应用环境微生物治理淡水湖泊微囊藻毒素污染的研究进展

近年来,随着水体富营养化程度的加剧,蓝藻水华现象时有发生,蓝藻及其释放的藻毒素对生态环境和人类健康构成严重威胁。在各种藻毒素中,以微囊藻毒素(Microcystins,MCs)毒性最强,对人类危害也最大,微囊藻毒素的化学性质相对稳定且难以通过常规水处理方法消除,因此如何有效去除环境中的MCs是国内外普遍关注的难题。研究发现自然界中的微生物能够有效降解和消除MCs污染,由此产生的环保技术极具应用价值。本文主要概述了微囊藻毒素的产生机理、化学结构以及毒性危害,总结了微囊藻毒素的自然分解过程以及微生物群落对微囊藻毒素的响应机制,重点分析了微生物群落在微囊藻毒素污染控制技术中的潜在应用,并对应用微生物技术治理微囊藻毒素污染的技术瓶颈提出了建议,以期加速微囊藻毒素微生物降解技术的完善和应用。     

Are Research Schools Necessary? Contrasting Models of 20th Century Research at Yale Led by Ross Granville Harrison, Grace E. Pickford and G. Evelyn Hutchinson

This paper compares and contrasts three groups that conducted biological research at Yale University during overlapping periods between 1910 and 1970. Yale University proved important as a site for this research. The leaders of these groups were Ross Granville Harrison, Grace E. Pickford, and G. Evelyn Hutchinson, and their members included both graduate students and more experienced scientists. All produced innovative research, including the opening of new subfields in embryology, endocrinology and ecology respectively, over a long period of time. Harrison's is shown to have been a classic research school; Pickford's and Hutchinson's were not. Pickford's group was successful in spite of her lack of department or institutional position or power. Hutchinson and his graduate and post-graduate students were extremely productive but in diverse areas of ecology. His group did not have one focused area of research or use one set of research tools. The paper concludes that new models for research groups are needed, especially for those, like Hutchinson's, that included much field research.     

Enhancement of physical weathering of building stones by microbial populations

Two limestones from Crete, Greece and a dolomite from Mansfield, UK were subjected to combined microbial and physical weathering simulation cycles, in an attempt to assess the contribution of each agent of decay. Sound stone discs were exposed to different temperature and wet/dry cycling regimes involving treatment with distilled water or solutions of sodium chloride or sodium sulphate. Before the weathering cycles, half of the discs were inoculated with mixed microbial populations (MMP), originally recovered from decayed building stone of Portchester Castle, Hampshire, UK. The presence of MMP greatly accelerated the rates of deterioration of stone of all treatments, measured by weight change and alteration of hydraulic properties of stone. A combination of physical and biological processes significantly enhanced the extent of decay when compared with the physical or biological agents acting alone. Populations of heterotrophic, sulphur-utilising, halotolerant and moderately halophilic bacterial populations remained large throughout the experiment. Biofilms formed by populations of microorganisms were visualised by staining and assessed by colorimetric measurement of total carbohydrate in the stone substrate. The relative contribution of microbial and physical weathering to the process is discussed.     

Some African fossil foot bones: a note on the interpolation of fossils into a matrix of extant species

Certain fossil foot bones (a terminal toe phalanx from Olduvai, specimens of tali from Spy, Skhūl, Olduvai, Kromdraai, Songhor and Rusinga) have been investigated by other workers using the multivariate statistical approach. The conclusions of their studies have, in the main, been based upon examination of early canonical variates alone. It is demonstrated here that if the full analyses (generalized distances) are taken into account, then almost exactly opposite conclusions obtain. The terminal toe phalanx from Olduvai is widely different from those of modern men; the Neandertal tali differ more from modern human bones than previously realized; the specimens from Olduvai, Kromdraai, Songhor and Rusinga are all completely dissimilar from both African ape and modern human tali.     

GOING FURTHER INTO LATE MESOZOIC MESOLYGAEIDS (HETEROPTERA, INSECTA)

A large collection of fossil insects has recently been recovered from the Late Mesozoic nonmarine sediments throughout East Asia, with many specimens regarded as the mesolygaeids, representing a new family Mesolygaeidae of Heteroptera. As Lycoptera Muller and Eosestheria Chen, Mesolygaeus Ping is the common genus of the Jehol fauna Since some of them are geographically widespread and can be easily collected, they are significant to stratigraphic divisions and correlations in East Asia.     

Interkingdom networking within the oral microbiome

Different sites within the oropharynx harbour unique microbial communities. Co-evolution of microbes and host has resulted in complex interkingdom circuitries. Metabolic signalling is crucial to these processes, and novel microbial communication factors are progressively being discovered. Resolving interkingdom networks will lead to better understanding of oral health or disease aetiology.     

A multi-level approach using Gambusia affinis as a bioindicator of environmental pollution in the middle-lower basin of Suquía River

The Suquía River middle-lower basin (Córdoba, Argentina) is subjected to a strong anthropogenic impact because it receives pollutants from different sources. The main goal of this study was to evaluate the introduced fish species Gambusia affinis as a bioindicator of environmental pollution in the middle-lower basin of the Suquía River. The assessment was performed by measuring biomarkers at different levels of biological organization, at two sampling sites (before and after Córdoba city), and at dry and wet seasons. Water quality evaluation was made through a water-quality index (based on physico-chemical parameters), heavy-metals and pesticides concentrations in water. The water quality varied between sampling sites, showing the most degraded conditions downstream Córdoba city. The same pattern of variation was detected in the biomarkers studied, mainly in: gill and liver histopathological indexes, copulatory organ (gonopodium) morphology and vitellogenin expression in males and females. The present study characterized the environmental conditions in the middle-lower basin of the Suquía River and revealed the low freshwater quality at the most polluted site. Although G. affinis is an introduced species, it could be considered a good sentinel of water resource quality of invaded Neotropical basins. Our results demonstrated the importance of addressing the environmental quality monitoring through an integrated analysis of water quality parameters together with histological, morphological and molecular parameters. Thus, our study provides a good model for application in other basins of South America.     

Habitat models of wood-inhabiting fungi along a decay gradient of Norway spruce logs

Information on the habitat requirements of wood-inhabiting fungi is needed to understand the factors that affect their diversity. We applied culture-free DNA extraction and 454-pyrosequencing to study the mycobiota of decaying Norway spruce (Picea abies) logs in five unmanaged boreal forests. Fungal habitat preferences in respect of wood density gradient were then estimated with generalized additive mixed models. Fungal diversity and wood density were inversely related, i.e., OTU richness generally increased as the log became increasingly decomposed. White-rot fungi (e.g., Phellinus nigrolimitatus) and members of Hyphodontia did not show a clear response to the wood-density gradient, whereas abundance of Phellinus viticola and brown-rot fungi (e.g., Fomitopsis pinicola, Antrodia serialis, Coniophora olivaceae) peaked during intermediate decay and mycorrhizal fungi (e.g., Piloderma, Tylospora, Russula) increased in the later stages. This information on fungal habitat requirements facilitates the development of management practices that preserve fungal diversity in managed forests.     

Urinary Biomarkers of Brain Diseases

Biomarkers are the measurable changes associated with a physiological or pathophysiological process. Unlike blood, urine is not subject to homeostatic mechanisms. Therefore, greater fluctuations could occur in urine than in blood, better reflecting the changes in human body. The roadmap of urine biomarker era was proposed. Although urine analysis has been attempted for clinical diagnosis, and urine has been monitored during the progression of many diseases, particularly urinary system diseases, whether urine can reflect brain disease status remains uncertain. As some biomarkers of brain diseases can be detected in the body fluids such as cerebrospinal fluid and blood,there is a possibility that urine also contain biomarkers of brain diseases. This review summarizes the clues of brain diseases reflected in the urine proteome and metabolome.     

Scale of classification based on biochemical markers in mussels: application to pollution monitoring in European coasts

A battery of biochemical parameters is used to evaluate the response of mussels to a contaminated coastal environment. In the European BIOMAR programme, a multimarker approach was developed, establishing a scale for the classification of the water quality in European coastal sites. AChE activity is highly sensitive to organophosphorus and carbamate insecticides but also to heavy metals. Catalase activity and lipid oxidation (evaluated as MDA) are markers of oxidative stress, GST activity is related to the conjugation of organic compounds and BPH activity is a marker of planar compounds (e.g. PAHs). These parameters were measured either in gills (AChE, GST) or digestive gland (BPH, GST, CAT, MDA). Contamination levels were estimated by measurement of PAHs and heavy metals in animals. For each biomarker, a discriminatory factor was calculated (maximum variation range/confidence interval) and a response index was allocated. For each site, a global response index was calculated as the sum of the response index of each of the five biomarkers. As a result of our calculation method, the quality of the coastal environment at each site can be classified with a five level scale. Mussels were collected during five cruises in 1995-1996 on the Baltic and Mediterranean coasts. The results show that water quality ranged from class 1 (clean areas in some sites of the French Riviera, Spanish Costa Brava and the Baltic coast) to class 5 (high pollution in main harbours, e.g. Kiel and Toulon). Some areas fall into class 4, e.g. Carteau, Cortiou, Barcelona, Warnemunde, Swinemunde, Ebro delta. The global Biomarker Index was positively correlated with the level of PAHs in mussels in Baltic transects. A number of other contaminants or stressors may be present in the marine environment and the Biomarker Index appeared to be relevant to classify coastal environmental pollution.