Draft Genome Sequences of Strains TAV3 and TAV4 (Verrucomicrobia: Opitutaceae), Isolated from a Wood-Feeding Termite, and In Silico Analysis of Their Polysaccharide-Degrading Enzymes.

Here, we report the high-quality draft genome sequences of Opitutaceae sp. strains TAV3 and TAV4, which were isolated from the hindgut of the wood-feeding termite Reticulitermes flavipes Using a combination of Illumina and PacBio sequencing, we constructed nearly complete assemblies totaling 5.84 and 5.91 Mbp in length for strains TAV3 and TAV4, respectively. In addition, we report an in silico analysis of potential lignocellulose-digesting enzymes present in these strains

Immobilization of Cellulase on Zinc Oxide Deposited on Zeolite Pellets for Enzymatic Saccharification of Cellulose

The consumption of fossil fuels to fulfill the global energy demand can cause global warming issues. Renewable energy, i.e., bioethanol, from lignocellulosic biomass, is a promising source of alternative energy to fossil fuels. The conversion of lignocellulosic biomass into bioethanol requires the release of fermentable sugars during the saccharification process using cellulase. However, the utilization of this enzyme on an industrial scale is not feasible due to its difficult separation, instability, and high cost. Here, we present a method for cellulase immobilization on functionalized zinc oxide prepared from either zinc nitrate hexahydrate (ZnO(I)) or zinc acetate dihydrate (ZnO(II)) solutions on zeolite (ZEO) pellets. The immobilized cellulase on ZnO-ZEO structures was characterized by scanning electron microscopy, Xray diffraction spectroscopy, and Fourier transform infrared spectroscopy. The immobilization efficiencies of immobilized cellulase either on ZnO(I)-ZEO or ZnO(II)-ZEO were determined as 58.17 ± 0.75% and 55.51 ± 0.81%, respectively. The immobilized cellulase on ZnO-ZEO was capable of catalyzing microcrystalline cellulose breakdown, releasing reducing sugars. The immobilized cellulase on these structures could be recycled up to four repetitive runs. Based on kinetic data, both the Michaelis constants (Km) and maximum reaction velocity (Vmax) of the immobilized cellulase on the ZnO-ZEO structures were lower than those of free cellulase. This suggests that immobilized cellulase has a higher affinity toward the substrate, but a lower reaction rate than the free enzyme

Utilization of Organic Wastes for Laccase Production by Pleurotus ostreatus

Production of laccase was achieved by using white-rot fungus, Pleurotus ostreatus, grown on economical and cost-effective materials. The fungus was cultivated in liquid medium containing mung bean pomace, soybean pomace and wastewater treatment sludge as sole carbon source for 15 days. In addition, different concentrations of an inducer, benzyl alcohol, were tested to induce laccase production. The results revealed that the highest laccase activity was equal to 1.859 ± 0.129 U/mL in mung bean pomace containing medium, and the lowest laccase activity was 0.234 ± 0.019 U/mL in soybean pomace medium. Addition of 10 mm benzyl alcohol enhanced laccase production up to 2.952 ± 0.080 U/mL in the mung bean pomace medium at day 15 of cultivation. Level of laccase production increased correspondingly with increasing concentration of the inducer. The high level of laccase production in mung bean medium could contribute to high C/N ratio and excessively high levels of carbon and nitrogen contents in soybean suppressed laccase production

Immobilization of Cellulase on Zinc Oxide Deposited on Zeolite Pellets for Enzymatic Saccharification of Cellulose

The consumption of fossil fuels to fulfill the global energy demand can cause global warming issues. Renewable energy, i.e., bioethanol, from lignocellulosic biomass, is a promising source of alternative energy to fossil fuels. The conversion of lignocellulosic biomass into bioethanol requires the release of fermentable sugars during the saccharification process using cellulase. However, the utilization of this enzyme on an industrial scale is not feasible due to its difficult separation, instability, and high cost. Here, we present a method for cellulase immobilization on functionalized zinc oxide prepared from either zinc nitrate hexahydrate (ZnO(I)) or zinc acetate dihydrate (ZnO(II)) solutions on zeolite (ZEO) pellets. The immobilized cellulase on ZnO-ZEO structures was characterized by scanning electron microscopy, Xray diffraction spectroscopy, and Fourier transform infrared spectroscopy. The immobilization efficiencies of immobilized cellulase either on ZnO(I)-ZEO or ZnO(II)-ZEO were determined as 58.17 ± 0.75% and 55.51 ± 0.81%, respectively. The immobilized cellulase on ZnO-ZEO was capable of catalyzing microcrystalline cellulose breakdown, releasing reducing sugars. The immobilized cellulase on these structures could be recycled up to four repetitive runs. Based on kinetic data, both the Michaelis constants (Km) and maximum reaction velocity (Vmax) of the immobilized cellulase on the ZnO-ZEO structures were lower than those of free cellulase. This suggests that immobilized cellulase has a higher affinity toward the substrate, but a lower reaction rate than the free enzyme

Complete Genome Sequence of the Opitutaceae Bacterium Strain TAV5, a Potential Facultative Methylotroph of the Wood-Feeding Termite Reticulitermes flavipes.

The Opitutaceae bacterium strain TAV5, a member of the phylum Verrucomicrobia, was isolated from the wood-feeding termite hindgut. We report here its complete genome sequence, which contains a chromosome and a plasmid of 7,317,842 bp and 99,831 bp, respectively. The genomic analysis reveals genes for methylotrophy, lignocellulose degradation, and ammonia and sulfate assimilation

Complete Genome Sequence of the Opitutaceae Bacterium Strain TAV5, a Potential Facultative Methylotroph of the Wood-Feeding Termite Reticulitermes flavipes.

The Opitutaceae bacterium strain TAV5, a member of the phylum Verrucomicrobia, was isolated from the wood-feeding termite hindgut. We report here its complete genome sequence, which contains a chromosome and a plasmid of 7,317,842 bp and 99,831 bp, respectively. The genomic analysis reveals genes for methylotrophy, lignocellulose degradation, and ammonia and sulfate assimilation