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罗汉果内生菌及其周边土壤中产α-淀粉酶菌株的筛选 总被引:1,自引:0,他引:1
对罗汉果内生菌及其种植区土壤中的微生物进行分离,筛选淀粉酶产生菌,并研究其发酵条件,结果得到15株内生菌和8株微生物,从中筛选到2株产淀粉酶高的菌株2-1(土壤)和R-4(根部内生菌)。经初步鉴定,菌株2-1为球菌,菌株R-4为芽孢杆菌,均为革兰氏阳性菌。研究显示,菌株2-1产酶条件为1.0%氯化铵、0.5%酵母粉、1.0%可溶性淀粉、0.4%氯化钠,发酵温度为40℃,发酵3 d,其产酶量为127.65 U/m L;R-4菌株产酶条件为0.5%酵母粉、1.0%氯化铵、0.05%氯化钠、2.0%可溶性淀粉,发酵温度为40℃,发酵3 d,其产酶量为197.21 U/m L。 相似文献
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转化白藜芦醇苷虎杖内生真菌的分离和鉴定 总被引:1,自引:0,他引:1
为提高虎杖中白藜芦醇得率,采用虎杖内生真菌直接发酵虎杖转化白藜芦醇苷为白藜芦醇,通过从虎杖根、茎中初筛得到6株内生真菌,复筛以虎杖煮提液为底物发酵,采用高效液相色谱法定量检测发酵液中白藜芦醇苷和白藜芦醇含量。结果表明:6株内生真菌均具有转化白藜芦醇苷为白藜芦醇能力,其中分离于茎内的J1转化率最高为25.6%。J1经形态学观察及ITS-5.8S rDNA序列分析,鉴定为草酸青霉Penicillium oxalicum,Genbank登录号为HQ732137。 相似文献
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利用德氏乳杆菌L.bulgaricus KLDS08021为宿主菌,采用次级感染的方法筛选自发突变的抗噬菌体菌株,将筛选出的有抗性的7株菌株进行RAPD-PCR鉴定,然后进行EOP、遗传稳定性、溶源性检测,并对其中的2株抗性菌BIM1、BIM7及野生株进行发酵性能测定。结果显示,7株菌RAPD-PCR电泳图谱一致,均来自宿主菌,是遗传性稳定的非溶源性菌;无论噬菌体是否存在2株抗性菌BIM1、BIM7其发酵活菌数、产酸能力都比野生株高,且制作的发酵乳黏度与硬度也比野生菌株强,适于作为酸奶发酵菌株。 相似文献
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《食品与发酵工业》2014,(11):41-45
为获得新来源的乳酸发酵菌株,以采自云南省德宏州的3份传统傣家酸鱼为供试样品,分离纯化菌株。通过Ca CO3-溴甲酚紫产酸平板、摇瓶发酵、色谱分析等手段筛选出产乳酸菌株。采用传统分类方法结合16S r DNA序列分析方法,对产乳酸菌株进行鉴定并保藏,并用EDTA定钙法研究了菌株的乳酸产量。结果表明,从3份传统傣家酸鱼中分离到10个菌株,筛选出乳酸发酵菌株sy1、sy3、sy4,色谱分析表明,3株菌的发酵产物均为乳酸。采用传统分类方法结合16S r DNA序列分析方法,确定3株菌均为植物乳杆菌。3株菌均能迅速产酸,能在p H 3.5以下生长;在初始葡萄糖浓度为100 g/L的培养基中发酵72 h,测得菌株sy1、sy3、sy4乳酸产量分别为66、76和69 g/L,表明3株菌均有较好的乳酸发酵能力,可作为乳酸发酵的出发菌株进行进一步研究。 相似文献
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以酸奶发酵常用菌株嗜热链球菌为出发菌株,反复使用高密度噬菌体培养处理,初步获得9株抗噬菌体突变株。对抗性菌株进行遗传稳定性、溶源性、EOP检测,及抗性菌株正常条件下发酵性能测定,综合各方面特性,筛选出遗传稳定,生长、发酵性能优于野生菌株的抗性菌株,对优于野生株的抗性菌株与敏感菌株一起在较高浓度噬菌体的环境中进一步发酵,测定其对噬菌体的抵抗能力、产酸能力、发酵后酸奶的黏度、硬度、乳清析出、口感及后酸化程度。结果表明:9株抗性菌株有6株遗传性比较稳定,其均为非溶源性菌,其中有3株生长能力、产酸能力、发酵乳黏度、硬度、接近于野生菌。这3株抗性菌株在高噬菌体浓度下发酵,有2株菌生长产酸正常,黏度、硬度、口感较好,凝乳时间较短、乳清析出较少并且后酸化程度相对较弱,适宜工业生产。 相似文献
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该研究通过采用高效液相色谱(HPLC)法测定苯乳酸含量,从50株鱼肠道来源的乳酸菌中筛选高产苯乳酸的菌株,通过形态观察、生理生化试验及分子生物技术对其进行菌种鉴定,并以苯乳酸产量为响应值,通过单因素试验和响应面试验对其产苯乳酸发酵条件进行优化。结果表明,筛选到1株产苯乳酸能力较好的菌株DY2,其苯乳酸产量达2.45 mg/m L,经鉴定,菌株DY2为融合魏斯氏菌(Weissella confuse)。菌株DY2产苯乳酸的最适发酵条件为初始pH 6.0,发酵时间50 h,接种量3%、发酵温度34℃。在此优化条件下,苯乳酸产量达2.99 mg/m L,是优化前的1.22倍。 相似文献
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[目的]筛选优良乳酸菌菌株以构建萝卜专用的泡菜发酵菌种。[方法]从不同地区收集萝卜老坛泡菜母水,采用稀释涂布法从泡菜母水中分离乳酸菌,通过生理鉴定、形态学鉴定(菌落观察和,革兰氏染色法)、16S rDNA基因测序和系统发育树构建确定种类并对其生长特性、耐受能力和风味物质进行检测。[结果]分离筛选结合生理鉴定共获得120株菌株,其菌落为圆形凸起,镜检呈杆状或球状且均为革兰氏阳性菌。进一步通过产酸能力测试获得15株产酸能力较强的菌株。分子鉴定表明,1株为芽孢杆菌属、13株为植物乳杆菌属,1株为戊糖片球菌属。对不同类型发酵菌株进行生长特性分析,发现菌株LA-8与LA-11的生长速度比其他菌株快;菌株LA-8的产酸能力强,耐10%盐和15%蔗糖。4株不同类型菌株均具有较强的降解亚硝酸盐能力。萝卜发酵初试试验表明,菌株LA-8和LA-11的发酵能力较强,产酸速度快。4株不同类型乳酸菌发酵萝卜所产生的挥发性物质存在差异。[结论]从不同地区萝卜老坛泡菜母水中筛选得到3个不同类型的优势发酵菌,可作为萝卜泡菜产业生产的菌种来源。 相似文献
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以糯红高粱中分离出的内生酵母为研究对象,筛选具有产蛋白酶功能的内生酵母,采用形态学观察和26S rDNA D1/D2区序列分析对内生酵母进行分类鉴定,并分析其氮源利用能力以及产酶发酵特性。结果发现:从糯红高粱分离得到33株产蛋白酶内生酵母;经26S rDNA D1/D2区序列分析,这些菌株隶属于1门、4目、13属,优势目为银耳目(Tremellales),占57.62%;优势种属为Papiliotrema rajasthanensis,占27.3%。氮源利用能力研究发现,7株内生酵母具有产利用菜籽饼粕氮源的蛋白酶,J3-74菌株产酶能力最强;5株能产利用明胶的蛋白酶,J6菌株产酶能力最优;7株能产利用干酪素的蛋白酶,J3-78菌株的产酶能力最强。对其中2株产蛋白酶菌株的发酵条件优化发现,J6菌株在接种量为1%、pH为9.0、温度为25℃、葡萄糖为碳源、牛肉膏为氮源时产蛋白酶的活力最高。而J24菌株在接种量为2%、pH为5.0、温度为25℃、葡萄糖为碳源、牛肉膏为氮源时产蛋白酶的活力最高。结果表明,糯红高粱内生酵母种类及其功能具有多样性,可为功能菌株的进一步开发和利用提供支撑。 相似文献
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The effects of resveratrol on the prevention of apoptosis as well as insulin production are unclear. To examine the effects, we treated insulin-secreting beta cells with methylglyoxal (MG), a metabolite known to induce apoptosis and diabetes in the presence or absence of resveratrol. The MG treatment induced the expression of apoptotic signaling molecules and decreased insulin production. Pretreatment with resveratrol resulted in an increase in insulin synthesis via upregulation of peroxisome proliferator-activated receptor gamma (PPARgamma) and pancreatic-duodenal homeobox-1 (PDX-1). Resveratrol also inhibited MG-mediated expression of CCAAT/enhancer-binding protein beta (C/EBPbeta), a negative regulator of insulin production. Moreover, resveratrol strongly activated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), which resulted in the attenuation of oxidative stress. These results suggest that resveratrol can attenuate MG-induced oxidative stress in pancreatic cells and increase insulin levels. 相似文献
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利用降落重叠延伸PCR和连接酶连接的方法,构建了组成型表达载体pMD18-VvRs-At4cl,该表达载体带有大肠杆菌甘油醛三磷酸脱氢酶启动子(pGAP),拟南芥(Arabidopsis thalianna)4-香豆酸辅酶A连接酶(At4CL)基因和葡萄(Vitis vinifera)白藜芦醇合酶(VvRS)基因。表达载体转化大肠杆菌BW27784,并通过PCR鉴定和酶切鉴定后,获得重组菌株。对重组菌株进行发酵培养,对发酵液进行HPLC检测,发酵液中白藜芦醇含量为4.51mg/L。这表明,拟南芥的4cl基因与金手指葡萄的rs基因在重组大肠杆菌中成功得到了表达,并且表达产物利用对香豆酸为前体物质合成了白藜芦醇。 相似文献
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Huch Née Kostinek M Hanak A Specht I Dortu CM Thonart P Mbugua S Holzapfel WH Hertel C Franz CM 《International journal of food microbiology》2008,128(2):258-267
Two Lactobacillus strains, Lactobacillus plantarum BFE 6710 and Lactobacillus fermentum BFE 6620, were used to start cassava fermentations in a pilot study under field production conditions in Kenya, to determine their potential to establish themselves as predominant lactobacilli during the fermentation. Predominant strains from three fermentations were isolated throughout the 48 h fermentation period. The use of these strains in high numbers clearly resulted in 1 to 2 log higher lactic acid bacteria (LAB) counts over the course of the fermentation when compared to the uninoculated control. 178 predominant LAB isolates were grouped based on their phenotypic characteristics, and were characterised to strain level by RAPD-PCR, followed by PFGE strain typing. Overall, L. plantarum strains represented the majority of the isolates, followed by Weissella confusa and Lactococcus garvieae strains. The results of RAPD-PCR and PFGE strain typing techniques indicated that L. plantarum BFE 6710 was successful in asserting itself as a predominant strain. In contrast, L. fermentum BFE 6620 failed to establish itself as a predominant organism in the fermentation. The success of the L. plantarum strains to predominate in the cassava fermentation demonstrates the potential for development of Lactobacillus starter cultures to industrialise the Gari production process. 相似文献
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Saccharomyces cerevisiae associated with the spontaneous fermentation of tequila agave juice
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A. Aldrete‐Tapia R. Martínez‐Peniche D. Miranda‐Castilleja M. Hernández‐Iturriaga 《Journal of the Institute of Brewing》2018,124(3):284-290
Saccharomyces cerevisiae dominates the spontaneous fermentation of blue agave juice. Because of the batch heterogeneity, the aim of this work was to determine the strain diversity of S. cerevisiae among fermentations. During January and February 2015, agave juice was sampled in triplicate from four sampling points at a tequila distillery. The heterogeneity of yeast strains and the production of carbon dioxide were assessed during fermentation, whereas the amount of ethanol produced was measured at the end of the process. The fermentation cycle times varied widely (9 to 25 days), as did fermentation efficiency (2.5–45.5%). Yeast isolates were identified at the species level by ITS‐5.8S rRNA restriction fragment length polymorphism and differentiated at the strain level by random amplified polymorphic DNA. A total of 199 isolates were obtained and identified as S. cerevisiae, showing 69 different random amplified polymorphic DNA profiles. There was no clear dominance of any strain during fermentation. However, two strains (P1 and P2) were detected in all fermentation samples, suggesting their residency in the distillery, despite the deep‐cleaning applied to the tanks after each fermentation batch. According to the RAPD profiles, the number of strains isolated from fermentation samples increased from 17 in January to 25 in February. © 2018 The Institute of Brewing & Distilling 相似文献
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采用高效液相色谱法测定天津茶淀玫瑰香葡萄酒精发酵过程中白藜芦醇含量变化,并结合感官评价手段,确定最优的玫瑰香葡萄酒酒精发酵时间.结果表明,在天津茶淀玫瑰香酒精发酵过程中,随着时间的变化,原酒中白藜芦醇含量出现先升高再降低最后趋于稳定的趋势,酒精发酵96h时的原酒白藜芦醇含量最高,感官评价的得分为最高分85,酒精度达到10%vol以上. 相似文献
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对筛选自我国广西毛葡萄产区的汉逊酵母属的Hanseniaspora thailandica(MSF1-4、MG4、MG6、MSF6-2)、伊萨酵母属的Issatchenkia terricola(MG3-1)、酿酒酵母属的Saccharomyas cerevisiae(MSF8-1)和毕赤酵母属的Pichia pastoris(MG1)共7 株酵母酿造‘桂葡3号’干白葡萄酒,分析探讨其理化指标及挥发性香气物质,并以商业酵母K1发酵酒样为对照。结果表明:7?株菌发酵酒各理化指标均符合GB?15037—2006《葡萄酒》要求;共检测到68?种香气物质,实验组香气总量均大于对照组K1;其中辛酸乙酯在乙酯类总含量中高达46.05%,而对照组K1中辛酸乙酯占乙酯总含量的7.12%;MG3-1、MG1、MSF6-2特征香气物质为乙酸苯乙酯、壬醛、4-萜烯醇、芳樟醇、1-辛醇、1-癸醇,MG6的特征香气物质为乙酸异戊酯、香茅醇,MSF8-1、K1、MG4特征香气物质为乙酸乙酯,MSF1-4的香气特征物质为玫瑰醚、月桂酸乙酯、辛酸、癸酸、癸酸乙酯、辛酸乙酯、丁酸乙酯、乙酸己酯、己酸乙酯、辛酸甲酯;其中K1、MG4发酵实验组香气特征最为接近,MG6、MSF1-4发酵实验组香气特征差异最大。上述结果分析得出7?株野生酵母菌具有较强的产辛酸乙酯的能力,MG1、MSF1-4产香能力最好,适合进一步研究开发。 相似文献
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人参果自然发酵醪中酵母菌种筛选及其发酵性能 总被引:1,自引:0,他引:1
为筛选适合甘肃河西走廊特产人参果酒精发酵的优良酵母菌株,以人参果自然发酵醪为原料,通过镜检等方法从分离纯化的20株酵母菌中进一步筛选得到11株发酵性能良好的酵母菌,分别命名为TY8、TY5、TY6、Y3、Y4、Y5、LY3、LY1、Y1、Y2、TY2。以葡萄酒活性干酵母作为对照菌株,通过酵母发酵力比较、耐乙醇能力、耐SO2能力、理化指标分析及感官评价,筛选出1株适于人参果果酒发酵的酿酒酵母TY8。以此菌株发酵生产的人参果果酒香气特征明显,酒体澄清透明,具有人参果果酒典型风味。 相似文献