Genome-guided analysis of transformation efficiency and carbon dioxide assimilation by Moorella thermoacetica Y72.

We determined a draft genome sequence for Moorella thermoacetica strain Y72, a syngas-assimilating bacterium with high transformation efficiency. This strain was confirmed to be M. thermoacetica because its overall genome sequence characteristics were similar to those of M.

High-coverage gene expression profiling analysis of the cellulase-producing fungus Acremonium cellulolyticus cultured using different carbon sources.

The gene expression of a cellulase-producing fungus, Acremonium cellulolyticus, was investigated after culturing with three different carbon sources: glycerol, lactose, and Solka-Floc powdered cellulose (SF). High-coverage gene expression profiling (HiCEP) analysis, a method requiring no prior sequence knowledge, was used to screen genes upregulated at the early stage of cellulase production. SF was used as a strong inducer of cellulase production, lactose was used as an inducer of the expression of cellulase genes at the early stage of the culture, and glycerol was used as a negative control.

Combination of hot compressed water treatment and wet disk milling for high sugar recovery yield in enzymatic hydrolysis of rice straw.

Rice straw has attracted significant interest in Japan as a potential raw material for biorefineries. Combination of hot-compressed water treatment (HCWT) and wet disk milling (WDM) was investigated to improve the enzymatic digestibility of rice straw and enhance sugar recovery yield. Rice straw, cut to <3 mm, was autoclaved at 121, 135, and 150 °C for 60 min, and subsequently treated by wet disk milling.

Production and characterization of cellulases and hemicellulases by Acremonium cellulolyticus using rice straw subjected to various pretreatments as the carbon source.

Cellulases and hemicellulases are key enzymes in the production of alternative fuels and chemicals from lignocellulosic biomass-an abundant renewable resource. Carbon source selection is an important factor in the production of cellulases and hemicellulases. Rice straw--a potential ethanol source--has recently gained considerable interest in Asian countries.

Enhancement on biodegradation and anaerobic digestion efficiency of activated sludge using a dual irradiation process.

A dual irradiation process involving aerobic thermophilic irradiation pretreatment (ATIP) and intermittent irradiation anaerobic digestion was developed to improve the digestion of waste-activated sludge. First, the effect of ATIP on further anaerobic digestion of activated sludge in batch mode was investigated. When exposed to ATIP for 24 h, the digestion reactor gave the highest methane yield, removed the most dissolved organic carbon (DOC) and showed the most effective reduction of VS compared to other irradiation times.

Wet disk milling pretreatment without sulfuric acid for enzymatic hydrolysis of rice straw.

Rice straw has recently attracted interest in Japan as a potential source of raw material for ethanol production. Wet disk milling, a continuous pretreatment to enhance the enzymatic digestibility of rice straw, was compared with conventional ball milling and hot-compressed water treatment. Pretreated rice straw was evaluated by enzymatic hydrolysis using Acremonium cellulase and characterized by X-ray diffraction and scanning electron microscopy.

Effect of ammonium addition on methanogenic community in a fluidized bed anaerobic digestion.

After immobilization of anaerobes on carbon felt in a fluidized-bed anaerobic digester at an ammonium concentration of 500 mg N/l, the results of real-time PCR analysis indicated that the cell densities of the immobilized methanogens and bacteria increased compared with those of the free-living methanogens and bacteria in the original anaerobically digested sewage sludge, respectively. The results of the clone analysis of the original sludge suggested that the major methanogens were Methanosaeta sp. and the members of the order Methanomicrobiales, and that after immobilization, these were changed to Methanobacterium and Methanosarcina sp.

Analysis of effluent after anaerobic digestion of liquid phase separated from liquidized garbage.

The organic compositions of the liquid phase separated from liquidized garbage as the influent and its effluent after anaerobic digestion at an overloading rate were analyzed. A large amount of organic acids was found in the effluent. The accumulation of organic acids suggests that the rate of methanogenesis is lower than that of acidogenesis.

Removal of 3-chlorobenzoate using granules in the upflow anaerobic sludge blanket method.

The possibility of removing 3-chlorobenzoate from water using granules in the upflow anaerobic sludge blanket (UASB) method without the addition of a dechlorinating culture was studied on a laboratory scale. After three months of operation, the 3-chlorobenzoate concentration in the effluent decreased to less than 1 mg.l(-1).

Simultaneous methanogenesis and phototrophic bacterial growth in relatively dry sewage sludge under light.

Anaerobically digested sewage sludge with a variety of moisture content, namely 81%, 86%, 90% and 98%, were anaerobically cultured at 35 degrees C under light. Phototrophic bacteria grew in the 86% moisture sludge (bacteriochlorophyll a, 0.46 g/L), 90% sludge (bacteriochlorophyll a, 0.

Performance of a fixed-bed reactor packed with carbon felt during anaerobic digestion of cellulose.

The anaerobic digestion of cellulose was assessed in batch and semi-continuous studies using a carbon felt fixed-bed reactor. In the batch operation, the volatile solids reduction (%) and the cumulative methane production during the mesophilic and thermophilic digestion were 52.2% and 15.