椰子纳塔发酵条件研究

研究了一株醋酸杆菌（Ａｃｅｔｏｂａｃｔｅｒｓｐ．）在椰子水培养液中发酵产生纳塔（ｎａｔａ）的适宜工艺条件：蔗糖７％,ＮＨ４Ｃｌ０．４％,ＫＨ２ＰＯ４０．２％,ＭｇＳＯ４０．０２％,ＣａＣｌ２０．０２％,ＦｅＳＯ４０．０００５％（Ｗ／Ｖ）,酵母膏０．０５％,柠檬酸０．０２％,椰子水５０％～１００％（Ｖ／Ｖ）,ｐＨ４．０,用大口容器盛装,３０℃静置培养１４～１８ｄ。在此条件下,于５００ｍｌ烧杯中发酵１６ｄ,最高可收获１８２ｇ重,３．３ｃｍ厚的纳塔,其外观和品质均符合纳塔食品的加工要求。     

纳塔产生菌的分离鉴定和发酵特性研究

纳塔(nata)是一种由微生物经液态发酵形成于液体表面的凝胶膜状物[1],主要成分是纤维素[2,3]。目前在台湾和大陆的商品名叫“椰果”、“高纤椰果”,因其外形极象嫩椰肉,且最常用的发酵原料是椰子水。由于它持水性好,具有独特的凝胶状半透明质构,其最广泛的应用是加工成各?..     

细菌纤维素发酵条件的优化及结构分析

以木葡糖酸醋杆菌Gyll为目标菌株,采用单因素法对液体发酵生产细菌纤维素的发酵条件(氮源、碳源、初始pH值、种龄、接种量和静态发酵周期)进行了优化,并对其代谢生产的细菌纤维素的微观结构进行了观察。结果表明,最优发酵条件为蔗糖5%,玉米浆干粉5%;初始培养基pH 6.2,发酵液中接种量10%;采用动静三步结合发酵时,一级种子的种龄24h,二级种子扩大化培养时种龄为20h,静态培养周期为8d。菌株最高产量为11.49g/L,约是优化前的5倍。通过红外光谱(FT-IR)、扫描电镜(SEM)、X射线衍射对细菌纤维素的表征,确定制得的细菌纤维素属于Ⅰ型纤维素,具有典型的网状结构,纤维束尺寸为纳米级且结晶度很高。     

细菌纤维素管的发酵条件优化及结构性能研究

木醋杆菌是一种革兰氏阴性专性需氧菌,采用透气管材硅胶管作为发酵容器生产细菌纤维素(Bacterial Cellulose,BC)管,实验中考察发酵培养基种类、发酵时间、接种量对BC管产量的影响。结果表明,最适发酵时间为6 d,发酵培养基为复合培养基,最适接种量为4%(v/v)。采用FTIR、XRD对BC管的结构性能进行表征,结果发现BC管的结晶度稍低于BC膜,BC管的拉伸性能达到50.25 MPa,与BC膜相当。采用原子力显微镜(AFM)观察BC管的微观形貌,发现BC管是由纤维束高度缠绕而形成,与BC膜相比,BC管的纤维束大小相差较大,这也可能是造成BC管在结晶度和拉伸性能上稍低于BC膜的原因。该研究可为BC管在高附加值的食品包装材料、组织工程支架材料等的应用提供基础数据。     

醋杆菌产纤维素发酵条件的优化

本文在已筛选出在摇瓶培养条件下高产细菌纤维素菌株--醋杆菌C2的基础上,研究了不同发酵条件对该菌株产纤维素的影响。实验结果表明,醋杆菌C2 发酵产生细菌纤维素的最适温度为27℃,最适pH为4.5,装液量50ml/250ml三角瓶,转速为160r/min,发酵终点204h。     

乳铁蛋白基因工程菌培养条件研究

对乳铁蛋白基因工程菌发酵条件进行了初步研究,在廉价高效的原则下对培养基组分进行了选择性优化,同时对几个主要的发酵参数进行了优化。     

振荡条件对发酵生产颗粒状细菌纤维素的影响

为打破静置发酵生产膜状细菌纤维素的传统模式,并开发出新型细菌纤维素,采用摇床振荡培养的方法,发酵生产外观均匀且为颗粒状的细菌纤维素.利用单因素试验,以粒径为0.5cm～0.8cm的细菌纤维素颗粒产量及其占总纤维素比率为考察指标,研究转速、装液量、温度、接种量、种龄及培养时间对形成细菌纤维素颗粒的影响,探索最佳振荡条件.结果表明,转速及装液量对颗粒的形成及粒径影响较大,温度、接种量、发酵时间、种龄主要影响细菌纤维素颗粒产量;最优培养条件为140r/min,30℃、60mL装液量,种龄48h,3％接种量发酵5d,此条件下产物中粒径为0.5cm～0.8cm的颗粒纤维素占有率高,其产量达28.5g/100mL.     

木醋杆菌M096生产细菌纤维素的发酵条件

探讨温度、初始pH值、碳源和氮源对细菌纤维素产量的影响,以确定生产菌株发酵生产细菌纤维素的条件.结果显示,木醋杆菌M096发酵生产细菌纤维素的培养条件是:发酵温度25℃,初始pH值最适范围是5.8～6.6,最佳碳源为蔗糖且最适浓度是8%,最佳氮源为牛肉膏且最适浓度是1.5%.     

Acetobacter xylinum CGMCC5173发酵生产细菌纤维素的条件优化

为提高Acetobacter xylinum CGMCC5173生产细菌纤维素(BC)的产量,对该菌生产BC的条件进行优化。研究表明,采用CJMF培养基,培养到第二代时BC产量最高,达到43.91 g/L;采用HMF培养基,当接种量为10%,蔗糖、乙酸钠、乙醇和L-乳酸的含量分别为10%、1.0%、1.5%和0.25%时,细菌纤维素产量最高,分别达到14.79 g/L、7.47 g/L、4.24 g/L、40.07 g/L和21.92g/L;而D-乳酸越多,BC产量越低;采用80%HMF与20%CJMF混合复配的发酵液,BC的产量最高为29.30 g/L。结果表明,控制A.xylinum 5173的培养代数和用HMF与CJMF复配的发酵液可稳定和有效地提高BC产量。     

玉米浆做Acetobacter xylinum培养基生产纤维素的发酵条件优化

以玉米浆作为木醋杆菌营养氮源,探索出发酵培养基的 最优配方,并利用单因素优选法对发酵条件进行了优化。 结果表明,葡萄糖4％,玉米浆5.5％,磷酸氢二钠0.5％,生 物素25mg／L,咖啡因2mg/L,柠檬酸0.1％,pH为6,利用 木醋杆菌静止浅层培养法,纤维素的产量高迭7.22g/L, 比酵母膏做氮源的纤维素产量提高了1倍。      

Fermentation of Monascus purpureus on Bacterial Cellulose-nata and the Color Stability of Monascus-nata Complex

Nata, a bacterial cellulose produced by Acetobacter aceti ssp. xylinum , was colored by means of fermentation with Monascus purpureus. Scanning electron microscopy (SEM) observations showed that the Monascus mycelium could grow through the cellulose network of nata. Rice powder as a major carbon source and monosodium glutamate (MSG) as a nitrogen source gave an appealing coloration after 12 d of fermentation at 30 °C. Compared to dyed nata, the color of the Monascus -nata complex had better resistance to washing, heat, freezing, acidification, and alkalization. A 66.1% decolorization was found under irradiation with 366 nm ultraviolet light after 36 h. The Monascus -nata complex has the potential to be a new vegetarian foodstuff.     

Influence of Bacterial Cellulose (nata) on the Physicochemical and Sensory Properties of Frankfurter

The physicochemical and sensory characteristics of pork frankfurters containing different levels (10% to 30%) of bacterial cellulose (nata) were evaluated. Emulsion stability of the raw meat batter decreased with the addition of nata. For nata‐added treatments, increasing levels of nata in frankfurters resulted in decreased textural hardness and shear values. Sensory results indicated that N10 and N20 had significantly higher firmness scores than N30 and control. However, juiciness score did not differ for all treatments. Incorporation of nata at lower levels (10% to 20%) did not have detrimental effects on the physicochemical, textural, sensory, and microbiological properties of regular‐fat frankfurters. Addition of a higher level (30%) of nata essentially produced comparable sensory properties to the control, but lower levels of nata in frankfurters yielded higher sensory firmness and instrumental hardness values. Based on the composite results, manufacture of regular‐fat frankfurter containing 10% to 20% high‐fiber nata resulted in product quality comparable to the control.     

超声波促进高纤椰果发酵的研究

为了提高高纤椰果发酵产量,在浅层静态发酵过程中尝试加载超声波,研究了超声波处理条件对高纤椰果发酵的影响。结果表明,适宜的超声波处理条件对高纤椰果发酵有促进作用,利用超声波(400 W,28 kHz)从发酵48h开始进行处理,每次处理时间为180 s,每隔1.5 h处理1次,发酵240 h,纤维素干重可达到1.88 g,比空白实验提高了20.5%。     

Quality Characteristics of Chinese-style Meatball Containing Bacterial Cellulose (Nata)

ABSTRACT: The physicochemical, textural, and quality characteristics of Chinese-style meatball (20% fat) containing varying levels of bacterial cellulose (nata) were evaluated. Cooking losses of nata-containing Chinese-style meatballs were higher than those of control (containing no nata and 20% fat [C20]). Raw nata-added batter had higher water-holding capacity than control, but the pattern was reversed after cooking. N10 (10% nata) and C20 had the highest springiness scores. Textural hardness and shear-force value were significantly higher for C20, but both attributes for nata-added treatments decreased with increasing nata levels. Addition of 10% nata to Chinese-style meatballs produced products with acceptable textural and sensory qualities. Nata showed potential as a functional ingredient in Chinese-style emulsified meat products such as Chinese-style meatballs.     

产细菌纤维素菌株中间葡糖醋杆菌的分离与发酵条件优化

从中国传统固态发酵食醋醋醅中分离出5株产细菌纤维素(BC)的菌株,经生理生化特征及16S rDNA序列分析,它们均属于中间葡糖醋杆菌(Gluconacetobacter intermedius),其中编号为1-17的菌株初始产量较高。应用扫描电镜技术(SEM)和傅里叶红外光谱技术(FT-IR)分析了BC结构特征。采用单因素研究了温度、培养时间、碳源、初始pH对BC合成的影响。确定菌株1-17最适温度为35℃,发酵时间为7d,甘油和葡萄糖为最适碳源,最适初始pH为6.0,乳酸根离子和钙离子能够促进BC的合成。通过培养条件优化使得细菌纤维素产量从初始的(3.90±0.08)g/L增加到(7.90±0.19)g/L。     

动态发酵合成球形细菌纤维素条件研究

细菌纤维素(BC)是优良的新型生物材料,尤其以球形BC为代表,在各领域应用广泛。目前,动态发酵产BC多以不规则团块状、星球状、丝状为主,应用范围较局限。故通过控制生产条件,获得均匀度较高的球形BC有着迫切的需要。在动态发酵时,以椰冻驹形杆菌（Komagataeibacter nataicola）Y19作为生产菌株,以中等大小BC的质量及数量百分比为考察指标,研究转速、发酵液液深及发酵容器直径引起的供氧效率及剪切力变化对动态发酵产球形BC合成规律的影响。结果表明,供氧效率提高、剪切力增大时,可使球形颗粒变小,颗粒数量增加。在发酵容器直径为6.0 cm,液深为2.40～2.75 cm,转速为130 r/min时,中球BC质量与数量百分比均＞40%,均匀度最佳。     

细菌纤维素发酵条件的优化及结构的初步研究

通过单因素及正交实验探索出AcetobacterxylinumNUST4·2合成细菌纤维素的发酵条件为:葡萄糖1·5%、蔗糖1·0%、蛋白胨1·5%、醋酸0·08%、Na2HPO40·27%、MgSO40·025%,接种量8%,pH5·5,28℃静置培养7d,纤维素产量为3·348g/L培养基(干重)。接着利用活性炭柱分离和气-质联用色谱(GC-MS)鉴定了发酵产物的单体成分为葡萄糖;采用固体CP/MAS13CNMR、透射电镜(TEM)、X-射线衍射表征了发酵产物的结构,得知该产物具有典型的网状结构,纤维束尺寸为纳米级且结晶度很高。