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1.
Ramila Azat Yan Liu Wei Li Abdurihim Kayir Ding-bo Lin Wen-wen Zhou Xiao-dong Zheng 《Journal of Zhejiang University. Science. B》2016,17(8):597-609
Six lactic acid bacterial (LAB) strains were isolated from traditionally fermented Xinjiang cheese and evaluated for functional and probiotic properties and potentials as starter cultures. The isolated six LAB strains comprised Lactobacillus rhamnosus (one strain), Lactobacillus helveticus (one strain), and Enterococcus hirae (four strains). All of the six strains were tolerant to acidic and bile salt conditions. Among which, the L. rhamnosus R4 strain showed more desirable antimicrobial, auto-aggregation, and hydrophobic activity. In addition, the strain L. rhamnosus R4 exhibited the highest level of free radical scavenging activity (53.78% of 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals and 45.79% of hydroxyl radicals). L. rhamnosus R4 also demonstrated cholesterol and triglyceride degradation by 50.97% and 28.92%, respectively. To further examine the health-promoting effects of these LAB strains on host lifespan, Caenorhabditis elegans was used as an in vivo model. Worms fed LAB as a food source had significant differences in lifespan compared to those fed Escherichia coli OP50 (as a negative control). Feeding of L. rhamnosus R4 extended the mean lifespan of C. elegans by up to 36.1% compared to that of the control. The results suggest that the strains isolated from Xinjiang fermented dairy products have high potential as starter cultures in the cheese industry. 相似文献
2.
Ping Li Xuan Li Qing Gu Xiu-yu Lou Xiao-mei Zhang Da-feng Song Chen Zhang 《Journal of Zhejiang University. Science. B》2016,17(8):569-579
Objective
In previous studies, Lactobacillus plantarum ZJ316 showed probiotic properties, such as antimicrobial activity against various pathogens and the capacity to significantly improve pig growth and pork quality. The purpose of this study was to reveal the genes potentially related to its genetic adaptation and probiotic profiles based on comparative genomic analysis.Methods
The genome sequence of L. plantarum ZJ316 was compared with those of eight L. plantarum strains deposited in GenBank. BLASTN, Mauve, and MUMmer programs were used for genome alignment and comparison. CRISPRFinder was applied for searching the clustered regularly interspaced short palindromic repeats (CRISPRs).Results
We identified genes that encode proteins related to genetic adaptation and probiotic profiles, including carbohydrate transport and metabolism, proteolytic enzyme systems and amino acid biosynthesis, CRISPR adaptive immunity, stress responses, bile salt resistance, ability to adhere to the host intestinal wall, exopolysaccharide (EPS) biosynthesis, and bacteriocin biosynthesis.Conclusions
Comparative characterization of the L. plantarum ZJ316 genome provided the genetic basis for further elucidating the functional mechanisms of its probiotic properties. ZJ316 could be considered a potential probiotic candidate.3.
乳酸菌具有促进营养物质的消化和吸收、降低血清胆固醇、调节肠道菌群平衡、激活机体免疫系统、改善食品风味和预防癌症等多方面的生理功能。利用益生乳酸菌发酵而成的饲料对促进动物的健康生长具有重要的实践意义,这种功能性发酵饲料近年在我国畜牧业中发展十分迅速,有着广阔的生产和应用前景。本文就近几年来关于乳酸菌的生理功能、益生菌发酵饲料的种类及乳酸菌发酵饲料在动物生产中的应用进行综述,并对其发展前景进行展望。 相似文献
4.
以饲料为原料筛选出一株既产乳酸又产芽孢的益生菌,经过分子生物学鉴定为凝结芽孢杆菌(Bacillus coagulans),命名为T-8。从培养基碳源、氮源、有机物浸出液、培养基pH、培养温度、培养时间等方面对菌株T-8展开发酵特性研究,结果表明,最优培养基配方为:玉米粉6 g/L、豆粕粉15 g/L、小麦麸皮浸出液60%、酵母粉5 g/L、蛋白胨10 g/L、氯化钠10 g/L,pH 5.0。以5%的接种量将种子液转接至最优培养基,在47℃的摇床中以200 r/min的转速振荡培养28 h,菌株T-8的细胞密度达到4.8×109 CFU/mL,芽孢率达到95.2%。本试验可为益生菌凝结芽孢杆菌应用于饲用微生物菌剂的工业化生产提供参考。 相似文献
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6.
Liu P Shen SR Ruan H Zhou Q Ma LL He GQ 《Journal of Zhejiang University. Science. B》2011,12(11):923-930
Naturally fermented pickles harbour many lactic acid bacteria (LAB). Forty-three LAB strains with conjugated linoleic acid
(CLA)-producing ability were isolated from three naturally fermented pickle brines. Of these isolates, lp15 identified as
Lactobacillus plantarum by API 50 CHL system and full-length 16S rDNA sequence analysis exhibited the highest CLA-producing ability (26.1% conversion)
at 48 h in de Man Rogosa Sharpe (MRS) broth in the presence of 100 μg/ml of linoleic acid (LA). Compared to other strains,
L. plantarum strain lp15 showed the highest tolerance upon increased levels of LA in the medium, i.e., up to 600 μg/ml. This strain converted
about 25% of LA into CLA isomers [predominantly cis-9, trans-11 CLA (9-CLA) and trans-10, cis-12 CLA (10-CLA)], of which 75% was 9-CLA. Interestingly, though the conversion rate of LA into CLA by lp15 remained stable
between 100 to 600 μg/ml LA levels in the medium, it dropped sharply at 1000 μg/ml. Taken together, the lp15 strain displayed
relatively high LA tolerance with higher conversion rate, which implies that this strain is a valuable candidate for enhancing
the CLA content in food-sources like pickles. 相似文献
7.
目的:从葱的根、茎、叶中分离内生真菌,并进行初步抗菌活性检测,得到具有高抗菌活性的菌株。方法:1.用PDA培养基分离葱的内生真菌;2.用查氏培养基进行发酵实验。3.进行滤纸片抑菌实验。结果:从葱中分离出的17株内生真菌,均具有抗菌活性,其中,抑菌圈直径大于1.0cm的高抗菌性菌株有11株,占总分离菌株数的64.71%。结论:葱内生真菌具有类似宿主植物葱一样的广泛抗菌性(分离得到的17株内生真菌均具有抗菌性),但由于宿主植物本身所具有的强抗菌性,使分离得到的菌株种属多样性较少。 相似文献
8.
不同用量苹果酸对烟叶中非挥发性有机酸的影响 总被引：6，自引：0，他引：6
通过盆栽试验研究了不同用量的苹果酸对烟叶中非挥发性有机酸的影响，结果表明：处理1g/L降低了上、中部叶，但提高了下部叶非挥发性有机酸总量，处理2g／L和处理3g/L对非挥发性有机酸总量影响不明显；苹果酸处理还可提高多元羧酸在非挥发酸中的比例，降低饱和脂肪酸和非饱和脂肪酸的含量及其在非挥发酸中的比例，且多元羧酸、苹果酸含量随着苹果酸用量的增加而增加．因此，施用苹果酸对改善烟叶质量有积极作用． 相似文献
9.
Brijesh S Daswani PG Tetali P Rojatkar SR Antia NH Birdi TJ 《Journal of Zhejiang University. Science. B》2006,7(8):665-674
While data are available on the effect of medicinal plants on intestinal motility and their antibacterial action, there is a paucity of information on their mode of action on various aspects of diarrheal pathogenicity, namely colonization to intestinal epithelial cells and production/action of enterotoxins. Crude decoction of dried leaves of Pongamia pinnata was evaluated for its antimicrobial （antibacterial, antigiardial and antirotaviral） effect; and its effect on production and action of enterotoxins （cholera toxin, CT; Escherichia coli labile toxin, LT; and E. coli stable toxin, ST）; and adherence of enteropathogenic E. coli and invasion of enteroinvasive E. coli and Shigellaflexneri to epithelial cells. The decoction had no antibacterial, antigiardial and antirotaviral activity, but reduced production of CT and bacterial invasion to epithelial cells. The observed results indicated that the crude decoction ofP. pinnata has selective antidiarrheal action with efficacy against cholera and enteroinvasive bacterial strains causing bloody diarrheal episodes. 相似文献
10.
6种常用抗菌中药对3株常见病原性细菌的抑菌作用检测 总被引：2，自引：0，他引：2
目的:建立抗菌中药对临床常见病原性细菌抑菌作用的检测方法。方法:选择6种常用抗菌中药(黄连、苦参、连翘、大黄、生地、知母),分别采用水提法制备至质量浓度1mg/L。应用液体稀释法测定上述中药对金黄色葡萄球菌、大肠埃希菌和铜绿假单胞菌的最低抑菌浓度(MIC)。结果:建立了中药抑菌作用的检测方法。黄连、大黄与连翘抑制细菌的作用较强,MIC值均≤0.05mg/L,其中黄连对金黄色葡萄球菌的抑菌作用最强(MIC值为0.00625mg/L)。结论:应用本方法可以进行中药抑菌作用的检测。抗菌中药对所试验菌种表现不同的抑菌作用。 相似文献
11.
Chen-jian Liu Fu-ming Gong Xiao-ran Li Hai-yan Li Zhong-hua Zhang Yue Feng Hiroko Nagano 《Journal of Zhejiang University. Science. B》2012,13(4):298-306
This research was aimed at isolating and identifying the predominant lactic acid bacteria (LAB) in the traditional Chinese
salt-fermented soybean food, douchi, from Yunnan, China. The predominant LAB present were isolated and identified by conventional
culture-dependent methods combined with molecular biological methods. Two hundred and sixty isolates were obtained from thirty
kinds of traditional fermented douchi from six cities and counties in Yunnan, and those strains were divided into twelve groups
by their morphological and biochemical characteristics. Based on 16S ribosomal DNA (rDNA) sequencing and analysis, 56 representative
strains were identified as belonging to 6 genera and 14 species: Lactobacillus (4 spp.), Weissella (3 spp.), Pediococcus (2 spp.), Staphylococcus (2 spp.), Enterococcus (1 sp.), and Bacillus (2 spp.). The results show that douchi contains a large natural population of LAB of diverse composition from which some
strains could be selected as starters for functional fermented foods. This is the first study on the original douchi from
Yunnan, and the results suggest that it may be a useful source for the isolation of LAB. This study has also laid a foundation
for further research on developing functional douchi products. 相似文献
12.
金莲花为我国传统中药,主要成分有黄酮类、有机酸、生物碱等,其中黄酮类为其主要有效成分,药理学研究表明,金莲花提取物具有抑菌、抗病毒、抗氧化等活性。该文对近年来金莲花的药理活性及临床应用研究进展进行综述。 相似文献
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14.
通过考察乳酸,酒石酸,柠檬酸和有机酸Y组成的复合络合剂对镀速的影响,确定了合适的复合络合剂,其中复合络合剂由柠檬酸与有机酸Y组成,柠檬酸含量为10g/L,有机酸Y为20g/L.测定了该酸性化学镀镍的镀层的结合力以及孔隙率与耐蚀性,结果表明,该化学镀镍层光亮平整,结合力强,孔隙率分布较窄,耐硝酸点蚀120s,具有优良的耐蚀性能. 相似文献
15.
Eleyinmi AF 《Journal of Zhejiang University. Science. B》2007,8(5):352-358
Chemical composition of Gongronema latifolium leaves was determined using standard methods. Aqueous and methanol G. latifolium extracts were tested against thirteen pathogenic bacterial isolates. Crude protein, lipid extract, ash, crude fibre and nitrogen flee extractives obtained are： 27.2%, 6.07%, 11.6%, 10.8% and 44.3% dry matter respectively. Potassium, sodium, calcium, phosphorus and cobalt contents are 332, 110, 115, 125 and 116 mg/kg respectively. Dominant essential amino acids are leucine, valine and phenylalanine. Aspartic acid, glutamic acid and glycine are 13.8%, 11,9% and 10.3% respectively of total amino acid. Saturated and unsaturated fatty acids are 50.2% and 39.4% of the oil respectively. Palmitic acid makes up 36% of the total fatty acid. Extracts show no activity against E. faecalis, Y. enterolytica, E. aerogenes, B. cereus and E. agglomerans. Methanol extracts were active against S, enteritidis, S. cholerasius ser typhimurium and P. aeruginosa （minimum inhibitory concentration （MIC） 1 mg; zone of growth inhibition 7, 6.5 and 7 mm respectively）. Aqueous extracts show activity against E. coli （MIC 5 mg） and P. aeruginosa （MIC 1 mg） while methanol extracts are active against P. aeruginosa and L. monocytogenes. G. lafifolium has potential food and antibacterial uses. 相似文献
16.
采用CO2超临界萃取法（SFE-CO2）提取紫花地丁的挥发油,采用气相色谱-质谱联用技术（GC-MS）对紫花地丁的挥发油化学成分进行分离鉴定,共分离出了23种化学成分,主要为十四烷（17.628%）,肉豆蔻酸（12.654%）,植物醇（11.909%）,甲酯-9,12,15-十八碳三烯酸（10.954%）,邻苯二甲酸二丁酯（6.440%）,1,19-二十烷二烯（6.439%）等.首次定量地测定了紫花地丁挥发油的抑菌活性,结果表明挥发油对供试菌种沙门氏菌,金黄色葡萄球菌,福氏痢疾杆菌均有明显的抑制作用,对大肠杆菌无抑制作用. 相似文献
17.
为了研究不同环境下二氧化氯的消毒效果及其稳定性,试验以大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌、白色念珠菌为测试菌株,采用菌悬液定量杀菌试验、压缩雾化法和平板计数的方法,对二氧化氯的杀菌效果进行试验。结果表明：在菌液密度为5×10^6 CFU/mL的条件下,90 mg/L的二氧化氯作用5 min,即可对测试菌株达到100%的杀灭效果。不同的pH值、温度及不同浓度有机物存在的条件下,二氧化氯同样具有极强的消毒效果。雾化的二氧化氯对空气自然菌及雾化菌液气溶胶的杀灭效果同样可以达到100%。试验表明二氧化氯作为一种高效、稳定的广谱消毒剂具有良好的杀菌效果。 相似文献
18.
The objectives of this study were to assess the potential of two photosynthetic bacteria （PSB）, Rhodopseudomonas palustris HZ0301 and Rhodobacter sphaeroides HZ0302, as probiotics in aquaculture. The viability of HZ0301 and HZ0302 in simulated gastric transit conditions （pH 2.0, pH 3.0 and pH 4.0 gastric juices） and in simulated small intestinal transit conditions （pH 8.0, with or without 0.3% bile salts） was tested. The effects of HZ0301 and HZ0302 on the viability and permeability of intestinal epithelial cell in primary culture of tilapias, Oreochrornis nilotica, were also detected. All the treatments were deter- mined with three replicates. The simulated gastric transit tolerance of HZ0301 and HZ0302 strains was pH-dependent and correspondingly showed lower viability at pH 2.0 after 180 min compared with pH 3.0 and pH 4.0. Both HZ0301 and HZ0302 were tolerant to simulated small intestine transit with or without bile salts in our research. Moreover, there was no significant difference （P〉0.05） among three treatments including the control and the groups treated with HZ0301 or HZ0302 both in intestinal epithelial cell viability and membrane permeability, showing no cell damage. In summary, this study demonstrated that HZ0301 and HZ0302 had high capacity of upper gastrointestinal transit tolerance and were relatively safe for intestinal epithelial cells of tilapias. 相似文献
19.
为探究稀土水杨酸8-羟基喹啉三元配合物RE(sal)2hq(RE=Pr、Gd)对大肠杆菌的抑菌效果.实验采用杯碟法和二倍稀释法,通过测量抑菌圈直径探讨了两种配合物及其配体的抑菌能力.结果表明:配体8-羟基喹啉、配合物RE(sal)2hq(RE=Pr、Gd)都具有很好的抑菌效果,而配体水杨酸及稀土(RE=Pr、Gd)离子抑菌效果都不明显.配合物Pr(sal)2hq、Gd(sal)2hq和配体8-羟基喹啉的最小抑菌浓度MIC值分别为:0.5 mmo/lL、1 mmo/lL和1 mmo/lL.最小杀菌浓度MBC值分别为:4mmo/lL、5mmo/lL和14mmo/lL.初步推测稀土水杨酸8-羟基喹啉三元配合物可以作为药物运用于有害大肠杆菌的防治中. 相似文献
20.
测定了肉桂醛及其衍生物对4种致病菌（金黄色葡萄球菌、大肠杆菌、沙门氏菌、炭疽杆菌）的最小抑菌浓度（MIC）.结果表明：肉桂醛、α-溴代肉桂醛、肉桂酸对4种致病菌都有明显的抑菌效果,肉桂醇仅对金黄色葡萄球菌有抑菌效果.4种化合物中抑菌效果最好的是肉桂酸,对金黄色葡萄球菌、大肠杆菌、沙门氏菌、炭疽杆菌的抑菌浓度分别为0.4、0.4、0.6、0.4 mmol/L. 相似文献