Isolation of a newly Trichoderma asperellum LYS1 with abundant cellulase-hemicellulase enzyme cocktail for lignocellulosic biomass degradation.

As the most abundant and renewable natural resource in the world, lignocellulose is a promising alternative to fossil energy to relieve environmental concerns and resource depletion. However, due to its recalcitrant structure, strains with efficient degradation capability still need exploring. In this study, a fungus was successfully isolated from decayed wood and named as Trichoderma asperellum LYS1 by phylogenetic and draft genomic analysis. The further investigations showed that strain LYS1 had an outstanding performance on lignocellulose degradation, especially for hemicellulose-rich biomass. After the analysis of encoded CAZymes, mainly on GH family, a large amount of genes coding ß-glucosidase and xylanase may contribute to the high degradation of cellulose and hemicellulose. Collectively, the results generated in this study demonstrated that T. asperellum LYS1 is a potential cell factory for lignocellulose biorefinery.

Preparation of the porous carbon-based solid acid from starch for efficient degradation of chitosan to D-glucosamine.

Effective degradation of chitosan to D-glucosamine is considered to make a great contribution for the development of the medical industry. To address this issue, a porous carbon-based solid acid catalyst (PCSA) functionalized with -OH, -COOH and -SO3H groups was successfully prepared. Typically, the physicochemical properties of PCSA were deeply determined by a series of characterization technique including FT-IR, TGA, RM, NH3-TPD, SEM and Element Analysis. Moreover, the catalytic performances of PCSA towards to D-glucosamine production from chitosan were evaluated. In particular, the effects of catalyst acid density, ratio of acidic groups, chitosan concentration, reaction temperature, reaction time and catalyst dosage on the yield of D-glucosamine were investigated in detail. Interestingly, the experimental results indicated that a yield of D-glucosamine as high as 90.5% was achieved, and no obvious deactivation occurred even after six consecutive cycles. In light of the advantages of superior activity/recyclability and low cost, the starch-derived solid acid developed in this work might possess the broad industrial application prospects.

Microbial application of thermophilic Thermoanaerobacterium species in lignocellulosic biorefinery.

Recently, thermophilic Thermoanaerobacterium species have attracted increasing attentions in consolidated bioprocessing (CBP), which can directly utilize lignocellulosic materials for biofuels production. Compared to the mesophilic process, thermophilic process shows greater prospects in CBP due to its relatively highly efficiency of lignocellulose degradation. In addition, thermophilic conditions can avoid microbial contamination, reduce the cooling costs, and further facilitate the downstream product recovery. However, only few reviews specifically focused on the microbial applications of thermophilic Thermoanaerobacterium species in lignocellulosic biorefinery. Accordingly, this review will comprehensively summarize the recent advances of Thermoanaerobacterium species in lignocellulosic biorefinery, including their secreted xylanases and bioenergy production. Furthermore, the co-culture can significantly reduce the metabolic burden and achieve the more complex work, which will be discussed as the further perspectives. KEY POINTS: • Thermoanaerobacterium species, promising chassis for lignocellulosic biorefinery. • Potential capability of hemicellulose degradation for Thermoanaerobacterium species. • Efficient bioenergy production by Thermoanaerobacterium species through metabolic engineering.

Biofilm application in the microbial biochemicals production process.

Biofilms can be naturally formed through the attachment of microorganisms on the supporting materials. However, natural biofilms formed in the environment may cause some detrimental effects, such as the equipment contamination and food safety issues et al. On the contrary, biofilms mediated microbial fermentation provides a promising approach for the efficient biochemicals production owing to the properties of self-immobilization, high resistance to toxic reactants and maintenance of long-term cells activity. While few reviews have specifically addressed the biological application of biofilms in the microbial fermentation process. Accordingly, this review will comprehensively summarize the biofilms formation mechanism and potential functions in the microbial fermentation process. Furthermore, the construction strategies for the formation of stable biofilms through synthetic biology technology or the modification of suitable supporting materials will be also discussed. The application of biofilms mediated fermentation will provide an outlook for the biorefinery platform in the future.