海水中亚硝化细菌的分离鉴定研究

从海水样品中分离到1株严格自养的氨氧化细菌GW201210,对该株茵的形态特征、培养特性、生理生化特性等生物学特性进行了初步研究。结果表明,它为革兰氏染色阴性,无鞭毛,不产芽孢,细胞短杆状,呈单个排列或排列成直线。该菌株能将氨氮氧化成亚硝酸盐,不能还原硝酸盐,能利用CO2,在7％NaCl条件下生长,在肉汤培养基中不生长,其特性均符合亚硝酸菌的特征,并用PCR方法扩增该菌株的16SrDNA基因,进行16SrDNA序列比较、同源性分析并构建系统发育树,将菌株GW201210初步鉴定为亚硝化单胞菌属（Nitro．somonascommunis）o     

Residual dynamics of thiacloprid in medical herbs marjoram, thyme, and camomile and in soil

Thiacloprid is a new insecticide of the chloronicotinyl family. To assess its risk after application, residual characteristics of thiacloprid in marjoram, thyme, and camomile and in soil were studied under field conditions. The active ingredient was extracted from the plant material using a mixture of acetone-water. After filtration, the extract was concentrated to the aqueous phase, diluted with water, and portioned against ethyl acetate on a matrix solid phase dispersion column. Thiacloprid was extracted from soil using a mixture of methanol-water, filtered, and re.extracted （clean up） with dichloromethane. The residues were quantified using HPLC-MS-MS. The methods were validated by recovery experiments. Thiacloprid residues in marjoram, thyme, and camomile and in soil persisted beyond 10, 14, 14, and 21 d but no residues were detected after 14, 21, 21, and 28 d, respectively. The data obtained in this study indicated that the biexponential model is more suitable than the first-order function to describe the decline of thiacloprid in fresh marjoram, fresh thyme, and dried camomile flowers with half-life （t1/2） of 1.1, 0.7, and 1.2 d, respectively. However, both the first-order function and biexponential model were found to be applicable for dissipation of thiacloprid in soil with almost the same t1/2 values of 3.5 and 3.6 d. The results indicated that thiacloprid dissipates rapidly and does not accumulate in the tested herbs and in soil.     

Phosphatase activity and culture conditions of the yeast Candida mycoderma sp. and analysis of organic phosphorus hydrolysis ability

Orthophosphate is an essential but limiting macronutrient for plant growth. About 67% cropland in China lacks sufficient phosphorus, especially that with red soil. Extensive soil phosphorus reserves exist in the form of organic phosphorus, which is unavailable for root uptake unless hydrolyzed by secretory acid phosphatases. Thus, many microorganisms with the ability to produce phosphatase have been exploited. In this work, the activity of an extracellular acid phosphatase and yeast biomass from Candida mycoderma was measured under different culture conditions, such as pH, temperature, and carbon source. A maximal phosphatase activity of 8.47 × 10^5±0.11× 10^5 U/g was achieved by C. Mycoderma in 36 hr under the optimal conditions. The extracellular acid phosphatase has high activity over a wide pH tolerance range from 2.5 to S.0 （optimum pH 3.5）. The effects of different phosphorus compounds on the acid phosphatase production were also studied. The presence of phytin, lecithin or calcium phosphate reduced the phosphatase activity and biomass yield significantly. In addition, the pH of the culture medium was reduced significantly by lecithin. The efficiency of the strain in releasing orthophosphate from organic phosphorus was studied in red soil （used in planting trees） and rice soil （originating as red soil）. The available phosphorus content was increased by 230% after inoculating 20 days in rice soil and decreased by 50% after inoculating 10 days in red soil. This work indicates that the yeast strain C. mycoderma has potential application for enhancing phosphorus utilization in plants that grow in rice soil.     

噻吩磺隆降解菌Staphylococcus sp.的分离及其降解特性与途径

采用富集培养技术从磺酰脲类除草剂污染土壤中筛选得到1株降解噻吩磺隆的细菌,命名为ZWS13.经形态特征和16S rRNA基因序列分析,初步鉴定为葡萄球菌属(Staphylococcus sp.).采用HPLC研究了初始底物浓度、温度、接种量、pH等因素对菌株ZWS13降解噻吩磺隆的影响.结果表明,菌株ZWS13对噻吩磺隆的降解具有较广的底物浓度范围,在7 d内对初始浓度5.0~100.0 mg·L~(-1)噻吩磺隆的降解率达到60%以上;菌株ZWS13降解噻吩磺隆的较适pH为8.0,较适温度为40℃,较适接种量为1%;其中,菌株培养温度为40℃时,菌株在10 d内对50.0mg·L~(-1)噻吩磺隆的降解率达到99%以上.降解谱测定结果表明,菌株对烟嘧磺隆、吡嘧磺隆和甲磺隆亦具有良好的降解效果.采用HPLC-MS分析确定了菌株对噻吩磺隆的5个降解产物,推测菌株对噻吩磺隆的降解途径主要为磺酰脲桥C—N键的断裂、脱甲基作用或脱酯作用的甲基丢失及三嗪环的开裂.研究表明,菌株ZWS13能够有效地降解噻吩磺隆,具有生物修复噻吩磺隆污染的潜力.     

黄山市蜡梅属植物资源的调查研究与利用

报告了采用踏查法和访问调查法对黄山市蜡梅属植物资源的种类及其利用现状的调查研究结果,阐述了蜡梅属植物的利用价值,提出了开发利用柳叶蜡梅植物资源的建议.     

高羊茅草坪草间小黑蛛水平分布格局研究

研究了高羊茅草坪草间小黑蛛的水平分布格局,采用聚集强度的5种指数测定其空间格局。结果显示：①聚集强度指数为扩散系数C〉1,久野指数CA〉0,丛生指数I〉1,聚块性指数Iw〉1,负二项分布中的K〉0,表明草间小黑蛛在高羊茅草坪水平分布为聚集格局。②通过Iwao和Taylor的线性回归分析方法得出了草间小黑蛛种群空间格局的特性为聚集型,且个体间相互吸引。     

假单胞菌好氧降解四溴双酚A的特性

为了解四溴双酚A(TBBPA)的好氧降解特性,采用选择富集法从活性污泥中分离出一株能够高效降解四溴双酚A的菌株。根据其形态、生理生化特性及16S rDNA核苷酸序列分析,该菌株被鉴定为假单胞菌属(Pseudomonas sp.)。研究结果表明,该菌株可通过好氧共代谢方式实现四溴双酚A的降解,葡萄糖是四溴双酚A降解的最佳碳源,其最优降解条件为葡萄糖8 g/L,牛肉膏0.5 g/L,pH值为7.0,培养温度为35℃,摇床转速为150 r/min。在该条件下其生物降解过程符合一级动力学模型,6 d后的降解率高达95.6%。LC-MS结果表明,四溴双酚A在好氧降解过程中会生成异丙苯酚类物质。     

小叶锦鸡儿在北方道路护坡中的应用研究

摘要：在公路建设中，传统的工程护坡方式经济性差、景观效果差，不利于沿途的生态系统平衡。采取切实可行的生态护坡方法，利用锦鸡儿属做植被护坡，能克服传统护坡方式的缺点，提高景观效果，也增加经济效益。灌木、乔木在恶劣环境中生长的顽强．是护坡中的先锋植物。利用植被涵水固土的原理，对于容易发生滑坡和泥石流的特殊路段的护坡能发挥固沙的作用，减轻坡面的不稳定性和侵蚀，快速有效地治理荒漠化和恢复因修公路而破坏的自然环境，还可以起到美化生态环境作用。     

雷波县猕猴桃属植物资源调查与开发利用

通过对四川省雷波县猕猴桃属植物的全面系统调查研究,发现雷波县有猕猴桃种类8个,变种5个,不但种类多,而且果实蕴藏量较大,具有巨大的潜在开发利用价值.针对当前猕猴桃属植物利用率低的现状,提出了开发利用对策.     

四川天门冬属植物资源

经实地调查采集及标本整理鉴定,确认四川天门冬属植物有14种,其中大理天门冬、甘肃天门冬和昆明天门冬为四川分布新记录,并编制了14种植物的检索表。