聚乙烯醇降解菌的选育及降解特性研究

从印染废水及污水处理厂污泥中分离得到7株聚乙烯醇(PVA)降解菌，经紫外线诱变，获得高活性变异菌株UV2．对UV2进行PVA降解试验，确定了其降解特性参数，并与出发菌株B自的降解性能相比较．研究表明，诱变菌株W2对模拟废水中PVA的降解速率及降解活性均明显高于出发菌株B白，且适应环境的能力更强．在最佳降解条件下，对PVA的降解率达93％以上，比出发菌株提高了30％．     

试论聚乙烯醇浆料的环保性能(上)

为了探讨聚乙烯醇浆料的环保性能,介绍了环保型纺织浆料的判别原则,分析了PVA浆料的毒性、生物降解性和对环境的影响,阐述了PVA浆料的生物降解机理和PVA降解酶难以商业化的原因.指出,PVA浆料的生物降解性较差,可以通过对PVA降解菌进行驯化这一途径,提高PVA的生物降解性.     

试论聚乙烯醇浆料的环保性能(下)

为了探讨聚乙烯醇浆料的环保性能,介绍了环保型纺织浆料的判别原则,分析了PVA浆料的毒性、生物降解性和对环境的影响,阐述了PVA浆料的生物降解机理和PVA降解酶难以商业化的原因.指出:PVA浆料的生物降解性较差,可以通过对PVA降解菌进行驯化这一途径,提高PVA的生物降解性.     

聚乙烯醇降解酶在纯PVA上浆棉织物退浆中的应用

针对目前纺织用聚乙烯醇浆料存在生物降解性差的问题,采用聚乙烯醇降解酶对PVA上浆的棉织物进行退浆,它可以高效分解织物上的PVA浆料,显著降低退浆废水的处理成本。从酶活方面对PVA降解酶粗酶液的酶学性质进行研究,并将该酶用于纯PVA上浆的棉织物退浆过程中。实验结果表明,PVA降解酶的适宜反应条件为pH值7-8,温度30℃,反应时间3 h,且可对PVA进行降解。当采用PVA降解酶退浆时,浆液中PVA含量与棉布上残留PVA量之和小于100%,而采用缓冲溶液和热水退浆,PVA总量变化不大。     

生物降解聚乙烯醇研究进展

聚乙烯醇(PVA)在纺织工业中被广泛用作上浆剂.经PVA上浆的棉织物必须经过退浆处理,以增加棉织物对水的吸收性.相对于传统的热水退浆法,生物降解PVA可以节省较多的热能,其生物分解性好,没有二次污染.因此,很多研究者致力于PVA的生物降解的研究并已取得一定的研究成果.在总结文献的基础上,重点介绍了PVA降解菌的培养特性、共生关系,PVA降解酶的性质及对PVA的生物降解过程,PVA降解酶相关基因的研究进展,并给出了PVA降解酶将来可能的发展方向.     

末端限制性酶切片段长度多态性分析一个能够降解聚乙烯醇的混合体系

用末端限制性酶切片段长度多态性(Terminal restriction fragment length polymorphism,T-RFLP)技术在DNA水平分析了一个能够彻底降解1 g/L聚乙烯醇(PVA)1799的混合微生物体系在降解PVA过程中,混合体系的微生物种类及数量的变化.并用高效液相法(HPLC)对该混合体系降解PVA1799的中间产物进行了初步研究,发现在降解过程中有乙酸及甲基酮类物质生成,提出了该混合体系降解PVA1799的可能途径.     

棉织物的复合酶退浆工艺

使用前期研究中筛选出的能高效降解聚乙烯醇PVA1799的混合菌系,制得PVA降解酶。用该PVA降解酶与淀粉酶复配,对混合上浆棉织物协同退浆。通过考察酶用量、pH值、温度、时间等因素对棉织物退浆效果的影响,得到较优的退浆工艺:C_(淀粉酶)/C_(PVA酶)为1/10,p H值为6.0,温度50℃,时间30 min。在此条件下,应用PVA_(降解酶)与淀粉酶协同退浆,棉织物退浆率与碱退浆相当;再结合果胶酶精练后,织物润湿性得以改善,且断裂强度高于碱法前处理。     

碳、氮源对PVA降解混合体系降解能力的影响及PVA降解机理初探

以能完全降解1g／LPVA的一个混合体系为研究对象，研究了碳、氮源对该混合体系降解PVA的影响。实验表明，补充有机氮源有利于混合体系菌体的生长，并且能提高混合体系对PVA的降解能力。进一步的研究发现，其它碳源的补充有利于菌体的生长，但对混合体系降解PVA产生一定的抑制作用。根据初步研究结果推断，该混合体系所产的PVA降解酶主要结合在细胞膜上，部分PVA进入细胞后被降解。     

原生质体融合技术选育高效菌株降解聚乙烯醇

从自然界中分离聚乙烯醇(PVA)的降解细菌，经紫外线诱变，得到两株具有单重抗药性的突变菌株S7(Str^s，Kan^r)和K15(Str^r，Kan^s)，两者对PVA的去除率分别达到52％和58％．将S7和K15作为亲本菌株进行原生质体融合，并对融合条件进行优化，融合子F4菌株对PVA去除率达到79．9％，将其培养成活性污泥后，PVA去除率可达87％，是普通活性污泥的三四倍．     

聚乙烯醇双酶降解工艺条件优化

作为纺织和造纸工业中的重要污染物,聚乙烯醇(PVA)的高效降解广受关注。为提高PVA的降解效率,本研究中对PVA脱氢酶(PVADH)和氧化型PVA水解酶(OPH)降解PVA的工艺条件进行了优化。通过Box-Behnken实验和响应面分析,确定PVA双酶降解的反应条件为:PVA 1 g/L,PVADH 123 U/mL,OPH 12 U/mL,pH 7.7,酶解温度41℃,Ca~(2+)浓度1 mmol/L,PQQ浓度6μmol/L。在该条件下PVADH和OPH共同催化4 h,PVA降解率达到95%以上。上述结果表明,PVADH和OPH双酶能有效降解PVA。研究结果将促进酶法降解PVA的工业化应用。     

浓香型大曲白酒窖泥微生物研究进展

基于传统微生物技术和现代生物学技术对白酒窖泥微生物的研究,阐述了研究白酒酿造微生物所运用生物学技术的各种方法、原理及对窖泥微生物的研究现状。主要对宏基因组、聚合酶链式反应-变性梯度凝胶电泳（PCR-DGGE）技术、高通量测序技术等现代分子生物技术在窖泥微生物代谢活动和群落代谢机制研究中的应用进行了综述,为解决白酒生产中遇到的实际问题提供了理论指导。     

Biodegradation of polyvinyl alcohol by Flammulina velutipes in an unsubmerged culture

To examine the biodegradation of polyvinyl alcohol (PVA), Flammulina velutipes (Enokitake) was cultivated in both liquid and quartz sand cultures. After incubation, discoloration of an iodide solution was observed in the filtrate recovered from the quartz sand culture, whereas discoloration was not observed in the filtrate recovered from the liquid culture. Gel permeation chromatography showed that the PVA recovered from the quartz sand culture was depolymerized and yielded low-molecular-weight portions. Infrared and ultraviolet spectrometry indicated that there was formation of carbonyl groups, and NMR analysis showed that the syndiotactic portions of PVA were preferably attacked. Based on these results, an unsubmerged cultivation of F. velutipes was considered suitable for the biodegradation of PVA, probably because the mycelium was sufficiently developed to produce PVA-degrading enzymes.     

Monitoring of the microbial communities involved in the soy sauce manufacturing process by PCR-denaturing gradient gel electrophoresis

Soy sauce is a traditional seasoning produced through the fermentation of soybeans and wheat using microbes. In this study, the microbial communities involved in the soy sauce manufacturing process were analyzed by PCR-Denaturing Gradient Gel Electrophoresis (PCR-DGGE). The bacterial DGGE profile indicated that the bacterial microbes in the koji were Weissella cibaria (Weissella confusa, Weissella kimchii, Weissella salipiscis, Lactobacillus fermentum, Lactobacillus plantarum, Lactobacillus iners, or Streptococcus thermophilus), Staphylococcus gallinarum (or Staphylococcus xylosus), and Staphylococcus kloosii. In addition to these bacteria, Tetragenococcus halophilus was also detected in the mash during lactic acid fermentation. The fungal DGGE profile indicated that the fungal microbes in the koji were not only Aspergillus oryzae but also several yeasts. In the mash, Zygosaccharomyces rouxii appeared in the early fermentation stage, Candida etchellsii (or Candida nodaensis) and Candida versatilis were detected at the middle fermentation stage, and Candida etchellsii was detected at the mature fermentation stage. These results suggest that the microbial communities present during the soy sauce manufacturing process change drastically throughout its production. This is the first report to reveal the microbial communities involved in the soy sauce manufacturing process using a culture-independent method.     

Phosphate-solubilizing Microbe from Saprists Peat Soil and their Potency to Enhance Oil Palm Growth and P Uptake

Constraint of peat land utilization is low nutrent content. This research was conducted to determine the potency of phosphate solubilizing microbes (PSM) in solubilizing P yto increase the growth and P uptake of plant in peat soil. Based on their ribosomal DNA the best PSM were identified as Burkholderia gladioli nd Penicillium aculeatum that yield the highesr growth aphosphate uptake of oil palm seedling.     

浓香型白酒发酵过程中酒醅的微生物区系分析

为了比较准确地把握浓香型白酒发酵过程中酒醅微生物区系的多样性及消长规律 ,以全兴酒厂正常生产窖池为试验窖 ,采用特制取样器跟踪发酵过程取样 ,对窖池酒醅中不同空间位置的微生物区系进行了动态分析 ,初步弄清了浓香型白酒窖池酒醅不同层面、不同区域微生物数量的分布及变化趋势 ,并通过形态、生理学特性的分析比较以及 16SrDNA、18SrDNA序列分析等 ,对发酵过程中主要微生物类群进行了分类鉴定     

基因芯片技术在食品微生物检测和研究中的应用

基因芯片技术为全面快速准确地分析鉴定水体、空气、土壤和食品等环境中的各种微生物提供了一种崭新的技术工具和平台。本文扼要综述了近年来基因芯片技术在食品微生物检测中的研究进展,着重讨论基因芯片检测微生物的基本原理与步骤, 样品的采集制备和分离纯化食品微生物DNA的方法和要求,基因芯片技术检测食品常见致病菌及其在食品微生物研究中的应用,该技术在食品微生物中的应用现状和前景。     

适当延长制曲中挺温度时间对制酒生产的影响

曲药培养过程中适当延长中挺温度时间,对曲药酶活力有适当的抑制作用,从而减小白酒中因酶活力过高而给生产和产酒质量带来的不利影响。适当延长中挺温度时间,有利于对曲药中微生物的驯化,增加微生物对生产环境的适应性;控制曲药的酶活和发酵力,更加有益于生产;增加曲药的复合香。(孙悟)     

泸香型白酒窖泥微生物生态功能研究进展

窖泥中含有大量的功能微生物,其作为白酒生香功能微生物的繁殖载体,在泸香型白酒的生产过程中发挥了重要作用。窖泥微生物是决定浓香型白酒风格的关键因素,目前基于传统微生物技术和现代生物学技术(如以聚合酶链式反应(PCR)技术、基因组学技术、高通量测序技术)等对白酒窖泥微生物的研究,已经取得了丰富的研究成果,检测到越来越多的窖泥微生物,发现微生物多样性越来越高。本文综述了窖泥微生物群落结构的多样性、窖泥功能微生物对白酒风味的贡献、新老窖泥中无机成分的质量评价,并针对研究存在的问题提出未来研究方向:进一步发掘窖泥微生物资源,提升功能微生物的应用潜力,以期为白酒生产中遇到的实际问题提供理论指导。     

Phage-based technologies for highly sensitive luminescent detection of foodborne pathogens and microbial toxins: A review

Foodborne pathogens and microbial toxins are the main causes of foodborne illness. However, trace pathogens and toxins in foods are difficult to detect. Thus, techniques for their rapid and sensitive identification and quantification are urgently needed. Phages can specifically recognize and adhere to certain species of microbes or toxins due to molecular complementation between capsid proteins of phages and receptors on the host cell wall or toxins, and thus they have been successfully developed into a detection platform for pathogens and toxins. This review presents an update on phage-based luminescent detection technologies as well as their working principles and characteristics. Based on phage display techniques of temperate phages, reporter gene detection assays have been designed to sensitively detect trace pathogens by luminous intensity. By the host-specific lytic effects of virulent phages, enzyme-catalyzed chemiluminescent detection technologies for pathogens have been exploited. Notably, these phage-based luminescent detection technologies can discriminate viable versus dead microbes. Further, highly selective and sensitive immune-based assays have been developed to detect trace toxins qualitatively and quantitatively via antibody analogs displayed by phages, such as phage-ELISA (enzyme-linked immunosorbent assay) and phage-IPCR (immuno-polymerase chain reaction). This literature research may lead to novel and innocuous phage-based rapid detection technologies to ensure food safety.