Mouse Chromosome 11

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46996/1/335_2004_Article_BF00648429.pd

Isolation and description of a globally distributed cryosphere cyanobacterium from Antarctica

A previously uncultured cyanobacterium, strain KNUA009, was axenically isolated from a meltwater stream on Barton Peninsula, King George Island, South Shetland Islands, Antarctica. Molecular evidences showed that the isolate belongs to groups of globally distributed cryosphere cyanobacterial clones and this new isolate represents the first laboratory culture to be assigned to these groups. Strain KNUA009 was able to thrive at low temperatures ranging between 5°C and 20°C, but did not survive at temperatures of 25°C and above. As the isolate morphologically resembled Oscillatoria species, it is suggested that this cyanobacterium may represent a new species clade with cold resistance within the genus Oscillatoria

Inoculação microbiana da alfafa para silagem sobre a digestibilidade total e ruminal em bovinos Microbial inoculation of alfalfa for silage on ruminal and total digestibility in bovines

Doze vacas (640 kg de PV) não-gestantes e não-lactantes foram distribuídas em um delineamento em blocos, em que os tratamentos corresponderam à silagem pré-secada de alfafa (60,0% de MS e 19,5% de PB) controle ou inoculada com o produto Silobac® (Lactobacillus plantarum e Pediococcus pentosaceus), com o objetivo de avaliar os efeitos da inoculação microbiana da silagem de alfafa sobre a digestibilidade total e ruminal em bovinos. A dieta experimental continha 50% de silagem de alfafa e 50% de concentrados, com base na matéria seca. O experimento teve duração total de 21 dias, sendo os dez últimos destinados à administração do marcador óxido crômio e os cinco últimos destinados à coleta de fezes e incubação dos sacos de náilon. A inoculação da silagem de alfafa não alterou a digestibilidade total da MS (inoculada = 70,0% vs. controle = 71,2%), PB (72,3% vs. 73,0%), EE (77,0% vs. 76,8%), FDN (61,2% vs. 55,9%), FDA (66,8% vs. 61,8%), EB (72,5% vs. 73,7%) ou NDT (70,6% vs. 71,8%) da dieta. Também não alterou o consumo de MS digestível (12,2 vs. 11,4 kg/animal/dia ou 1,7% vs. 1,8% do PV) ou o consumo de NDT (12,4 vs. 11,4 kg/animal/dia ou 1,8% vs. 1,8% do PV). Entretanto, a inoculação diminuiu a degradabilidade efetiva da MS da silagem de alfafa para taxas de passagem de 2%/h (61,2% vs. 65,1%), 5%/h (54,1% vs. 58,6%) e 8%/h (50,0% vs. 54,4%), bem como reduziu a degradabilidade efetiva da PB da Alfafa para taxas de passagem de 2%/h (84,8% vs. 86,8%) e 5%/h (79,9% vs. 82,5%).<br>Twelve non pregnant dry cows (640 kg LW) were assigned to a randomized block design, provided that the treatments were alfalfa haylage (60.0% DM and 19.5% CP) control or inoculated with Silobac® product (Lactobacillus plantarum and Pediococcus pentosaceus), with the objective to evaluate the effects of microbial inoculation of alfalfa silage on ruminal and total digestibility in bovines. Experimental diet was composing by 50% of alfalfa silage and 50% of concentrate as dry matter basis. The experimental period had duration of 21 days, the last ten was used for chromic oxide addition and the last five was used for feces sampling and nylon bags incubation. Inoculation of Alfalfa silage did not influence the total digestibility of DM (inoculated = 70.0% vs. control = 71.2%), CP (72.3% vs. 73.0%), EE (77.0% vs. 76.8%), NDF (61.2% vs. 55.9%), ADF (66.8% vs. 61.8%), GE (72.5% vs. 73.7%) or TDN (70.6% vs. 71.8%) of diet. Also, did not influence digestible DM intake (12.2 vs. 11.4 kg/anim./day or 1.7% vs. 1.8% LW) or TDN intake (12.4 vs. 11.4 kg/anim./day or 1.8% vs. 1.8% LW). However, inoculation decreased the effective degradability of alfalfa silage DM for passage rate of 2%/h (61.2% vs. 65.1%), 5%/h (54.1% vs. 58.6%) and 8%/h (50.0% vs. 54.4%), and effective degradability of alfalfa silage CP for passage rate of 2%/h (84.8% vs. 86.8%) and 5%/h (79.9% vs. 82.5%)

Algal biomass and pigments along a latitudinal gradient in Victoria Land lakes, East Antarctica

It is generally accepted that Antarctic terrestrial diversity decreases as latitude increases, but latitudinal patterns of several organisms are not always as clear as expected. The Victoria Land region is rich in lakes and ponds and spans 8 degrees of latitude that encompasses gradients in factors such as solar radiation, temperature, ice cover and day length. An understanding of the links between latitudinally driven environmental and biodiversity changes is essential to the understanding of the ecology and evolution of Antarctic biota and the formulation of hypotheses about likely future changes in biodiversity. As several studies have demonstrated that photosynthetic pigments are an excellent, although underused, tool for the study of lacustrine algal communities, the aim of the present study was to investigate variations in algal biomass and biodiversity across the latitudinal gradient of Victoria Land using sedimentary pigments. We test the hypothesis that the biodiversity of freshwater environments decreases as latitude increases. On the basis of our results, we propose using the number of sedimentary pigments as a proxy for algal diversity and the sum of chlorophyll a and bacteriochlorophyll a with their degradation derivatives as an index of biomass. Overall, our data show that biomass and diversity decrease as latitude increases but local environmental conditions, in particular, natural levels of eutrophy, can affect both productivity and diversity