(yàn)證植物乳桿菌抑菌活性。
取1.3.1制備的無菌上清液與乙腈按1∶1的比例混合均勻,4 ℃靜置20 min,振蕩15 s,室溫10 000×離心15 min,取上清液過濾后作為待測(cè)樣本。分析條件如下:
色譜柱選用Waters BEH C18(2.1 mm×100 mm,1.7m),進(jìn)樣體積為5L,流速0.32 mL/min。采用梯度洗脫,正離子模式下流動(dòng)相A為0.1%甲酸水溶液,流動(dòng)相B為0.1%甲酸乙腈溶液;負(fù)離子模式下,流動(dòng)相A為0.1%的氨水水溶液,流動(dòng)相B為純乙腈溶液;液相洗脫梯度為:0~3 min,98% A;3~9.5 min,90% A;9.5~11 min,70% B;11~13 min,90%B;13~14 min,50% B;14~15 min,98% A。
質(zhì)譜條件:離子源為ESI(Election Spray Ionization)電噴霧電離,數(shù)據(jù)采集模式為正、負(fù)子模式(ES+/-),質(zhì)荷比掃描范圍50~1 000 m/z。毛細(xì)管電壓為3.0 kV(+/-),去溶劑氣溫度450 ℃,去溶劑氣(氮?dú)猓┝髁?00 L/h。
采用MassLynx、Progenesis QI軟件對(duì)UPLC-Q TOF MS獲得的原始數(shù)據(jù)進(jìn)行峰提取,峰對(duì)齊、保留時(shí)間校正等處理。采集整理的數(shù)據(jù)導(dǎo)入Simca 14.1軟件,進(jìn)行主成分分析(PCA)、正交偏最小二乘判別(OPLS-DA)分析。使用MetaboAnalyst 5.0(http://www.metaboanalyst.ca)進(jìn)行統(tǒng)計(jì)分析與通路分析。結(jié)合OPLS-DA的VIP(變量投影重要性,Variable Importance in the Projection)值≥1、兩組間差異倍數(shù)≥2和值≤0.05相結(jié)合的方法找出兩組樣品中顯著差異性代謝物。
基于實(shí)驗(yàn)室前期定量測(cè)定的發(fā)酵上清液中乳酸(3.53 g/L)、乙酸(0.88 g/L)和丙酸(0.88 g/L)的含量,在黃曲霉孢子數(shù)相同的情況下分別用其1、2、3倍濃度的標(biāo)準(zhǔn)品對(duì)其抑制黃曲霉活性進(jìn)行驗(yàn)證。將不同濃度的3 種有機(jī)酸標(biāo)品與PDA培養(yǎng)基混勻倒入培養(yǎng)皿中,待培養(yǎng)基冷凝后,在培養(yǎng)皿中心位置點(diǎn)接5L黃曲霉孢子懸浮液,30 ℃培養(yǎng)3 d后觀察黃曲霉菌落生長(zhǎng)情況。
由表1可知,16株植物乳桿菌均可抑制黃曲霉,依據(jù)其抑菌圈直徑大小將其分為抑菌性強(qiáng)(+),即S組;抑菌性弱(-),即W組,共兩組。其中菌株IMAU80065、IMAU30162、IMAU20063等8株菌對(duì)黃曲霉的抑制效果較好。
依據(jù)抑菌試驗(yàn)所得結(jié)果,以純PDA培養(yǎng)基為對(duì)照,按照10%(體積百分比濃度)的添加量,將無菌上清液與PDA培養(yǎng)基混合,測(cè)定其對(duì)真菌菌絲生長(zhǎng)的抑制情況。結(jié)果顯示(圖1),S組、W組的無菌上清液均可抑制黃曲霉生長(zhǎng),且S組中菌株的無菌上清液抑菌活性較強(qiáng)。
2.3.1 OPLS-DA分析
為找到兩組樣品間的差異代謝產(chǎn)物,通過Simca 14.1軟件對(duì)具有不同抑菌活性的代謝產(chǎn)物進(jìn)行OPLS-DA分析,得出如圖2所示的離散程度得分圖。由圖2可知,S組的樣本與W組的樣本能夠完全區(qū)分,且組內(nèi)具有一定的類聚作用。該模型的區(qū)分程度較好。
2.3.2 差異代謝產(chǎn)物分析
使用MetaboAnalyst在線工具過濾數(shù)據(jù)后,依據(jù)KEGG數(shù)據(jù)庫的富集分析顯示,與W組對(duì)照相比,S組中酪氨酸代謝、脂肪酸合成、色氨酸代謝、丙酮酸代謝、苯丙氨酸代謝、嘧啶代謝等相關(guān)的幾種途徑顯著富集。同時(shí),與已報(bào)道乳酸菌抑菌物質(zhì)類型對(duì)測(cè)定到的物質(zhì)進(jìn)行對(duì)比,在16株植物乳桿菌發(fā)酵上清液中總計(jì)鑒定到30種可能與抑制真菌活性相關(guān)的物質(zhì),主要包括有機(jī)酸,脂肪酸類酸性物質(zhì)、氨基酸及其衍生物。
表1 16株植物乳桿菌抑制黃曲霉活性
注:“-”為抑菌圈直徑<6 mm;“+”為抑菌圈直徑?6 mm。
Note: “-” means the diameter of the inhibition zone<6 mm; “+” means the diameter of the inhibition zone?6 mm.
迄今為止,酸性物質(zhì)被認(rèn)為是植物乳桿菌產(chǎn)生的主要抑菌物質(zhì),在S組與W組的差異代謝物中,有機(jī)酸、脂肪酸類物質(zhì)最多達(dá)22種(表2)。與目前已報(bào)道的乳酸菌產(chǎn)生的具有抑菌活性的酸性物質(zhì)相比較,發(fā)現(xiàn)存在多個(gè)結(jié)構(gòu)一致或結(jié)構(gòu)相似的物質(zhì),如2-羥基-3-甲基丁酸、3-羥基-5-十二烯酸、苯甲酸、十四烷酸、十六烷酸、辛酸、3-羥基癸酸等[18-19]。同時(shí),吲哚乙酸的抗真菌活性已被報(bào)道[20],咪唑類物質(zhì)具有良好的抗菌效果,作為農(nóng)藥被廣泛應(yīng)用[21],因此,推測(cè)烷酸、烯酸、吲哚乙酸、咪唑乙酸類物質(zhì)具有一定的抑菌活性。
其他酸性物質(zhì)的抑菌活性也多次被報(bào)道,其中牛磺膽酸可降低培養(yǎng)基的表面張力,使菌體細(xì)胞膜損壞甚至使菌體裂解,從而能很好地抑制革蘭氏陽性菌[22]。苯乙酸具有很強(qiáng)的抑菌活性[23],十二烷酸被用作殺蟲劑[24]。苯丙酮酸可轉(zhuǎn)化為苯基乳酸,顯著抑制大腸桿菌、金黃色葡萄球菌、擴(kuò)展青霉和黃曲霉等霉菌生長(zhǎng)的活性[25]。乙酰磷酸是細(xì)菌合成乙酸或利用乙酸的中間代謝產(chǎn)物[26],乙酸是乳酸菌發(fā)酵產(chǎn)生的小分子抑菌物質(zhì),具有較好的抑菌活性。而甘草酸、二十二碳六烯酸具有消炎作用。由此推測(cè),這些酸性物質(zhì)具有抑菌活性。
表2 有機(jī)酸、脂肪酸及其衍生物
有研究表明,植物乳桿菌無菌上清液作用于黃曲霉后,黃曲霉被顯著抑制,其生長(zhǎng)量減少32%,黃曲霉毒素產(chǎn)量減少91%[27],而將上清液中和處理后,這種影響被逆轉(zhuǎn)。Sangmanee等[28]也指出,植物乳桿菌UM55產(chǎn)生的乳酸、棕櫚酸、硬脂酸等酸性物質(zhì)可抑制黃曲霉的生長(zhǎng)及黃曲霉毒素的產(chǎn)生,這些物質(zhì)與我們發(fā)現(xiàn)的十八烷酸、十六烷酸相一致。因此推測(cè),這些酸性物質(zhì)的協(xié)同作用是抑制黃曲霉的關(guān)鍵。
在差異代謝物中鑒定到的氨基酸及其衍生物中,主要以L-半胱氨酸、D-脯氨酸、L-苯丙氨酸等游離氨基酸為主,氨基酸衍生物較少,僅發(fā)現(xiàn)N-乙?;?L-天冬氨酸-L-谷氨酸一個(gè)物質(zhì)(表3)。其中L-苯丙氨酸代謝的副產(chǎn)物為苯乳酸,而苯乳酸是近年發(fā)現(xiàn)的一種新型天然廣譜抑菌劑[29],可能與抑制黃曲霉相關(guān)。
在植物乳桿菌產(chǎn)生的氨基酸類抗真菌物質(zhì)中,目前最認(rèn)可的是環(huán)二肽類物質(zhì),也有少數(shù)多肽、蛋白類物質(zhì)。Belal等[30]對(duì)植物乳桿菌IS10進(jìn)行研究發(fā)現(xiàn),其產(chǎn)生的多肽FPSHTGMSVPP對(duì)黃曲霉MD3有良好的抑菌活性。Ahmad等[31]對(duì)植物乳桿菌YML007菌株的無細(xì)胞上清液進(jìn)行分析顯示,1 256.6 kDa的新蛋白對(duì)黃曲霉、米曲霉具有抗真菌活性。推測(cè)這類物質(zhì)可能對(duì)黃曲霉具有抑制活性但貢獻(xiàn)較小。
表3 氨基酸及其衍生物類物質(zhì)
2.3.3 乳酸、乙酸、丙酸抑制黃曲霉活性
目前認(rèn)為,酸性物質(zhì)主要通過營造不利于有害菌生長(zhǎng)的低酸環(huán)境來達(dá)到抑制其生長(zhǎng)繁殖的目的。為驗(yàn)證酸性物質(zhì)對(duì)抑菌活性的影響,對(duì)發(fā)酵上清液進(jìn)行中和處理后,發(fā)現(xiàn),其抑制黃曲霉活性顯著降低,表明抑菌活性物質(zhì)本身為酸性或依賴于酸性環(huán)境。有機(jī)酸是植物乳桿菌最主要的酸性代謝物,其中乳酸的產(chǎn)量最高[14]。有研究指出,乙酸是乳桿菌最有效的抗真菌代謝產(chǎn)物[15]。而未解離的乳酸、乙酸和丙酸可擴(kuò)散穿過細(xì)胞膜并在細(xì)胞質(zhì)內(nèi)積累,造成細(xì)胞內(nèi)呈現(xiàn)酸性環(huán)境,而這種酸脅迫的抑菌機(jī)制也被廣泛認(rèn)可[32]。因此,本試驗(yàn)基于實(shí)驗(yàn)室前期定量測(cè)定的發(fā)酵上清液中乳酸和乙酸、丙酸的含量,在黃曲霉孢子數(shù)相同的情況下,分別用1倍、2倍、3倍濃度的標(biāo)準(zhǔn)品對(duì)抑菌活性進(jìn)行驗(yàn)證。發(fā)現(xiàn)抑菌活性從大到小依次為丙酸、乙酸、乳酸(圖3),乙酸濃度增加為3倍時(shí)可完全抑制黃曲霉,丙酸濃度為2倍時(shí)即可完全抑制其生長(zhǎng)。
1)本試驗(yàn)采用UPLC-Q TOF MS 技術(shù),研究了16株(兩組)具有不同抑制黃曲霉活性的植物乳桿菌發(fā)酵上清液的代謝組。結(jié)果發(fā)現(xiàn),抑菌活性好的S組與抑菌活性較差W組間有明顯差異(<0.05)。結(jié)合數(shù)據(jù)庫檢索及質(zhì)譜信息匹配,共篩選出十八烷酸、十六烷酸、L-苯丙氨酸、吲哚乙酸、癸酸等30個(gè)代謝物,其中包含多種具有抑菌作用的有機(jī)酸。
2)試驗(yàn)表明,起主要抑菌作用的為酸性物質(zhì),且其抑菌活性為各種物質(zhì)的共同混合作用,其抑菌活性依賴于低pH值下構(gòu)建的酸性環(huán)境。本研究驗(yàn)證了植物乳桿菌發(fā)酵上清液中3種主要有機(jī)酸(乳酸、乙酸、丙酸)可有效抑制黃曲霉,且其抑菌活性從大到小依次為丙酸、乙酸、乳酸。
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Preliminary study on active metabolites ofagainst
Chen Jiamin, Zhang Wenyi, Li Kangning, Menghe Bilige※
(,,,,,010018,)
Lactic acid bacteria have a long history of safe use in food. Among them, the antifungal properties ofare particularly interesting. Numerous studies have pointed out that the natural compounds produced bycan significantly inhibit the growth of fungi and, spores, thereby degrading aflatoxin, especially for the longer shelf life of a variety of food. Moreover, the acid is attributed to the antifungal activity of, where organic acid is the most important acidic metabolite of. In addition, acetic acid is the most effective antifungal metabolite among the many organic acids produced by. At the same time, there is the highest content of lactic acid, acetic acid, and propionic acid in thefermentation supernatant organic acid. However, the inhibitory effect ofonis mostly focused on the antifungal substances produced by a single strain in recent years. Only a few studies were on the differential metabolites of multiple strains with different antifungal activities. Moreover, standard products are still lacking to verify the activity of inhibitingon the quantitative amount of lactic acid, acetic acid, and propionic acid in the supernatant of. Therefore, the purpose of this research is to find the small molecular metabolites that inhibitthrough the comparison between multiple strains, with emphasis on the practical application of. 16 strains ofwith different antifungal activities were selected, 8 strains of which presented strong antifungal activity (Strong group) and the rest was weak (Weak group). Ultra-high performance liquid chromatography-quadrupole flight Time mass spectrometry combined with PCA (Principal Components Analysis) and OPLS-DA (Orthogonal Partial Least Square-Discriminate Analysis) was utilized to explore the different metabolites between strains with different antifungal activities, further to determine the substances with main antifungal effects. At the same time, standard products of 1, 2, and 3 times the concentration were used to verify the inhibit activity of, according to the quantitative determination for the content of lactic acid, acetic acid, and propionic acid in the fermentation supernatant ofin the early stage of the laboratory. The results showed that there were significantly different metabolites in the two groups offermentation supernatants (<0.05). Database comparison demonstrated 30 significantly different metabolites, including imidazoleacetic acid, tyrosine were identified (<0.05). Among them, acidic substances were relatively different, such as organic and fatty acids. Correspondingly, the acidic substance in the supernatant was attributed to the main antifungal effect, whereas the antifungal activity depended on the acidic environment of low pH value. Lactic acid, acetic acid, and propionic acid presented excellent antifungal activities among organic acids produced by. Specifically, the antifungal activity was ranked in order of propionic acid>acetic acid>lactic acid.Comprehensively, organic and fatty acids are widely expected to be the main antifungal substances, where theantifungal activity increased with the concentration of the acidic substances.
agriculture products; acid; lactobacillus plantarum; anti-aspergillus flavus activity; metabolites; non-targeted metabolomic
陳佳敏,張文羿,李康寧,等. 植物乳桿菌抑制黃曲霉活性代謝物的初步研究[J]. 農(nóng)業(yè)工程學(xué)報(bào),2021,37(18):315-321.doi:10.11975/j.issn.1002-6819.2021.18.036 http://www.tcsae.org
Chen Jiamin, Zhang Wenyi, Li Kangning, et al. Preliminary study on active metabolites ofagainst[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2021, 37(18): 315-321. (in Chinese with English abstract) doi:10.11975/j.issn.1002-6819.2021.18.036 http://www.tcsae.org
2021-04-16
2021-08-31
國家自然科學(xué)基金(31660450):地區(qū)科學(xué)基金項(xiàng)目
陳佳敏,研究方向?yàn)槿樗峋Y源開發(fā)與利用。Email:1259002269@qq.com
孟和畢力格,教授,博士生導(dǎo)師,研究方向?yàn)槿槠饭こ?。Email:mhblg@163.com
10.11975/j.issn.1002-6819.2021.18.036
TS201.3
A
1002-6819(2021)-18-0315-07