Astaxanthin is a highly value-added keto-carotenoid compound. The astaxanthin 3S,3′S-isomer is more desirable for food additives, cosmetics, and pharmaceuticals due to health concerns about chemically synthesized counterparts with a mixture of three isomers. Biosynthesis of 3S,3′S-astaxanthin suffers from limited content and productivity. We engineered Yarrowia lipolytica to produce high levels of 3S,3′S-astaxanthin. We first assessed various β-carotene ketolases (CrtW) and β-carotene hydroxylases (CrtZ) from two algae and a plant. HpCrtW and HpCrtZ from Haematococcus pluvialis exhibited the strongest activity in converting β-carotene into astaxanthin in Y. lipolytica. We then fine-tuned the HpCrtW and HpCrtZ transcriptional expression by increasing the rounds of gene integration into the genome and applied a modular enzyme assembly of HpCrtW and HpCrtZ simultaneously. Next, we rescued leucine biosynthesis in the engineered Y. lipolytica, leading to a five-fold increase in biomass. The astaxanthin production achieved from these strategies was 3.3 g/L or 41.3 mg/g dry cell weight under fed-batch conditions, which is the highest level reported in microbial chassis to date. This study provides the potential for industrial production of 3S,3′S-astaxanthin, and this strategy empowers us to build a sustainable biorefinery platform for generating other value-added carotenoids in the future.

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Comprehensive Summary Organic–inorganic metal‐halide perovskite solar cells (PerSCs) have achieved significant progresses due to their outstanding optoelectronic characteristics, and the power conversion efficiency (PCE) of single‐junction PerSCs has been boosted from 3.8% to a certified 25.2%. However, the efficiency of single‐junction cells is governed by the Shockley–Queisser (S–Q) radiative limit, and fabricating all‐perovskite tandem solar cells is a particularly attractive method to break the S–Q limit. Since the bandgap of lead (Pb)–based mixed halide perovskite can be tuned from 1.55 eV to 2.3 eV, and the mixed tin (Sn)–Pb perovskites have bandgap of ~1.2 eV, these perovskites become the best candidates for the front and rear subcells of all‐perovskite tandem device, respectively. In this review, we firstly summarize the current development progresses of two‐terminal (2‐T) all‐perovskite tandem solar cells. For further optimizing the device performance, the wide bandgap mixed halide perovskites for front subcell, mixed Sn–Pb narrow bandgap perovskites for rear subcell, and the interconnection layer (ICL) of 2‐T tandem device are then discussed. This review aims to open a pathway to realize highly efficient all‐perovskite tandem solar cells.

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Designed based on bi-directional DC / DC converter of the super-capacitor and battery hybrid energy storage system, using both on the technical performance have strong complementary features that can improve the battery charge and discharge process, so that the battery charge and discharge cycles decrease, prolong the service life of battery. In matlab/simulink environment, established a system simulation model, the result showed that the hybrid energy storage system can effectively restrain the DC bus voltage fluctuations, make the output voltage relatively stable.

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