产气肠杆菌(KLE-1)絮凝特性的研究

从土壤中筛选出一株产生菌KLE-1,经鉴定该菌株为产气肠杆菌(Klebsiella mobilis)．利用乳品废水作为发酵培养基,该菌株产生多糖类微生物絮凝剂;Ca^2 对该絮凝剂的助絮凝效果优于其它金属阳离子;采用红外扫描、zeta电位测定仪对絮凝机理进行研究,表明该絮凝剂主要以架桥作用为主．     

微生物絮凝剂絮凝条件的响应曲面法优化

筛选出一株絮凝剂产生菌TF10,鉴定为巨大芽孢杆菌(Bacillus megaterium).以高岭土悬浊液为絮凝对象,研究了pH值、絮凝剂用量和不同阳离子对TF10产生的絮凝剂P-TF10絮凝效率的影响.结果表明,P-TF10在偏酸和微碱范围内活性较高;絮凝剂存在最佳用量,不足或过高会导致絮凝率下降;Ca2+和Al3+对絮凝的促进作用明显,而Mg2+和Na+对絮凝无作用.应用响应曲面法对P-TF10的絮凝条件进行了优化,得到最佳条件为:pH=4.7,CaCl2浓度为7.0mmol.l-1,P-TF10的用量为34.6 mg.l-1,该条件下絮凝率可达(95.5±1.0)%.     

固氮菌J-25利用味精废水产生絮凝剂的研究

考察了微生物絮凝剂产生菌Azotobacter J-25在味精废水中发酵产生絮凝剂的絮凝特性。实验表明，味精废水经预处理后，加入有机碳源对絮凝剂产生菌Azotobaaer J-25进行培养，菌体在生长过程中产生絮凝剂，并将其分泌到细胞外，培养液的絮凝活性最高达98％以上。该絮凝剂在偏碱性的条件下，对高岭土悬浊液的絮凝效果最好．实际废水的净化实验表明，该微生物絮凝剂对多种废水具有良好的净化效果，尤其对石化废水处理效果最好，CODCr，SS，色度的去除率分别为66．7％，98．3％，93．7％。     

微生物絮凝剂生产菌T1的鉴定及其对生活污水絮凝特性

从活性污泥中分离筛选絮凝剂产生菌,得到一株对高岭土悬浊液具有较高絮凝活性的微生物絮凝菌T1.根据菌株的生理生化鉴定以及16S r DNA基因序列分析,确定该菌株为芽孢杆菌(Bacillus sp),该菌的絮凝活性物质分布在发酵液上清液中.通过正交实验确定最佳生活污水絮凝条件为絮凝剂投加量5%,污水p H值7.0,助凝剂Ca Cl2投加量为2%,在此条件下,T1发酵上清液对生活污水的絮凝率为83.85%.     

微生物絮凝剂产生菌的筛选及相关废水絮凝效果试验

用常规的细菌分高纯化方法从废水、土壤、活性污泥中分离出42株细菌，将单株菌培养于特殊的产絮凝剂液体培养基中，培养物离心后上液对高岭土县液絮凝效果作为指标衡量其絮凝活性及产絮凝剂能力，由此初步获得6株微生物絮凝剂产生菌：Ⅰ－23，Ⅰ－24，Ⅱ－4，Ⅲ－2，Ⅲ－8，Ⅲ-12．其发酵离心上液对造纸黑液、皮革废水、偶氮染料废水、硫化染料废水、电镀废水、彩印制板废水、石油化工废水、造币废水及蓝墨水、碳素墨水等进行的絮凝试验表明，废水固液分离效果良好，CODCr去除率55％～98％，悬浮物、色度、浊度去除率90％以上．     

微生物絮凝剂SC06的化学组成和特性

纤维堆囊菌（Sorangium cellulosum NUST 06）产生一种胞外多糖絮凝剂。用乙醇沉淀和Sepharose 4B凝胶层析纯化得到纯品SC06，通过气相色谱和红外光谱分析，SC06由葡萄糖、甘露糖和葡萄糖醛酸组成，其比较约为5∶3∶1，SC06的絮凝活性依赖于阳离子的存在，在pH2-9范围内絮凝活性稳定。     

微生物絮凝剂产生菌的筛选和优化以及在水处理中的应用

从土壤中筛到1株絮凝剂产生菌BY-28,该菌产生的絮凝剂对高岭土悬浊液的絮凝活性较高且稳定,鉴定为多粘类芽孢杆菌Paenibacillus polymyxa BY-28.菌BY-28产絮凝剂的最佳培养基和培养条件为:葡萄糖2％,KH2PO40.4％,黄豆饼粉0.1％,MgSO4·7H2O 0.05％,CaCl2 0.05％,pH 7.0,30℃,180 r/min摇床培养2-3 d,产生具有高絮凝活性的絮凝剂.该絮凝剂对水中无机悬浮物和有机染料具有较高的去除率,尤其是能够有效地去除肌苷发酵液和肌苷生产废水中的菌体及悬浮物.图3表4参16     

利用鱼粉废水生产生物絮凝剂及其性能研究

研究了不同培养时间下鱼粉废水中假单胞菌(Pseudomonas sp.)GX4—1菌的生长状况、培养液pH值和絮凝活性变化，发现该絮凝剂产生于菌生长过程中的，培养基灭菌与否对菌合成絮凝剂的特性无大影响．与其它几种常用絮凝剂相比，该絮凝剂对高岭土悬液的絮凝活性较高(絮凝率达95％以上)．发酵液经中速离心获得的上清液作为絮凝剂样品不仅具有良好的热稳定性，且在低温储存170d内活性稳定，对土壤悬液和大肠杆菌悬液表现出良好的絮凝能力。     

新型生物絮凝剂——生物材料的絮凝效果评价

自制生物材料是一种新型生物絮凝剂,分别以ＢＳＡ溶液、果汁溶液、泥土混浊液为研究对象,与其他四种常用絮凝剂相比,其絮凝效果优于其他絮凝絮凝剂,然后,研究其絮凝剂用量与絮凝效果的关系,絮凝动力学等。     

营养和环境条件对生物絮凝剂合成的影响

在考察了红平红球菌Rhodococcus erythropolis CCRC10900基本生长代谢特性的基础上，研究了营养条件对生物絮凝剂合成的影响。R.erythropolis CCRC10909合成的絮凝剂约80％以上分泌至胞外培养基中，仅20％左右的絮凝活性存在于菌体细胞上，蔗糖是该菌生长及絮凝剂合成的最佳碳源；玉米浆既能刺激菌体生长，又能显著提高絮凝剂的水平，生物絮凝剂的合成与培养基碳氮比密切相关，碳氮比在20－30之间时，絮凝活性达到最大，碳氮比低于10或高于100后，絮凝活性迅速下降，提出了促进絮凝剂合成的控制策略，发酵前期适当提高玉米浆的浓度，发酵后期按碳氮比为20－30，补加一定量的蔗糖和尿素，实验结果表明，采用这一策略，最终发酵液的絮凝活性和细胞生长量分别增长了8％和33．3％。     

Achieving Open Access to Conservation Science

Conservation science is a crisis discipline in which the results of scientific enquiry must be made available quickly to those implementing management. We assessed the extent to which scientific research published since the year 2000 in 20 conservation science journals is publicly available. Of the 19,207 papers published, 1,667 (8.68%) are freely downloadable from an official repository. Moreover, only 938 papers (4.88%) meet the standard definition of open access in which material can be freely reused providing attribution to the authors is given. This compares poorly with a comparable set of 20 evolutionary biology journals, where 31.93% of papers are freely downloadable and 7.49% are open access. Seventeen of the 20 conservation journals offer an open access option, but fewer than 5% of the papers are available through open access. The cost of accessing the full body of conservation science runs into tens of thousands of dollars per year for institutional subscribers, and many conservation practitioners cannot access pay‐per‐view science through their workplace. However, important initiatives such as Research4Life are making science available to organizations in developing countries. We urge authors of conservation science to pay for open access on a per‐article basis or to choose publication in open access journals, taking care to ensure the license allows reuse for any purpose providing attribution is given. Currently, it would cost $51 million to make all conservation science published since 2000 freely available by paying the open access fees currently levied to authors. Publishers of conservation journals might consider more cost effective models for open access and conservation‐oriented organizations running journals could consider a broader range of options for open access to nonmembers such as sponsorship of open access via membership fees. Obtención de Acceso Abierto a la Ciencia de la Conservación     

Some polyphagous Homoptera gain protection from their natural enemies by feeding on the toxic plantsSpartium junceum andErythrina corallodendrum (Leguminosae)

Summary Interactions were studied among alkaloid-containing legumes (Erythrina corallodendrum andSpartium junceum) and non-toxic plants (Citrus sinensis, Cucurbita moschata andEuphorbia tirucalli), several polyphagous homopterans,Aphis craccivora (Aphididae),Icerya purchasi, I. aegyptiaca (Margarodidae),Lepidosaphes ulmi (Diaspididae) andPlanococcus citri (Pseudococcidae), and some major natural enemies of these homopterans. Significant reductions in survival due to negative effects of alkaloid containing as compared with non-alkaloidal plants were recorded for the predatorsRodolia cardinalis andChilocorus bipustulatus, but not forCryptolaemus montrouzieri (Coleoptera: Coccinellidae),Chrysoperla carnea (Neuroptera: Chrysopidae) andSympherobius sanctus (Neuroptera: Sympherobiidae). The development time of the larvae or pupae ofR. cardinalis, C. carnea andS. sanctus was longer on the toxic plants than on the non-toxic ones. The percentage of parasitism ofA. craccivora collected from the non-alkaloidal plantsVicia palaestina andMelilotus albus was much higher than that onS. junceum. The parasitoid complexes ofA. craccivora differed between both plant groups. The nutritive value of honeydew ofI. purchasi andA. craccivora, as expressed by the life span ofEncyrtus infelix (Hymenoptera: Encyrtidae) adults, was also investigated. Life spans were significantly longer when the wasps fed on honeydew produced on non-alkaloidal plants (C. sinensis andPittosporum tobira) than on alkaloid containing plants whenI. purchasi — but notA. craccivora — was the producer. It is suggested that the chemical defense ofE. corallodendrum andS. junceum is exploited by polyphagous phytophages to reduce predation. In nature, population growth and density of four of the investigated homopterans are conspicuously high when they developed on the alkaloid containing plant species, and very low on non-alkaloid plants. The efficiency of their natural enemies may be reduced by sequestration of alkaloids (or other toxic plant compounds) or their transfer into excreted honeydew. Therefore it is assumed that a generalist phytophagous homopteran may be protected from its natural enemies, although at different rates of efficiency, if it can safely sequester the host allelochemical when it develops on toxic species within its host range.     

Importance of greater interdisciplinarity and geographic scope when tackling the driving forces behind biological invasions

Invasive non-native species are important drivers of ecosystem change, yet the driving forces of biological invasions themselves are poorly understood. Such information is essential to ensure policies focus on the most relevant drivers, and that future scenarios capture the full range of potential outcomes for invasive non-native species. I carried out a bibliometric analysis of articles published from 2000 to 2020 that address either invasive non-native species or biodiversity and ecosystem services and that also mention 1 or more drivers of ecosystem change. I examined 5 indirect drivers (demographic, economic, governance, sociocultural, and technological) and 6 direct drivers (climate change, invasive non-native species, land-use or sea-use change, natural hazards, pollution, and resource extraction). Using the Web of Science core collection of citation indexes, I undertook searches of article titles and keywords and retrieved 27,462 articles addressing invasive non-native species and 110,087 articles dealing with biodiversity or ecosystem services. Most research to date on biological invasions as well as on biodiversity and ecosystem services has focused on anthropogenic direct drivers of ecosystem change rather than indirect drivers. Yet currently, less than 18% of articles addressing biological invasions examined drivers of ecosystem change, a similar level to that found over 20 years ago for biodiversity or ecosystem services. Knowledge of the drivers of biological invasions is limited, emphasizes tractable drivers over those that require an interdisciplinary approach, and is biased toward developed economies. Drivers generally deemed important for biological invasions, such as governance and resource extraction, accounted for less than 2% of research effort. The absence of a systematic understanding of the forces that drive invasive non-native species and how they interact means that attempts to mitigate or forecast biological invasions are likely to fail. To address biological invasions requires a much better orientation of national and international research on drivers in relation to both their actual importance as well as their policy relevance.     

Sequestration of cucurbitacin analogs by New and Old World chrysomelid leaf beetles in the tribe Luperini

Summary Two South American polyphagous leaf beetles,Diabrotica speciosa andCerotoma arcuata, selectively accumulated the bitter tasting compound 23,24-dihydrocucurbitacin D in their body after ingesting root tissues of cucurbit plants. Similarly, three Asian Cucurbitaceae-feeding specialists in the genusAulacophora were found to sequester the same compound. Cucurbitacin analogs were shown to deter feeding by a bird predator, indicating an allomonal role for these compounds in cucurbitacin-associated chrysomelid leaf beetles both of New and Old Worlds. The strong affinity to cucurbitacins, selective sequestration of the analogs and consequent protection from predators suggested an ecological adaptation mechanism developed in common among these two geographically isolated subtribes in the Luperini.     

Mitigating the effects of climate change on the nests of sea turtles with artificial irrigation

For sea turtles, like many oviparous species, increasing temperatures during development threaten to increase embryonic mortality, alter offspring quality, and potentially create suboptimal primary sex ratios. Various methods are being implemented to mitigate the effects of climate change on reproductive success, but these methods, such as breeding programs, translocations, and shading, are often invasive and expensive. Irrigation is an alternative strategy for cooling nests that, depending on location, can be implemented relatively quickly and cheaply. However, multiple factors, including ambient conditions, nest substrate, and species characteristics, can influence irrigation success. Additionally, irrigation can vary in duration, frequency, and the volume of water applied to nests, which influences the cooling achieved and embryonic survival. Thus, it is critical to understand how to maximize cooling and manage risks before implementing irrigation as a nest-cooling strategy. We reviewed the literature on nest irrigation to examine whether artificial irrigation is feasible as a population management tool. Key factors that affected cooling were the volume of water applied and the frequency of applications. Embryonic responses varied with species, ambient conditions, and the timing of irrigation during development. Nest inundation was the key risk to a successful irrigation regime. Future irrigation regimes must identify clear targets, either primary or adult sex ratios, that maximize population viability. Monitoring population responses and adjusting the irrigation regime in response to population characteristics will be critical. Most studies reported on the manipulation of only one or two variables, further research is required to understand how altering multiple factors in an irrigation regime influences the cooling achieved and embryonic responses.     

Effects of Controlled Fire and Livestock Grazing on Bird Communities in East African Savannas

Abstract: In East Africa fire and grazing by wild and domestic ungulates maintain savannas, and pastoralists historically set fires and herded livestock through the use of temporary corrals called bomas. In recent decades traditional pastoral practices have declined, and this may be affecting biodiversity. We investigated the effects of prescribed fires and bomas on savanna bird communities in East Africa during the first and second dry seasons of the year (respectively before and after the rains that mark the onset of breeding for most birds). We compared abundance, richness, and community composition on 9‐ha burned plots, recently abandoned bomas, and control plots in the undisturbed matrix habitat over a 3‐year period. Generally, recently burned areas and abandoned bomas attracted greater densities of birds and had different community assemblages than the surrounding matrix. The effects of disturbances were influenced by interactions between primary productivity, represented by the normalized difference vegetation index, and time. Bird densities were highest and a greater proportion of species was observed on burned plots in the months following the fires. Drought conditions equalized bird densities across treatments within 1 year, and individuals from a greater proportion of species were more commonly observed on abandoned bomas. Yearly fluctuations in abundance were less pronounced on bomas than on burns, which indicate that although fire may benefit birds in the short term, bomas may have a more‐lasting positive effect and provide resources during droughts. Several Palearctic migrants were attracted to burned plots regardless of rainfall, which indicates continued fire suppression may threaten their already‐declining populations. Most notably, the paucity of birds observed on the controls suggests that the current structure of the matrix developed as a result of fire suppression. Traditional pastoralism appears critical to the maintenance of avian diversity in these savannas.     

Positive and Negative Effects of a Threatened Parrotfish on Reef Ecosystems

Species that are strong interactors play disproportionately important roles in the dynamics of natural ecosystems. It has been proposed that their presence is necessary for positively shaping the structure and functioning of ecosystems. We evaluated this hypothesis using the case of the world's largest parrotfish (Bolbometopon muricatum), a globally imperiled species. We used direct observation, animal tracking, and computer simulations to examine the diverse routes through which B. muricatum affects the diversity, dispersal, relative abundance, and survival of the corals that comprise the foundation of reef ecosystems. Our results suggest that this species can influence reef building corals in both positive and negative ways. Field observation and simulation outputs indicated that B. muricatum reduced the abundance of macroalgae that can outcompete corals, but they also feed directly on corals, decreasing coral abundance, diversity, and colony size. B. muricatum appeared to facilitate coral advancement by mechanically dispersing coral fragments and opening up bare space for coral settlement, but they also damaged adult corals and remobilized a large volume of potentially stressful carbonate sediment. The impacts this species has on reefs appears to be regulated in part by its abundance—the effects of B. muricatum were more intense in simulation scenarios populated with high densities of these fish. Observations conducted in regions with high and low predator (e.g., sharks) abundance generated results that are consistent with the hypothesis that these predators of B. muricatum may play a role in governing their abundance; thus, predation may modulate the intensity of the effects they have on reef dynamics. Overall our results illustrate that functionally unique and threatened species may not have universally positive impacts on ecosystems and that it may be necessary for environmental managers to consider the diverse effects of such species and the forces that mediate the strength of their influence. Efectos Positivos y Negativos de un Pez Loro Amenazado Sobre Ecosistemas Arrecifales     

Form-specific fragances fromOphrys insectifera L. (Orchidaceae) attract species of different pollinator genera. Evidence of sympatric speciation?

Two closely related forms ofOphrys insectifera were observed in the field to attract different pollinator species selectively.O. i. ssp.insectifera attracted males of two species ofArgogorytes (Sphecidae, Hymenoptera Aculeata) andO. i. ssp.aymoninii attractedAndrena combinata males (Andrenidae, Apoidea, Hymenoptera Aculeata). A third form,O. aff.i. ssp.insectifera, attracted none of these three species. Volatile compounds from flowers and inflorescences of the three forms (originating from Öland, Sweden, and Aveyron, France) were collected, using entrainment, enfleurage, and solvent extraction techniques, and identified by gas chromatography — mass spectrometry. Scent differences between the three forms were confirmed in the amounts of aliphatic hydrocarbons (C₁₁–C₁₉), methyl esters (C₁₄–C₁₈), short chain aliphatic 1-alcohols (C₆–C₁₂), and monoterpene alcohols (C₁₀).     

Effects of Coffee Management on Deforestation Rates and Forest Integrity

Knowledge about how forest margins are utilized can be crucial for a general understanding of changes in forest cover, forest structure, and biodiversity across landscapes. We studied forest‐agriculture transitions in southwestern Ethiopia and hypothesized that the presence of coffee (Coffea arabica)decreases deforestation rates because of coffee's importance to local economies and its widespread occurrence in forests and forest margins. Using satellite images and elevation data, we compared changes in forest cover over 37 years (1973–2010) across elevations in 2 forest‐agriculture mosaic landscapes (1100 km² around Bonga and 3000 km² in Goma‐Gera). In the field in the Bonga area, we determined coffee cover and forest structure in 40 forest margins that differed in time since deforestation. Both the absolute and relative deforestation rates were lower at coffee‐growing elevations compared with at higher elevations (?10/20% vs. ?40/50% comparing relative rates at 1800 m asl and 2300–2500 m asl, respectively). Within the coffee‐growing elevation, the proportion of sites with high coffee cover (>20%) was significantly higher in stable margins (42% of sites that had been in the same location for the entire period) than in recently changed margins (0% of sites where expansion of annual crops had changed the margin). Disturbance level and forest structure did not differ between sites with 30% or 3% coffee. However, a growing body of literature on gradients of coffee management in Ethiopia reports coffee's negative effects on abundances of forest‐specialist species. Even if the presence of coffee slows down the conversion of forest to annual‐crop agriculture, there is a risk that an intensification of coffee management will still threaten forest biodiversity, including the genetic diversity of wild coffee. Conservation policy for Ethiopian forests thus needs to develop strategies that acknowledge that forests without coffee production may have higher deforestation risks than forests with coffee production and that forests with coffee production often have lower biodiversity value. Efectos de la Administración Cafetalera sobre las Tasas de Deforestación y la Integridad de los Bosques     

What Every Conservation Biologist Should Know about Economic Theory

Abstract: The last century has seen the ascendance of a core economic model, which we will refer to as Walrasian economics. This model is driven by the psychological assumptions that humans act only in a self‐referential and narrowly rational way and that production can be described as a self‐contained circular flow between firms and households. These assumptions have critical implications for the way economics is used to inform conservation biology. Yet the Walrasian model is inconsistent with a large body of empirical evidence about actual human behavior, and it violates a number of basic physical laws. Research in behavioral science and neuroscience shows that humans are uniquely social animals and not self‐centered rational economic beings. Economic production is subject to physical laws including the laws of thermodynamics and mass balance. In addition, some contemporary economic theory, spurred by exciting new research in human behavior and a wealth of data about the negative global impact of the human economy on natural systems, is moving toward a world view that places consumption and production squarely in its behavioral and biophysical context. We argue that abandoning the straightjacket of the Walrasian core is essential to further progress in understanding the complex, coupled interactions between the human economy and the natural world. We call for a new framework for economic theory and policy that is consistent with observed human behavior, recognizes the complex and frequently irreversible interaction between human and natural systems, and directly confronts the cumulative negative effects of the human economy on the Earth's life support systems. Biophysical economics and ecological economics are two emerging economic frameworks in this movement.