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Comparing with other biological processes, a technological method associated with bio-energy has been developed as the result of the high possibility of fermentative hydrogen productivity; In addition, restricted fossil fuel has been also substituted. The production of fermentative hydrogen is a complicated process influenced by different factors including different kinds of micro-organisms, initial concentration of substrate, inoculum size, initial pH of the medium, concentration of nutrients metals, etc. Thus, the present study is aiming at detecting such different agents to obtain the highest yield of hydrogen and progressing its operation through improving the efficiency of these agents by reliable experimental design. Clostridium saccharoperbutylacetonicum N1-4(ATCC 13564) was applied to produce hydrogen in a batch manner. The highest yield of hydrogen has been resulted in 3.016 mol of hydrogen per mol glucose with production rate of 3.281 mole of hydrogen per hour at 37 °C, 10 % of inoculums size, 10 g/L of an initial glucose concentration, initial pH of medium of 6.5, 30 mg/L of FeSO4.7H2O. Furthermore, the experimental results were compared to kinetic model of Gompertz. Moreover, it was found out that the experimental issues were compatible with this kinetic model with the regression coefficient values of 0.989. [ABSTRACT FROM AUTHOR]

A novelDunaliella salina (D. salina)was isolated from Hoze-soltan Lake, Iran. The investigated strain was capable of producing carotenoids and protein, using different NaCl concentrations and pH variations in Hoze-soltan saline water. The experiment was carried out within 42 days. The results indicated that protein production and pigmentation correlated well with growth rate. The optimum amount for growth, carotenogenesis, and protein production was determined in a culture with 10% NaCl and pH 8.5. After 42-days incubation, 14.95 ± 0.6μg/mL of carotenoids and 186 ± 8.6μg/mL of protein were obtained in this medium. Further observation revealed that growth was inhibited in all samples with 30% NaCl. The amount of each biosynthesized component byDunaliella salinawas in accordance with growth stage, cell number, and growth pattern of microalgae. [ABSTRACT FROM AUTHOR]