Amylolytic activity of Thermomonospora fusca

Amylases which produce maltotriose as the major end-product from starch are relatively rare. The thermophilic actinomycete, Thermomonospora fusca, produced an extracellular -amylase which generated maltotriose as 61% of the identified products. The addition of maltotriose to a glucose-adapted exponential phase culture at 55°C in mineral salts medium caused rapid induction of amylase biosynthesis. Addition of glucose to cells growing on starch did not repress amylase biosynthesis because the actinomycete had a marked preference for maltotriose over glucose. The pH and temperature optima for the amylase activity of concentrated, washed extracellular protein were 6.0 and 65°C, respectively, with an energy of activation of 59kJ/mol. The thermostability of the concentrated, washed amylase was increased by the presence of its starch reaction products, but not by added Ca2+.     

Effect of carbon source on growth temperature and fatty-acid composition in Thermomonospora curvata

The growth-temperature range of the actinomycete, Thermomonospora curvata, was influenced by the nature of the soluble carbon sources used, which were derived from cellulose, pectin, starch and xylan. This thermophile had the broadest (38 to 65°C) and narrowest (42 to 59°C) temperature range during growth on cellobiose (from cellulose) and 4-deoxy-Lxxx-threo-t-hexoseulose uronic acid (from pectin), respectively. This substrate-temperature interaction was accompanied by changes in cellular fatty acids: uronic-acid-grown cells had relatively low amounts of branched chain fatty acids (particularly iso-16:0) and high amounts of monounsaturated fatty acids (particularly cis-18:1) compared with cells grown on any other substrate. Moreover, uronic-acid-grown cells could not respond to increased growth temperature by altering the ratio of branched chain fatty acids to straight chain fatty acids.F.J. Stutzenberger is with the Department of Microbiology, Clemson University, Clemson, SC 29634-1909, USA; T.C. Jenkins is with the Department of Animal, Dairy and Veterinary Sciences at the same university.     

Influence of Sphingolipid Bases,Fatty Acids and Tween 80 on the Folate Requirement of Tetrahymena pyriformis*

SYNOPSIS The fatty acids lauric, myristic, and oleic, as well as long-chain bases (LCBs) obtained from sphingolipids, and Tween 80 “spare” the requirement for folate by Tetrahymena pyriformis W. Since LCBs are metabolized by the ciliate to ethanolamine phosphate and fatty aldehydes which can be converted to either fatty acids or fatty alcohols, the latter compounds are used as precursors of phospho- and phosphonolipids and ether phospholipids. It is suggested that lipid biosynthesis is a rate-limiting step in growth of the ciliate as is the folate concentration. Removal of one restraint on growth rate mimics the effect of increased folate concentration. Alternatively, if the enzymes responsible for lipid synthesis are repressible, the presence of exogenous fatty acids would make available more formylmethionyl-tRNA for the initiation of synthesis of other proteins.     

Component-specific stimulation of cellulase secretion in Thermomonospora curvata by the surfactant Tween 80

The non-ionic surfactant, Tween 80, stimulated the secretion of extracellular proteins by 35–140% in Thermomonospora curvata during growth on a variety of substrates. Cellulase secretion was also stimulated but fractionation of extracellular proteins by ion-exchange high performance liquid chromatography showed that this stimulation was largely confined to a single enzymatic component (or group of closely related components) active against crystalline cellulose. The surfactant's effect was more pronounced during growth on cellobiose octaacetate than on the soluble sugar, cellobiose, or on crystalline cellulose.     

吐温80 在深部脏器肿瘤热化疗中的应用研究

目的：研究热增敏剂吐温80在深部肿瘤热化疗中的临床应用疗效。方法：采用吐温80合并热化疗综合治疗晚期肿瘤118例,并与同时期未采用吐温80的热化疗组98例进行比较。膀胱癌复发5例,伴腹水、腹膜转移7例。小剂量化疗用5-FU、丝裂霉素、顺铂等行膀胱灌注或腹腔注射,吐温80浓度为0．2％。肿瘤射频热疗机,f：41MHz。平均随访时间36个月。结果：复发性膀胱癌完全缓解率达60％,血尿消失,3例在12～34月随访期间膀胱镜检查未复发;伴腹水者完全缓解率达85．7％（CR6／7）,中位生存期8．5月,腹痛、腹胀、便血等消失。治疗未引起恶心、呕吐等明显的消化道症状,肝、肾和骨髓功能损害。结论：在肿瘤的热化疗中。合用吐温80不仅可以降低化疗药物的剂量,而且降低热疗时的温度,减少毒副作用,改善症状和体征。     

Effect of Tween 80 on the production of curdlan by Alcaligenes faecalis ATCC 31749

This study aims to investigate the effects of Tween 80 on curdlan production, cell growth, and glucosyltransferase activity. The addition of Tween 80 to the culture medium increased curdlan production. However, curdlan production did not increase further when excessive Tween 80 (>0.3% Tween 80) was added to the culture medium. The addition of Tween 80 to the culture medium did not affect cell growth. The glucosyltransferase activity involved in the curdlan synthesis increased with the increase of Tween 80 concentration. The glucosyltransferase activity did not increase further when excessive Tween 80 (>0.3% Tween 80) was added to the culture medium. Maximum curdlan was observed at day 5 and then levelled off. The biomass continued to increase until the end of the experimental period (6 d). Maximum glucosyltransferase activity was also observed at day 5 and decreased thereafter. The results indicate that the enhanced curdlan production by Tween 80 is highly correlated with glucosyltransferase activity.     

Kinetics of human alcohol dehydrogenase with ring-oxidized retinoids: effect of Tween 80

Human alcohol dehydrogenases (ADH1 and ADH4) actively use retinoids oxidized at the cyclohexenyl ring (4-oxo-, 4-hydroxy-, and 3,4-didehydro-retinoids), which are functional compounds in several cells and tissues (i.e., in human skin). Remarkably, activities with 4-oxo-retinal and 4-hydroxy-retinol (kcat = 2050 min(-1) for ADH4) are the highest among retinoids, similar to those of the best aliphatic alcohols. Thus, ADH1 and ADH4 provide a metabolic pathway for the synthesis of the corresponding retinoic acids. Tween 80, a widely used detergent in the retinoid activity assay, behaves as a competitive inhibitor. The Km values for all-trans-retinol (2-3 microM), estimated in the absence of detergent, are 10-fold lower than those obtained at the usual 0.02% Tween 80. This suggests a contribution of ADH to retinoid metabolism more relevant than previously expected. However, Tween 80 stabilizes retinoids in water solution and provides a reliable and reproducible assay, suitable for comparing different ADHs and different retinoid substrates.     

Effects of Tween 80 and rhamnolipid on the extracellular enzymes of Penicillium simplicissimum isolated from compost

Extracellular enzymes of microorganisms play an important role in the decomposition of macromolecules in the composting process. In this study, the effects of Tween 80 and rhamnolipid on the extracellular amylase, carboxymethyl cellulose enzyme (CMCase), xylanase and protease of Penicillium simplicissimum isolated from compost were investigated during solid-state fermentation. The results showed that the enzyme activities of amylase, CMCase and xylanase were increased by Tween 80 and rhamnolipid, which, however, had a negative effect on the protease production. The stimulative effects on the three enzymes were quite different during the whole fermentation process. Tween 80 and rhamnolipid also increased the fungal biomass slightly. As a result of the enhanced enzyme activities, the organic matter were also improved to different extents by both surfactants, and the decomposition rates of hemicellulose and cellulose were increased about 8.0% and 11.6% by Tween 80 at best, respectively, as well as 5% and 5.5% by rhamnolipid.     

Adsorption Behavior of Tween 80 on Soil in the Presence of CdCl2 and DDT

Batch experiments were conducted to investigate the adsorption behavior of Tween 80 in the systems composed of Tween 80, CdCl₂, and/or DDT. The results show that Cd²⁺ from CdCl₂ is the functional fraction influencing the adsorption of Tween 80 to soil, rather than Cl^?. Moreover, DDT can induce the increase of the critical micelle concentration (CMC) of Tween 80, which further impacts the Tween 80 adsorption behavior. The Tween 80 adsorption to soil in the Cd²⁺-DDT coexisted system follows the Langmuir isotherm, as in the Tween 80-Cd²⁺ or -DDT systems. Cd²⁺ and/or DDT decrease(s) the adsorption capacity of Tween 80 to soil, and the magnitude of decrease is dependent on the concentration of coexisting pollutants. Although DDT has a stronger inhibitory effect on Tween 80 adsorption than Cd²⁺ under the same DDT/Cd²⁺ concentrations, the coexistence of Cd²⁺ and DDT has an antagonistic effect on the adsorption of Tween 80. This effect is impacted by the concentrations of the coexisting pollutants, and is a result of the complex interaction among the three pollutants.     

Tween 80解除乙醇对内切葡聚糖酶(Cx)的抑制作用

通过还原糖量的测定,可知Cx酶在乙醇存在下活力降低。当该体系中加入一定浓度的Tween 80时,Cx酶抗乙醇抑制的能力增强。由紫外光谱及圆二色谱可见,乙醇使Cx酶中α-螺旋含量增加,Tween 80使Cx酶中α-螺旋含量减少,结构变得松散。适量的Tween 80能使Cx酶在乙醇中保持一种具有较高活力的构象。     

藜芦醇和吐温80对白腐菌产木质素降解酶的影响及在偶氮染料脱色中的作用

担子菌PM2在限氮液体培养下,分泌木质素过氧化物酶和锰过氧化物酶;藜芦醇、吐温 80的补充,提高了该菌锰过氧化物酶的产生,获得的最大锰过氧化物酶Mnp酶活为254.2u/L、190.2 u/L,分别是对照的3.4倍和2.5倍。选择三种偶氮染料,在染料体系下,进一步分析藜芦醇、吐温 80对担子菌PM2产过氧化物酶及染料脱色的影响。结果表明,担子菌PM2分泌的锰过氧化物酶Mnp与染料脱色有关,脱色程度受其分子结构特征影响;吐温80的补充,更有利于染料的脱色降解,48h后三种染料均可达到80%以上的脱色率。     

表面活性剂对绿色木霉产纤维素酶影响

利用绿色木霉,以稻草为唯一碳源,采用液态发酵的方法,分别加入生物表面活性剂鼠李糖脂和化学表面活性剂Tween 80,重点研究了生物表面活性剂对绿色木霉产纤维素酶的影响。实验分析了加入不同浓度的表面活性剂时滤纸酶活、羧甲基纤维素酶活、微晶纤维素酶活及酶液的表面张力随时间的变化情况。结果表明,添加鼠李糖脂能够促进绿色木霉产酶,分别使滤纸酶活、羧甲基纤维素酶活、微晶纤维素酶活最大提高了1.08倍,1.6倍和1.03倍。与Tween 80相比,鼠李糖脂促进产酶的效果明显优于Tween 80。     

Effect of Surfactant Tween 80 on the Anaerobic Degradation and Desorption of HCHs and DDX in Aged Soil under Saturated Condition with Low Liquid/Solid Ratio

The application of surfactant Tween 80 was investigated to accelerate the anaerobic degradation of HCHs (α-, β-, γ- and δ-hexachlorocyclohexane) and DDX (p,p′-DDT, o,p′-DDT, p,p′-DDE and p,p′-DDD) in aged soil from a former organochlorine pesticide manufacturing plant under saturated condition with low liquid/solid ratio (liquid/solid ratio = 0.50). The surfactant Tween 80 did not facilitate the degradation of HCHs and DDX in the soil used in this experiment. Subsequent desorption experiment results also showed that the surfactant Tween 80 did not increase the pollutant desorption from the soil. The results in this study are not in accordance with the results reported in previous literature. This difference might be due to the fact that the soils used in this experiment were polluted by HCHs and DDX for more than 20 years, and soil aging reduced the desorption of HCHs and DDX in soil. Furthermore, the surfactants might be adsorbed by soils in low liquid/solid ratio condition.     

Column Flushing of Phenanthrene and Copper (II) Co-Contaminants from Sandy Soil Using Tween 80 and Citric Acid

The clean-up of soils co-contaminated with heavy metals and organic compounds is a contemporary issue of remediation efforts. Column flushing was conducted to investigate the performance of nonionic surfactant and/or organic acid solutions, 4000 mg/L Tween 80 (TW80), and/or 0.04 mol/L citric acid (CA), to enhance the simultaneous removal of phenanthrene and copper (II) from the co-contaminated sandy soil. The flushing effects were compared when TW80, CA, TW80 after CA (CA/TW80), CA after TW80 (TW80/CA), and a mixture of TW80 and CA (TW80-CA) were used as flushing agents. The maximum concentrations of phenanthrene in effluent solutions occurred at 3.3, 4.7, 5.3, and 15.3 h during TW80, TW80/CA, TW80-CA, and CA/TW80 flushing and those of copper (II) at 2.7, 3.3, 3.3, and 14.0 h during CA, CA/TW80, TW80-CA, and TW80/CA flushing, respectively. Phenanthrene was mainly desorbed through partitioning into TW80 micelles in aqueous phase while copper (II) was effectively removed through complexation with CA. The removal efficiencies were up to 81.5%, 5.9%, 99.9%, 91.6%, and 99.8% for phenanthrene, and 0.1%, 76.7%, 85.7%, 78.1%, and 84.4% for copper (II) by TW80, CA, TW80/CA, TW80-CA, and CA/TW80. However, it took a long time to use TW80/CA and CA/TW80 to clean phenanthrene and copper (II) efficiently. The overall removal efficiencies of contaminants in the soil column increased with flushing time in the Sigmoidal Model. The results indicated that a combination of TW80 and CA has potential for in situ clean-up of heavy metals and polycyclic aromatic hydrocarbons (PAHs) from co-contaminated soils.     

60Coγ射线诱变褐色高温单孢菌及其在粪便发酵中的应用研究

本试验以褐色高温单孢菌(Therm om onospora fusca)为出发菌株,通过60Coγ射线诱变孢子悬液,采用透明圈法初筛和摇瓶培养复筛的方法,获得了一株纤维素酶高产菌株AV5,与出发菌株相比,其产酶能力提高1.8倍。接种牛粪发酵后,牛粪中粗纤维含量降低率为32.95%,是接种出发菌株相对降解率的1.7倍。     

Tween 80 influences the production of intracellular lipase by Schizochytrium S31 in a stirred tank reactor

Marine microorganisms are a potential source of enzymes with structural stability, high activity at low temperature and unique substrate selectivity. Thraustochytrids are marine heterotrophic microbes, well known for the production of omega-3 fatty acids. In this study the effect of Tween 80 as a carbon source was investigated with regard to biomass, lipase and lipid productivity in Schizochytrium sp. S31. Tween 80 (1%) and 120 h of incubation were the optimum condition period for biomass, lipid and lipase productivity in a stirred tank reactor. The yields obtained were 0.9 g L⁻¹ of biomass, 300 mg g⁻¹ of lipid and 39 U/g of lipase activity. Sonication was optimised in terms of time and acoustic power to maximise the yield of extracted lipase. The extracted lipase from Schizochytrium S31 was observed to hydrolyse long chain polyunsaturated fatty acids DHA and EPA.     

Effect of sealing and Tween 80 on the antifungal susceptibility testing of essential oils

Concentrations of essential oils showing high volatility decreased substantially in broth and agar media when incubated under open conditions. The decrease in the half life was from 0.7 to 38 hr in broth medium at 27 C. When evaporation was prevented by sealing, MIC values against Aspergillus fumigatus, Candida albicans and Trichophyton mentagrophytes by broth or agar dilution assay were lowered two to eight-fold, as compared with those obtained under open conditions. Addition of Tween 80 caused a rise of the MICs against A. fumigatus by two to four-fold in broth dilution assay, but little affected the MICs in agar dilution assay.     

Effects of CuDIPS and tween 80 on SJL/J tumorigenesis

Plasma copper and zinc levels were measured in SJL/J mice, an inbred strain characterized by a high, spontaneous incidence of reticulum cell sarcoma (RCS). The changes with age in mean concentrations of these metals were consistent with a physiological response that is required for remission of neoplasia. Treatment of SJL/J mice with a copper complex, Cu(II)(3,4-diisopropylsalicylate)₂ (Cu 3,5-DIPS), dissolved in a 10% Tween 80-saline solution revealed a decrease in survival and decline in the incidence of RCS at 52 wk of age. The toxic effects of Cu 3,5-DIPS therapy appeared to be related to the intraperitoneal route of administration and to extracellular deposition of collagen. The inhibitory effect on tumor development was not related to Cu 3,5-DIPS. Rather, Tween 80 was found to be the factor of importance.     

洗涤剂对蚕豆根和叶片的作用

研究了家用洗衣粉对蚕豆根生长、细胞分裂和叶片叶绿素含量的影响。结果表明:不同浓度的洗衣粉均能抑制蚕豆根的生长,降低根尖细胞有丝分裂指数,诱发细胞产生高频率的微核且是明显的时间与剂量效应关系和叶绿素含量明显下降。