藏灵菇乳中具有优良抗氧化活性乳酸菌的筛选鉴定

为了得到具有抗氧化活性的乳酸菌,采用1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）法和抑制脂质过氧化法对11 株来源于西藏藏灵菇乳的乳酸菌抗氧化活性进行测定,包括它们的完整细胞和无细胞提取物,发现HN05菌株有较好的抗氧化活性。根据菌株的表型、生理生化特征和基因型的特性,初步将HN05菌株鉴定为清酒乳杆菌清酒亚种（Lactobacillus sakei subsp. sakei）。     

“藏灵菇”酸乳中优势乳酸菌的分离鉴定

利用碳酸钙平板法从藏灵菇菌块为发酵剂制备的发酵酸乳中分离到2株产酸细菌,对其进行形态、生理生化测定及16SrRNA序列分析。结果表明,发酵凝乳中的这两株优势乳酸菌是乳酸乳球菌乳酸亚种。本研究结果为开发稳定的优良发酵剂提供菌种资源,并为进一步研究藏灵菇酸奶的保健功能奠定基础。     

藏灵菇中高产胞外多糖乳酸菌的筛选及其发酵性能的研究

本研究采用高通量筛选技术和苯酚-硫酸法获得高产胞外多糖的乳酸菌菌株，并对其发酵性能和酸奶品质进行测试。筛选的八株菌均具有高产胞外多糖和良好的发酵性能。其菌种鉴定结果是：菌株KTx、 KL1、J1为干酪乳杆菌（Lactobacillus casei），菌株Tx为嗜热链球菌（Streptococcus thermophilus），菌株KS4、J4、Pl、P5为乳酸乳球菌乳酸亚种（Lactococcus lactis subsp．1actis），其中嗜热链球菌Tx制备发酵剂的粘度最高，凝乳时间最短，感官综合评分最高，可利用此菌株进一步开发研制具有良好稳定性的功能性酸奶。     

分离自藏灵菇的乳酸菌的益生特性

从藏灵菇中分离纯化5株乳酸菌,初步鉴定2株为嗜酸乳杆菌,3株为乳酸乳球菌。选取其中2株菌研究其益生特性。结果表明,从藏灵菇中分离出的乳酸菌具有良好的益生特性,2株乳酸菌在pH值为4～6可生长良好;耐热范围为30～60℃;胆盐耐受性为0.1%～0.5%;发酵液对金黄色葡萄球菌、沙门氏菌、大肠杆菌等肠道病原菌有抑制作用;对抗生素有不同程度的耐药性。     

藏灵菇牦牛酸乳发酵过程中乳酸菌和酵母菌对品质的作用

藏灵菇酸乳是由乳酸菌、酵母菌、醋杆菌和霉菌共同发酵形成的一种发酵乳制品,其品质特征与普通酸乳有显著差异。为研究藏灵菇发酵酸乳中乳酸菌和酵母菌分别发挥的作用,利用放线菌酮和青链霉素分别抑制发酵过程中的酵母菌和乳酸菌,测定并比较正常发酵酸乳、抑制乳酸菌发酵酸乳和抑制酵母菌发酵酸乳的风味、口感和质构等相关指标。实验结果显示抑制酵母菌发酵的酸乳中乙醇含量由1.85g/kg上升为2.77g/kg,VB2含量由168μg/100g下降为157μg/100g,与正常发酵组差异较大;抑制乳酸菌发酵的酸乳中酸度由18°T上升为28°T,氨基酸态氮由65mg/100g下降为53mg/100g,乳酸含量持续2mg/g,乙酸由1mg/g下降为0.7mg/g,VB1含量由20μg/100g下降为18μg/100g,与正常发酵组差异较大。乳酸菌在酸乳发酵过程中,对酸度、氨基酸态氮、质构、乳酸、乙酸与VB1的生成贡献较大;酵母菌对乙醇、VB2的生成贡献较大。     

藏灵菇耐胃肠道环境酵母菌和乳酸菌的筛选

以藏灵菇发酵乳液为原料,分别利用改良的马铃薯乳糖培养基和改良MRS培养基分离出8株酵母菌和10株乳酸菌。以pH值为3.0,质量分数为0.3%牛胆盐的培养液模拟胃肠道环境作为初筛条件,以不同pH值和牛胆盐质量分数作为耐酸和耐胆盐的复筛条件,筛选得到耐受性好活力高的两株酵母菌C3和C8,两株乳酸菌M1和M3。     

藏灵菇发酵产胞外多糖的影响因素及其应用研究

利用苯酚-硫酸法从15个不同地区藏灵菇样品中筛选出3个高产胞外多糖样品（K4、K7、K12）。通过单因素分析确定K4、K7、K12高产胞外多糖的条件为:接种量K4为9%、K7和K12为7%;发酵时间K12为12 h、K4和K7为18 h;发酵温度均为37℃;脱脂乳浓度均为11%。藏灵菇K4、K12分别与商业发酵剂搭配制备发酵乳,结果表明,K12发酵乳的凝乳时间最短（4.52 h）,胞外多糖含量和活菌数分别保持在50 mg/L左右和8.20 log cfu/m L以上,且具有较高的持水力和黏度。      

藏灵菇中醋酸菌和酵母菌的分离及初步鉴定

结合藏灵菇扫描电镜结果,从藏灵菇叶中分离出1株醋酸菌和4株酵母菌依据其彤态、培养特征和部分生理牛化研究,初步鉴定醋酸菌为巴氏醋杆菌（Acetobacter pasteurianus）,4株酵母菌分别为酒香酵母属（Brettanomyces）、类酵母属（Saccharomycodes）和酵母属（Saccharomycs）的菌株。     

高抗氧化乳酸菌的筛选鉴定

为了寻找天然的抗氧化剂,对18株乳酸菌的菌体细胞和无细胞提取物的DPPH自由基清除能力、羟自由基的清除能力、超氧阴离子自由基的清除能力、还原能力、抗脂质过氧化能力等5项抗氧化指标进行比较,并对高抗氧化活性的乳酸菌进行抗性筛选,鉴定出符合要求的菌株。结果表明:18株乳酸菌具有不同的抗氧化能力,编号为L4、L5、L8、L14、L18的菌株具有较高的抗氧化活性,其中,菌株L14抗人工胃液和胆盐的能力较强,有作为天然抗氧化剂的应用前景。结合生化特性鉴定和16S r DNA鉴定,确定其为类干酪乳杆菌类干酪亚种(Lactobacillus paracasei subsp.paracasei)。     

藏灵菇及其优势菌群的发酵性能研究

以藏灵菇为发酵剂生产酸乳的工艺条件为:发酵温度37℃,发酵时间10h。获得的酸乳产品pH较低。用MRS培养基、Elliker培养基、TYC培养基和SL培养基从藏灵菇中分离出乳球菌、乳杆菌、链球菌和明串珠菌。将优选的分离菌组合发酵鲜牛乳,产酸速度更快,黏度较高。     

青藏高原牦牛酸奶中具高抗氧化能力乳酸菌的筛选

研究了从青藏高原牦牛酸奶中分离的881株乳酸菌的H2O2耐受能力,从中筛选出了8株对H₂O₂具有较强耐受能力的乳酸菌,并对它们清除DPPH自由基、OH自由基、O₂^-自由基的能力以及T-AOC活性做了进一步研究。结果显示,乳酸菌对DPPH自由基的清除能力都是活细胞体高于无细胞提取物;而在对OH自由基、O₂^-自由基的清除和T-AOC活性上恰好相反。菌株BX62、XS40和XM5在对自由基的清除中表现突出,在菌体浓度为10⁹ CFU/m L时,BX62的活细胞体对DPPH自由基的清除率最高（33.53%）,其无细胞提取物对O₂^-自由基的清除率同样最高（48.85%）。而在乳酸菌无细胞提取物对OH自由基的清除中XS40表现最好（52.12%）。此外,3株乳酸菌都具有较强的T-AOC活性。经16S r RNA鉴定和系统进化分析,3株菌分别为Lactobacillus parplantarum BX62,Lactobacillus plantarum XM5和Pediococcus acidilactici XS40。本研究从青藏高原牦牛酸奶中筛选的3株乳酸菌的确具有高抗氧化活性,有作为天然抗氧化剂的应用前景。      

藏灵菇源酵母菌和乳酸菌降胆固醇蛋乳发酵饮料的研制

利用藏灵菇中筛选的马克斯克鲁维酵母菌(Kluyveromyces marxianus) M3、干酪乳杆菌(Lactobacillus casei) KL1、嗜热链球菌(Streptococcus thermoptilus) Tx、乳酸乳球菌乳酸亚种(Lactococcus lactis sub sp.lactis) KS4混合发酵,以鸡蛋和牛奶为原料,研制降胆固醇蛋乳发酵饮料.利用KL1、Tx、KS4这3株乳酸菌进行一次发酵,再利用酵母菌进行二次发酵.采用3因素3水平正交试验优化发酵条件为发酵温度34℃,接种量1％,发酵时间24h.在优化条件下,蛋乳发酵饮料的降低胆固醇率为74.99％,显示藏灵菇源酵母菌M3菌株具有良好的降胆固醇作用.     

开菲尔活菌型酸乳饮料的研制

以鲜牛奶、蔗糖为主要原料,Kefir M为发酵剂,羧甲基纤维素钠和高甲氧基果胶为稳定剂,通过对不同配方及工艺条件进行正交试验,确定了开菲尔酸乳饮料的最佳工艺和配方。结果表明,当发酵温度为28 ℃,羧甲基纤维素钠为0.20%,高甲氧基果胶为0.20%,蔗糖为8%,制作的开菲尔活菌型酸乳饮料口感和稳定性较好。     

Amino acid profiles of lactic acid bacteria, isolated from kefir grains and kefir starter made from them

The characteristics of cell growth, lactic acid production, amino acid release and consumption by single-strain cultures of lactic acid bacteria (isolated from kefir grains), and by a multiple-strain kefir starter prepared from them, were studied. The change in the levels of free amino acids was followed throughout the kefir process: single-strain kefir bacteria and the kefir starter (Lactococcus lactis C15-1%+Lactobacillus helveticus MP12-3%+(Streptococcus thermophilus T15+Lactobacillus bulgaricus HP1 = 1:1)-3%) were cultivated in pasteurized (92 degrees C for 20 min) cow's milk (3% fat content) at 28 degrees C for 5 h (the kefir starter reached pH 4.7) and subsequently grown at 20 degrees C for 16 h; storage was at 4 degrees C for 168 h. The strain L. helveticus MP12 was unrivaled with respect to free amino acid production (53.38 mg (100 g)(-1)) and cell growth (17.8 x 10(8) CFU ml(-1)); however, it manifested the lowest acidification activity. L. bulgaricus HP1 released approximately 3.7 times less amino acids, nearly 5 times lower cell growth, and produced about 1.2 times more lactic acid. S. thermophilus T15 demonstrated dramatically complex amino acid necessities for growth and metabolism. With L. lactis C15, the highest levels of growth and lactic acid synthesis were recorded (18.3 x 10(8) CFU ml(-1) and 7.8 g l(-1) lactic acid at the 21st hour), and as for free amino acid production, it approximated L. bulgaricus HP1 (17.03 mg (100 g)(-1) maximum concentration). In the L. lactis C15 culture, the amino acids were used more actively throughout the first exponential growth phase (by the 10th hour) than during the second growth phase. The unique properties of the L. helveticus MP12 strain to produce amino acids were employed to create a symbiotic bioconsortium kefir culture, which, under conditions of kefir formation, enhanced lactic acid production and shortened the time required to reach pH 4.7; intensified cell growth activity, resulting in a respective 90- and 60-fold increase in the concentration of lactobacilli and cocci in the mixed culture compared to individual cultures; and accumulated free amino acids in the final kefir with higher total concentrations (56.88 mg (100 g)(-1)) and an individual concentration of essential amino acids (1.5 times) greater than that of yogurt.     

Lactic acid bacteria from fermented table olives

Table olives are one of the main fermented vegetables in the world. Olives can be processed as treated or natural. Both have to be fermented but treated green olives have to undergo an alkaline treatment before they are placed in brine to start their fermentation. It has been generally established that lactic acid bacteria (LAB) are responsible for the fermentation of treated olives. However, LAB and yeasts compete for the fermentation of natural olives. Yeasts play a minor role in some cases, contributing to the flavour and aroma of table olives and in LAB development.     

森永乳酸菌糖

生产企业：森永制菓株式会社关键字：乳酸菌在本期焦点选题中,饮料行业年度总结对乳酸菌饮料做了较高的肯定,而乳酸菌这一品类势必能成为今后食品的一项主要发展方向,森永制菓株式会社生产的乳酸菌糖,正在成为日本流行的全民热销品。一颗一颗,晶莹剔透,透着诱人光泽的乳酸菌糖味道酸酸甜甜,     

Assessment of antioxidant capacity by method comparison and amino acid characterisation in buffalo milk kefir

This study aimed to analyse the antioxidant capacity and total phenolic content of buffalo milk kefir fermented with grains or a commercial starter culture, as well as characterisation of the amino acid profile. During fermentation, the ferrous‐reducing activity of samples increased, while the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and 2,2′‐azino‐bis‐(3‐ethylbenzothiazoline‐6‐sulphonic acid) (ABTS) scavenging activity decreased. The highest value of the ABTS and DPPH scavenging activity was recorded for buffalo milk kefir with grain, which also showed a lower ferric‐reducing antioxidant power during storage. Statistical analyses showed a significant effect of starter culture type and fermentation/storage time on the antioxidant capacity of buffalo kefir.     

Effects of kefir supernatant and lactic acid bacteria isolated from kefir grain on cytokine production by macrophage

The objective of this study was to investigate the in vitro immuno-modulating capacity and mechanisms of lactic acid bacteria (LAB) isolated from kefir grains and their individual supernatants by cytokine profiles through a toll-like receptor pathway. Results demonstrated that kefir supernatants, obtained from kefir fermented more than 24 h, induced the production of pro-inflammatory cytokines in RAW 264.7 cells. Among four LAB isolated from kefir grains and their supernatants, Lactobacillus kefiranofaciens M1 and its supernatant had strong potential to induce in vitro production of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and IL-12 in RAW 264.7 cells and murine peritoneal macrophages. Moreover, blocking toll-like receptor (TLR)-2 using anti-TLR-2 mAb and TLR-2^?/? mice showed a significant inhibition (p < 0.05) of IL-6 and TNF-α production. These findings indicated that kefir influenced the secretion of pro-inflammatory cytokines TNF-α and IL-6 through TLR-2, which would potentially have beneficial effects on promotion of cell-mediated immune responses against tumors and also against intracellular pathogenic infections. The putative immunomodulin in the kefir supernatant was also characterized and may be a protein with a molecular mass larger than 30 kDa.