葡糖醋杆菌FBFS97产苯乳酸的液态发酵条件优化

该试验以葡糖醋杆菌（Gluconacetobacter sp.）FBFS97为出发菌株,在单因素试验的基础上,通过Plackett-Burman试验、最陡爬坡试验、Box-Behnken响应面法优化菌株产苯乳酸的液态发酵条件。结果表明,优化后的发酵条件为果糖100 g/L、酵母粉40 g/L、K2HPO4 1.2 g/L,pH 4.4,接种量5%（V/V）,装液量24 mL/250 mL,于28 ℃、150 r/min培养8 d。在此优化条件下,苯乳酸产量为217 mg/L,是优化前的3.52倍。     

Some properties of bacterial cellulose produced by new native strain Gluconacetobacter sp. A06O2 obtained from Turkish vinegar

The aim of the study was to isolate and identify an acetic acid bacterial strain having high cellulose yield and to investigate some physicochemical properties of bacterial cellulose (BC). Acetic acid bacteria were isolated by using 62 samples (vinegar, fruit, vegetable, and soil) from different region of Turkey. The cellulose production ability of 153 isolates was determined. A strain (A06O2) having high and stable cellulose yield was identified by biochemical tests and 16S rRNA gene sequencing and compared with type strain Gluconacetobacter xylinus NRRL B‐759. Based on the results, strain A06O2 was named at the genus level as Gluconacetobacter, however, species level identification could not be made. Celluloses from both strains were purified to investigate the physicochemical properties such as thermal properties, solubility in various solvents, elemental composition, tensile properties, and surface properties by FTIR and SEM. The results showed that the cellulose samples of two bacterial strains differed in the physicochemical properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

葡糖醋杆菌的研究进展

葡糖醋杆菌是醋酸菌科的一个重要属,与人类关系密切,属下部分菌株能产生细菌纤维素或乙酰胶,而另一些菌株则是植物固氮菌.综述了葡糖醋杆菌的研究进展,重点介绍了其生理生化特征、分类进展、主要应用及鉴定.     

Effect of oenological practices on microbial populations using culture-independent techniques

Sulphur dioxide (SO(2)) addition and yeast inoculation are well-established practices in winemaking for restricting the growth of indigenous yeasts and bacterial populations. The effect of these oenological practices on wine microbial populations has been evaluated using culture-independent methods. These are quantitative PCR (qPCR) for the enumeration of yeasts, lactic acid bacteria (LAB) and acetic acid bacteria (AAB), and PCR-DGGE to determine the yeast and bacteria species diversity. The PCR-DGGE method detected a low yeast and bacteria species diversity. On the contrary, the specificity of the primers designed for the qPCR allowed that minor microbial groups such as Hanseniaspora were accurately quantified regardless of a large presence of other microbial groups such as Saccharomyces. From an oenological point of view, inoculation increased the proportion of Saccharomyces vs. non-Saccharomyces in a shorter time. Hanseniaspora increased during the first phase and decreased during the latter phases of the process, especially in the sulphited fermentations. Both yeast inoculation and SO(2) kept the LAB populations at very low level, while the AAB populations were hardly affected by these two practices.     

红茶菌对饮食诱导肥胖小鼠体重控制的研究

本实验以高脂饲料喂食的C57BL/6J 小鼠为动物模型,进行为期11 周的实验,以小鼠体重增加、体内脂肪含量、血清脂质水平、小鼠脏器系数、肝组织形态、脂肪组织形态为检测指标,研究茶叶浸出液、A 4(Gluconacetobacter sp. A4)发酵液、红茶菌原液发酵液对小鼠体重控制的影响。结果表明,茶叶浸出液、A4 发酵液、红茶菌原液发酵液,均能够减缓小鼠体重增长的进程,减少小鼠体内脂肪含量,并能够减少脂肪在肝脏中的蓄积以及减缓脂肪细胞增大的进程。其中,以A4 发酵液的效果最为明显,表现出对饮食诱导小鼠的很好的体重控制的作用。     

葡糖醋杆菌J2-1静态发酵生产细菌纤维素的培养基优化

为提高葡糖醋杆菌（Gluconacetobacter）J2-1发酵生产细菌纤维素的产量,采用静态发酵方式,利用单因素试验对发酵培养基的碳源、氮源、乙醇、有机酸及无机盐进行优化,并在此基础上选取葡萄糖、MgSO4·7H2O和酵母粉添加量进行正交试验优化。结果表明,发酵培养基最优组分为：葡萄糖80 g/L、酵母粉18 g/L、乙醇2%（V/V）、Na2HPO4·12H2O 3 g/L、乳酸2 g/L、MgSO4·7H2O 0.4 g/L。在此优化发酵培养基条件下,葡糖醋杆菌J2-1静态发酵生产细菌纤维素产量达到9.34 g/L,是优化前的1.89倍。     

木葡糖酸醋杆菌发酵黄酒糟酶解液产细菌纤维素的研究

该研究利用单因素比较法,分别考察了培养基组成、培养条件及黄酒糟酶解条件对木葡糖酸醋杆菌（Gluconacetobacter xylinus）发酵产细菌纤维素的影响。结果表明,木葡糖酸醋杆菌BC19-2产细菌纤维素的培养基组成为黄酒糟酶解液6%、红茶2 g/100 mL;培养条件为初始pH 6.0、培养温度30℃、接种量6%;黄酒糟酶解条件为酶解时间3 h,黄酒糟酶解液体积分数90%。在此优化条件下,细菌纤维素产量最高为26.5 g/L,且性能较好,为低成本的细菌纤维素生产奠定了基础。     

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。     

利用糖蜜制备细菌纤维素的研究

细菌纤维素（BC）是一类由微生物产生的纤维素。细菌纤维素以其独特的物理和化学性质被广泛应用于医药、食品、造纸、纺织等领域。然而，BC应用的最大挑战是其生产成本，尤其是发酵生产碳源的成本相对较高。以相对廉价的糖蜜为原料，研究比较了不同预处理方法（硫酸-热处理、热处理和未处理）以及生产菌种（木葡糖醋杆菌和红茶菌）对细菌纤维素产量的影响。结果表明，硫酸-热处理之后的糖蜜获得的细菌纤维素产量最高，可达6．0g/L，比用葡萄糖制备细菌纤维素的产量提高了78％。当以红茶菌为菌种，细菌纤维素的产量可达12．0g/L，是木葡糖醋杆菌作为菌种的两倍。与葡萄糖和果糖相比，糖蜜制备的细菌纤维素同样具有三维网状结构，但是含水率较低，杨氏模量较小。     

Yield and soil nutrient balance of a sugarcane plant–ratoon system with conventional and organic nutrient management in sub-tropical India

A 3-year field trial of sugarcane, comprising 11 treatment combinations of different organic manures with and without Gluconacetobacter diazotrophicus (Gd), NPK and an absolute control, on an inceptisol was conducted to assess the effect of these treatments on sugarcane total and economic yield, the benefit:cost ratio, nutrient balance and soil quality in a sugarcane plant–ratoon system. The highest cane yield (78.6 t ha⁻¹) was recorded in the plant crop given vermicompost + Gd, whereas ratoon yields (first and second) were highest (80.8 and 74.9 t/ha⁻¹, respectively) with sulphitation press mud cake (SPMC) + Gd. In both plant and ratoon crops, a number of different organic manures produced the highest cane yield that was also statistically similar to those obtained with using the recommended NPK levels (76.1, 78.2 and 71.7 t/ha for plant crop and subsequent two ratoons, respectively). The highest benefit:cost (B:C) ratio in the plant and two ratoon crops (1.28, 2.36, 2.03 respectively) were obtained with the addition of SPMC + Gd. The nutrient balance for NPK in the soil was highest in the SPMC + Gd treatment. The highest increase in organic C (94%) and total N (87%), in comparison to the initial level, and soil microbial biomass C (113%) and soil microbial biomass N (229%), in comparison to the control treatment, was recorded with the addition of SPMC + Gd. The maximum decrease in soil bulk density (BD) (12%) with an increase in soil aggregate (17%) and water infiltration rate (35%) was obtained with the addition of SPMC. Overall, the sugarcane crop responded well to different organic manures in a multiple ratooning system with a better economic output and improved soil quality. Strategic planning in terms of an integrated application of these manures with inorganic chemicals will not only sustain our soils but will also be beneficial for our farmers in terms of reducing their dependence and expenditure on chemical fertilizers.