蜡状芽孢杆菌发酵南极磷虾生成活性物质的研究

南极磷虾具有分布量广、营养价值高、贮藏量大等特点,是一种重要的海洋蛋白新资源,有待开发利用。从深海泥样中分离筛选出一株能够以南极磷虾为唯一碳氮源生长的蜡状芽孢杆菌,利用该菌发酵南极磷虾。对发酵条件进行了初步优化,研究了发酵液的抗氧化能力以及发酵液中风味物质的种类和含量的变化情况。结果显示,30℃恒温培养48 h,DPPH清除率为44.05%,总酚含量为0.059 2 mg/m L,亚铁离子螯合能力为92.23%,还原力为200.13μmol/L,总蛋白含量为2.952 g/100 g,有机酸组成丰富,游离氨基酸含量(227.540 2 mg/m L)比发酵前(106.5796 mg/m L)增加一倍。本研究使南极磷虾这一丰富的资源得到最大限度的利用,同时也使南极磷虾的生物活性物质能够在生产中发挥潜在的作用。     

双歧杆菌发酵对豆芽汁中大豆异黄酮含量及组分影响的研究

目的探讨双歧杆菌发酵对豆芽汁中大豆异黄酮含量及组分影响.方法采用HPLC法检测波长260 nm,测定豆芽汁中金省异黄素、大豆黄素的含量.结果表明通过发酵处理后,豆浆中总大豆异黄酮浓度没有明显的变化(P＞0.05);大豆异黄酮甙元的浓度较未经过发酵处理的豆浆组明显增加(P＜0.05);而大豆异黄酮糖甙的浓度却明显降低(P＜0.05).结论豆浆中的大豆异黄酮糖甙在双歧杆菌的β葡萄糖苷酶作用下水解为异黄酮甙元,异常酮甙元的浓度显著增加.     

以豆浆为培养基的三种药食用真菌发酵过程多糖变化的研究

为研究豆浆对药食用真菌发酵产多糖的影响,对灵芝、金耳、冬虫夏草三种真菌以豆浆为培养基得到的多糖进行了结构和离子交换层析分析。研究结果表明,三种药食用真菌多糖的结构和性质具有较大差异,在单糖组成方面,葡萄糖、阿拉伯糖和半乳糖三种主要单糖的摩尔百分比具有较大差异,同时多糖中不同分子量的各个组分比例也有较大差异。红外光谱图分析结果显示,金耳和灵芝发酵液较虫草发酵液,多糖峰型变化较大,但二者峰型较相似。三种真菌多糖经离子交换柱分离纯化后发现,三种多糖都是由中性和酸性多糖组成,但冬虫夏草发酵液中的中性多糖比例远低于酸性多糖,而金耳和灵芝多糖中酸性多糖比例高于中性多糖。本研究以豆浆为培养基探究三种药食用真菌发酵多糖结构的变化,不仅为多糖结构研究提供理论支持,还为真菌豆浆发酵产品的开发奠定良好的实践基础。     

重组大肠杆菌BL21(pUC19-Hyp)产羟脯氨酸的补料分批培养

利用自主构建的组成型重组大肠杆菌BL21(pUC19-Hyp)为出发菌株,运用间歇流加、指数流加和恒速流加3种流加C源的方式进行补料分批培养。结果表明:在装液量为4 L的7 L发酵罐中,以0.30 g/min恒速流加为最优,在发酵44 h时,羟脯氨酸的质量浓度达到最高,为42.50 g/L,脯氨酸转化率为81%,此时细胞干质量为21.33g/L,残糖质量浓度为0.17 g/L。L-羟脯氨酸含量与摇瓶发酵时的1.39 g/L相比,提高了大约30倍,比日本株式会社的发酵产量提高了1.50 g/L,发酵过程中糖酸转化率约为4.0∶1。发酵液中的氨基酸分析结果表明,除脯氨酸、羟脯氨酸外的其他氨基酸质量浓度均低于0.1 g/L,发酵液中主要氨基酸为脯氨酸和羟脯氨酸。     

树状多节孢发酵生产紫杉醇工艺条件的初步研究

研究了树状多节孢HQD33内生真菌融合子TPF－1瓶发酵工艺条件,进行了2．8L和10L通用式机械搅拌罐的发酵试验。结果表明,HQD33适宜发酵工艺条件是：发酵时间16－18d,培养基中蔗糖、苯丙氨酸、醋酸钠、酪氨酸,2,4-氯苯氧乙酸和亚油酸的加量分别为180g/L、1mg/L,1.5g/L,15mg/L,5mg/L和15mg/L,摇瓶装置为150ml/500ml,在此条件下摇瓶发酵液中紫杉醇平均含量为448．52μg/L;2.8L和10L罐发酵液中紫杉醇含量达406．95和395．12μg/L（平均值）。     

丹贝发酵过程中大豆异黄酮组分与含量的变化

用HPLC方法检测大豆[Glycine max(Linn.)Merr.]发酵食品－丹贝的发酵过程中异黄酮各组分含量变化。在发酵的最初24h内,大部分异黄酮由糖甙转化成甙元,随着发酵时间的延长转化率逐渐降低,发酵终产物中异黄酮主要以大豆甙元和染料木素形式存在,发酵64h的丹贝中总异黄酮摩尔含量比未发酵的大豆高51．25％。     

HPLC法检测蛇足石杉内生真菌胶胞炭疽发酵液中石杉碱甲和石杉碱乙的含量

建立了高效液相色谱(HPLC)测定蛇足石杉(Huperzia serrate)内生真菌胶胞炭疽发酵液中石杉碱甲(Huperzina A)和石杉碱乙(Huperzine B)含量的方法,并以此方法检测胶胞炭疽发酵液中石杉碱甲和石杉碱乙含量的积累。内生真菌发酵液经氯仿萃取、甲醇溶解、过滤后进行高效液相检测分析,选用Agilent Eclipse plus-C18色谱柱(250 mm×4.6 mm,5μm),以0.015 mol/L乙酸铵(p H 6.8)和甲醇溶液(70∶30)为流动相进行等度洗脱,流速1 mL/min,检测波长为308 nm,连续检测内生真菌胶胞炭疽发酵液中第6–15天石杉碱甲和石杉碱乙的含量积累。结果表明,发酵提取液中的石杉碱甲和石杉碱乙可在25 min内进行很好的分离和分析,石杉碱甲在1.50-48.00μg/mL范围内线性关系良好(相关系数r为0.999 5),石杉碱乙在0.25-7.50μg/mL范围内线性关系良好(相关系数r为0.999 7),石杉碱甲和石杉碱乙的平均加标回收率分别为106.83%、108.06%,相对标准偏差(RSD)分别为3.34%、3.60%。该方法简便、快速、精密度高、结果准确,适用于内生真菌发酵液中石杉碱甲和石杉碱乙含量检测。在发酵过程中,内生真菌发酵液中石杉碱甲和石杉碱乙的含量呈现先增后减,随后有所增加继而又减少的趋势。石杉碱甲和石杉碱乙的含量分别在内生真菌发酵第14天、第8天达到最高,分别为12.417 0μg/mL、4.660 3μg/mL。该方法学的建立为内生真菌胶胞炭疽合成石杉碱甲与石杉碱乙的机制研究提供了检测手段,从而有利于药物新资源的开发。     

大豆异黄酮糖苷酶产生菌培养条件优化及转化

将经过筛选的产大豆异黄酮糖苷水解酶的菌株米曲霉3042经过单因子及正交试验,确立了产酶的最适培养基配方为：玉米芯＋麸皮4%,（NH4）2SO40.1%,水扬苷0.01%,KH2PO40.1%,Vc 0.1%,MgSO40.1%.产酶的最佳培养条件为：发酵培养基起始pH 6.0,发酵温度27℃,摇床转速160r/min,发酵时间84 h时酶活力最高.粗提取的大豆异黄酮经发酵液转化后,其结合态含量降低,游离态含量增加.     

L-精氨酸高产菌红曲霉的筛选及发酵初步研究

对不同样品中的真菌进行了L-精氨酸高产菌株的筛选,从红曲米中分离出1株高产L-精氨酸菌株红曲霉H13,其初始发酵液中L-精氨酸产量为1.67 g/L.通过单因素实验对其液体发酵进行研究.结果表明,最佳碳源是可溶性淀粉,最佳浓度为10％,最佳氮源是蛋白胨,最佳浓度为3％,最佳pH值4.5,温度30℃,种子培养时间为18 h,摇瓶装液量50 mL/250 mL.转速为120 r/min,发酵时间7d.在此条件下进行发酵培养,所得发酵液产L-精氨酸4.08 g/L,菌丝体干重为10.32 g/L,菌丝体中L-精氨酸含量为24.17 mg/g.     

河南太行红豆杉产紫杉醇内生真菌的筛选

目的：筛选出高产紫杉醇的内生菌株,为发酵生产紫杉醇提供菌种。方法：从不同来源的红豆杉根、茎、叶中分别分离内生真菌,并对其进行发酵,用HPLC法对菌丝体和发酵液中的紫杉醇含量进行检测,获得高产菌株。结果：获得54株产紫杉醇的内生真菌,其中根、茎、叶分别为29株、16株、9株。根、茎、叶三部位产紫杉醇菌株的平均产量分别为248.57μg/L、149.09μg/L、104.94μg/L;其中一株产量高达622.75μg/L。结论：从野生红豆杉的根部分离内生真菌效果较好,并获得了一株高产菌株。     

Brazilian Kefir-Fermented Sheep’s Milk,a Source of Antimicrobial and Antioxidant Peptides

Fermented milks are a source of bioactive peptides and may be considered as functional foods. Among these, sheep’s milk fermented with kefir has not been widely studied and its most relevant properties need to be more thoroughly characterized. This research study is set out to investigate and evaluate the antioxidant and antimicrobial properties of peptides from fermented sheep’s milk in Brazil when produced by using kefir. For this, the chemical and microbiological composition of the sheep’s milk before and after the fermentation was evaluated. The changes in the fermented milk and the peptides extracted before the fermentation and in the fermented milk during its shelf life were verified. The antimicrobial and antioxidant activities of the peptides from the fermented milk were evaluated and identified according to the literature. The physicochemical properties and mineral profile of the fermented milk were like those of fresh milk. The peptide extract presented antimicrobial activity and it was detected that 13 of the 46 peptides were able to inhibit the growth of pathogenic microorganisms. A high antioxidant activity was observed in the peptides extracted from fermented milk (3.125 mg/mL) on the 28th day of storage. Two fractions displayed efficient radical scavenging properties by DPPH and ABTS methods. At least 11 peptides distributed in the different fractions were identified by tandem mass spectrometry. This sheep’s milk fermented by Brazilian kefir grains, which has antioxidant and antimicrobial activities and probiotic microorganisms, is a good candidate for further investigation as a source for bioactive peptides. The fermentation process was thus a means by which to produce potential bioactive peptides.     

Production of yogurt with enhanced levels of gamma-aminobutyric acid and valuable nutrients using lactic acid bacteria and germinated soybean extract

Yogurt with high levels of gamma-aminobutyric acid (GABA), free amino acids and isoflavones was developed using lactic acid bacteria (LAB) and germinated soybean extract. Fermented soya milk (GABA soya yogurt) produced with starter and substrate had the GABA concentration of 424.67 microg/gDW, whereas fermented milk produced by a conventional method had GABA less than 1.5 microg/gDW. The GABA soya yogurt also contained significantly high levels of free amino acids and isoflavones compared with other conventional yogurts. The results suggested that the Lactobacillus brevis OPY-1 and germinated soybean possessed a prospect to be applied in dairy and other health products with high nutritive values and functional properties.     

一株产碱性蛋白酶芽孢杆菌的筛选、鉴定及应用初探

为了筛选碱性蛋白酶产生菌并探讨其对蛋白质饲料的发酵效果,以肉粉厂表层土壤为菌株分离源,利用脱脂牛奶培养基分离和纯化蛋白酶产生菌,通过形态特征、生理生化和16S rRNA基因序列分析确定菌株的分类地位,并采用L9(33)正交设计研究筛选出的优势菌种的接种量(3％、6％和12％)、种子液培养时间(12 h、24h和48 h...     

灌溉对毛竹冬笋品质的影响

选取同一地形、长势一致的毛竹林为材料,分析比较灌溉与不灌溉毛竹林冬笋外观品质(个体重量、最大直径、长度、可食率)、营养品质(淀粉、蛋白质、脂肪、可溶性糖、维生素C)、呈味物质(单宁、草酸)、纤维素类物质(纤维素、木质素)以及不同类氨基酸含量的差异,研究灌溉对毛竹冬笋品质的影响,为冬笋的科学培育提供依据。结果表明：(1)灌溉显著提高了毛竹冬笋的个体重量、最大直径、长度以及可食率(P<0.05)。(2)灌溉显著提高了毛竹冬笋的淀粉和维生素C含量,并显著降低了单宁、草酸、纤维素以及木质素含量(P<0.05),但对蛋白质、脂肪、可溶性糖等指标含量影响不显著。(3)灌溉显著提升了毛竹冬笋中必需氨基酸、半必需氨基酸、鲜味氨基酸的含量以及占比(P<0.05),但对甜味和苦味氨基酸总含量影响不显著。研究发现,灌溉改善了毛竹冬笋生长和外观品质,以及呈味物质、纤维素类物质、必需氨基酸、半必需氨基酸和鲜味氨基酸含量等营养品质指标,从而显著提升了冬笋品质。     

头孢霉AL031真菌氨基酸和无机元素分析

从一产生光敏活性物质的头孢霉AL0 31真菌的菌丝体和发酵液中 ,测得 1 6种氨基酸 ,总含量分别为 1 5.53%和 0 .0 1 5%。该真菌菌丝体中含 1 4种无机元素 ,发酵液中有无机元素 1 2种。以上结果 ,为进一步探讨该真菌的开发应用价值提供了依据。     

玉米灵芝菌粮营养成分及加工特性变化研究

玉米作为主要的杂粮谷物,营养价值高,维生素、膳食纤维等含量丰富,可以预防多种亚健康疾病,受到市场追捧。但是玉米粉营养结构不均衡、加工性差,限制其应用。有研究表明,微生物发酵技术可以改善谷物的营养成分、大分子物质结构和加工特性。基于此,利用灵芝固态发酵玉米,得到玉米灵芝菌粮（简称菌粮）,从营养成分、大分子物质结构和加工特性3个方面对其进行评价。结果显示,与未发酵玉米相比,菌粮中碳水化合物、蛋白质含量分别提高了748%、28.00%,且蛋白质的氨基酸评分提高,而脂肪含量降低了52.56%;维生素C、核黄素和烟酸含量均显著提高（P<0.05）,分别提高了56.19%、73.91%和20.27%,且玉米中缺乏的硫胺素在菌粮中被检测到;菌粮中各类淀粉和纤维的含量也发生了显著变化（P<0.05）,淀粉、支链淀粉含量分别降低了11.17%、34.70%,直链淀粉含量提高了26.66%,粗纤维、不溶性膳食纤维含量分别降低了21.07%、21.47%,可溶性膳食纤维含量提高了13.57%;菌粮粉粘度降低,水溶性指数提高,吸水性指数和溶胀力降低;此外,与灵芝子实体相比,菌粮中灵芝三萜和灵芝酸含量均显著提高（P<0.05）,分别为灵芝子实体的1.68和2.07倍。灵芝固态发酵玉米得到的玉米灵芝菌粮,营养结构更加均衡,功能活性提高,具有更高的营养价值;大分子物质结构发生改变,加工特性得到改善,冲调特性更好。研究结果为食用菌发酵改良谷物特性的研究提供了参考和指导。     

传统腌酵调味食品中真菌的概述

文中对豆酱、酱油、腐乳等主要的传统盐腌发酵调味食品的真菌进行了归纳总结。为发酵食品生产中有益真菌菌种的开发应用以及发酵过程中微生态的研究提供了数据,并为食品安全标准的制定、有害真菌的识别与防治提供了相关依据。     

Fermented functional foods based on probiotics and their biogenic metabolites

The claimed health benefits of fermented functional foods are expressed either directly through the interaction of ingested live microorganisms, bacteria or yeast with the host (probiotic effect) or indirectly as a result of ingestion of microbial metabolites produced during the fermentation process (biogenic effect). Although still far from fully understood, several probiotic mechanisms of action have been proposed, including competitive exclusion, competition for nutrients and/or stimulation of an immune response. The biogenic properties of fermented functional foods result from the microbial production of bioactive metabolites such as certain vitamins, bioactive peptides, organic acids or fatty acids during fermentation.     

食用菌鲜味物质研究进展

本文介绍了食用菌鲜味物质的研究进展,可以为食用菌调味品的开发提供理论基础和指导。文章主要综述了食用茼鲜味物质氨基酸和核苷酸的组成、呈鲜特点、提取以及食用菌在调味品中的开发现状。食用菌中氨基酸和核苷酸类的含量都比较高,是食用菌重要的鲜味物质。这些鲜味物质的酶法提取比传统方法的效果好、提取率高。当今食用菌调味品生产工艺简单,大多为粗加工品,且食用菌中的鲜味物质和其它的功能性成分没有充分释放出来,需要研发新方法来充分释放其中的鲜味物质及其它的营养成分,并且要加强食用菌抽提物产品研制的新技术。     

Putting microbes to work: dairy fermentation, cell factories and bioactive peptides. Part I: overview

A variety of milk-derived biologically active peptides have been shown to exert both functional and physiological roles in vitro and in vivo, and because of this are of particular interest for food science and nutrition applications. Biological activities associated with such peptides include immunomodulatory, antibacterial, anti-hypertensive and opioid-like properties. Milk proteins are recognized as a primary source of bioactive peptides, which can be encrypted within the amino acid sequence of dairy proteins, requiring proteolysis for release and activation. Fermentation of milk proteins using the proteolytic systems of lactic acid bacteria (LAB) is an attractive approach for generation of functional foods enriched in bioactive peptides given the low cost and positive nutritional image associated with fermented milk drinks and yoghurt. In this review, we discuss the exploitation of such fermentation towards the development of functional foods conferring specific health benefits to the consumer beyond basic nutrition. In particular, in Part I, we focus on the release of encrypted bioactive peptides from a range of food protein sources, as well as the use of LAB as cell factories for the de novo generation of bioactivities.