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Cellulosic biomass is an abundant renewable resource for bio-based chemical products such as liquid sugar, biofuel, or organic acid. However, conventional cellulose conversion methods need several steps, chemicals, and expensive enzymes to obtain the final desired product. Therefore, this research studied cellulosic conversion through the consolidated bioprocessing (CBP) method. CBP is a considered method to eliminate enzyme usage and reduce process steps. CBP worked in one reactor combining cell growth, enzyme production, hydrolysis, and fermenting of cellulosic biomass. This study investigates the conversion of α-cellulose and oil palm empty fruit bunch (EFB) using Clostridium thermocellum. Various substrate concentrations were explored in a 100 mL working volume of fermentation. The result showed that C. thermocellum could convert α-cellulose and alkaline explosion treated-EFB into several products that were glucose, ethanol, lactic acid, and acetic acid. Glucose is the highest product in the final broth fermentation. For α-cellulose as substrate, 5 g/L of the substrate could obtain 2.18 g/L of glucose, 0.22 g/L of lactic acid, 0.88 g/L of acetic acid, and 0.90 g/L of ethanol. Whereas 10 g/L of EFB produced 2.48 g/L of glucose, 0.41 g/L of acetic acid, and 0.75 g/L of ethanol. These results indicated that the CBP method using C. thermocellum could be an alternative method to cellulosic conversion without external enzyme usage for the efficiency of cost biorefinery. [ABSTRACT FROM AUTHOR]

This study involves the prediction of the function and structure of putative genes in the genome of Clostridium acetobutylicum for the better elucidation of cellular metabolism. One bacterial strain was used in this study. About 50 hypothetical genes were retrieved from the whole-genome of C. acetobutylicum. KEGG, Pfam, UniProt, InterPro, ScanProsite, SMART, ProtParam, SignalP 4.0, TargetP 2.0, NCBI blast, HHpred, CPH modeling, PSIpred were the bioinformatic tools used in this study. Out of the 50 hypothetical genes, 3 genes were predicted. The function was analyzed for CA_C0024, CA_C0082, and CA_C00412 and they showed e value of 7.7e-16, 9.9e-81, and 7.6e-34 Conclusion: Based on the bioinformatics online tools tentative function and structure for CA_C0024, CA_C0082, and CA_C00412 were predicted. The functions were found to be transmembrane protein, transferase, and virulence-associated functions for CA_C0024, CA_C0082, and CA_C00412 respectively. The prediction for the gene CA_C0024 by HHpred and CPH modeler showed similarity to transferase from gram-positive bacteria. [ABSTRACT FROM AUTHOR]

This work is a pilot study for further analysis of the organism Trypanosoma cruzi (T. cruzi) and the influences of the Pentose's Pathway on the parasite Clostridium acetobutylicum, already cataloged in the database of OptFlux program. We used the approach parcimonius Flux Balance Analysis (pFBA) to simulate the wild type organism and the mutant with an inhibition of the R_01056 reaction in pentose's pathway. Results showed a reduction of approximately 1/3 of the biomass and 2/3 of the butanol production. This reduction shows the direct influence of the Pentose's Pathway on the primary production of metabolites and the biomass generation from the Clostridium metabolites. This information prompted us to build in the future an SBML parameter file to represent the flow of T.cruzi pathways, which will be essential for the development of new drugs against. [ABSTRACT FROM AUTHOR]

Increasing demand of energy and awareness about environmental pollution has led to increase interest in alternative, clean and renewable energy sources. Biobutanol is considered as the candidate liquid biofuel to replace gasoline. In this study, the capability of a newly isolated strain of local Clostridium acetobutylicum YM1 was tested to produce biobutanol in batch fermentation. Various culture conditions including glucose concentration, initial pH, incubation temperature and inoculum size were investigated for their effects on production of biobutanol using strain YM1. The results showed that the optimal biobutanol production was obtained at glucose concentration 50 g/L, initial pH 6.2, temperature 30°C and inoculum size 10%. These results show that C. acetobutylicum YM1 as a mesophilic bacterium is a potential candidate for biobutanol production. [ABSTRACT FROM AUTHOR]

In this paper, the stochastic growth logistic model with aftereffect for the cell growth of C. acetobutylicum P262 and Luedeking-Piret equations for solvent production in batch fermentation system is introduced. The parameters values of the mathematical models are estimated via Levenberg-Marquardt optimization method of non-linear least squares. We apply Milstein scheme for solving the stochastic models numerically. The effciency of mathematical models is measured by comparing the simulated result and the experimental data of the microbial growth and solvent production in batch system. Low values of Root Mean-Square Error (RMSE) of stochastic models with aftereffect indicate good fits. [ABSTRACT FROM AUTHOR]