Enhancement of biohydrogen production from starch processing wastewater and further inside its ecosystem disclosed by 16S rDNA sequencing and FISH

ABSTRACT Biohydrogen production from starch processing wastewater in this study resulted the highest yield of 61.75 mL H2/g COD at initial pH 7.0, thermophilic temperature, and iron concentration 800 mg Fe/L. The yield was 2-folded higher than the operation at mesophilic temperature or without iron addition. Cell immobilization by addition of biomaterials (BM) could improve the hydrogen yield by 2-folded comparing to the non-addition. BM from plants (loofa sponge) was found producing higher yield than that from animals (silk cocoon), and optimal concentration of BM was 5% (V/V). Furthermore, it was revealed further inside its ecosystem using SEM, 16S rDNA sequencing and FISH. There was found rod-shaped microorganisms of Bacillus cereus, which reported as efficient starch-utilizing hydrogen producers, was dominant in the system with population of 47% of all specie identified