利用根霉和假丝酵母联合发酵生产甜酒的研究

在研究从泰国优质甜酒曲中分离出来的假丝酵母菌株L1、L2和我国根霉菌株Q的生长特性的基础上,进行了不同配比的甜酒试饭试验。结果表明:当假丝酵母菌株L2接种量为1%,根霉菌株Q接种量为3%时,最有利于试饭时产糖。     

工业糖化酶固态发酵木薯渣制取单细胞蛋白饲料的研究

木薯是广西的主要经济作物之一,主要用于生产淀粉,其副产物木薯渣中仍残留大量淀粉,弃之会造成浪费和环境污染.本研究旨在探索一条利用木薯渣的新途径.以木薯渣为原料,利用工业糖化酶和产朊假丝酵母(Candida utilis)固态发酵,制取单细胞蛋白饲料.结果表明:通过高压灭菌预处理物料效果较好;氮源的添加量分别为:尿素3%,硫酸铵6%;通过单因素正交实验得最佳工艺条件为:糖化酶用量为4%,含水量为70%,发酵时间72 h,酵母接种量10%.粗蛋白质含量由底物的11.59%提高到产物的28.28%,提高了16.69个百分点.与其它方法比较,本方法利用工业糖化酶,发酵过程易于控制,不需要选育淀粉分解菌,使培养成本降低,具有一定的工业应用潜力.     

纯钛镀制类金刚石薄膜的真菌黏附与细胞毒性研究

采用脉冲电弧离子镀膜法在纯钛表面制备类金刚石膜(DLC)并在口内使用.利用表面粗糙度仪、分光光度仪、扫描电镜分别研究镀制类金刚石膜、氮化钛膜、阳极氧化膜以及未表面处理的齿科纯钛试件表面白色念珠菌黏附情况和细胞毒性.结果表明,类金刚石膜表面菌数最少,粗糙度增加值和反射率下降值最小.类金刚石膜表面的L-929细胞增值良好.类金刚石膜可以显著降低纯钛义齿表面的白色念珠菌黏附量,可以承受日常口腔刷牙的磨耗应用于人体,对齿科修复体具有大的潜在应用价值.     

The yeast flora of stored ready-to-use carrots and their role in spoilage

Spoilage of ready-to-use grated raw carrots packaged in polymeric films and stored at 10°C was investigated for involvement of yeasts. Cryptococcus albidus was only isolated during the first 3 days of storage, increasing to levels of 10⁵–10⁶g^-1. Candida lambica was more commonly isolated after 3–7 days of storage, and reached 10⁷–10⁸g^-1 after 12 days. Candida sake was present throughout storage, increasing from 10⁵–10⁶ after 3 days to 10⁷–10⁸ after 12 days. In some samples, Candida parapsilosis and Candida tropicalis were also isolated at levels similars to C. sake . All the yeasts isolated at the end of storage were fermentative species and their metabolism was characterized with a Warburg apparatus. Neither the number of yeasts nor the composition of the yeast flora were related to the deterioration of the product. Although Candida lambica inoculated on grated carrots caused spoilage after 12 days at 10°C, the high O₂ permeable film was most effective in reducing exudate.     

双株酵母混合培养处理酒精蒸馏废水生产饲料酵母的研究

以薯干酒精废水为原料,采用双株耐酸性假丝酵母,在优化试验条件下,16 000 L发酵罐混合培养,结果表明,在培养温度32~33℃、培养时间8~9 h,pH值4,适当添加营养盐和通风供氧情况下,干酵母平均得率为11.26 g/L,废水CODcr平均去除率为62.74%,pH值平均由3.8升至6.3,大大减轻了环境污染,经处理后的废水可重复用于酒精生产,所产干酵母蛋白质含量51.3%,是一种优良的饲料添加剂。     

山毛豆发芽过程中营养成分的变化

对山毛豆发芽过程中营养成分含量的变化进行分析。结果表明:脂肪和还原糖含量随时间的延长而下降,而蛋白质、VC和异黄酮含量在发芽后均较未发芽时增加。其中VC的含量增加最多,从第4天到第5天增幅达到了200%,蛋白质含量在发芽初期持续上升,第4天的时候达到最大值349.1 mg/g,还原糖含量在第4天时达到最大值64.1 mg/g,以后又逐渐减少,到了第9天下降至46.1 mg/g。脂肪的含量在1-4 d下降得较快,在第4天的时候下降幅度达到24.48%。总糖含量在第2天下降幅度达28.92%。第9天下降至6.82%,比发芽前减少38.56%。异黄酮含量在发芽4 d时达到最大7.8 mg/g,以后有缓慢下降。     

Antimicrobial Efficacy and Permeability of Various Sealing Materials in Two Different Types of Implant–Abutment Connections

The presence of a microgap along an implant–abutment connection (IAC) is considered the main disadvantage of two-piece implant systems. Its existence may lead to mechanical and biological complications. Different IAC designs have been developed to minimise microleakage through the microgap and to increase the stability of prosthodontic abutments. Furthermore, different sealing materials have appeared on the market to seal the gap at the IAC. The purpose of this study was to evaluate the antimicrobial efficacy and permeability of different materials designed to seal the microgap, and their behaviour in conical and straight types of internal IACs. One hundred dental implants with original prosthodontic abutments were divided into two groups of fifty implants according to the type of IAC. Three different sealing materials (GapSeal, Flow.sil, and Oxysafe gel) were applied in the test subgroups. The contamination of implant–abutment assemblies was performed by a joint suspension containing Candida albicans and Staphylococcus aureus. It was concluded that the IAC type had no significant influence on microleakage regarding microbial infection. No significant difference was found between the various sealing agents. Only one sealing agent (GapSeal) was found to significantly prevent microleakage. A complete hermetic seal was not achieved with any of the sealing agents tested in this study.