Bio-Electroreduction of Chromium (VI) using Immobilized Sulfate Reducing Bacteria on Conductive Microbial Cellulose Biocathode

The present study evaluated effect of conductive microbial cellulose (MC) biocathode as a carbohyrate biopolymer in hexavalent chromium bio-electroreduction using immobilized sulfate reducing bacteria (SRB). The morphology studies using SEM shows that the biofilm of SRB was formed a good density on the conductive microbial cellulose biocathode. The Brunauer, Emmett and Teller (BET) analysis revealed that the particle-size distribution in the conductive biocathode was 0.9 nm. The kinetic studies shows that the Cr (VI) removal process fallow of pseudo-first-order kinetics with a constant rate was 0.6 h− 1. The energy consumption of the bio-electroreduction system was 2.7×10− 2 kWh/m3. The EDXA spectrum of sediments showed the presence of chromium peak, indicating that Cr (VI) was reduced on the bio-resuction system. The obtained results indicate that proposed bio-electroreduction system using immobilized sulfate reducing bacteria on the conductive microbial cellulose biocathode could be an efficient method for chromium bio-reduction from wastewaters.

Anaerobic Cellulolytic Microbial Communities From Various Sources Of Inocula Under Various Culture Conditions

To date studies focusing on microbial cellulose hydrolysis have focused on pure cultures such as Clostridium themocellum, or isolated environmental cellulolytic strains. Microbial communities fed with crystalline cellulose were cultivated in continuous culture, and optimal growth conditions and culture approaches have been investigated Inocula from different environments were tested to determine microbial cellulose hydrolysis and growth, as well as the effect of temperature and media composition. Differences in microbial hydrolysis existed not only between sources of inocula, but within inocula themselves. It was found that microbial consortia cultured from direct environmental inocula had more robust microbial activity than enriched inocula. Cultures grown at 60℃ showed higher biomass-specific cellulose hydrolysis, resulting in more efficient cellulose hydrolysis. This study provides evidence of differences in sources of inocula for the culture of cellulolytic consortia, and suggests culture approaches for the further study of possible applications of microbial consortia in bioprocessing technology.

Anaerobic Cellulolytic Microbial Communities From Various Sources Of Inocula Under Various Culture Conditions

To date studies focusing on microbial cellulose hydrolysis have focused on pure cultures such as Clostridium themocellum, or isolated environmental cellulolytic strains. Microbial communities fed with crystalline cellulose were cultivated in continuous culture, and optimal growth conditions and culture approaches have been investigated Inocula from different environments were tested to determine microbial cellulose hydrolysis and growth, as well as the effect of temperature and media composition. Differences in microbial hydrolysis existed not only between sources of inocula, but within inocula themselves. It was found that microbial consortia cultured from direct environmental inocula had more robust microbial activity than enriched inocula. Cultures grown at 60℃ showed higher biomass-specific cellulose hydrolysis, resulting in more efficient cellulose hydrolysis. This study provides evidence of differences in sources of inocula for the culture of cellulolytic consortia, and suggests culture approaches for the further study of possible applications of microbial consortia in bioprocessing technology.