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Microbial synthesis of plant‐based (−)‐menthol is of great interest because of its high demand (≈30 kiloton per year) as well as unique odor and cooling characteristics. However, this remains a great challenge due to the yet unfilled gap between (−)‐limonene and (+)‐cis‐isopulegone. Herein, the first artificial and effective system was developed for (+)‐cis‐isopulegone biosynthesis from (−)‐limonene by recruiting two bacterial enzymes to replace their inefficient counterparts from Mentha piperita, limonene‐3‐hydroxylase, and isopiperitenol dehydrogenase. A cofactor self‐regenerative recombinant Escherichia coli strain was constructed by introducing a formate dehydrogenase for nicotinamide adenine dinucleotide phosphate (NADPH) regeneration and an engineered microbial isopiperitenol dehydrogenase. The production of (+)‐cis‐isopulegone (up to 281.2 mg L−1) was improved by 36 times compared with that of the initial strain. This work lays a reliable foundation for the microbial synthesis of (−)‐menthol. [ABSTRACT FROM AUTHOR]

Structure-guided engineering of Pseudomonas dacunhae L -aspartate β-decarboxylase (AspBDC) resulted in a double mutant (R37A/T382G) with remarkable 15 400-fold improvement in specific activity reaching 216 mU mg−1, towards the target substrate 3(R)-benzyl- L -aspartate. A novel strategy for enzymatic synthesis of L -homophenylalanine was developed by using the variant as a biocatalyst affording 75% product yield within 12 h. Our results underscore the potential of engineered AspBDC for the biocatalytic synthesis of pharmaceutically relevant and value added unnatural L -amino acids. [ABSTRACT FROM AUTHOR]

Microbial synthesis of plant-based (-)-menthol is of great interest because of its high demand (≈30 kiloton per year) as well as unique odor and cooling characteristics. However, this remains a great challenge due to the yet unfilled gap between (-)-limonene and (+)-cis-isopulegone. Herein, the first artificial and effective system was developed for (+)-cis-isopulegone biosynthesis from (-)-limonene by recruiting two bacterial enzymes to replace their inefficient counterparts from Mentha piperita, limonene-3-hydroxylase, and isopiperitenol dehydrogenase. A cofactor self-regenerative recombinant Escherichia coli strain was constructed by introducing a formate dehydrogenase for nicotinamide adenine dinucleotide phosphate (NADPH) regeneration and an engineered microbial isopiperitenol dehydrogenase. The production of (+)-cis-isopulegone (up to 281.2 mg L -1 ) was improved by 36 times compared with that of the initial strain. This work lays a reliable foundation for the microbial synthesis of (-)-menthol., (© 2021 Wiley-VCH GmbH.)

Aims: Hypertrophic cardiomyopathy (HCM) with left ventricular apical aneurysm (LVAA) is associated with an increased risk of adverse cardiovascular events. However, the clinical significance of LVAA in apical HCM (ApHCM) has not been reported. This study aimed to investigate the prevalence, cardiac magnetic resonance (CMR) characteristics, and prognosis of LVAA in ApHCM patients., Methods and Results: A total of 1332 consecutive ApHCM patients confirmed by CMR in our hospital were retrospectively analysed. LVAAs were identified in 31 patients of all ApHCM patients (2.3%, 31/1332). Besides, 31 age- and gender-matched ApHCM patients without LVAA were used for comparison. Of the 31 aneurysm patients (mean age, 53.8 ± 15.1 years old), 28 (90.3%) had clinical symptoms, and 3 (9.7%) had a family history of HCM. The rate of missed diagnosis of echocardiography for detecting LVAA was 64.5% (20/31), most (90%, 18/20) of unidentified LVAAs by echocardiography were small aneurysms (<20 mm). Compared with ApHCM patients without LVAA, the proportion of systolic mid-cavity obstruction and late gadolinium enhancement (LGE) presence, and the LGE extent in ApHCM patients with LVAA were significantly higher (all P<0.05). The Kaplan-Meier curves showed that the event-free survival rate in ApHCM patients with LVAA was significantly lower than that in ApHCM patients without LVAA (log rank, P = 0.010)., Conclusion: ApHCM with LVAA is a very rare condition, which is often missed by echocardiography and could be reliably detected with CMR and is associated with a higher risk of adverse cardiovascular events compared with ApHCM without LVAA., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)

Nitrogen removal in constructed wetlands (CWs) is highly affected by the supply of organic carbon. Thus, to enhance nitrogen removal in the horizontal subsurface flow of CWs, plant carbon sources were added during the downstream portion of the wetland. Moreover, the characteristics of static release and the denitrification potential of Typha were evaluated using three different pretreatment methods (i.e., minced, acid-heated, and alkali-heated). The average concentrations of COD released and the nitrate removal rate with the alkali-heated, acid-heated, and minced Typha were 89.57 mg·L -1 and 75.2%, 67.27 mg·L -1 and 67.2%, and 54.45 mg·L -1 and 23.5%, respectively. The results showed that different pretreatment methods resulted in the release of different amounts of acetic acid, and the alkali-heated Typha performed much better than the other pretreatments. Therefore, the alkali-heated Typha was selected and added to the middle of the horizontal subsurface flow CW, which improved the nitrogen-removal rate significantly; the average removal rate of TN and TP was higher than that of a control CW by 30.3% and 33.9%, respectively. However, the COD concentration of the CW with the alkali-heated Typha was not significantly increased.