滇西北鹤庆草海湿地紫水鸡生态适应的初步观察

中国南方紫水鸡(Porphyrio porphyrio)在快速扩散,探究其生态适应十分必要。2014年3月至2015年8月在云南鹤庆草海湿地的观察,得到以下结果。紫水鸡集中分布在以开阔水域为主并有足够植被覆盖的西草海,很少见于附近干扰频繁的其他湿地,其适宜的生境开阔水域约占49.6%、水生植被覆盖水面占39.3%、陆地占11.1%;紫水鸡早间(7:00~9:00时)频繁活动在开阔水域、高草丛、岸边草地,中午后逐渐远离岸边而藏掖草丛中;白天活动的紫水鸡集群大小在1~7只之间,1~2只的集群占62.0%,大的集群中常有司职警戒、领头的个体;紫水鸡用于觅食、休息、警戒的时间分别占47.8%、23.5%、15.1%,很少互动交流,但常驱赶靠近的其他鸟类以维护个体自身的"领域";紫水鸡应对干扰威胁的警戒、避让、惊飞平均距离分别是26.4 m、20.5 m和17.6 m。在鹤庆的紫水鸡集中分布于西草海湿地并避让人为干扰,说明其以避让和逃逸方式应对人为干扰和生境胁迫,应该考虑立法给予重点保护。     

Population structure of Purple Sandpipers (Calidris maritima) as revealed by mitochondrial DNA and microsatellites

The Purple Sandpiper (Calidris maritima) is a medium‐sized shorebird that breeds in the Arctic and winters along northern Atlantic coastlines. Migration routes and affiliations between breeding grounds and wintering grounds are incompletely understood. Some populations appear to be declining, and future management policies for this species will benefit from understanding their migration patterns. This study used two mitochondrial DNA markers and 10 microsatellite loci to analyze current population structure and historical demographic trends. Samples were obtained from breeding locations in Nunavut (Canada), Iceland, and Svalbard (Norway) and from wintering locations along the coast of Maine (USA), Nova Scotia, New Brunswick, and Newfoundland (Canada), and Scotland (UK). Mitochondrial haplotypes displayed low genetic diversity, and a shallow phylogeny indicating recent divergence. With the exception of the two Canadian breeding populations from Nunavut, there was significant genetic differentiation among samples from all breeding locations; however, none of the breeding populations was a monophyletic group. We also found differentiation between both Iceland and Svalbard breeding populations and North American wintering populations. This pattern of divergence is consistent with a previously proposed migratory pathway between Canadian breeding locations and wintering grounds in the United Kingdom, but argues against migration between breeding grounds in Iceland and Svalbard and wintering grounds in North America. Breeding birds from Svalbard also showed a genetic signature intermediate between Canadian breeders and Icelandic breeders. Our results extend current knowledge of Purple Sandpiper population genetic structure and present new information regarding migration routes to wintering grounds in North America.     

Spawn and development of the olivid gastropod Olivancillaria carcellesi from north Patagonia,Argentina

Olivancillaria carcellesi occurs in shallow sandy shores from north Patagonia, in intertidal and subtidal sandy bottoms. Females of O. carcellesi exhibited a remarkable specificity for spawning on the shells of living males and females, indiscriminately, of the buccinanopsid Buccinastrum deforme, measuring 26.9 ± 4.7 mm in shell length. The egg capsule was semispherical and attached to B. deforme shells by a small elliptical and wide base. The capsule was translucid when spawned, with a thick and semirigid wall and a hatching aperture of 1.8 ± 0.1 mm (n = 111) in diameter. Each egg capsule contained a single egg that measured 1367 ± 34 μm (n = 5) in diameter before cleavage. The embryo developed a small bilobed velum and an operculum, which were both lost before hatching as a crawling juvenile of 1762 ± 47 μm (n = 28) in shell length. As in other species in the genus, the eggs of O. carcellesi are among the largest in the caenogastropods with direct development. The time from oviposition to hatching is estimated to be approximately 6 months.     

紫甘薯花色苷色素的抑菌机理研究

<正>人类和动物的食品安全有赖于生产的各个环节,使用无污染、无残留、无毒副作用的食品添加剂是解决食品中药物残留的关键。     

紫色非硫细菌固体石蜡双层平板培养法

紫色非硫细菌是一类不产氧光合细菌,具有重要的生态学意义和应用价值。建立固体石蜡双层平板法,与传统的培养法相比较,发现该方法可以更方便、更快捷地计数和分离紫色非硫细菌。结合分子生物学技术,将该方法应用于水稻土紫色非硫细菌的研究,发现以甲酸为碳源的固体石蜡双层平板法可以很好地对环境中可培养的紫色非硫细菌多样性进行研究。该方法的建立将更有助于紫色非硫细菌的研究。     

Nitrate reduction in a new strain ofRhodoferax fermentans

Using an enrichment technique avoiding the dominating fast-growing species Rhodobacter capsulatus and Rhodobacter sphaeroides, a new strain (designated B2c; DSM 10 139) of Rhodoferax fermentans, a facultatively phototrophic member of the β subclass of Proteobacteria, was isolated. In contrast to the type strain of this species, strain B2c was capable of reducing nitrate. Strain B2c contained a highly active nitrate reductase [0.3–0.4 μmol min^–1 (mg protein)^–1] which, in extracts from spheroplasts prepared by ultrasonic treatment, was associated with the membrane fraction. The physiological role of nitrate reductase depended on the growth conditions. The enzyme enabled the strain to grow with nitrate as a nitrogen source and to maintain redox balance in a culture medium with a highly reduced carbon compound. Received: 21 April 1995 / Accepted: 14 August 1995     

高脱氮活性海洋着色菌YL28生物膜特性

【背景】细菌生物膜在废水处理领域显示出良好的前景,但目前应用于海水养殖水体处理的菌株主要源自淡水菌株,存在难以适应海水高盐环境的问题。源自红树林的海洋着色菌(Marichromatiumgracile)YL28应用于海水养殖水体处理,不仅具有高效除氮能力,而且趋光贴壁能力很强。【目的】阐明海洋着色菌(Marichromatium gracile) YL28的生物膜形成特性和规律,以期为海水养殖水体生物膜反应系统的开发和应用提供参考。【方法】以生物膜和游离菌体生物量、脱氢酶活性、生物膜多糖含量和蛋白含量、无机三态氮去除活性为测定指标,在光照厌氧环境中研究海洋着色菌YL28菌株的生物膜形成规律、生物活性和脱氮效果。【结果】随着时间延长,4 000 lx光照时游离菌体生物量逐渐升高,但在稳定期前快速降低,而成膜生物量经过延滞期后逐渐升高并趋于稳定,表明培养过程中游离菌体能趋光贴壁生长并形成生物膜。在0-5 000 lx光照范围内培养4 d,低光照强度(500 lx)时成膜率(71.21%)最高,1 000-4 000 lx光照强度下成膜率虽然不是最高(54.64%-68.66%),但适宜菌体成膜,膜生物量干重达到0.60-0.80 mg/cm2。除了5 000 lx光照对成膜菌体脱氢酶活性有不利影响外,成膜菌体和游离菌体脱氢酶活性随光照强度升高而升高,而且没有明显差异。生物膜的形成会导致光反应器内部光照受限,但反应器内部游离菌体的脱氢酶活性并没有降低,由此表明,培养液中的菌体主要在生物膜及其界面生长并游离扩散至培养液中。随光照强度(1 000-5 000 lx)和培养时间(4-10 d)的变化,胞外复合物(Extracellularpolymericsubstances,EPS)中蛋白含量变异较大,多糖含量变化较小;随时间延长,蛋白含量升高,其中3 000 lx时蛋白含量最高;4 000 lx时生物膜菌体与游离菌体脱氮活性相比,单位质量菌体的氨氮和亚硝氮去除活性未受到明显影响,而硝氮去除活性有所降低。【结论】海洋着色菌YL28具有良好的生物膜形成能力,其成膜过程主要是菌体趋光贴壁生长成膜,成膜菌体具有良好的脱氮活性,这为利用生物膜系统消除海水养殖水体氮污染奠定了基础。     

Orientation of intrinsic proteins in photosynthetic membranes. Polarized infrared spectroscopy of chloroplasts and chromatophores

In order to estimate the degree of orientation of the α-helices of intrinsic proteins in photosynthetic membranes, polarized infrared spectroscopy has been used to measure the dichroism of the amide I and amide II absorption bands of air-dried oriented samples of purple membranes, chloroplasts and chromatophores from Rhodopseudomonas sphaeroides. Using purple membrane, in which the orientation of the α-helices is precisely known (Henderson, R. (1977) Annu. Rev. Biophys. Bioeng. 6, 87–109), as a standard to calibrate our measurements and estimating the mosaic spread (extent of orientation) of the membranes from linear dichroism measurements performed in the visible spectral range, it is concluded that in photosynthetic membranes, the α-helices of intrinsic proteins are tilted at less than 40° with respect to the normal to the plane of the membrane.     

Microbial community on industrial salty bovine hides: From the slaughterhouse to the salting

The leather-making industry is an age-old industry and desiccation with salt has been one of the most used methodologies for obtaining valuable skins. However, halophiles may proliferate and affect the integrity of the hide-collagen structure, as well as leading to undesirable red colorations or less-frequent purple stains. To understand the basis of these industrial hide contaminations, the microbial community from raw hide samples, salt-cured samples and four different industrial salts, was analyzed by 16S rRNA gene metabarcoding together with standard cultivation methods.Comparison of raw hides and correctly cured hides revealed a core microbiome that was absent from contaminated hides. In addition, archaea were missing from well-cured hides, whereas Psychrobacter and Acinetobacter were highly represented (23 % and 17.4 %, respectively). In damaged hides, only a few operational taxonomic units (OTUs), from among the hundreds detected, were able to proliferate and, remarkably, a single Halomonas OTU represented 57.66 % of the reads. Halobacteria, mainly Halovenus, Halorubrum and Halovivax, increased by up to 36.24–39.5 % in the red- and purple-affected hides. The major contaminants were isolated and hide infections, together with collagenase activity, were evaluated. The results showed that hides enriched with the non-pigmented isolate Halomonas utahensis COIN160 damaged the collagen fibers similarly to Halorubrum, and together they were considered to be one of the major causes. Putative degrading inhibitors were also identified from among the Alkalibacillus isolates.It was concluded that hide contaminations were driven by clonal outbreaks of a few specific microbes, which may have been non-pigmented collagen degraders. Acinetobacter and Alkalibacillus, members of the core microbiome of raw and well-cured salted hides, are suggested as hide contaminant inhibitors that need further analysis.