金龟甲对蓖麻叶挥发物的触角电位和行为反应

为了探明金龟甲偏爱选择有害非寄主植物蓖麻的原因,应用触角电位（EAG）仪和“Y”型嗅觉仪,分别测定了华北大黑鳃金龟、暗黑鳃金龟和铜绿丽金龟雌、雄虫对5种蓖麻叶挥发物的触角电位和选择行为反应。EAG测定结果表明,3种金龟甲雄虫对各处理挥发物的EAG反应值均比参照挥发物顺-3-己烯-1-醇强。华北大黑鳃金龟对邻苯二甲酸二丁酯和肉桂醛的EAG反应值相对较高,暗黑鳃金龟对苯甲醇的EAG反应值相对较高,铜绿丽金龟对邻苯二甲酸二丁酯和苯甲醇的EAG反应值相对较高。选择行为反应测定结果表明,当顺-3-己烯-1-醇与其他挥发物配对测试时,华北大黑鳃金龟对邻苯二甲酸二丁酯和肉桂醛2种蓖麻叶挥发物表现出明显的选择偏好,暗黑鳃金龟对蓖麻叶挥发物苯甲醇表现出明显的选择偏好,铜绿丽金龟则更偏好选择蓖麻的绿叶气味物质顺-3-己烯-1-醇。总之,蓖麻叶的挥发性物质与引诱金龟甲偏爱选择密切相关,且偏爱的挥发物因金龟甲的种类而异。     

Bromochlorophenols and a brominated diphenylmethane in red algae

Identification of chlorinated bromophenols and a 2,3,2′,3′-tetrabromo-4,5,4′,5′-tetrahydroxydiphenylmethane in Polysiphonia nigrescens and Rhodomela confervoides was made by stepwise extraction followed by GC-MS analysis. Four different forms of the brominated and brominated-chlorinated benzyl alcohols in red algae are suggested (i) free phenols, (ii) sulphated potassium salts, (iii) constituents of brominated diphenylmethanes and (iv) part of the red pigment floridorubin.     

Cloning of a dibutyl phthalate hydrolase gene from Acinetobacter sp. strain M673 and functional analysis of its expression product in Escherichia coli

A dibutyl phthalate (DBP) transforming bacterium, strain M673, was isolated and identified as Acinetobacter sp. This strain could not grow on dialkyl phthalates, including dimethyl, diethyl, dipropyl, dibutyl, dipentyl, dihexyl, di(2-ethylhexyl), di-n-octyl, and dinonyl phthalate, but suspensions of cells could transform these compounds to phthalate via corresponding monoalkyl phthalates. During growth in Luria–Bertani medium, M673 produced the high amounts of non-DBP-induced intracellular hydrolase in the stationary phase. One DBP hydrolase gene containing an open reading frame of 1,095 bp was screened from a genomic library, and its expression product hydrolyzed various dialkyl phthalates to the corresponding monoalkyl phthalates.     

Use of surfactants and slurrying to enhance the biodegradation in soil of compounds initially dissolved in nonaqueous-phase liquids

A study was conducted to find means of enhancing the biodegradation of hydrophobic organic compounds in nonaqueous-phase liquids (NAPLs). The effects of surfactants, identity of the NAPL and agitation was investigated. When present in NAPLs, phenanthrene, di-(2-ethylhexyl) phthalate (DEHP) and biphenyl were mineralized slowly in soil. Addition of Triton X-100 or Alfonic 810-60 did not enhance the degradation of phenanthrene initially in hexadecane or dibutyl phthalate. Slurrying the soil increased the rate and extent of mineralization of phenanthrene initially in hexadecane but not in dibutyl phthalate. Addition of either of the two surfactants to the slurries did not promote the transformation. Triton X-100, Alfonic 810-60 and Tergitol 15-S-9 below their critical micelle concentrations increased the rate and sometimes the extent of mineralization in soil slurries of phenanthrene initially in 2,2,4,4,6,8,8-heptamethylnonane, but other surfactants were not stimulatory. Slurrying the soil promoted the initial mineralization of DEHP initially in dibutyl phthalate, and Alfonic 810-60 and Triton X-100 further stimulated the rate and extent of degradation in the slurries. Alfonic 810-60 increased the extent of mineralization in slurries of biphenyl in hexadecane but not in dibutyl phthalate, cyclohexane, kerosene or two oils. Little mineralization of biphenyl or DEHP initially in dibutyl phthalate occurred in soil slurries, but Tween 80, Tergitol 15-S-40 and Tergitol 15-S-9 increased the extent of mineralization. However, vigorous agitation of the slurries of soil acclimated to DEHP or the use of small volumes of the NAPL resulted in marked enhancement of the degradation. Thus, biodegradation of constituents of NAPLs in soil can be increased by the use of some surfactants, slurrying or intense agitation, but the effect will vary with the NAPL and the constituents.     

Fungal biodegradation of dibutyl phthalate and toxicity of its breakdown products on the basis of fungal and bacterial growth

Phthalates are esters of phthalic acid that give flexibility to polyvinyl chloride. Diverse studies have reported that these compounds might be carcinogenic, mutagenic and/or teratogenic. Radial growth rate, biomass, hyphal thickness of Neurospora sitophyla, Trichoderma harzianum and Aspergillus niger, grown in two different concentrations of dibutyl phthalate (DBP) (500 and 1,000 mg/l) in agar and in submerged fermentation were studied. The inhibitory concentration (IC₅₀) and the constant of biodegradation of dibutyl phthalate in Escherichia coli cultures were used to evaluate toxicity. The radial growth rate and thickness of the hypha were positively correlated with the concentration of phthalate. The pH of the cultures decreased as the fermentation proceeded. It is shown that these fungi are able to degrade DBP to non-toxic compounds and that these can be used as sole carbon and energy sources by this bacterium. It is demonstrated that the biodegradation of the DBP is directly correlated with the IC₅₀. This is the first study that reports a method to determine the biodegradation of DBP on the basis of the IC₅₀ and fungal growth, and the effect of this phthalate on the growth and thickness of hyphae of filamentous fungi in agar and in submerged fermentation.     

Identification and Characterization of a Cold-Active Phthalate Esters Hydrolase by Screening a Metagenomic Library Derived from Biofilms of a Wastewater Treatment Plant

A cold-active phthalate esters hydrolase gene (designated dphB) was identified through functional screening of a metagenomic library derived from biofilms of a wastewater treatment plant. The enzyme specifically catalyzed the hydrolysis of dipropyl phthalate, dibutyl phthalate, and dipentyl phthalate to the corresponding monoalkyl phthalate esters at low temperatures. The catalytic triad residues of DphB were proposed to be Ser159, Asp251, and His281.     

Gas chromatographic—mass spectrometric detection of circulating plasticizers in surgical patients

Gas chromatographic and gas chromatographic—mass specrometric analytical techniques were employed to quantitate and confirm levels of circulating organic plasticizers in critically ill surgical patients. Two plasticizers, dibutyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP), have been identified. DEHP can be found in many plastic medical devices. The DEHP levels were significant soon after transfusion or in the presence of renal dysfunction. The source of DBP is not clear at present and requires further study. The prevention of this contamination and the toxicity of these plasticizers should be investigated to ensure the safe use of plastic medical devices.     

Effects of organic solvents on membrane of<Emphasis Type="Italic">Taxus cuspidata</Emphasis> cells in

The effects of organic solvents (oleic acid and dibutyl phthalate) on viability and membrane integrity of Taxus cuspidata cells were investigated in two-liquid-phase suspension cultures. It has been found that the cell viability, electrical conductivity and concentration of malonyl dialdehyde did not change obviously when the content of oleic acid or dibutyl phthalate was 2% (v/v), but varied markedly when the contents of oleic acid or dibutyl phthalate were raised to 6% (v/v) or more, indicating that the organic solvents at higher concentrations severely affected the cell membrane permeability.     

云南干巴菌挥发油化学成分的研究

利用气相色谱－质谱联用技术对云南干巴菌的挥发油化学成分进行了研究,共鉴定出49种组分。其中主要成分为业油酸甲酯、棕榈酸、1,1－二乙氧基乙烷、苯乙醛、十六碳烯酸、十五烷酸、邻苯二甲酸二丁 、苯甲酸、苯乙醇、硬脂酸、二十一烷、肉豆蔻酸、十八碳烯酰胺、苯乙酸等,其中亚油酸甲酯的含量最高,占挥发油成分总量的27.12％,检出成分占挥发油总量的90％。     

Cathepsin B inhibitory activities of phthalates isolated from a marine Pseudomonas strain

Two cathepsin B inhibitors were isolated from the culture supernatant of a marine Pseudomonas sp. PB01 (GenBank Accession No. EU126129). Their structures were elucidated by spectroscopic analyses as dibutyl phthalate and di-(2-ethylhexyl) phthalate. Both dibutyl phthalate and di-(2-ethylhexyl) phthalate showed dose-dependent cathepsin B inhibitions with IC(50) of 0.42 and 0.38 mM, respectively. It is also observed from kinetic analyses that dibutyl phthalate and di-(2-ethylhexyl) phthalate acted as noncompetitive inhibitors with K(i) values of 0.64 and 0.42 mM, respectively. Furthermore, both of them caused inactivation of the pericellular cathepsin B of murine melanoma cell with no acute cytotoxicity. The IC(50) values were found to be 0.23 mM for dibutyl phthalate and 0.14 mM for di-(2-ethylhexyl) phthalate, respectively, and were 50% compared to that of purified cathepsin B.     

Exocrine gland involvement in trailing behaviour in the Argentine ant (Formicidae: Dolichoderinae)

Experimental trails run off natural field trails of Iridomyrmex humilis have been used to demonstrate the range of exocrine glands involved in trailing behaviour. Complex trailing reactions were recorded by high-speed movie photography, and their interactions were assessed by multivariate analysis. Pavan's gland is confirmed as the source of major trailing pheromone(s) deposited on the substrate, which act as strong, persistent attractants and activators. The mandibular glands produce volatile, transient behavioural signals in air; the anals produce anti-trailants; and the pharyngeals and venoms may possibly be implicated as the producers of trailing synergists. The findings for I. humilis are considered in relation to the evolution of trailing behaviour through the Formicidae.     

Bioactive substances produced by marine isolates of Pseudomonas

Pseudomonas is a genus of non-fermentative gram-negative Gammaproteobacteria found both on land and in the water. Many terrestrial isolates of this genus have been studied extensively. While many produce bioactive substances, enzymes, and biosurfactants, other Pseudomonas isolates are used for biological control of plant diseases and bioremediation. In contrast, only a few marine isolates of this genus have been described that produce novel bioactive substances. The chemical structures of the bioactive substances from marine Pseudomonas are diverse, including pyroles, pseudopeptide pyrrolidinedione, phloroglucinol, phenazine, benzaldehyde, quinoline, quinolone, phenanthren, phthalate, andrimid, moiramides, zafrin and bushrin. Some of these bioactive compounds are antimicrobial agents, and dibutyl phthalate and di-(2-ethylhexyl) phthalate have been reported to be cathepsin B inhibitors. In addition to being heterogeneous in terms of their structures, the antibacterial substances produced by Pseudomonas also have diverse mechanisms of action: some affect the bacterial cell membrane, causing bacterial cell lysis, whereas others act as acetyl-CoA carboxylase and nitrous oxide synthesis inhibitors. Marine Pseudomonas spp. have been isolated from a wide range of marine environments and are a potential untapped source for medically relevant bioactive substances.     

Ceramide and inositol content of the lipopeptidophosphoglycan from Trypanosoma cruzi.

Inositol (2.5%), 17-methyl-sphinganine (4.8%) and sphinganine (1.5%) have been identified as constituents of the lipopeptidophospholycan isolated from whole cells of epimastigote forms of $\text{Trypanosoma cruzi}$. The branched chain base was characterized by combined gas chromatography — mass spectrometry.     

藏药短管兔耳草挥发性化学成分的研究

采用毛细管气相色谱—质谱联用技术对藏药短管兔耳草挥发性化学成分进行了研究,经毛细管色谱分离出62个峰,共确定了其中41种化学成分,所鉴定的化合物含量占全挥发油的77．32％;用气相色谱面积归一化法测定了各化学成分的相对含量,其主要化学成分为：二苯胺(16．47％)、邻苯二甲酸丁基—8—甲基壬基酯(6．42％)、二十六碳烷(4．76％)、十六烷酸(3．66％)、二十四碳烷(3．40％)、邻苯二甲酸二丁酯(3．38％)、二十二碳烷(3．30％)、二十碳烷(3．26％)、十六烷酸乙酯(2．77％)、十八碳烷(2．76％)、戊酸(2．48％)、3—乙基环辛烯(2．05％)等。     

Source of alate excitant pheromones in the red imported fire antSolenopsis invicta (Hymenoptera: Formicidae)

At the onset of mating flights inSolenopsis invicta, workers swarm excitedly over the mound as alates prepare to fly. Previous studies demonstrated that this excitement is stimulated by the male and female alates. We investigated the glandular source(s) of pheromones produced by the alates that cause excitement. The only common female and male alate body part that elicited excitement when crushed was the head. Within the head, excised mandibular glands were found to be responsible for worker excitement. Fire ant workers are very sensitive to external stimuli and some excitement was elicited by crushed female gasters and male thoraces, but the response was never as significant as with crushed heads. Tests with summer and winter alates revealed similar results, except that gasters of winter female alates had a greater excitant effect than did gasters of summer female alates. This may be due to the production of attractant pheromones by the poison glands of overwintering female alates. We conclude that the mandibular gland is the source of alate excitant pheromones.     

Maturation of the head of bacteriophage T4. I. DNA packaging events

Pulse-chase experiments in wild-type and mutant phage-infected cells provide evidence that the following particles called prohead I, II and III are successive precursors to the mature heads. The prohead I particles contain predominantly the precursor protein P23 and possibly P22 (mol. wt 31,000) and IP III (mol. wt 24,000) and have an s value of about 400 S. Concomitantly with the cleavage of most of P23 (mol. wt 55,000) to P231 (mol. wt 45,000), they are rapidly converted into prohead II particles which sediment with about 350 S. The prohead II particles contain, in addition to P231, the major constituents of the viral shella—a core consisting of proteins P22 and IP III. In cell lysates, prohead I and prohead II particles contain no DNA in a DNase-resistant form and are not bound to the replicative DNA. We cannot, however, positively rule out the possibility that these particles may have contained some DNA while in the cells.The prohead II particles are in turn converted into particles which sediment with about 550 S after DNase treatment (prohead III). During this conversion about 50% of normal DNA complement becomes packaged in a DNase-resistant form, and roughly 50% of the core proteins P22 and IP III are cleaved. In lysates the prohead III particles are attached to the replicative DNA. The prohead III particle appears to be the immediate precursor of the full mature head (1100 S). Cleavage of protein P22 to small polypeptides and conversion of IP III IP III1 are completed at this time. No precursor proteins are found in the full heads. Studies with various mutant phage showed that the prohead II to III conversion is blocked by mutations in genes 16 and 17 and that the conversion of the prohead III particles to the mature heads is blocked by mutations in gene 49. Cleavage of the head proteins, however, occurs normally in these mutant-infected cells. We conclude that the cleavage of the major component of the viral shell, P23, into P231 precedes the DNA packaging event, whereas cleavage of the core proteins P22 and IP III appears to be intimately linked to the DNA packaging event. Models relating the cleavage processes to DNA encapsulation are discussed.     

一株邻苯二甲酸二丁酯降解菌的筛选及其降解特性

【目的】从自然环境中筛选邻苯二甲酸二丁酯(Dibutyl phthalate,DBP)降解能力较强的微生物,并研究其降解特性和代谢途径。【方法】从杭州市河道污水出口的淤泥中筛选到DBP降解菌ZJUTW,对其进行形态、生理生化特征、16SrRNA基因序列分析,考察该菌株对DBP的降解特性,并用GC-MS分析降解中间产物。【结果】该菌株经鉴定为Arthrobacter sp.,降解DBP的最适温度和最适pH值分别为30°C和7.0-8.0,可降解多种邻苯二甲酸酯类化合物;当DBP浓度为800 mg/L时,半衰期为10.47 h;菌株的休止细胞(OD_(600)=1.2)可在20 h内将1 200 mg/L的DBP完全降解。利用GC-MS进行中间产物分析,该菌株可通过酯交换方式起始DBP的降解。【结论】Arthrobacter sp.ZJUTW对DBP有较强的降解能力和较高的耐受性,具有潜在的应用前景。     

Potential for Biodegradation of Phthalic Acid Esters in Marine Regions

Di-(2-ethylhexyl) phthalate was the major phthalic acid ester in the Mississippi River estuary, with mean levels of 0.1 μg/g (dry weight) in surface sediments, 1.0 μg/liter in river water, and 0.7 μg/liter in delta water. Bacteria that grew aerobically on dibutyl phthalate and o-phthalic acid were readily detected in the sediments and water. Pure cultures of bacteria were isolated on seven different phthalic acid esters from freshwater and marine sources. The marine isolates were taxonomically diverse and grew on a variety of phthalic acid esters. Dibutyl phthalate and o-phthalic acid supported growth in full-strength synthetic sea-water medium, but Na⁺ -dependent catabolism was demonstrable only for o-phthalic acid.