本文主要研究内容
作者陈鸿宇（2019）在《嗜热链球菌MN-ZLW-002各生长时期转录组及sRNA差异分析》一文中研究指出：随着消费者健康观念的增强,以酸奶为代表的发酵乳制品越来越受到欢迎,截至2018年底,我国酸奶市场销售额就已经突破1400亿人民币。作为最重要的乳制品发酵菌株之一,嗜热链球菌的市场需求量也随之不断增长。在工业化发酵剂制备过程中,高密度培养基各营养成分的设计是获得最优生物量的关键。嗜热链球菌是营养缺陷型菌株,对培养基中各营养成分的需求极为苛刻,特别是碳源、氮源和核酸三个主要成分。在发酵过程,对这三个组分的代谢机制的研究是优化嗜热链球菌高密度培养基的组分和发酵参数的关键,而关于这部分的研究也正是目前所缺乏的。本研究以嗜热链球菌为研究对象,对其在化学合成培养基中进行增殖培养。通过高通量测序技术,获得在各生长时期转录水平表达的基因和在非编码RNA水平表达的sRNA,从而阐明在各生长时期菌株体内关键代谢路径基因表达情况及sRNA潜在的调控机制。本研究通过转录组学测序,共获得1937个基因,并进行功能(GO)注释和代谢路径(KEGG)注释。基于基因在每个样本中表达量的差异,筛选出在每个生长时期发生差异表达的基因,并进行功能富集和代谢路径富集分析。本研究重点对发酵过程中核酸代谢、碳代谢、氨基酸代谢全局转录情况进行评估。在核酸代谢中,嘌呤从头合成途径主要发生在对数期,其中pur操纵子在对数前期表达上调超过5倍,在对数末期表达量下调约2倍。然而嘧啶从头合成路径在整个生长时期反应活性都处于低表达的状态,但是在稳定期,pyr操纵子的表达轻微上调。在碳代谢过程中,半乳糖代谢主要发生在对数期,两个关键基因lacS和lacZ在对数前期表达上调1.2倍,在对数末期的表达上调3倍;然而在迟滞期,半乳糖代谢受到抑制,两个基因的表达均下调超过1倍;此外,编码半乳糖激酶的galk在整个生长时期均高度表达,特别是在迟滞期和对数期,表明Streptococcus thermophilus MN-ZLW-002可能具有代谢半乳糖的能力。糖酵解作为发酵过程中重要的供能途径,迟滞期为糖酵解最为活跃的时期,该途径的关键基因glk、pyk、pgk上调均超过5倍。在对数期和稳定期,该路径中的基因表达均发生不同程度的下调。丙酮酸作为糖酵解的产物,结果表明丙酮酸被还原成乙酸的反应主要发生在迟滞期和对数前期,催化该反应的ldh在两个时期表达量分别上调1.6倍和0.2倍。丙酮酸转变乙酰辅酶A的反应主要在对数末期发生,催化该反应的pbh BCD在对数末期表达均上调1.9倍。脂肪酸代谢主要发生在迟滞期和对数前期,此过程中的限速基因accB在迟滞期表达上调2.9倍,在对数前期表达量未发生变化,然而在对数末期和稳定期表达呈现下调趋势。在氨基酸代谢路径中,差异表达的基因主要富集在谷氨酸、丙氨酸、天冬氨酸、精氨酸、甘氨酸、丝氨酸、半胱氨酸、甲硫氨酸、缬氨酸、亮氨酸、异亮氨酸代谢路径中,并且在不同生长时期,这些氨基酸的代谢也表现出差异。迟滞期是氨基酸代谢最为活跃的时期,几乎所有发生差异变化的基因均上调;在对数期,主要发生的反应为天冬氨酸转变为延胡索酸和草酰乙酸,谷氨酸转化成琥珀酸、6-磷酸葡萄糖、5-磷酸核糖胺和氨基甲酰磷酸酯,丝氨酸转化为丙酮酸和色氨酸,甲硫氨酸转化为N-甲酰-L-甲硫氨酸,精氨酸酸脱亚胺酶路径(ADI);在稳定期主要发生的反应有谷氨酸生成6-磷酸葡萄糖,丝氨酸转化为丙酮酸,支链氨基酸代谢路径中二氢硫辛酰胺-E转化为硫辛酰胺-E。通过small RNA测序,共获得530个sRNA序列,其中135个来自基因间区,198个来自于反义链,197个来自于非翻译区。通过IntaRNA对sRNA的靶基因进行预测,390个靶基因被富集到99个代谢路径中。对sRNA差异表达情况分析表明,分别有238、83、194和139个sRNA在各生长时期发生显著性变化。对来自各生长时期的14个变化最显著的sRNA进一步分析,结果表明这些潜在的靶基因被富集的主要代谢途径涉及碳代谢,氨基酸生物合成,ABC转运蛋白,氨基糖和核苷酸糖的代谢,嘌呤代谢和磷酸转移酶系统。结合转录组学数据中这些靶基因的表达情况对上述sRNA潜在的调控机制进行了初步分析。在迟滞期发生差异表达的sRNA对潜在的靶基因具有正向调控的作用;在对数前期,一些sRNA可能扮演着管家基因的角色,通过对靶基因负向调控,从而控制胞内代谢流速;在对数末期,发生差异表达的sRNA对靶基因负向调节,通脱抑制菌株内代谢活性,保证菌株在复杂的生长环境中能稳定生存;在稳定期,6S RNA通过对嘧啶代谢的正向调节,起到维持细胞稳态的作用。
Abstract
sui zhao xiao fei zhe jian kang guan nian de zeng jiang ,yi suan nai wei dai biao de fa jiao ru zhi pin yue lai yue shou dao huan ying ,jie zhi 2018nian de ,wo guo suan nai shi chang xiao shou e jiu yi jing tu po 1400yi ren min bi 。zuo wei zui chong yao de ru zhi pin fa jiao jun zhu zhi yi ,shi re lian qiu jun de shi chang xu qiu liang ye sui zhi bu duan zeng chang 。zai gong ye hua fa jiao ji zhi bei guo cheng zhong ,gao mi du pei yang ji ge ying yang cheng fen de she ji shi huo de zui you sheng wu liang de guan jian 。shi re lian qiu jun shi ying yang que xian xing jun zhu ,dui pei yang ji zhong ge ying yang cheng fen de xu qiu ji wei ke ke ,te bie shi tan yuan 、dan yuan he he suan san ge zhu yao cheng fen 。zai fa jiao guo cheng ,dui zhe san ge zu fen de dai xie ji zhi de yan jiu shi you hua shi re lian qiu jun gao mi du pei yang ji de zu fen he fa jiao can shu de guan jian ,er guan yu zhe bu fen de yan jiu ye zheng shi mu qian suo que fa de 。ben yan jiu yi shi re lian qiu jun wei yan jiu dui xiang ,dui ji zai hua xue ge cheng pei yang ji zhong jin hang zeng shi pei yang 。tong guo gao tong liang ce xu ji shu ,huo de zai ge sheng chang shi ji zhuai lu shui ping biao da de ji yin he zai fei bian ma RNAshui ping biao da de sRNA,cong er chan ming zai ge sheng chang shi ji jun zhu ti nei guan jian dai xie lu jing ji yin biao da qing kuang ji sRNAqian zai de diao kong ji zhi 。ben yan jiu tong guo zhuai lu zu xue ce xu ,gong huo de 1937ge ji yin ,bing jin hang gong neng (GO)zhu shi he dai xie lu jing (KEGG)zhu shi 。ji yu ji yin zai mei ge yang ben zhong biao da liang de cha yi ,shai shua chu zai mei ge sheng chang shi ji fa sheng cha yi biao da de ji yin ,bing jin hang gong neng fu ji he dai xie lu jing fu ji fen xi 。ben yan jiu chong dian dui fa jiao guo cheng zhong he suan dai xie 、tan dai xie 、an ji suan dai xie quan ju zhuai lu qing kuang jin hang ping gu 。zai he suan dai xie zhong ,piao ling cong tou ge cheng tu jing zhu yao fa sheng zai dui shu ji ,ji zhong purcao zong zi zai dui shu qian ji biao da shang diao chao guo 5bei ,zai dui shu mo ji biao da liang xia diao yao 2bei 。ran er mi ding cong tou ge cheng lu jing zai zheng ge sheng chang shi ji fan ying huo xing dou chu yu di biao da de zhuang tai ,dan shi zai wen ding ji ,pyrcao zong zi de biao da qing wei shang diao 。zai tan dai xie guo cheng zhong ,ban ru tang dai xie zhu yao fa sheng zai dui shu ji ,liang ge guan jian ji yin lacShe lacZzai dui shu qian ji biao da shang diao 1.2bei ,zai dui shu mo ji de biao da shang diao 3bei ;ran er zai chi zhi ji ,ban ru tang dai xie shou dao yi zhi ,liang ge ji yin de biao da jun xia diao chao guo 1bei ;ci wai ,bian ma ban ru tang ji mei de galkzai zheng ge sheng chang shi ji jun gao du biao da ,te bie shi zai chi zhi ji he dui shu ji ,biao ming Streptococcus thermophilus MN-ZLW-002ke neng ju you dai xie ban ru tang de neng li 。tang jiao jie zuo wei fa jiao guo cheng zhong chong yao de gong neng tu jing ,chi zhi ji wei tang jiao jie zui wei huo yue de shi ji ,gai tu jing de guan jian ji yin glk、pyk、pgkshang diao jun chao guo 5bei 。zai dui shu ji he wen ding ji ,gai lu jing zhong de ji yin biao da jun fa sheng bu tong cheng du de xia diao 。bing tong suan zuo wei tang jiao jie de chan wu ,jie guo biao ming bing tong suan bei hai yuan cheng yi suan de fan ying zhu yao fa sheng zai chi zhi ji he dui shu qian ji ,cui hua gai fan ying de ldhzai liang ge shi ji biao da liang fen bie shang diao 1.6bei he 0.2bei 。bing tong suan zhuai bian yi xian fu mei Ade fan ying zhu yao zai dui shu mo ji fa sheng ,cui hua gai fan ying de pbh BCDzai dui shu mo ji biao da jun shang diao 1.9bei 。zhi fang suan dai xie zhu yao fa sheng zai chi zhi ji he dui shu qian ji ,ci guo cheng zhong de xian su ji yin accBzai chi zhi ji biao da shang diao 2.9bei ,zai dui shu qian ji biao da liang wei fa sheng bian hua ,ran er zai dui shu mo ji he wen ding ji biao da cheng xian xia diao qu shi 。zai an ji suan dai xie lu jing zhong ,cha yi biao da de ji yin zhu yao fu ji zai gu an suan 、bing an suan 、tian dong an suan 、jing an suan 、gan an suan 、si an suan 、ban guang an suan 、jia liu an suan 、xie an suan 、liang an suan 、yi liang an suan dai xie lu jing zhong ,bing ju zai bu tong sheng chang shi ji ,zhe xie an ji suan de dai xie ye biao xian chu cha yi 。chi zhi ji shi an ji suan dai xie zui wei huo yue de shi ji ,ji hu suo you fa sheng cha yi bian hua de ji yin jun shang diao ;zai dui shu ji ,zhu yao fa sheng de fan ying wei tian dong an suan zhuai bian wei yan hu suo suan he cao xian yi suan ,gu an suan zhuai hua cheng hu po suan 、6-lin suan pu tao tang 、5-lin suan he tang an he an ji jia xian lin suan zhi ,si an suan zhuai hua wei bing tong suan he se an suan ,jia liu an suan zhuai hua wei N-jia xian -L-jia liu an suan ,jing an suan suan tuo ya an mei lu jing (ADI);zai wen ding ji zhu yao fa sheng de fan ying you gu an suan sheng cheng 6-lin suan pu tao tang ,si an suan zhuai hua wei bing tong suan ,zhi lian an ji suan dai xie lu jing zhong er qing liu xin xian an -Ezhuai hua wei liu xin xian an -E。tong guo small RNAce xu ,gong huo de 530ge sRNAxu lie ,ji zhong 135ge lai zi ji yin jian ou ,198ge lai zi yu fan yi lian ,197ge lai zi yu fei fan yi ou 。tong guo IntaRNAdui sRNAde ba ji yin jin hang yu ce ,390ge ba ji yin bei fu ji dao 99ge dai xie lu jing zhong 。dui sRNAcha yi biao da qing kuang fen xi biao ming ,fen bie you 238、83、194he 139ge sRNAzai ge sheng chang shi ji fa sheng xian zhe xing bian hua 。dui lai zi ge sheng chang shi ji de 14ge bian hua zui xian zhe de sRNAjin yi bu fen xi ,jie guo biao ming zhe xie qian zai de ba ji yin bei fu ji de zhu yao dai xie tu jing she ji tan dai xie ,an ji suan sheng wu ge cheng ,ABCzhuai yun dan bai ,an ji tang he he gan suan tang de dai xie ,piao ling dai xie he lin suan zhuai yi mei ji tong 。jie ge zhuai lu zu xue shu ju zhong zhe xie ba ji yin de biao da qing kuang dui shang shu sRNAqian zai de diao kong ji zhi jin hang le chu bu fen xi 。zai chi zhi ji fa sheng cha yi biao da de sRNAdui qian zai de ba ji yin ju you zheng xiang diao kong de zuo yong ;zai dui shu qian ji ,yi xie sRNAke neng ban yan zhao guan jia ji yin de jiao se ,tong guo dui ba ji yin fu xiang diao kong ,cong er kong zhi bao nei dai xie liu su ;zai dui shu mo ji ,fa sheng cha yi biao da de sRNAdui ba ji yin fu xiang diao jie ,tong tuo yi zhi jun zhu nei dai xie huo xing ,bao zheng jun zhu zai fu za de sheng chang huan jing zhong neng wen ding sheng cun ;zai wen ding ji ,6S RNAtong guo dui mi ding dai xie de zheng xiang diao jie ,qi dao wei chi xi bao wen tai de zuo yong 。
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论文详细介绍
论文作者分别是来自东北农业大学的陈鸿宇，发表于刊物东北农业大学2019-08-27论文，是一篇关于嗜热链球菌论文,高密度培养论文,转录组学论文,靶基因论文,差异表达论文,东北农业大学2019-08-27论文的文章。本文可供学术参考使用，各位学者可以免费参考阅读下载，文章观点不代表本站观点，资料来自东北农业大学2019-08-27论文网站，若本站收录的文献无意侵犯了您的著作版权，请联系我们删除。
标签：嗜热链球菌论文; 高密度培养论文; 转录组学论文; 靶基因论文; 差异表达论文; 东北农业大学2019-08-27论文;