摘要：Photosynthetic terpene production represents one of the most carbon and energy-efficient routes for converting CO_(2)into *** photosynthetic organisms,metabolic engineering has led to limited success in enhancing terpene productivity,partially due to the low carbon *** this study,we employed systems biology analysis to reveal the strong competition for carbon substrates between primary metabolism(e.g.,sucrose,glycogen,and protein synthesis)and terpene biosynthesis in Synechococcus elongatus PCC *** then engineered key“source”and“sink”***“source”limitation was overcome by knocking out either sucrose or glycogen biosynthesis to significantly enhance limonene production via altered carbon ***,a fusion enzyme complex with geranyl diphosphate synthase(GPPS)and limonene synthase(LS)was designed to further improve pathway kinetics and substrate *** synergy between“source”and“sink”achieved a limonene titer of 21.0 mg/***,the study demonstrates that balancing carbon flux between primary and secondary metabolism can be an effective approach to enhance terpene bioproduction in *** design of“source”and“sink”synergy has significant potential in improving natural product yield in photosynthetic species.

摘要：Human noroviruses(HuNoVs)are major foodborne pathogens that cause nonbacterial acute gastroenteritis *** the tissue-culture system for HuNoVs is not mature enough for routine detection of the virus,detection is mainly dependent on molecular approaches such as reverse transcription polymerase chain reaction(RT-PCR)and reverse transcription quantitative real-time polymerase chain reaction(RTqPCR).The widely used primers and probes for RT-qPCR were established in the early *** HuNoVs are highly variant viruses,viral genome mutations result in previously designed primers and/or probes that were perfectly matched working less efficiently over *** this study,a new duplex RT-qPCR(ND-RT-qPCR)was designed for the detection of genogroup Ⅰ(GⅠ)and genogroup Ⅱ(GⅡ)HuNoVs based on an analysis of viral sequences added in the database after *** long transcribed viral RNAs,the results demonstrate that the sensitivity of ND-RT-qPCR is as low as one genomic copy for both GⅠ and GⅡ *** performance of ND-RT-qPCR was further evaluated by a comparison with the commonly used Kageyama primer/probe sets for RT-qPCR(Kageyama RT-qPCR)for 23 HuNoV-positive clinical *** five GⅠ samples were registered as positive by ND-RT-qPCR,whereas only two samples were registered as positive by Kageyama *** 18 GⅡ samples were registered as positive by ND-RT-qPCR,while 17 samples were registered as positive by Kageyama *** sensitivity reflected by the quantification cycle(Cq)value was lower in ND-RT-qPCR than in Kageyama *** data suggest that ND-RT-qPCR could be a good fit for the detection of current strains of HuNoVs.