Novel proton-conducting polymer electrolyte membranes have been prepared from bacterial cellulose by incorporation of phosphoric acid (H3PO4/BC) and phytic acid (PA/BC). H3PO4 and PA were doped by immersing the BC membranes directly in the aqueous solution of H3PO4 and PA, respectively. Characterizations by FT-IR, TG, TS and AC conductivity measurements were carried out on the membrane electrolytes consisting of different H3PO4 or PA doping level. The ionic conductivity showed a sensitive variation with the concentration of the acid in the doping solution through the changes in the contents of acid and water in the membranes. Maximum conductivities up to 0.08 S cm-1 at 20oC and 0.11 S cm -1 at 80oC were obtained for BC membranes doped from H3PO4 concentration of 6.0 mol L-1 and, 0.05 S cm-1 at 20oC and 0.09 S cm -1 at 60oC were obtained for BC membranes doped from PA concentration of 1.6 mol L-1. These types of proton-conducting membranes share not only the good mechanical properties but also the thermal stability. The temperature dependences of the conductivity follows the Arrhenius relationship at a temperature range from 20 to 80oC and, the apparent activation energies (Ea) for proton conduction were found to be 4.02 kJ mol-1 for H3PO4/BC membrane and 11.29 kJ mol-1 for PA/BC membrane, respectively. In particular, the membrane electrode assembly fabricated with H3PO4/BC and PA/BC membranes reached the initial power densities of 17.9 mW cm-2 and 23.0 mW cm-2, which are much higher than those reported in literatures in a real H2/O2 fuel cell at 25oC.

A new carbon source for bacterial cellulose production was successfully developed from konjac powder by using dilute acid hydrolysis and was detoxified by different alkaline treatment methods to remove microbial growth inhibitors. The various treatments included the addition of calcium hydroxide or sodium hydroxide to pH 10, and subsequent adjustment of the pH to 5 with acid as well as treatment with activated charcoal or laccase, respectively. The results showed that the detoxification effect using Ca(OH)2 was much better than that using NaOH. If activated charcoal or laccase was added in the process, the detoxification effects would go further and bacterial cellulose production could be improved more. Based on the same concentration of total sugars, bacterial cellulose production using the hydrolyzates was 3 times higher than that using glucose, 6 times higher than that using mannose, and 5 times higher than that using glucose-mannose mixture as carbon source in static cultures. The addition of extra calcium in glucose media in the form of CaCl2 at pH 5 did result in an improvement of less than 50% in BC production, which was not comparable to the Ca(OH)2 treatments at pH 10. The possible mechanisms behind the findings were discussed and potential stimulatory factors for the fermenting bacterium formed during the alkaline processing deserve further attention. The results indicate that konjac powder could serve as a feedstock for bacterial cellulose production and cultivation of Amorphophallus rivieri Durieu would bring more economic benefits to farmers in future.