Phylogenetic analysis and phenotypic characterization were used to assign a multicellular magnetotactic prokaryote the name ‘Candidatus Magnetoglobus multicellularis’. ‘Candidatus Magnetoglobus multicellularis' lives in a large hypersaline coastal lagoon from Brazil and has properties that are unique among prokaryotes. It consists of a compact assembly or aggregate of flagellated bacterial cells, highly organized in a sphere, that swim in either helical or straight trajectories. The life cycle of ‘Candidatus Magnetoglobus multicellularis' is completely multicellular, in which one aggregate grows by enlarging the size of its cells and approximately doubling the volume of the whole organism. Cells then divide synchronously, maintaining the spherical arrangement; finally the cells separate into two identical aggregates. Phylogenetic 16S rRNA gene sequence analysis showed that ‘Candidatus Magnetoglobus multicellularis' is related to the dissimilatory sulfate-reducing bacteria within the Deltaproteobacteria and to other previously described, but not yet well characterized, multicellular magnetotactic prokaryotes.

Magnetotactic bacteria show an ability to navigate along magnetic field lines because of magnetic particles called magnetosomes. All magnetotactic bacteria are unicellular except for the multicellular prokaryote (recently named 'Candidatus Magnetoglobus multicellularis'), which is formed by an orderly assemblage of 17-40 prokaryotic cells that swim as a unit. A ciliate was used in grazing experiments with the M. multicellularis to study the fate of the magnetosomes after ingestion by the protozoa. Ciliates ingested M. multicellularis, which were located in acid vacuoles as demonstrated by confocal laser scanning microscopy. Transmission electron microscopy and X-ray microanalysis of thin-sectioned ciliates showed the presence of M. multicellularis and magnetosomes inside vacuoles in different degrees of degradation. The magnetosomes are dissolved within the acidic vacuoles of the ciliate. Depending on the rate of M. multicellularis consumption by the ciliates the iron from the magnetosomes may be recycled to the environment in a more soluble form.

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The aim of this study was to analyze the economic viability of producing dairy goat kids fed liquid diets in alternative of goat milk and slaughtered at two different ages. Forty-eight male newborn Saanen and Alpine kids were selected and allocated to four groups using a completely randomized factorial design: goat milk (GM), cow milk (CM), commercial milk replacer (CMR) and fermented cow colostrum (FC). Each group was then divided into two groups: slaughter at 60 and 90 days of age. The animals received Tifton hay and concentrate ad libitum. The values of total costs of liquid and solid feed plus labor, income and average gross margin were calculated. The data were then analyzed using the Monte Carlo techniques with the @Risk 5.5 software, with 1000 iterations of the variables being studied through the model. The kids fed GM and CMR generated negative profitability values when slaughtered at 60 days (US$ −16.4 and US$ −2.17, respectively) and also at 90 days (US$ −30.8 and US$ −0.18, respectively). The risk analysis showed that there is a 98% probability that profitability would be negative when GM is used. In this regard, CM and FC presented low risk when the kids were slaughtered at 60 days (8.5% and 21.2%, respectively) and an even lower risk when animals were slaughtered at 90 days (5.2% and 3.8%, respectively). The kids fed CM and slaughtered at 90 days presented the highest average gross income (US$ 67.88) and also average gross margin (US$ 18.43/animal). For the 60-day rearing regime to be economically viable, the CMR cost should not exceed 11.47% of the animal-selling price. This implies that the replacer cannot cost more than US$ 0.39 and 0.43/kg for the 60-and 90-day feeding regimes, respectively. The sensitivity analysis showed that the variables with the greatest impact on the final model's results were animal selling price, liquid diet cost, final weight at slaughter and labor. In conclusion, the production of male dairy goat kids can be economically viable when the kids diet consists mainly of either cow milk or fermented colostrum, especially when kids are slaughtered at 90 days of age.

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RESUMOO alto polimorfismo encontrado no lócus do gene da α S1 -caseína em caprinos, classificado em quatro níveis de expressão -alto, médio, baixo e nulo -, está associado à produção de 3,6; 1,6; 0,6 e 0g/L/alelo, respectivamente. O estudo foi realizado para investigar possíveis variações na produção de leite e seus constituintes, no perfil de caseínas e na lipólise da gordura. Quarenta e quatro cabras foram distribuídas em cinco genótipos: dois homozigotos, um para alta (AA) e outro para produção intermediária (EE), e três heterozigotos chamados AE, AF e EF, para α s1 -caseína. Para a lipólise, o leite foi subamostrado em quatro alíquotas que sofreram tratamento térmico no momento da ordenha e após 24h de resfriamento. Diferenças entre genótipos foram observadas para a produção de caseína e de suas frações. As demais variáveis não diferiram entre genótipos. O genótipo AA apresentou os maiores conteúdos de caseína (28,6g/L) e de α S1 -cn (22,3%). Os demais genótipos apresentaram média de 20,4g/L. Os grupos AE e AF apresentaram média de 12,1, EE-10,1 e EF-9,1% de α S1 -cn. O resfriamento do leite por 24 horas aumentou a taxa de lipólise no leite. A genotipagem das cabras para α S1 -cn pode ser usada como ferramenta de seleção com objetivo de obter produtos lácteos com distintos perfis de proteínas.Palavras-chave: cabra, constituintes lácteos, caseína, genótipo, lipólise of expression, named high, medium, and low, associated with production of 3.6, 1.6, 0.6, and ABSTRACT A high polymorphism is found in the locus of goat α S1 -casein gene and it is classified in four levels

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