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抗氧化活性乳酸菌的筛选 总被引:1,自引:0,他引:1
以获得高抗氧化活性乳酸菌菌株为目的,从泡菜汁、鹅肠、鸡嗉囊等材料中分离获得20株乳酸菌。以对DPPH自由基和O2- ·的清除率为初筛指标,总抗氧化(T-AOC)能力和总超氧化物歧化酶(T-SOD)活力为复筛指标,筛选得到两株具有较高抗氧化活性的菌株L8和L17。利用糖发酵实验、生理生化实验和16S rDNA序列比对的方法对其进行鉴定,发现它们均为干酪乳杆菌。 相似文献
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乳酸菌抗氧化活性及检测方法 总被引:17,自引:3,他引:17
通过对30株乳酸菌清除DPPH自由基和抗亚油酸过氧化能力的实验,筛选出了抗氧化活性较强的乳酸菌L3和L4。从得到的两株乳酸菌分别制备无细胞提取物(菌数为1010mL-),利用6种方法对这两株乳酸菌无细胞提取物的抗氧化性能进行了检测分析,发现L31和L4可螯合Fe2+,分别为54.3×10-和41.3×10-,清除超氧自由基分别为14.9%和87.0%,清除羟自由基分别为83.5%和45.7%,并具有还原66活性。进一步研究发现乳酸菌L4SOD活性为(73.70±1.77)U/mg,但这2株乳酸菌均未检测到GSH-Px活性。 相似文献
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《食品与发酵工业》2016,(11):171-178
以酸奶中常见的保加利亚乳杆菌和嗜热链球菌为测试菌株,探究其富铁最佳工艺条件,以及富铁菌株的抗氧化活性。在单因素试验基础上,确定起始p H、接种量、培养温度取值范围,通过响应面优化确定菌株的最佳富铁条件。试验结果表明:保加利亚乳杆菌最佳富铁条件为:培养液起始p H 6.7,接种量5.86%,培养温度35.55℃,富铁率为52.14%;嗜热链球菌为:培养液起始p H 7.23,接种量6.06%,培养温度40℃,富铁率为97.05%;富铁后的乳酸菌对于1,1-二苯基-2-三硝基苯肼(DPPH)、2,2’-连氮基-双-(3-乙基苯并二氢噻唑啉-6-磺酸)(ABTS)自由基的清除率有所提高,但菌株还原力提高并不明显。 相似文献
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该文以贵州枇杷为原料,探究保加利亚乳杆菌、嗜酸乳杆菌及植物乳杆菌发酵枇杷浆过程中pH值、总酸含量、总酚含量、总糖含量、总黄酮含量、1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除率、2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐[2,2''-azinobis-(3-ethylbenzthiazoline-6-sulphonate),ABTS]阳离子自由基清除率及感官评分的变化,并分析指标间的相关性。结果表明,植物乳杆菌生长活力最强,3株乳酸菌利用枇杷浆为发酵基质产酸能力均较好;发酵过程中总酚含量、总黄酮含量及DPPH自由基清除率、ABTS+自由基清除率呈下降趋势,但总糖含量受乳酸菌代谢活动的影响呈先上升后下降的趋势,其中植物乳杆菌有较好的抗氧化能力;乳酸菌发酵后对感官评分存在影响,其中植物乳杆菌发酵30 h时感官评分最高。因此植物乳杆菌更适合枇杷浆的发酵。 相似文献
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对17株来自长寿老人粪便的菌株进行酸、胆盐和H2O2耐受性分析,初筛获得5株高耐受性菌株,通过体外抗氧化实验,进一步复筛高抗氧化活性的乳酸菌。研究发现,5株乳酸菌的DPPH清除能力、羟基自由基清除能力、超氧阴离子清除能力和总还原力分别为10.47%~89.73%、22.65%~66.17%、22.22%~88.95%和11.03%~51.86%;相对于其它组分,无细胞提取物具有更强的羟基自由基清除能力,而菌株发酵上清液的显示出更高DPPH自由基、超氧阴离子清除能力和总还原力。XM-LS01与XM-BL01菌株的抗氧化活性高于其它菌株,经形态学、生理生化和16 Sr DNA鉴定,其分别为清酒乳杆菌和动物双歧杆菌。 相似文献
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2株具有优良体外抗氧化能力乳酸菌的筛选与鉴定 总被引:1,自引:0,他引:1
已有研究表明乳酸菌可能具有缓解不同因素导致氧化应激的潜力。本研究利用体外过氧化氢氧化胁迫模型筛选出一些具有显著体外抗氧化能力的乳酸菌,以还原活性高低、抑制脂质过氧化能力、DPPH自由基和羟自由基清除能力、亚铁离子和铜离子螯合性能等体外抗氧化能力评价指标评价了乳酸菌分离物的体外抗氧化性能,并最终确定了2株具有优良体外抗氧化能力的乳酸菌CCFM8661和CCFM1566。结果表明,CCFM8661和CCFM1566还原力分别达到(226.47±4.68)、(212.35±6.45)μmol/L半胱氨酸当量;对脂质过氧化的IC50值分别达到8.1、8.3Log10(CFU/mL);对DPPH自由基和羟基自由基清除率均在60%以上,并具有较高的亚铁离子及铜离子螯合能力。经生理生化鉴定和16SrDNA分子鉴定,该2株菌为植物乳杆菌CCFM8661和干酪乳杆菌CCFM1566。 相似文献
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Pyroglutamic acid is present in high amounts (0.5g/ 100g) in many cheese varieties-and particularly in extensively ripened Italian cheeses such as Grana Padano and Parmigiano Reggiano. An in vivo model system for cooked mini-cheese production and ripening acceleration was set up to demonstrate the ability of thermophilic lactic acid bacteria, used as a starter, to produce pyroglutamic acid (pGlu). In mini-cheeses stored at 38 and 30 degrees C for up to 45 d, all starters tested produced different amounts of pGlu. In descending order of pGlu production, the bacteria analyzed were: Lactobacillus helveticus, Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus thermophilus, and Lactobacillus delbrueckii subsp. lactis. Evidence for the presence of glutamine to pGlu cyclase activity in lactic acid bacteria was provided. Cell lysates obtained from cultures of L. helveticus, L. delbrueckii subsp. bulgaricus, L. delbrueckii subsp. lactis, and S. thermophilus showed the ability to cyclize glutamine to pGlu, resulting in processing yields from 1.4 to 30.3%, depending on the subspecies. Formation of pGlu from free glutamine appeared to be similar to that observed using a glutamine-glutamine dipeptide substrate. Under the experimental conditions applied, pGlu aminopeptidase activity was only detected in L. helveticus. Thus, pGlu formation in long-ripened cooked cheese may depend on the activity of thermophilic lactic acid bacteria. 相似文献
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抗氧化乳酸菌L4的SOD活性及其发酵乳的抗氧化作用 总被引:1,自引:0,他引:1
从30株乳酸菌中筛选出的抗氧化活性相对较高的乳酸菌L3和L4进行实验,发现乳酸菌L4的抗H2O2的能力明显要高于乳酸菌L3和保加利亚乳杆菌。并检测到乳酸菌L4无细胞提取物SOD活性为(73.70±1.77)U/mg。但未检测到乳酸菌L3和L4具有GSH-Px活性。利用PCR技术扩增了乳酸菌L4的SOD基因,通过DNA序列测定,发现乳酸菌L4的SOD基因与E.coli的Mn-SOD基因有高度的同源性。并发现乳酸菌L4发酵乳的还原活性和螯合Fe2+作用均明显高于未发酵乳。 相似文献
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论述了乳酸菌的生物拮抗作用,包括对致病菌和乳酸菌之间的拮抗。并简要论述了产生拮抗作用的可能因素或机理,为乳酸菌进一步开发提供一种理论依据。 相似文献
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Gatti M De Dea Lindner J Gardini F Mucchetti G Bevacqua D Fornasari ME Neviani E 《Journal of dairy science》2008,91(11):4129-4137
The aim of this work was to investigate in which phases of ripening of Parmigiano Reggiano cheese lactic acid bacteria aminopeptidases present in cheese extract could be involved in release of free amino acids and to better understand the behavior of these enzymes in physical-chemical conditions that are far from their optimum. In particular, we evaluated 6 different substrates to reproduce broad-specificity aminopeptidase N, broad-specificity aminopeptidase C, glutamyl aminopeptidase A, peptidase with high specificity for leucine and alanine, proline iminopeptidase, and X-prolyl dipeptidyl aminopeptidase activities releasing different N-terminal amino acids. The effects of pH, NaCl concentration, and temperature on the enzyme activities of amino acid β-naphthylamide (βNA)-substrates were determined by modulating the variables in 19 different runs of an experimental design, which allowed the building of mathematical models able to assess the effect on aminopeptidases activities over a range of values, obtained with bibliographic data, covering different environmental conditions in different zones of the cheese wheel at different aging times. The aminopeptidases tested in this work were present in cell-free Parmigiano Reggiano cheese extract after a 17-mo ripening and were active when tested in model system. The modeling approach shows that to highlight the individual and interactive effects of chemical-physical variables on enzyme activities, it is helpful to determine the true potential of an amino-peptidase in cheese. Our results evidenced that the 6 different lactic acid bacteria peptidases participate in cheese proteolysis and are induced or inhibited by the cheese production parameters that, in turn, depend on the cheese dimension. Generally, temperature and pH exerted the more relevant effects on the enzymatic activities, and in many cases, a relevant interactive effect of these variables was observed. Increasing salt concentration slowed down broad-specificity amino-peptidase C, glutamyl aminopeptidase A, proline iminopeptidase, and peptidase with high specificity for leucine and alanine. Interestingly, this variable did not affect broad-specificity aminopeptidase N and positively affected X-prolyl dipeptidyl aminopeptidase. The models elaborated varying pH, temperatures, and salt concentration and were a useful, low cost, and fast tool to understand the role of the main peptidases in the different phases of cheese ripening in relation to the major environmental factors influencing enzyme activity. 相似文献
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H. Kimoto-Nira N. Moriya S. Hayakawa K. Kuramasu H. Ohmori S. Yamasaki M. Ogawa 《Journal of dairy science》2017,100(7):5936-5944
It has recently been reported that the rare sugar d-allulose has beneficial effects, including the suppression of postprandial blood glucose elevation in humans, and can be substituted for sucrose as a low-calorie food ingredient. To examine the applications of d-allulose in the dairy industry, we investigated the effects of d-allulose on the acid production of 8 strains of yogurt starter (Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus) and 4 strains of lactococci, including potential probiotic candidates derived from dairy products. Acid production by 2 L. delbrueckii ssp. bulgaricus yogurt starter strains in milk was suppressed by d-allulose, but this phenomenon was also observed in some strains with another sugar (xylose), a sugar alcohol (sorbitol), or both. In contrast, among the dairy probiotic candidates, Lactococcus lactis H61, which has beneficial effects for human skin when drunk as part of fermented milk, was the only strain that showed suppression of acid production in the presence of d-allulose. Strain H61 did not metabolize d-allulose. We did not observe suppression of acid production by strain H61 with the addition of xylose or sorbitol, and xylose and sorbitol were not metabolized by strain H61. The acid production of strain H61 after culture in a constituted medium (tryptone–yeast extract–glucose broth) was also suppressed with the addition of d-allulose, but growth efficiency and sugar fermentation style were not altered. Probiotic activities—such as the angiotensin-converting enzyme inhibitory activity of H61-fermented milk and the superoxide dismutase activity of H61 cells grown in tryptone–yeast extract–glucose broth—were not affected by d-allulose. d-Allulose may suppress acid production in certain lactic acid bacteria without altering their probiotic activity. It may be useful for developing new probiotic dairy products from probiotic strains such as Lactococcus lactis H61. 相似文献