Screening of cyanophytes from mosquito breeding places (mostly rice fields) with emphasis on unicellular species : potential recipients of Bti genes

35 genera with more than 60 species of cyanophytes were determined in samples collected from rice fields primarily in the malaria areas of Indonesia, China, French Guiana, Japan and the south-east Turkey and in various Anopheles breeding places in Cameroon, Uganda, and Syria. The most abundant unicellular genera observed were Synechococcus, Merismopedia, and Synechocystis which often occurred in high concentrations (approximately 102 cells per ml). Arthrospira platensis collected in Cameroon was the only species forming a water bloom. We successfully isolated 5 unicellular strains which occurred the most frequently (Synechococcus sp., Microcystis sp., Merismopedia tenuissima, Chroococcus minor, and Synechocystis sp.). Isolated strains grew well in culture and were kept and available in the Culture Collection of Autotrophic Organisms (CCALA) at Trebon. Two unicellular strains, i.e. Chroococcus minor strain CEPAK 1993/1 and Synechococcus sp. strain CEPAK 1996/1 were prospective for Bti gene introcuction due to their easy ingestibility and digestibility and rapid growth in culture.