Residual Effects of Glyphosate Herbicide in Ecological Restoration

This study assesses the risks in ecological restoration arising from transplanting into soil containing glyphosate residues. Four Australian restoration species were grown for 60 days in nonadsorbing media treated continuously with glyphosate to establish threshold concentrations for damage. Visual signs of injury were observed in three species, and severe effects on root growth in all species, at solution concentrations as low as 18 mg/L. Only the perennial grass Themeda sp. died at this concentration, with other species surviving at concentrations in the range 36–360 mg/L, beyond which all plants died. Fourteen days exposure followed by removal of glyphosate from root media produced similar effects. Field and glasshouse experiments with the relatively tolerant tree species Angophora costata showed that application rates in the range 10–50 L/ha of herbicide product (360 g/L) would be needed to sustain damage to young plants transplanted into soil typical of local restoration sites. The volume of spray delivered using a hand‐operated sprayer varied between operators by 5‐ and 10‐fold to complete the same tasks, at the high end presenting a potential risk to the most tolerant species under field conditions, even when spray concentrations follow label instructions. For all but the most sensitive species, the risk of glyphosate residues in ecological restoration should be minimized by training operators of unregulated applicators to deliver controlled volumes of herbicide when spot spraying prior to transplanting.     

粤北一种虫草分离菌的抗酵母现象

CR 95 1 2是一株分离自粤北一种虫草的无孢丝状真菌 ,经培养初步鉴定为无孢菌目(^{Agonomycetales})的丝核菌属 (^Rhizoctonia)。对包括革兰氏阳性及阴性细菌、放线菌、丝状真菌和酵母菌在内的 2 6株致敏菌株的抗性测定表明 ,CR 95 1 2对包括红酵母属 (^Rhodotorula)、酵母属 (^{Saccharomyces})、毕赤氏酵母属 (Pichia)和隐球酵母属 (^Cryptoc     

Characteristics of Bacteria from Oilseed Rape in Relation to their Biocontrol Activity against Verticillium dahliae

The potential of bacteria that are adapted to the oilseed rape root environment for use in the biological control of Verticillium dahliae, Kleb was investigated in both controlled and non‐sterile growth conditions. Bacterial strains dominated by the red‐pigmented members of enterobacteriaceae were isolated from thoroughly washed and air‐dried root segments of symptomless young rape plants. Other associated strains found either belonged to Alcaligenes sp., Stenotrophomonas spp. and Pseudomonas spp. (Pseudomonas acidovorans and Pseudomonas putida) or were unidentified according to fatty acid methyl ester profile analysis. A total of 19 strains isolated in this study together with two previously studied strains, Serratia proteamaculans and Pseudomonas chlororaphis, were characterized on the basis of their interactions with V. dahliae and a number of functional characteristics. In line with earlier observations with root‐colonizing fungi also from oilseed rape, all bacterial strains suppressed the pathogen not only directly and but also indirectly in in vitro assays. Mechanisms of suppression were apparently multifold among the strains, but production of hydrogen cyanide does not seem to be involved in indirect inhibition. The majority of the strains possessed the ability to produce cellulases, proteases and phosphatases and some even produced chitinases and induced hypersensitive responses, indicating their potential for nutrient acquisition as well as colonization capacity and active recognition by the plant cells. Investigations in non‐sterile field soil revealed that some strains protected rape plants from V. dahliae partly by delaying symptom development. None of the strains, however, was strongly deleterious to rape growth either in the presence or absence of the pathogen. Light microscopic observations of roots and results based on agar printing techniques revealed the potential of the studied strains to colonize or interfere with the pathogen colonization. This study provides some insight into the evolved relationship of bacterial residents with their host in terms of their potential importance in its fitness.     

Janibacter sp.对活性污泥反应器中二苯并呋喃降解的强化作用及其遗传学分析

二苯并呋喃（DF）是研究二英类化合物生物降解的模式化合物之一。本文报道了一种降解菌Janibacter sp.对活性污泥降解二苯并呋喃的强化作用,以及对其降解基因的分析结果。向反应器中添加5%的降解菌,与活性污泥共同作用,可在48h内将约56mg/L剂量的DF几乎完全降解,提高降解率28%以上。利用PCR方法,克隆和测序分析证明有DF降解基因丛的存在,并且发现以丰富培养基在高温下培养可去除该基因丛;丢失该基因丛的突变株同时失去利用DF作为唯一碳源进行生长的能力,显示其很可能位于一个大质粒上。     

侧孢霉液体深层发酵生产木质纤维素分解酶

近年来,直接利用农业秸秆及其废弃物通过微生物转化生产纤维素酶和蛋白饲料引起了广大的关注（Buswelletal,1996,okekeetal,1993）。但目前对木质素分解酶的研究报导很少。本文采用7L搅拌式发酵罐,对侧抱霉（砂orotrichumsp．）直接利用甜菜渣液体深层发酵生产木质纤维素分解酶及酶反应条件进行了初步探讨。l材料与方法1．l菌种和培养条件侧抱震（》orotrichumsp）由中国农科院原子能利用研究所提供。菌株PDA斜面在4℃冰箱条件下保存,用于本项研究。液体种子培养基（g／L）：结晶纤维素10;酵母粉l;无机盐溶液10ml。发酵培养基（g…     

苯酚高效降解菌的筛选和降解特性研究

从东华理工学院北区原化学系排污口土壤中筛选到一株高效的苯酚降解细菌PS1。该菌为球菌,革兰氏染色阴性,能以苯酚为唯一碳源和能源生长。经16S rRNA基因部分序列分析PS1为Raoultella属菌株(Raoultella sp.strain PS1),其最高苯酚耐受和降解浓度在3500mg/L以上,当苯酚浓度为500mg/L和1000mg/L时,22h和32h可完全降解,在1500mg/L~3000mg/L时,32h~50h可完全降解,2500mg/L时降解速率最快,达78.1mg/h。通过正交试验得出该菌最适生长条件为25℃、pH6.5、葡萄糖500mg/L;最佳苯酚降解条件为20℃、pH7.0、葡萄糖500mg/L。     

The specificity of 1-naphthol oxygenases from three bacterial isolates, Pseudomonas spp. (NCIB 12042 and 12043) and Rhodococcus sp. (NCIB 12038) isolated from garden oil

Abstract Three bacterial isolates which appeared to use the insecticide, carbaryl (1-naphthyl, N -methyl-carbamate) as their sole carbon and nitrogen sources were originally selected from garden soil. Only one isolate, Pseudomonas sp. (NCIB 12043) could metabolise carbaryl rapidly to 1-naphthol and methylamine. The other two isolates, Pseudomonas sp. (NCIB 12042) and Rhodococcus sp. (NCIB 12038) relied on slow chemical hydrolysis of carbaryl to 1-naphthol and methylamine. All three isolates used 1-naphthol as their sole carbon source; however, their ability to use naphthalene and a range of mono- and dihydroxy-substituted naphthalene compounds varied. NCIB 12038 and NCIB 12043 showed little or no growth on naphthalene, 2,3-dihydroxynaphthalene or 1,3-dihydroxynaphthalene as sole carbon sources and their 1-naphthol oxygenases had little activity with these substrates. In contrast, NCIB 12042 could use these compounds as sole carbon sources and its 1-naphthol oxygenase also showed activity with them. We conclude that 1-naphthol oxygenase from NCIB 12042 is a relatively non-specific dioxygenase, whereas the 1-naphthol oxygenases from NCIB 12038 and NCIB 12043 are relatively specific monooxygenases requiring hydroxylated naphthalene compounds as substrates.     

Biosorption of Copper (II) by the Microorganisms Isolated from the Crude-Oil-Contaminated Soil

The objective of this study was to isolate and screen the highly efficient copper-removing microorganisms from the petroleum hydrocarbon (PH)-contaminated sites in the Amazonian rain forest in Ecuador. Two bacterial strains (strain UEAB3 and UEAB6) have shown 100% microbial resistance on the nutrient medium containing 100 mM of MgCl₂, FeCl₃, and Al₂(SO₄)₃ separately. Though these two strains were less tolerant of ZnCl₂ and CuSO₄.5H₂O, they have proven 100% resistance at the lower concentrations of these two metals. According to atomic absorption spectroscopy (AAS) analysis, the filamentous fungi (strains UEAFr and UEAFg) were significantly (p<0.05) effective at bacteria in the biosorption (97–100%) of copper (5 mg L^?1) over 7 d. As per 16/18S rDNA sequences, UEAB3, UEAB6, UEAFr, and UEAFg were Bacillus thuringiensis, Bacillus cereus, Geomyces pannorum, and Geomyces sp., respectively. From these results, it can be comprehensively concluded that the isolated microbial cultures had a capacity to remove the copper metal from the liquid medium.     

内生真菌对姜黄素的微生物转化

目的:调查姜黄根茎内生真菌对姜黄素的微生物转化,以期获得一些姜黄素的结构类似物或衍生物。方法:利用表面消毒法分离内生真菌;采用薄层层析和高效液相色谱(HPLC)技术筛选生物转化姜黄素的内生真菌;利用硅胶柱层析和制备型HPLC分离纯化生物转化产物;应用波谱技术解析转化产物的化学结构;通过形态学特征和内转录间隔区(ITS)序列分析对内生真菌进行初步鉴定。结果:从姜黄根茎中分离出18株内生真菌,经筛选发现其中1株丝状真菌能转化姜黄素,其产物分别为去甲基姜黄素和二去甲基姜黄素。初步鉴定该内生真菌属于Diaporthe sp.。结论:内生真菌Diaporthe sp.能对姜黄素进行去甲基化修饰,推测它可能具有O-去甲基化酶系。     

棉蝗肠道真菌Phoma sp. HC03除草和免疫抑制成分研究

从棉蝗肠道菌Phoma sp.HC03中分离得到一个化合物,由波谱数据解析鉴定为epoxydon 6-methylsalicylate ester。药理实验表明该化合物具有较强的除草活性和中等的免疫抑制活性。     

Occurrence and correlations of nematodes,Fusarium oxysporum and edaphic factors on banana plantations

Problems caused by nematodes and Fusarium wilt (Panama disease) on banana plantations are responsible for yield losses and are limiting to its cultivation. In the state of Goias, there is little information about the nematode occurence on this crop, and its relation with the incidence of Fusarium oxysporum f.sp. cubense (Foc). This research had the purpose to identify the occurrence of plant‐parasitic nematodes on banana plantations and to verify its correlation with the Fusarium wilt and with the soil attributes (pH, texture, nutrients). Twelve banana orchards in the state of Goias were sampled in the municipalities of Anapolis, Caiaponia, Goiatuba, Itaguaru, Itumbiara (two areas), Jatai, Morrinhos, Ouro Verde, Palestina, Taquaral and Uruana. All sampled areas, except Morrinhos, revealed contamination with Foc, and all areas had different genera of nematodes either in the soil or in the roots samples. Meloidogyne sp., Helicotylenchus sp. and Rotylenchus sp. were the main genera of plant‐parasitic nematodes found in the samples, with Meloidogyne sp. and Rotylenchus sp. being the most dominant and abundant genera. The presence of Pratylenchus sp. increases the population levels of F. oxysporum. Helicotylenchus sp. is highly correlated with high concentrations of Mn. High population density of Meloidogyne sp. was found in irrigated areas with low concentrations of P, Ca, Mg and soil pH.     

Shewanella putrefaciens in a fuel-in-water emulsion from the Prestige oil spill

Microorganisms that colonize the fuel-in-water emulsion from the Prestige spill have been compared with those from Exxon-Valdez. Both emulsions contained non-fermentative gram-negative rods but unlike Exxon-Valdez's, the Prestige's spill contained anaerobic bacteria and no fungi. Our main finding has been the identification of Shewanella putrefaciens , a bacterium promising for bioremediation.     

Kinetics of pure cultures of hydrogen-oxidizing denitrifying bacteria and modeling of the interactions among them in mixed cultures

In this study we report the isolation of four denitrifying bacteria from a batch reactor, where the progress of hydrogenotrophic denitrification was examined. Only three of the strains had the ability to use hydrogen as electron donor. In the present work, kinetic batch experiments were carried out in order to study the dynamic characteristics of pure and defined mixed cultures of hydrogen-oxidizing denitrifying bacteria, under anoxic conditions, in a defined synthetic medium, in the presence of nitrates. Kinetic models were developed and the kinetic parameters were determined from the batch experiments for each bacterium separately. The behavior of mixed cultures and the interactions between the bacteria were described using kinetic models based on the kinetic models developed for each bacterium separately and their predictions were compared with the results from mixed culture experiments. The mathematical models that were developed and validated in the present work are capable of describing the behavior of the bacteria in pure and mixed cultures, and in particular, the kinetics of nitrate and nitrite reduction and cell growth.     

Physical properties of palm fruits processed with tools by wild bearded capuchins (Cebus libidinosus)

Habitually, capuchin monkeys access encased hard foods by using their canines and premolars and/or by pounding the food on hard surfaces. Instead, the wild bearded capuchins (Cebus libidinosus) of Boa Vista (Brazil) routinely crack palm fruits with tools. We measured size, weight, structure, and peak-force-at-failure of the four palm fruit species most frequently processed with tools by wild capuchin monkeys living in Boa Vista. Moreover, for each nut species we identify whether peak-force-at-failure was consistently associated with greater weight/volume, endocarp thickness, and structural complexity. The goals of this study were (a) to investigate whether these palm fruits are difficult, or impossible, to access other than with tools and (b) to collect data on the physical properties of palm fruits that are comparable to those available for the nuts cracked open with tools by wild chimpanzees. Results showed that the four nut species differ in terms of peak-force-at-failure and that peak-force-at-failure is positively associated with greater weight (and consequently volume) and apparently with structural complexity (i.e. more kernels and thus more partitions); finally for three out of four nut species shell thickness is also positively associated with greater volume. The finding that the nuts exploited by capuchins with tools have very high resistance values support the idea that tool use is indeed mandatory to crack them open. Finally, the peak-force-at-failure of the piassava nuts is similar to that reported for the very tough panda nuts cracked open by wild chimpanzees; this highlights the ecological importance of tool use for exploiting high resistance foods in this capuchin species.     

Emission of isoprenoids from natural vegetation in the Beijing region (Northern China)

ABSTRACT

A survey was conducted to identify plants emitting isoprenoids in the Beijing area which could potentially contribute to smog episodes when combined with anthropogenic pollutants. The emission pattern was similar to that observed in the previously surveyed boreal ecosystems (Europe, North America). Most deciduous oaks are strong isoprene emitters; however, some of them do not emit isoprenoids and are therefore more suitable for the urban environment of Beijing. No emission of monoterpenes was found in Chinese oaks, and this trait seems therefore confined to the Mediterranean environment. The emission of isoprene was found in poplars and in some of the bamboo widespread in city parks and in the riparial vegetation surrounding the city. Chinese pine species emit monoterpenes when wounded, and the emission is not qualitatively different among species. Pinus tabulaeformis, one of the most important trees in China, is a low emitter compared to other pine species.     

Isolation and characterization of bacterial strains with the ability to utilize high concentrations of levulinic acid,a platform chemical from inedible biomass

Nineteen levulinic acid (LA)-utilizing bacteria were isolated from environmental samples. Following examination of the use of 80 g/L LA by some isolated strains, Brevibacterium epidermidis LA39–2 consumed 62.6 g/L LA following 8 days incubation. The strain also utilized both 90 and 100 g/L LA, with consumption ratio of 84.3 and 53.3%, respectively, after 10 days incubation.     

FIELD ASSAYS FOR MEASURING NITRATE REDUCTASE ACTIVITY IN ENTEROMORPHA SP. (CHLOROPHYCEAE), ULVA SP. (CHLOROPHYCEAE), AND GELIDIUM SP. (RHODOPHYCEAE)1

In situ and in vitro nitrate reductase (NR) activity assays designed for use in the field on Enteromorpha sp., Ulva sp., and Gelidium sp. are described. In optimizing each assay, a variety of compounds and assay conditions were tested for their ability to extract NR and preserve its activity. Enteromorpha sp. had similar levels of in vitro NR activity after exposure to the in situ assay buffer, demonstrating that neither NR induction nor activation likely occurs during the in situ assay. Storing freshly collected Enteromorpha sp. led to a reduction in NR activity over time. However, the use of liquid nitrogen to freeze algal tissue on site and subsequent storage at ?80° C preserved NR activity and allowed for later laboratory use of the optimized in vitro assay. Application of the in situ and in vitro assays to stands of Enteromorpha sp., Ulva sp., and Gelidium sp. in the field consistently found NR activity. In situ NR activity over 9 consecutive days in January demonstrated that Enteromorpha sp. responds to increases in nitrate availability. The influence of light on diel patterns of in vitro NR activity in the field was demonstrated for the first time as well. For the three species tested, these two assays provide a reliable tool for field investigation of the interaction between environmental signals (e.g. nutrient levels) and physiological signals (e.g. tissue metabolite levels) on nitrate reduction.     

Shiraia sp.SUPER-H168液态发酵产竹红菌素过程中生理特征初步研究

通过对竹黄菌株SUPER-H168产竹红菌素及不产竹红菌素时生理特征的研究,发现MDA、胞内及胞外的总抗氧化力、过氧化氢、维生素C的含量均比对照组高;CAT的活力上升,而SOD活力总体稍有下降。实验结果表明,菌体产竹红菌素初期伴随着其自身氧化水平的上升。添加终浓度为40μmol/L的过氧化氢可以促进竹红菌素生成。