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The nutritional value, astaxanthin level and population growth of Moina macrocopa fed with Chlorella sp., Saccharomyces cerevisiae and Phaffia rhodozyma in eight treatments (C1: 1 × 105 cells/ml; C2: 1 × 106 cells/ml; S1: 4 × 106 cells/ml; S2: 4 × 107 cells/ml; P1: 4 × 107 cells/ml; P2: 4 × 108 cells/ml; SP1: S + P 4 × 106 : 4 × 107 cells/ml; and SP2: S + P 4 × 106 : 4 × 108 cells/ml) were examined. The results showed that lipid content was significantly different among the treatments but protein and carbohydrate were not. C2 had the highest lipid content (11.83 ± 0.87%) whereas C1 and SP1 had the highest protein (76.26 ± 2.84%) and carbohydrate (14.56 ± 3.04%), respectively. In addition, SP1 had the highest astaxanthin level (0.83 ± 0.19 μg/g) and S1 showed fastest population growth rate (0.81 day−1). This indicated that feeding on S. cerevisiae resulted in high lipid and astaxanthin levels and a concentration of 4 × 106 cells/ml enhanced the population growth of M. macrocopa. Therefore, it could replace or be used as supplementary to Chlorella sp. for cladoceran production in mass cultures.

The effects of cyanobacteria and chemical fertilizer on growths and yields of rice (Oryza sativa L.) cv. Pathum Thani 1 were studied in pot trials. Nine treatments were set up without cyanobacteria and fertilizer (control), inoculated with cyanobacteria Nostoc carneum TUBT04 (T1), inoculated with Nostoc commune TUBT05 (T2), and inoculated with combination of N. carneum TUBT04 and N. commune TUBT05 (T3), full dose of recommended use of fertilizer (T4), half dose of recommended use of the fertilizer (T5), half dose of fertilizer combined with N. carneum TUBT04 (T6), half dose of fertilizer combined with N. commune TUBT05 (T7), and half dose of fertilizer combined with N. carneum TUBT04 plus N. commune TUBT05 (T8). Each treatment divides into five replications. Growth parameters including length and fresh and dry weights of shoot and root were measured in the seedlings. The number of spikes per plant and the amount and weight of rice grains per spike were measured after harvesting. The supplement with cyanobacteria promoted rice seedling growth and yield compared to the control treatment. Inoculation with cyanobacteria showed significant increase in root length (p = 0.41). In addition, the combined biofertilizer with a half of the recommended dose of chemical fertilizer significantly enhanced rice production including total number and weight of grain per spike and a total weight of 100 grains (p < 0.001). Therefore, using a half dose of chemical fertilizer with cyanobacteria is suggested to decrease rice production cost of farmers without any effects on rice quantity and quality.