Lignocellulose is a kind of renewable bioresource containing abundant polysaccharides, which can be used for biochemicals and biofuels production. However, the complex structure hinders the final efficiency of lignocellulosic biorefinery. This review comprehensively summarizes the hydrolases and typical microorganisms for lignocellulosic degradation. Moreover, the commonly used bioprocesses for lignocellulosic biorefinery are also discussed, including separated hydrolysis and fermentation, simultaneous saccharification and fermentation and consolidated bioprocessing. Among these methods, construction of microbial co-culturing systems via consolidated bioprocessing is regarded as a potential strategy to efficiently produce biochemicals and biofuels, providing theoretical direction for constructing efficient and stable biorefinery process system in the future.

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β-Carotene is a kind of high-value tetraterpene compound, which shows various applications in medical, agricultural and industrial areas owing to its antioxidant, anti-tumor and anti-inflammatory activities. In this study, Yarrowia lipolytica was successfully metabolically modified through the construction and optimization of β-carotene biosynthetic pathway for β-carotene production. The β-carotene titer in the engineered strain Yli-C with the introduction of the carotenogenesis genes crtI crtE and crtYB can reach 34.5 mg/L. With the overexpression of key gene in MVA pathway and the enhanced expression of fatty acid synthesis pathway, the β-carotene titer of the engineered strain Yli-CAH reached 87 mg/L, which was 152% higher than that of the strain Yli-C. Through the further expression of the rate-limiting enzyme tHMGR and the copy number of β-carotene synthesis related genes, the β-carotene production of Yli-C2AH2 strain reached 117.5 mg/L. The final strain Yli-C2AH2 produced 2.7 g/L β-carotene titer by fed-batch fermentation in a 5.0 L fermenter. This research will greatly speed up the process of developing microbial cell factories for the commercial production of β-carotene.

β-Carotene is a kind of high-value tetraterpene compound, which shows various applications in medical, agricultural and industrial areas owing to its antioxidant, anti-tumor and anti-inflammatory activities. In this study, Yarrowia lipolytica was successfully metabolically modified through the construction and optimization of β-carotene biosynthetic pathway for β-carotene production. The β-carotene titer in the engineered strain Yli-Cwith the introduction of the carotenogenesis genes crtI, crtEand crtYB can reach 34.5 mg/L. With the overexpression of key gene in MVA pathway and the enhanced expression of fatty acid synthesis pathway, the β-carotene titer of the engineered strain Yli-CAH reached 87 mg/L, which was 152% higher than that of the strain Yli-C. Through the further expression of the rate-limiting enzyme tHMGR and the copy number of β-carotene synthesis related genes, the β-carotene production of Yli-C2AH2 strain reached 117.5 mg/L. The final strain Yli-C2AH2 produced 2695.5 mg/L β-carotene titer by fed-batch fermentation in a 5.0 L fermenter. This research will greatly speed up the process of developing microbial cell factories for the commercial production of β-carotene.

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