固定化地衣芽孢杆菌R08吸附Pd^2＋的研究

比较了四种固定菌体的方法。结果以聚乙烯醇一海藻酸钠包埋地衣芽孢杆菌(Bacillus licheniformis)R08菌体,制成直径约2mm的颗粒,然后用磷酸缓冲液处理,5％戊二醛溶液交联,制得的固定化R08菌体(PIRB)对Pd^2 的吸附率最高。PIRB吸附Pd^2 的最适pH值为3．5。吸附作用是一种迅速的过程。在5℃—60℃范围内,吸附作用不受温度的影响。溶液中的PIRB含量和Pd^2 起始浓度影响吸附作用,在0．5gPIRB/L、200mg Pd^2 /L、pH3．5和30℃条件下,吸附60min,吸附量达94．7mg／g干重。吸附过程符合Freundlich和Langmuir吸附等温式。Au^3 等离子抑制PIRB对Pd^2 的吸附。用1mol/L HCl洗脱PIRB所吸附的Pd^2 ,解吸率为83．6％。在填充床反应器中,在流速2mL/min、100mgPd^2 /L、2．5g PIRB(干重)、pH3．5和30℃条件下,反复吸附—解吸附,最初5批的饱和吸附量、吸附率和解吸率分别平均为44．3mgPd^2 /g干重、89．4％和82．5％。在与上述相同的条件下,PIRB对废钯催化剂处理液中的Pd^2 的吸附量为41．3mg／g,吸附率为88．6％。     

固定化啤酒酵母废菌体吸附Pd2+的研究

用2％海藻酸钠与l％明胶混合为包埋剂固定啤酒酵母废菌体。SEM、X-射线能谱和TEN研究结果表明,该固定化啤酒酵母废菌体(ISCWB)颗粒中的菌体分布较均匀,ISCWB不仅能吸附Pd^2 ,而且能将Pd^2 还原成Pd^0。ISCWB吸附Pd^2 的最适pH值为3．5。在30℃～70℃范围内,吸附作用不受温度的影响。吸附作用是一个较快的过程,在最初的5min内吸附量可达最大吸附量的36％。吸附作用受ISCWB浓度、Pd^2 起始浓度和共存离子的影响。在起始Pd^2 浓度100mg/L,ISCWB浓度1．8g/L、pH3．5和30℃条件下振荡吸附90min,吸附量为40．6mg/g.以0．5mol／L盐酸作为解吸剂解吸率达98．7％。连续吸附与解吸附试验结果表明,ISCWB的最大饱和吸附量为46．3mg/g,解吸率为98％。     

细菌吸附Pd2+的研究

从不同来源的细菌菌株中筛选获得一株吸附Ｐｄ＾２＋能力较强的菌株Ｒ０８,经鉴定为地衣芽孢杆菌（Ｂａｃｉｌｌｕｓ ｌｉｃｈｅｎｉｆｏｒｍｉｓ）Ｒ０８。Ｒ０８死菌体吸附Ｐｄ＾２＋的最适ｐＨ值３．５,其吸附作用是一种快速而非依赖温度的过程。吸附作用受菌体浓度和Ｐｄ＾２＋浓度影响。在起始Ｐｄ＾２＋浓度２００ｍｇ／Ｌ、菌浓度０．４ｇ／Ｌ、ｐＨ３．５和３０℃条件下,吸附４５ｍｉｎ,吸附量为２２４．８ｍｇ／ｇ。透     

细菌吸附Pd2+的研究

从不同来源的细菌菌株中筛选获得一株吸附Pd²⁺能力较强的菌株R08,经鉴定为地衣芽孢杆菌(\%Bacillus licheniformis)\%R08。R08死菌体吸附Pd²⁺的最适pH值为3.5,其吸附作用是一种快速而非依赖温度的过程。吸附作用受菌体浓度和Pd²⁺浓度影响。在起始Pd²⁺浓度200mg/L\,菌浓度0.4g/L\,pH35和30℃条件下,吸附45min,吸附量为2248mg/g。透射电镜观察显示,R08死菌体能够还原Pd²⁺成Pd0颗粒。红外光谱分析表明,细胞壁上的COO－和ＨＰＯ４２－基团可能与Pd²⁺的生物吸附有关。     

固定化啤酒酵母废菌体吸附Pd2+的研究

用2％海藻酸钠与1％明胶混合为包理剂固定啤酒酵母废菌体。SEM、X-射线能谱和TEM研究结果表明,该固定化啤酒酵母废菌体(ISCWB)颗粒中的菌体分布较均匀,ISCWB不仅能吸附Pd²⁺,而且能将Pd²⁺还原成Pd0。ISCWB吸附Pd²⁺的最适pH值为3.5。在30℃～70℃范围内,吸附作用不受温度的影响。吸附作用是一个较快的过程,在最初的5min内吸附量可达最大吸附量的36％。吸附作用受ISCWB浓度、Pd²⁺起始     

地衣芽孢杆菌原生质体电转化方法的研究

为了解决地衣芽孢杆菌(Bacillus licheniformis)工业菌株难以转化的问题,将原生质体制备、电穿孔和原生质体再生技术相结合,建立了一种地衣芽孢杆菌原生质体电击转化方法。在对菌体生长状态、溶菌酶作用时间、电转电压、渗透压保护剂等条件进行优化后,试验了将不同类型的表达载体,即游离型质粒p GJ103(3.3kb)和整合型质粒p AX01(9.3kb),分别转入两株地衣芽孢杆菌工业生产菌株B.licheniformis CICC 10181和B.licheniformis CICC 20204中。实验结果显示,对数生长期后期的菌体酶解40min后制备的地衣芽孢杆菌原生质体得率为96%,再生率达25%以上。原生质体与质粒DNA在最适电压0.6k V/mm下电击转化,并以0.5mol/L山梨醇或甘露醇作为渗透压保护剂进行再生培养后,最终游离型质粒的转化率可达0.88×102~1.1×102CFU/μg p GJ103,整合型质粒的转化率达到0.45×102~0.52×102CFU/μg p AX01。该方法为地衣芽孢杆菌野生工业菌株的遗传改造提供了一种新的、高效的转化手段。     

地衣芽孢杆菌的应用现状及展望

地衣芽孢杆菌是一种革兰氏染色呈阳性的益生菌,俗称整肠生,其细胞呈杆状排列、单生,能产生近中生的芽孢,形态为椭圆状,孢囊稍膨大。它在生活中主要应用于饲料添加、医药、工业等方面,本文综述了地衣芽孢杆菌的主要应用。     

不同抑制剂对地衣芽孢杆菌生长影响的研究

报道了地衣芽孢杆菌对不同抑制剂的反应。结果表明,当ｐＨ在７．０时,链霉素浓度为５００μｇ／ｍＬ,青霉素浓度１０００μｇ／ｍＬ,头孢唑啉钠浓度为５００μｇ／ｍＬ时对地衣芽孢杆菌有明显抑制作用。这对正确使用地衣芽孢杆菌制剂（整肠生）提供了可靠的理论依据。     

胶质芽孢杆菌对Zn2+、Cd2+的生物吸附

目的:考察胶质芽孢杆菌对Cd2 、Zn2 的耐受能力.方法:通过改变培养条件及吸附条件研究胶质芽孢杆菌对Cd2 、Zn2 的生物吸附性能.在此实验基础上,在含有Cd2 、Zn2 的培养基中对胶质芽孢杆菌进行不同浓度梯度驯化,提高其对Cd2 Zn2 的生物富集能力.结果:胶质芽孢杆菌最大Cd2 耐受浓度在100mg·L-1左右,最大Zn2 耐受浓度在100～110mg·L-1.通过改变吸附条件,考察吸附时间、吸附pH值、菌体投加量对其生物吸附性能的影响,结果表明:当Cd2 、Zn2 浓度均为5mmol·L-1,菌投量分别为40.0gdry cell·L-1、29.8gdry cell·L-1时,胶质芽孢杆菌对Cd2 、zn2 的吸附率分别可达87.45%、97.50%.胶质芽孢杆菌经重金属离子浓度梯度驯化培养数代,经过8、9代的驯化,对Cd2 、Zn2 吸附性能均有改善.结论:胶质芽孢杆菌经过驯化,在适宜的吸附条件下可以对Cd2 、Zn2 进行有效的生物吸附,在处理重金属离子废水方面有潜在的应用前景.     

地衣芽孢杆菌20386株特性及其生态制剂的研究

作者在1986年从1例正常待产妇女的阴道中,分离出1株革兰氏阳性需氧地衣芽孢杆菌(Bacillus licheniformis)BL_(20386)株。该株体外试验(In Vitro Test)对金葡萄和白念珠菌具有明显的拮抗作用;体内试验(In vivo Test)表明具有调整肠道菌群和治疗作用。对BL_(20386)株的生物特性、生物毒性、生物拮抗、生物耗氧研究显示了安全、有效的指征,符合生态制剂生产用菌株。用该菌株制备的生态制剂—整肠生, 治疗婴幼儿感染性腹泻和非感染性腹泻治愈率分别为70％和85％;成年人细菌感染性腹泻3天治愈率为50％,5天为81％,7天为96.2％。整肠生具有治疗和预防肠道疾病的前景。     

土生鳞伞对Cd2+的吸附特性

以土生鳞伞（Pholiota terrestris Overh.）子实体为生物吸附剂吸附水溶液中的Cd2+,分析吸附剂用量、初始pH值、初始重金属浓度、反应时间这4个因素对吸附的影响,并采用Langmuir和Freundlich等温吸附模型及准一级、准二级动力学模型拟合土生鳞伞的生物吸附特性.结果表明:水溶液中Cd2+...     

固定化海洋微藻对污水中Ni2+的吸附

采用海藻酸钠包埋小球藻和叉鞭金藻,制得含藻细胞的固定化胶球,用其对Ni^2 进行生物吸附,研究了固定化小球藻和固定化叉鞭金藻对污水中Ni^2 的吸附率。结果表明：对于同一种固定化微藻,处于对数生长中期时对Ni^2 吸附效果较好,且吸附过程主要在前4h完成;Ni^2 浓度越大,吸附率越高;固定化微藻比悬浮态微藻吸附率高;在相同的实验条件下,固定化小球藻比固定化叉鞭金藻吸附率高。     

Enhancement of Lead(II) Biosorption by Microalgal Biomass Immobilized onto Loofa (Luffa cylindrica) Sponge

A unicellular green microalga, Chlorella sorokiniana, was immobilized on loofa (Luffa cylindrica) sponge and successfully used as a new biosorption system for the removal of lead(II) ions from aqueous solutions. The biosorption of lead(II) ions on both free and immobilized biomass of C. sorokiniana was investigated using aqueous solutions in the concentration range of 10–300 mg/L. The biosorption of lead(II) ions by C. sorokiniana biomass increased as the initial concentration of lead(II) ions increased in the medium. The maximum biosorption capacity for free and immobilized biomass of C. sorokiniana was found to be 108.04 and 123.67 mg lead(II)/g biomass, respectively. The biosorption kinetics were found to be fast, with 96 % of adsorption within the first 5 min and equilibrium reached at 15 min. The adsorption of lead(II) both by free and immobilized C. sorokiniana biomass followed the Langmuir isotherm. The biosorption capacities were detected to be dependent on the pH of the solution; and the maximum adsorption was obtained at a solution pH of about 5. The effect of light metal ions on lead(II) uptake was also studied and it was shown that the presence of light metal ions did not significantly affect lead(II) uptake. The loofa sponge‐immobilized C. sorokiniana biomass could be regenerated using 0.1 M HCl, with up to 99 % recovery. The desorbed biomass was used in five biosorption‐desorption cycles, and no noticeable loss in the biosorption capacity was observed. In addition, fixed bed breakthrough curves for lead(II) removal were presented. These studies demonstrated that loofa sponge‐immobilized biomass of C. sorokiniana could be used as an efficient biosorbent for the treatment of lead(II) containing wastewater.     

整肠生菌纯培养物的环境动力学研究

采用振荡培养研究了温度、PH值和不同培养基的环境因素对整肠生菌（地衣芽孢杆菌）消长的影响．通过对整肠生菌的动力学基础数据按计算作图的动力学研究结果表明：整肠生菌最适生长温度在35～37℃时，活菌数15─17.2×10~7／ml,是30℃和40℃时的1.26倍和1.2倍．最适PH值在5.5～7.5时,活菌数为4.15─7.55×10~8／ml,是PH值4.5和9.5时的13.l倍和13.2倍．ABC三种培养基的结果表明,培养基C最适合地衣芽孢杆菌生长，菌数最高，为69.05×10~8／ml．对数期的世代时间也最短，G=20min,比AB号培养基中培养时缩短2─6min．生长比速度（μ=0.035)最大，是AB培养基培养时的1.27倍．残废率较低,5.2％．环境因素与整肠生菌消长的这种动力学关系，为利用地衣芽孢杆菌发酵生产“整肠生”制剂的调控以及该菌剂的治疗机制方面研究提供了科学依据．     

Characteristics of Aluminum Biosorption by Sargassum fluitans Biomass

Biomass of nonliving brown seaweed Sargassum fluitans pretreated by different methods is capable of taking up more than 10% (11 mEq/g) of its dry weight in aluminum at pH 4.5. There are indications that the biomass hydroxyl groups were involved in sequestering the aluminum in the form of polynuclear aluminum species. Aluminum-alginate complex (like cotton candy) was formed in the aluminum sorption solution as alginate was partially released from the biomass. Aluminum uptake of S. fluitans biomass was independent of residual alginate content in the biomass. Sodium ion added for pH adjustment was not adsorbed at all in the presence of aluminum ion. Received March 11, 1998; accepted October 9, 1998.     

Parametric Studies on Batch Degradation of a Plasticizer Di-n-Butylphthalate by Immobilized Bacillus sp

Summary Di-n-butylphthalate (DBP) is one of the phthalate esters (PAEs) used in the manufacture of plasticizers, insect repellents and synthetic fibres and contributes to environmental pollution. We report a novel bacterium belonging to the genus, Bacillus (NCIM 5220), which has the ability to utilize DBP as the sole source of carbon and energy. This bacterium was immobilized in alginate. The degradation of DBP by immobilized cells was compared with free cells. The effects on the degradation of DBP of different factors like gel (alginate) concentration, gel bead size, temperature, and pH were investigated. Oxygen uptake in the presence of DBP by free and immobilized cells was also studied. The results showed that the degradation of DBP by immobilized cells was more efficient than by free cells. Further, the effect of various factors tested on the degradation of DBP by alginate-immobilized cells showed that the degradation of DBP was remarkably affected by alginate concentration between 2 and 5% and drastically decreased between bead size 2 and 5 mm. A change of 10 °C of reaction temperature from 30 to 40 °C did not alter the degradation of DBP, and maximum degradation was appeared to be favoured over a broad pH range of 6.5–7.5 for immobilized cells as compared to free cells, which showed an optimum temperature of about 35 °C and pH of 7.0. The immobilized cells showed higher oxidation of DBP than free cells. Thus more efficient degradation of DBP could be achieved by immobilizing Bacillus sp. in alginate beads.     

Equilibrium and Kinetic Studies of Cd2+ Biosorption by the Brown Algae Sargassum fusiforme

A fundamental investigation of the biosorption of Cd²⁺ from aqueous solution by the edible seaweed Sargassum fusiforme was performed under batch conditions. The influences of experimental parameters, such as the initial pH, sorption time, temperature, and initial Cd²⁺ concentration, on Cd²⁺ uptake by S. fusiforme were evaluated. The results indicated that the biosorption of Cd²⁺ depended on the initial Cd²⁺ concentration, as well as the pH. The uptake of Cd²⁺ could be described by the Langmuir isotherm model, and both the Langmuir biosorption equilibrium constant and the maximum biosorption capacity of the monolayer decreased with increasing temperature, thereby confirming the exothermic character of the sorption process. The biosorption kinetics follows the pseudo-second-order kinetic model, and intraparticle diffusion is the sole rate-limiting step for the entire biosorption period. These fundamental equilibrium and kinetic results can support further studies to the removal of cadmium from S. fusiforme harvested from cadmium-polluted waters.