不同培养方式下兽疫链球菌发酵生产透明质酸的研究

对摇瓶的分批和补料、小罐的分批和流加发酵生产透明质酸（ＨＡ） 进行了比较研究,并对发酵机制进行了初步的探讨．在耗糖量相同的情况下,分批发酵比多次加料或流加发酵具有更高的ＨＡ产量和转化率;分批发酵初糖７％ ,发酵２４ ｈ 左右,产ＨＡ３．６ ｇ／Ｌ,转化率５．３ ％ ,流加发酵初糖３％ ,１５ ｈ 耗糖７％ ,此时,ＨＡ 为３ ．０ ｇ／Ｌ,转化率Ｙｐ／ｓ４．２％ ,继续发酵至２０ ｈ ,产ＨＡ４ ．０％ ,此时转化率Ｙｐ／ｓ３ ．６％ ,两种发酵所产ＨＡ 的Ｍｒ 均为２ ．０×１０６ ． 分批发酵中ＨＡ、副产物乳酸都和菌体生长相偶联,流加发酵中乳酸和菌体生长是偶联的,其含量均不断增加,ＨＡ含量表现为在菌体生长前期与之偶联,而后下降．流加发酵的菌体比生长速率远高于分批发酵．     

采用高效菌提高普通活性污泥系统抗2,4-DCP负荷冲击能力

研究了用于处理生活污水的普通活性污泥反应器(CAS)受到2,4-二氯酚(2,4-DCP)间歇性负荷冲击时,投加高效菌的生物强化系统和对照系统对污染物的响应及系统稳定性,并考察了长期运行过程中强化系统对目标污染物去除能力的变化.结果表明,投加5%和15% 2,4-DCP复合高效菌的强化CAS系统,其对目标污染物的降解能力及抗负荷冲击能力得到显著提高.当系统受到间歇性2,4-DCP负荷冲击[110.37～171.60 mg/(L·d)]时,对于单次投菌后前30日内发生的间歇性负荷冲击,强化系统有效保持了对目标污染物的强化效果;在无2,4-DCP存在的情况下连续运行70d,当系统再次受到2,4-DCP负荷冲击时,强化系统的强化效果与前几次相比已明显下降,不能够快速有效去除污染物并维持系统稳定,因此有必要再次投加高效菌.     

基于光合色素的化学分类法在淡水藻类研究中的应用

采用反相高效液相色谱技术(RP HPLC)系统研究了我国主要淡水藻类--蓝藻、绿藻、硅藻、甲藻、金藻、裸藻和隐藻等的光合色素,在8种纯培养藻类中共确定类胡萝卜素、叶绿素及其衍生物19种。分离到的主要标志性色素按洗脱时间分别为脱植基叶绿素a、19′ 丁酰氧岩藻黄素、叶绿素c、脱镁叶绿素a、多甲藻素、甲基脱植基叶绿素a、岩藻黄素、新黄质、紫黄质、蓝藻叶黄素、硅甲藻黄素、硅藻黄质、叶黄素、玉米黄素、叶绿素b异构体、叶绿素b、叶绿素a异构体、叶绿素a和β 胡萝卜素;其中在纯培养的铜绿微囊藻中首次鉴定到19′ 丁酰氧岩藻黄素;通过官桥基地的实际监测,证实了该技术应用的可行性,为基于HPLC分析技术的浮游植物化学分类法提供了理论依据。     

Conservation of Vascular Epiphyte Diversity in Mexican Coffee Plantations

Abstract:  Coffee plantations have replaced many lower-montane forests in the Neotropics, and ongoing intensification is converting traditional polycultures with a variety of shade trees to plantations with no or monospecific shade trees. To evaluate the impact of coffee cultivation on epiphyte diversity, I surveyed vascular epiphytes on shade trees in nine different coffee plantations and compared records with those in four natural forests in central Veracruz, Mexico. Eighty-nine species occurred in coffee plantations, and 104 species occurred in natural forests. The number of epiphytic species in traditional polycultures with old shade trees, mostly of the genus Inga , was similar to that in forests, but plantations with small trees and sparse shade hosted fewer epiphytes than those with large trees. Epiphyte communities were, however, more homogeneous in coffee plantations than in forests, possibly because of a drier microclimate and the lack of large and long-lived trees. These results demonstrate the value of traditional polycultures for epiphyte diversity, show the importance of conserving large shade trees, and suggest that these coffee systems may not be suitable for all epiphytes.     

深海热液喷口周围微氧耐压细菌的培养研究

研究采用析因实验设计,探讨了培养基的水源、培养温度和生长pH等因素对喷口细菌生长繁殖的影响,初步探索了常压下东太平洋某海底喷口周围微氧耐压细菌的生长条件。样品培养10d后,对培养液中细菌量进行显微计数,实验数据用SPSS11.0统计软件中的方差分析程序进行处理。统计结果显示:在标准大气压下,从研究样品中获得最多细菌数的较优培养条件为:培养基水源为单蒸水;生长pH为7.60;培养温度为50℃。在该条件的培养液中细菌平均浓度达2.596×10个/mL。研究结果为进一步认识、鉴定与开发利用深海喷口周围细菌资源打下了基础。     

混合型微生物絮凝剂产生菌的最佳培养条件

从活性污泥中筛选出具有较高絮凝活性的混合菌MBFH,研究了各种条件对混合菌产絮凝剂的影响.结果表明,混合菌MBFH产絮凝剂的最佳培养条件为:温度30℃、初始pH8.0、摇床转速为120r/min、培养基含糖量2%、相对接种量15%,其对高岭土悬浊液的絮凝率可达到88%.图5表4参9     

PP333在库拉索芦荟组培快繁中的应用研究

以MS 6-BA2.5mg/L NAA0．2mg/L为初代培养基，以MS 6-BA2.0mg/L NAA0．1mg/L为增殖培养基，1，3MS IBA0.5mg/L为生根培养基，添加不同浓度的PP333，其结果表明：初代培养基中添加0．5mg/LPP333有利于库拉索芦荟外植体出芽，增殖培养基中添加0．1-0．5mg/LPP333对库拉索芦荟试管苗增殖有效，而在生根培养基中添加0．5—1．0mg／LPP333有利于生根和移栽，其中以1／3MS IBA0．5mg/L PP3330．5mg/L培养基对库拉索芦荟试管苗生根和移栽有良好效应．     

Highly efficient and selective removal of phosphate from wastewater of sea cucumber aquaculture for microalgae culture using a new adsorption-membrane separation-coordinated strategy

● A new adsorption-membrane separation strategy is used for phosphate removal. ● PVC/Zr-BT shows a selective adsorption ability to low-concentration phosphate. ● Low concentration of P below 0.05 mg/L was achieved in actual wastewater treatment. ● Algal biomass production served as a demonstration of phosphorus recycling. Enhanced phosphorus treatment and recovery has been continuously pursued due to the stringent wastewater discharge regulations and a phosphate supply shortage. Here, a new adsorption-membrane separation strategy was developed for rational reutilization of phosphate from sea cucumber aquaculture wastewater using a Zr-modified-bentonite filled polyvinyl chloride membrane. The as-obtained polyvinyl chloride/Zr-modified-bentonite membrane was highly permeability (940 L/(m²·h)), 1–2 times higher than those reported in other studies, and its adsorption capacity was high (20.6 mg/g) when the phosphate concentration in water was low (5 mg/L). It remained stable under various conditions, such as different pH, initial phosphate concentrations, and the presence of different ions after 24 h of adsorption in a cross-flow filtration system. The total phosphorus and phosphate removal rate reached 91.5% and 95.9%, respectively, after the membrane was used to treat sea cucumber aquaculture wastewater for 24 h and no other water quality parameters had been changed. After the purification process, the utilization of the membrane as a new source of phosphorus in the phosphorus-free f/2 medium experiments indicated the high cultivability of economic microalgae Phaeodactylum tricornutum FACHB-863 and 1.2 times more chlorophyll a was present than in f/2 medium. The biomass and lipid content of the microalgae in the two different media were similar. The innovative polyvinyl chloride/Zr-modified-bentonite membrane used for phosphorus removal and recovery is an important instrument to establish the groundwork for both the treatment of low concentration phosphate from wastewater as well as the reuse of enriched phosphorus in required fields.     

Oxidative and genotoxic effects of bisphenol A on primary gill cell culture of Lake Van Fish (Alburnus tarichi Güldenstädt, 1814)

Lake Van is the largest lake in Turkey. The lake limits lifespan due to its high pH and brackish water. For this reason, only a single species of fish (Van Fish) is living in the lake that has been adapted to these conditions. In the present study, we investigated the total oxidant status (TOS), total antioxidant status (TAS), malondialdehyde (MDA) level and DNA damage effect of bisphenol A (BPA) (10^?7, 10^?6 and 10^?5?M) on primary gill cell culture of Van Fish for 24 and 48?h of incubation periods. TAS levels were not changed when compared to those of the control group, but TOS levels were decreased in both 24 and 48?h. The MDA level increased only at the highest concentration (10^?5) at the end of 12 and 24?h (p?.05). DNA damage increased only at the 10^?5?M concentration after 48?h. At the end of the experiment, BPA exposure caused lipid peroxidation and genotoxic effect. These results indicate that high levels of BPA exposure induced oxidative stress and DNA damage by time- and concentration-dependent fashion in the gill cell culture of Van Fish. Gill cell culture is a useful model for the rapid identification of the harmful effects of chemicals in the aquatic environment.     

土壤中两种手性有机氯农药的选择性降解研究

为了更深入的了解和阐释手性有机氯农药在土壤中的转化和环境归趋,采用实验室室内避光培养方法,研究了o,p＇-DDT及o,p＇-DDD 2种手性有机氯农药的外消旋体在水稻土厌氧培养体系和菜园土好氧培养体系中的选择性降解情况。为了更好的利用土壤中土著微生物的活性,我们选择了厌氧微生物比较丰富的水稻土和好氧微生物丰度比较高的菜园土来做培养实验。结果表明实验体系中o,p＇-DDT及o,p＇-DDD在水稻土和菜园土中的降解均没有明显的对映体选择性。这一结果与2种手性化合物不同对映体在自然环境中的含量普遍具有差异性有所不同,说明野外环境条件和室内模拟实验条件的差异会影响手性化合物的降解选择性。在2种体系中,o,p＇-DDT的降解速率均高于o,p＇-DDD的降解速率。这与以前的研究报道一致,DDD比DDT更难降解。通过2个体系的比较,发现DDT的降解速率在厌氧体系中高于好氧体系,而DDD的降解速率与之相反,好氧体系高于厌氧体系。这应该与DDT和DDD 2种化合物的化学结构及2种土壤中微生物群落的差异有关。对于厌氧体系中的2种水稻土,采自中山的水稻土中DDT的降解速率高于江门的水稻土,这应该与中山水稻土有机质含量高于江门的水稻土有关。有机质含量的高低直接反映了土壤中微生物的多少,进而会影响污染物的降解速率。研究发现本实验所用水稻土和菜园土总有机碳含量偏低可能是影响2种化合物的对映体无降解选择性的因素之一。此外,由于本研究采用缓冲溶液将pH 调控在中性,因此本文的土壤 pH 对降解选择性的影响仍有待进一步研究。本研究中好氧体系和厌氧体系对目标物的降解选择性无明显差异。