JACI MENDES VIEIRA1, RANYSE B. QUERINO2, FERNANDO L. CÔNSOLI1 & ROBERTO A. ZUCCHI1 1Departamento de Entomologia e Acarologia, ESALQ, Universidade de São Paulo, Caixa Postal 9, 13418-900 Piracicaba, SP, Brazil. E-mail: [email protected]; [email protected]; [email protected] 2Empresa Brasileira de Pesquisa Agropecuária, Embrapa Meio-Norte, 64006-220 Teresina, Piauí, Brazil. E-mail: ranyse.silv...

The nitrogenase gene cluster in cyanobacteria has been thought to comprise multiple operons; however, in Anabaena variabilis, the promoter for the first gene in the cluster, nifB1, appeared to be the primary promoter for the entire nif cluster. The structural genes nifHDK1 were the most abundant transcripts; however, their abundance was not controlled by an independent nifH1 promoter, but rathe...

Anabaena variabilis ATCC 29413 is a filamentous, heterocyst-forming cyanobacterium that has served as a model organism, with an extensive literature extending over 40 years. The strain has three distinct nitrogenases that function under different environmental conditions and is capable of photoautotrophic growth in the light and true heterotrophic growth in the dark using fructose as both carbo...

Chlorella variabilis strain NC64A is an intracellular photobiont of the ciliate Paramecium bursaria. NC64A was isolated from P. bursaria nearly 50 years ago and was thereafter cultivated outside the host. This study was undertaken to detect changes in its infectivity to P. bursaria and its auxotrophy for growth outside the host induced during long-term cultivation. NC64A can grow in Modified Bo...

Anabela Sousa Oliveira1,2, Enrico Mendes Saggioro3, Thelma Pavesi3, Josino Costa Moreira3 and Luis Filipe Vieira Ferreira1 1Centro de Química-Física Molecular and Institute of Nanosciences and Nanotechnology, Instituto Superior Técnico, Universidade Técnica de Lisboa, Lisboa, 2Centro Interdisciplinar de Investigação e Inovação, Escola Superior de Tecnologia e Gestão, Instituto Politécnico de Po...

Triangular cells are formed during early logarithmic growth of Trigonopsis variabilis. Good triangularity is obtained with methionine, proline, hydroxyproline, or alanine as a nitrogen source.

Five anabolic and two catabolic enzymes of arginine metabolism were neither repressed nor induced after inclusion of arginine in the growth medium of Anabaena variabilis.

The present study was carried out in order to examine and characterize the bidirectional hydrogenase in the cyanobacterium Nostoc sp. strain PCC 73102. Southern hybridizations with the probes Av1 and Av3 (hoxY and hoxH, bidirectional hydrogenase small and large subunits, respectively) revealed the occurrence of corresponding sequences in Anabaena variabilis (control), Anabaena sp. strain PCC 71...

Synganglia, salivary gland, midgut, ovary, fat body and muscle alone and in combination from the ixodid tick, Dermacentor variabilis (Say), or the argasid tick, Ornithodoros parkeri Cooley, were incubated in vitro in separate experiments with L-[methyl-(3)H]methionine and farnesoic acid or with [1-(14)C]acetate. Life stages examined in D. variabilis were 3 and 72 h old (after ecdysis) unfed nym...