ABSTRACT São Marcos Bay is an estuarine complex with semidiurnal tides that can reach more than 7 m during equinoctial spring tides. It is situated in the second largest Brazilian coastline and is subjected to continuous human activities holding an important port complex of Latin America. In order to contribute to the knowledge about the structure of the phytoplankton in a macrotidal systems, this study aims to evaluate the phytoplankton community and its relationship with environmental conditions in the São Marcos Bay. Five surveys in 2010 and 2011 were carried out on four sampling points during the rainy and dry seasons. Samples were taken during the flood and ebb phases at neap tides. Hydrological parameters were correlated with biological data (phytoplankton composition, abundance and biomass) using statistical analysis. The phytoplankton biomass (chlorophyll a) characterized the bay as quite productive (10.43±7.62 mg m-3) with the nanophytoplankton as the dominant fraction. Seasonal variation was observed in phytoplankton abundance with higher values (34,262±18,422 cells L-1) in the rainy season. Diatoms were the most important phytoplankton group, pointing out Nitzschia sp., Diploneis weissflogii and Synedra sp. as the dominant species. This study revealed that the composition of phytoplankton community was mainly influenced by the local dynamics, governed by macrotides, and precipitation regime that mostly contributed to the seasonal fluctuations of the environmental conditions, such as salinity, dissolved oxygen, and nutrients.

A endonuclease de restrição BliAI, um isoesquisômero de ClaI, que reconhece a seqüência 5'- AT<FONT FACE=Symbol>¯</FONT>CGAT - 3', foi purificada de um isolado natural identificado como Bacillus licheniformis. A endonuclease de restrição em questão foi isolada a partir de um extrato celular em um único passo cromatográfico utilizando uma coluna contendo a resina fosfocelulose. A endonuclease de restrição é ativa à 37ºC e em uma ampla escala de pH e concentração de sais. O peso molecular da enzima purificada corresponde a um valor de kDa 39.

The restriction endonuclease BliAI, an isoschizomer of ClaI, which recognizes the sequence 5'- AT<FONT FACE=Symbol>¯</FONT>CGAT - 3', was purified from a natural isolate identified as Bacillus licheniformis. The restriction endonuclease was isolated from cell extracts using single-step purification by phosphocellulose column chromatography. The restriction endonuclease is active at 37ºC and over a wide range of pH and salt concentration. The molecular weight of the purified restriction enzyme is consistent with a value of 39 kDa.