树状多节孢原生质体的制备和再生

研究了酶系组成、酶解时间、酶解温度、渗透压稳定剂、PH值,培养基成分、培养方式,预处理、保护剂等因素对紫杉醇产生菌树状多孔孢原生质体制备和再生的影响。结果表明：将树状多节孢在PDA液体培养其中静止培养2－3d,离心收集菌体,用PH5．5－6．0的0．7mol/L的NaCl配制成的含有3％纤维素酶、2％蜗牛酶和1％溶菌酶的复合酶,30℃恒温酶解9h,原生质体制备率最高。但是考虑到原生质体的再生,参酶解7h左右为宜,获得的原生质体经过纯化,用0.7mol/LNaCl配制的PDA再生培养基进行双层平板培养法再生,原生质体的再生率最高。本研究为以后通过原生质体诱变、转化、融合构建紫杉醇工程菌株奠定了基础,图3表9参16     

平菇原生质体的高效制备及再生优化条件

以杂优1号平菇为出发菌株,对其原生质体制备、再生的各关键因子及条件进行比较研究,结果表明,其原生质体制备的优化条件为:以0.6 mol/L MgSO4为稳渗剂配制浓度为15 mg/mL新鲜溶壁酶液,菌丝与酶液比w/V=1mg:8μL,取培养6 d的菌丝200 mg,自然pH下28℃小平板酶解6 h,原生质体得率可达2.80×107个/mL.原生质体再生实验结果表明,50 U/mL链霉素能有效控制平菇原生质体再生的杂菌污染.孟加拉红对平菇原生质体再生具强抑制作用,抑制率达93%.进一步研究证实,0.6 mol/L的MsSO4、KCI等无机盐稳渗剂对原生质体制备的得率较高,而0.6 mol/L的蔗糖作为稳渗剂的平菇原生质体再生率较高.图4表3参23     

产碱性果胶酶的枯草芽孢杆菌ZGL14原生质体制备与再生条件

原生质体融合技术是一种重要的微生物育种方法.以能产碱性果胶酶的枯草芽孢杆菌ZGL14为出发菌株,探讨影响其原生质体制备和再生的主要因素.通过研究菌龄、溶菌酶浓度、酶解时间、酶解温度、渗透压稳定剂的p H值、再生培养基类型和培养方式等对枯草芽孢杆菌ZGL14原生质体制备与再生的影响,确定其最优化条件.结果显示:枯草芽孢杆菌ZGL14原生质体制备的最优条件为菌龄9 h,溶菌酶浓度0.2 mg/m L,酶解时间10 min,酶解温度32℃,渗透压稳定剂的p H值7.0.在此条件下,枯草芽孢杆菌ZGL14原生质体的形成率为98%,再生率达30%.枯草芽孢杆菌ZGL14原生质体再生培养基以琥珀酸钠作为渗透压稳定剂并结合Ca~(2+)再生效果较好,再生方式以单层培养较好.本研究获得了枯草芽孢杆菌ZGL14原生质体制备和再生的最佳条件,可为实现其融合育种提供技术支持.     

氢化可的松高转化菌株的选育及其发酵条件

利用酮康唑抗性突变选育氢化可的松高转化菌株，即将经过紫外线诱变处理的新月弯孢霉原生质体倾注于含有酮康唑最小抑制浓度(10μmoL／L)的培养基平板上，获得了136株酮康唑抗性突变株，氢化可的松转化率高于出发菌株的有14株．其中抗性突变株KA-91，其氢化可的松转化率为出发菌株的1．42倍，达到68．05％．研究了菌株的发酵性能，优化了培养基组成和发酵工艺条件，氢化可的松转化率达到73．6％．图7表3参5     

硫杆菌的分离鉴定及其对煤矿废弃物的氧化脱硫特性

从宁夏大武口高硫煤矸石山的酸性废水中分离得到一株自养硫氧化细菌CMTF-32．该菌极端耐酸，能氧化低价态硫化物，氧化单质硫的能力强，在d11时单质硫的氧化率达到65．6％，日产硫酸能力最高时能达3．0g／L．培养基pH值在培养过程中明显下降．16S rDNA序列分析表明，该菌株与Acidithiobacillus thiooxidans相似性为99％，结合形态、生理生化实验结果，确定菌株CMTF-32为嗜酸氧化硫硫杆菌．煤矸石的脱硫实验表明，在煤矸石粒径小于2mm，初始pH为1．5，30℃培养条件下脱硫效果最佳，d14时脱硫量为2．72g／L，脱硫率可达到84．5％，使煤矸石的硫污染得到了有效的控制．图5表1参13     

红豆杉内生真菌发酵培养基和原生质体制备酶系统的筛选

在对红豆杉内生真菌(Ozoniumsp.)适生碳源、氮源和生长情况研究的基础上,通过正交试验筛选了其发酵培养基和原生质体制备的酶系统;用L9(34)安排了四因素三水平并考虑交互作用的正交试验,对实验结果进行了分析.结果表明,最优的发酵培养基为果糖1%、蔗糖1%、蛋白胨0.2%、酵母粉0.5%、KH2PO40.5%、MgSO4·7H2O0.3%、VB10.001%;分离原生质体的最优酶系统为1.5%溶壁酶 0.5%蜗牛酶 1.5%纤维素酶 1.0%溶菌酶;用此酶系统在30℃条件下酶解3h,原生质体的产量达6.55×107个/mL酶液;经荧光素二醋酸酯(FDA)染色评估原生质体活力,表明该条件下分离的原生质体活力较高,原生质体的再生率为2.56%.该研究为利用生物技术手段改良紫杉醇生产菌奠定了基础.图6表4参32     

绿色木霉T-99株产纤维素酶的研究

从土壤中筛选获得一株产纤维素酶的优良菌株绿色木霉 Ｔ９９ ,采用固体培养产生纤维素酶,对培养基成分进行优化,并分析酶的理化性质,研究了稻草酶解的适宜条件．在最优培养条件下,产酶活力λ（ Ｆ Ｐ） ｍ － １ Ｄ Ｗ≈１２０ Ｕ／ｇ ,λ（ Ｃ Ｍ Ｃａｓｅ） ｍ － １ Ｄ Ｗ≈１１０ ～１２５ Ｕ／ｇ,λ（β Ｇａｓｅ） ｍ － １ Ｄ Ｗ≈９０ Ｕ／ｇ ,在５０ ℃,ｐ Ｈ４ ．０ ,底物浓度５ ％ ,酶解３６ ｈ 条件下,底物得糖率３３ ．４９ ％ ,全纤维转化率６１ ．３３ ％     

产类胡萝卜素菌株的筛选及其培养条件初探

从土壤、植物落花、细菌污染的组织培养二三角瓶里的培养基上及被细菌污染的LB琼脂平板上分离筛选出十几株产类胡萝卜素的菌株，其中从污染的LB琼脂平板上分离的一株菌落颜色为黄色的菌株PBH，分类鉴定为库特氏菌属(Kurthia sp.)．菌株在以葡萄糖为碳源，添加番茄汁(3．6mL／L)、芝麻油(1．6mL／L)、Na2CO3(6g/L)和磷酸缓冲盐的液体培养基中28℃振荡培养5d，每mL培养液细胞生物量湿重达到65．57mg，类胡萝卜素产量达到9．896μg，菌体每g湿重细胞胡萝卜素含量为150．9μg．图10参13     

石油降解菌的分离、鉴定及其降解能力的研究

从含油污泥中,筛选出能以２０ ＃ 机械润滑油为唯一碳源的３ 株石油降解菌菌株,经鉴定分别为动胶菌属（ Ｚｏｏｇｌｏｅａ ｓｐ ．） 、氮单胞菌属（ Ａｚｏｍｏｎａｓｓｐ ．） 和假单胞菌属（ Ｐｓｅｕｄｏｍｏｎａｓ ｓｐ ．） ．通过其降解能力的测试,以动胶菌 Ｄ２ 菌株对２０ ＃ 机油的降解能力最强：在含油浓度ρ＝ ５００ ～１ ５００ ｍｇ／ Ｌ 的摇瓶试验中,其除油率为２０ ．８ ％ ～２５ ％ ．利用动胶菌 Ｄ２ 菌株进行生物接触氧化法处理含油废水模拟试验,当入流浓度为１ ０００ ｍｇ／ Ｌ 时,除油率可达９０ ．５ ％ ～１００ ％ ．这一结果表明,动胶菌 Ｄ２ 菌株生物接触氧化法处理含油废水具有很好的应用前景     

嗜碱细菌降解木质素的复合碳源共代谢研究Ⅱ—营养条件调控机制的研究

文章研究了在蔗糖（第一碳源）＋麦草木质素（第二碳源）的复合碳源组合方式培养条件下,嗜碱木质素降解菌降解木质素的降解率及营养条件调控机制对其的影响。结果表明,蔗糖初始浓度为1g/L,添加0．3％的T－80和0.5mmol/L的ABTS并静置培养对菌株的产酶及降解能力有较大的促进作用。     

Rapid,recurring, structured survey versus bioblitz for generating biodiversity data and analysis with a multispecies abundance model

A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.     

Compliance with and ecosystem function of biodiversity offsets in North American and European freshwaters

Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.     

A palaeo-hydrogeological model for arsenic contamination in southern and south-east Asia

An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.     

Cost‐effective conservation of an endangered frog under uncertainty

How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well‐developed tools exist for prioritizing areas for one‐time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost‐effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost‐effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost‐effectiveness analysis. This allowed us to discern between cost‐effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost‐effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost‐effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost‐effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost‐effective conservation under uncertainty.     

Threats to intact tropical peatlands and opportunities for their conservation

Large, intact areas of tropical peatland are highly threatened at a global scale by the expansion of commercial agriculture and other forms of economic development. Conserving peatlands on a landscape scale, with their hydrology intact, is of international conservation importance to preserve their distinctive biodiversity and ecosystem services and maintain their resilience to future environmental change. We explored threats to and opportunities for conserving remaining intact tropical peatlands; thus, we excluded peatlands of Indonesia and Malaysia, where extensive deforestation, drainage, and conversion to plantations means conservation in this region can protect only small fragments of the original ecosystem. We focused on a case study, the Pastaza‐Marañón Foreland Basin (PMFB) in Peru, which is among the largest known intact tropical peatland landscapes in the world and is representative of peatland vulnerability. Maintenance of the hydrological conditions critical for carbon storage and ecosystem function of peatlands is, in the PMFB, primarily threatened by expansion of commercial agriculture linked to new transport infrastructure that is facilitating access to remote areas. There remain opportunities in the PMFB and elsewhere to develop alternative, more sustainable land‐use practices. Although some of the peatlands in the PMFB fall within existing legally protected areas, this protection does not include the most carbon‐dense (domed pole forest) areas. New carbon‐based conservation instruments (e.g., REDD+, Green Climate Fund), developing markets for sustainable peatland products, transferring land title to local communities, and expanding protected areas offer pathways to increased protection for intact tropical peatlands in Amazonia and elsewhere, such as those in New Guinea and Central Africa which remain, for the moment, broadly beyond the frontier of commercial development.     

Human Influence and Classical Biogeographic Predictors of Rare Species Occurrence

Biogeographic theory predicts that rare species occur more often in larger, less‐isolated habitat patches and suggests that patch size and connectivity are positive predictors of patch quality for conservation. However, in areas substantially modified by humans, rare species may be relegated to the most isolated patches. We used data from plant surveys of 81 meadow patches in the Georgia Basin of Canada and the United States to show that presence of threatened and endangered plants was positively predicted for patches that were isolated on small islands surrounded by ocean and for patches that were isolated by surrounding forest. Neither patch size nor connectivity were positive predictors of rare species occurrence. Thus, in our study area, human influence, presumably due to disturbance or introduction of competitive non‐native species, appears to have overwhelmed classical predictors of rare species distribution, such that greater patch isolation appeared to favor presence of rare species. We suggest conservation planners consider the potential advantages of protecting geographically isolated patches in human‐modified landscapes because such patches may represent the only habitats in which rare species are likely to persist. Influencia Humana y Predictores Biogeográficos Clásicos de la Ocurrencia de Especies Raras     

Seasonal dynamics of macro-algae in the South Lake of Tunis

The macro-algae communities observed in the south lake of Tunis are characterized by the predominance of nitrophilous algae which are in the order of biomass importance:Ulva, Cladophora andEnteromorpha. We have noted seasonal changes of alga distribution. The wind appears to be one of the most important factors influencing this distribution. The total biomass reaches a maximum in the spring. Rapid decomposition of the biomass leads to a severe ecological imbalance, resulting in crises of anoxia and fish death. A restoration project has already started. It aims at removal of contaminated muds and the introduction of a new circulation system. The main objectives of this work were to collect information on the distribution and biomass of the phytobenthic communities as a first step in the constitution of a database for further comparison.     

Patterns and biases of climate change threats in the IUCN Red List

International Union for Conservation of Nature (IUCN) Red List assessments rely on published data and expert inputs, and biases can be introduced where underlying definitions and concepts are ambiguous. Consideration of climate change threat is no exception, and recently numerous approaches to assessing the threat of climate change to species have been developed. We explored IUCN Red List assessments of amphibians and birds to determine whether species listed as threatened by climate change display distinct patterns in terms of habitat occupied and additional nonclimatic threats faced. We compared IUCN Red List data with a published data set of species’ biological and ecological traits believed to infer high vulnerability to climate change and determined whether distributions of climate change‐threatened species on the IUCN Red List concur with those of climate change‐threatened species identified with the trait‐based approach and whether species possessing these traits are more likely to have climate change listed as a threat on the IUCN Red List. Species in some ecosystems (e.g., grassland, shrubland) and subject to particular threats (e.g., invasive species) were more likely to have climate change as a listed threat. Geographical patterns of climate change‐threatened amphibians and birds on the IUCN Red List were incongruent with patterns of global species richness and patterns identified using trait‐based approaches. Certain traits were linked to increases or decreases in the likelihood of a species being threatened by climate change. Broad temperature tolerance of a species was consistently related to an increased likelihood of climate change threat, indicating counterintuitive relationships in IUCN assessments. To improve the robustness of species assessments of the vulnerability or extinction risk associated with climate change, we suggest IUCN adopt a more cohesive approach whereby specific traits highlighted by our results are considered in Red List assessments. To achieve this and to strengthen the climate change‐vulnerability assessments approach, it is necessary to identify and implement logical avenues for further research into traits that make species vulnerable to climate change (including population‐level threats).     

Parasitic wasps orient to green leaf volatiles

Summary Undamaged plants emit low levels of green leaf volatiles (GLVs), while caterpillar-damaged and artificially damaged plants emit relatively higher levels of certain GLVs. Female braconid parasitoids,Microplitis croceipes, oriented to both damaged plants and to individual GLVs in no-choice tests in a wind tunnel, but seldom oriented to undamaged plants. Female ichneumonid parasitoids,Netelia heroica, also oriented to individual GLVs in a wind tunnel. Males of both wasp species failed to orient to the GLVs. These data show that leaf-feeding caterpillars can cause the release of GLVs, and that parasitic wasps can respond to these odors by flying upwind (chemoanemotactic response), which brings the wasps to their caterpillar hosts. This supports the hypothesis that plants communicate with members of the third trophic level,i.e., plants under herbivore attack emit chemical signals that guide natural enemies of herbivores to sites of plant damage. In this interaction, the GLVs serve as tritrophic plant-to-parasitoid synomones. That parasitoids from two different wasp families oriented to GLVs suggests that the response may be widespread among the Hymenoptera.Mention of a commercial or proprietary product does not constitute an endorsement by the U.S. Department of Agriculture