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携氧剂(H2O2)对野油菜黄单胞菌合成黄原胶的影响 总被引:2,自引:0,他引:2
黄原胶(Xanthan Gum)是由野油菜黄单胞菌(Xanthomonas campestris)碳水化合物为主要底物,经发酵产生的‘种酸性胞外杂多糖。发酵中后期黏度增大,氧的传质能力下降,从而影响了黄原胶的产量。本课题研究黄原胶生物合成过程中,H2O2对供氧和提高产胶率的影响。根据添加H2O2实验得出,H2O2添加量为1ml即在发酵液中浓度为4.4mmol/L左右为最适的添加量,最佳添加时刻为48h左右。得出低浓度的H2O2能提高黄原胶的产量,产胶率平均提高了3.28%。 相似文献
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低分子质量黄原胶具有抑菌、益生及抗氧化等多种生物活性,因此通过水解制备低分子质量黄原胶具有广阔应用前景。该研究将来源于绵羊瘤胃元基因组的内切β-1,4-葡聚糖酶首次在毕赤酵母中表达,其在pH 7.0和75℃下发挥最佳作用,并有较高的pH和温度稳定性。此后,建立了毕赤酵母和野油菜黄单胞菌的共培养体系并对发酵条件进行优化,其中野油菜黄单胞菌生成的黄原胶可以被毕赤酵母分泌的内切β-1,4-葡聚糖酶直接降解产生低分子质量黄原胶。摇瓶水平下,共培养体系中总糖最高为11.4 g/L,水解产物中重均分子质量为2 500 Da的低分子质量黄原胶达到93.79%。该研究为功能性低分子质量黄原胶的工业化生产提供了一个潜在的策略。 相似文献
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利用琼脂和啤酒糟为基质,加入营养液培养野油菜黄单胞菌生产黄原胶。研究了培养基组分、基质含水率、培养时间及培养基厚度对黄原胶产量的影响。结果表明,琼脂表面培养生产黄原胶的浓度3%~3.5%,与液体深层培养相当。蔗糖和黄豆饼粉分别是生产黄原胶最适碳源和氮源。基质含水率达到75%时,培养基厚度为6cm时发酵5d,黄原胶产量最大,为35.3g/kg。 相似文献
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黄原胶(Xanthan gum)是新发展起来的一种微生物多糖,由于它有许多优良而独特的理论性能,且经毒理学安全试验达到了食品卫生标准,所以1983年在罗马召开的国际食品添加剂会议上被世界卫生组织批准为一种新的食品添加剂。黄原胶在食品中有着极其广泛的应用。一、黄原胶的微生物来源黄原胶是由甘兰黑腐病黄单胞菌(Xanthomonas campestris)发酵产生的一 相似文献
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Xanthan gum is a water-soluble exo-polysaccharide. It is produced industrially from carbon sources by fermentation using the gram-negative bacterium Xanthomonas campestris. There have been various attempts to produce xanthan gum by fermentation method using bacteria and yeast by using various cheap raw materials. This review explains the recent methods of production, recovery and applications of various industries such as food, agriculture, oil, paint and cosmetics. 相似文献
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《Food research international (Ottawa, Ont.)》2003,36(5):425-430
Xanthan gum of medium molecular weight was produced by Xanthomonas Campestris ATCC 1395 in a laboratory fermenter without pH control by applying a stirrer speed of 600 rpm and its stabilization properties in salad dressing emulsions were evaluated. The gum performed satisfactorily as an emulsion stabilizer and thickener although it had to be used in higher concentrations in order to be as effective as the commercially available xanthan gum. Furthermore, resilient gel structures resulted when the gum was used in an admixture with locust bean gum. The gel texture profile was different compared to that of the commercial sample/locust bean gum mixture, suggesting that the gum could present an alternative for the preparation of gels of acceptable textural properties. 相似文献
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黄原胶的特性、生产及应用进展 总被引:3,自引:0,他引:3
黄原胶是Xanthomnas.sp分泌的胞外水溶性多糖,由于其有突出的高粘性和水溶性、独特的流变特性、优良的温度稳定性和pH稳定性、极好的兼容性以及安全环保等特性,已被广泛于石油开采、食品工业、纺织和化妆品等诸多行业。主要综述了黄原胶的分子结构、分子特性、生产以及应用的研究进展。 相似文献
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Tuncay Gumus A. Sukru Demirci Mustafa Mirik Muhammet Arici Yesim Aysan 《Food science and biotechnology》2010,19(1):201-206
Xanthan gum were produced from the following Xanthomonas strains; standard strain Xanthomonas campestris NRRL B-1459 and isolated strains Xanthomonas arbicola pv. juglandis, Xanthomonas axonopodis pv. vesicatoria, Xanthomonas axonopodis pv. begonia, Xanthomonas axonopodis pv. dieffenbachia. The viscosity features of the xanthan gums obtained were determined at 25–80°C with different pH values and were compared
to commercial xanthan gum. Our results indicate that X. arbicola pv. juglandis showed the highest productivity (8.22±1.52 g/L gum). This was followed by X. axonopodis pv. begonia (7.74±1.30 g/L gum), and the control bacterial strain X. campestris NRRL B-1459 (7.46±0.28 g/L gum). X. axonopodis pv. vesicatoria showed the lowest productivity (6.40±0.55 g/L gum). No xanthan gum could be obtained from X. axonopodis pv. dieffenbachia. Xanthan gum produced by X. axonopodis pv. vesicatoria showed the highest viscosity value (428 mPa·sec at 1% solution) in all Xanthomonas strains isolated from plants. 相似文献
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该文对从甘蓝腐烂根部的土壤中分离选育的黄单胞杆菌C2发酵产黄原胶的条件进行了优化。通过单因素试验对培养基(碳源、氮源及碳氮源的浓度)和发酵条件(接种量、发酵时间、温度、pH、装液量)进行优化;为提高黄原胶的胶体性能,在培养中添加不同量的游离丙酮酸。结果表明,液态发酵生产黄原胶的最佳碳源、氮源分别为蔗糖55 g/L,鱼粉10 g/L。黄单胞杆菌C2菌株在接种量为4%,pH值为7,于28 ℃、130 r/min条件下发酵60 h时,黄原胶产量达到34 g/kg。添加游离丙酮酸2 g/L时发酵液黏度为16.0 Pa·s,此时胶体性能最好。 相似文献
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Blanco Y Blanch M Piñón D Legaz ME Vicente C 《Journal of Bioscience and Bioengineering》2005,99(4):366-371
Xanthomonas albilineans, a pathogenic bacterium that produces leaf scald disease of sugarcane, secretes a xanthan-like gum that invades both xylem and phloem of the host. Xanthan production has been verified after experimental infection of stalk segments of healthy plants. Moreover, Gluconacetobacter diazotrophicus is a nitrogen-fixing endosymbiont of sugarcane plants that antagonizes with X. albilineans by impeding the production of the bacterial gum. The physiological basis of this antagonism has been studied using tissues of sugarcane stalks previously inoculated with the endosymbiont, then immobilized in calcium alginate and maintained in a culture medium for Gluconacetobacter. Under these conditions, bacteria infecting immobilized tissues are able to secrete to the medium a lysozyme-like bacteriocin that inhibits the growth of X. albilineans. 相似文献