摘要：
Abstract Pimpinella smithii Wolff is endemic in China. In this study, the complete chloroplast genome of P. smithii was determined. The total genome size was 147,130 bp in length. It was found to possess the quadripartite structure, containing a pair of inverted repeats (IRs) of 18,264 bp, which were separated by large single copy (LSC) and small single copy (SSC) of 93,158 bp and 17,444 bp, respectively. A total of 129 genes were identified, including 85 protein-coding genes, 36 tRNA genes, and eight rRNA genes. The maximum-likelihood phylogenetic analysis indicated that P. smithii has close relationship with genus Angelica.
期刊：
Bioprocess and Biosystems Engineering,2020年43(4):701-710 ISSN：1615-7591
通讯作者：
Sun, Weifeng
作者机构：
[Chen, Xiaohua; Sun, Weifeng; Liu, Yi] Hengyang Normal Univ, Coll Life Sci & Environm, Hengyang 421008, Peoples R China.;[Wang, Li; Lin, Lu; Wu, Lunjie; Ding, Wenwu; Che, Zhenming; Wu, Yuanming] Xihua Univ, Sch Food & Biotechnol, Key Lab Food & Biotechnol, Chengdu 610039, Peoples R China.;[Zhu, Longbao] Anhui Polytech Univ, Sch Biochem Engn, Wuhu 241000, Anhui, Peoples R China.
通讯机构：
[Sun, Weifeng] H;Hengyang Normal Univ, Coll Life Sci & Environm, Hengyang 421008, Peoples R China.
关键词：
Auto-inducible expression;Bacillus subtilis;Beefy meaty peptide;Fermentation production;Pontryagin's maximum principle
摘要：
Currently, some cases about the expression of flavor peptides with microorganisms were reported owing to the obvious advantages of biological expression over traditional methods. However, beefy meaty peptide (BMP), the focus of umami peptides, has neither been concerned in its safe expression nor its overproduction in fermenter. In this study, multi-copy BMP (8BMP) was successfully auto-inducibly expressed and efficiently produced in Bacillus subtilis 168. First, 8BMP was successfully auto-inducibly expressed with srfA promoter in B. subtilis 168. Further, the efficient production of 8BMP was researched in a 5-L fermenter: the fermentation optimized by Pontryagin's maximum principle obtained the highest 8BMP yield (3.16 g/L), which was 1.2 times and 1.8 times than that of two-stage feeding cultivation (2.67 g/L) and constant-rate feeding cultivation (1.75 g/L), respectively. Overall, the auto-inducible expression of 8BMP in B. subtilis and fermentation with Pontryagin's maximum principle are conductive for overproduction of BMP and other peptides.
摘要：
Roxarsone is a phenyl-substituted arsonic acid comprising both arsenate and benzene rings. Few adsorbents are designed for the effective capture of both the organic and inorganic moieties of ROX molecules. Herein, nano zerovalent iron (nZVI) particles were incorporated on the surface of sludge-based biochar (SBC) to fabricate a dual-affinity sorbent that attracts both the arsenate and benzene rings of ROX. The incorporation of nZVI particles significantly increased the binding affinity and sorption capacity for ROX molecules compared to pristine SBC and pure nZVI. The enhanced elimination of ROX molecules was ascribed to synergetic adsorption and degradation reactions, through pi-pi* electron donor/acceptor interactions, H-bonding, and As-O-Fe coordination. Among these, the predominate adsorption force was As-O-Fe coordination. During the sorption process, some ROX molecules were decomposed into inorganic arsenic and organic metabolites by the reactive oxygen species (ROS) generated during the early stages of the reaction. The degradation pathways of ROX were proposed according to the oxidation intermediates. This work provides a theoretical and experimental basis for the design of adsorbents according to the structure of the target pollutant.
期刊：
Genetics and Molecular Biology,2020年43(4):1-6 ISSN：1415-4757
通讯作者：
Lu, Xu
作者机构：
[Wang, Long; Li, Ping; Lu, Gengyu; Huang, Lijin; Lu, Xu] China Pharmaceut Univ, Sch Tradit Chinese Med, State Key Lab Nat Med, Nanjing, Peoples R China.;[Liu, Hao] Hunan Acad Chinese Med, Inst Chinese Mat Med, Changsha, Peoples R China.;[Jiang, Weimin] Hengyang Normal Univ, Coll Life Sci & Environm, Hengyang, Hunan, Peoples R China.
通讯机构：
[Lu, Xu] C;China Pharmaceut Univ, Sch Tradit Chinese Med, State Key Lab Nat Med, Nanjing, Peoples R China.
关键词：
Abstract Gynostemma yixingense, an important medicinal member of the Cucurbitaceae family, is an endemic herbaceous species distributed in East China. It is morphologically similar to the plants in the same genus, which resulted in some confusion in identification and application. Meanwhile, there are still some controversies in taxonomy. Herein, the complete chloroplast genome sequence of G. yixingense was obtained by Illumina paired-end sequencing technology and compared to other chloroplast genome sequences of congeneric species. The complete chloroplast genome of G. yixingense is 157,910 bp in length with 36.94% GC content and contains a large single-copy (LSC) region of 86,791 bp, a small single-copy (SSC) region of 18,635 bp and a pair of inverted repeat (IR) regions of 26,242 bp. The whole genome contains 133 unique genes, including 87 protein-coding genes, 37 tRNA genes, eight rRNA genes and one pseudogene. In addition, 74 simple sequence repeats (SSRs) were identified, most of which were A/T rich. The phylogenetic analysis indicated that G. yixingense had the closest relationship to G. laxiflorum. The result of this study provided an important theoretical basis for chloroplast genome and phylogenetic analysis of G. yixingense. Keywords: Chloroplast genome, Cucurbitaceae;Gynostemma;phylogeny;simple sequence repeats
作者机构：
[Chen, Wei; He, Yufeng; Zhao, Jianxin; Wang, Gang; Zhang, Hao; Jin, Xing] Jiangnan Univ, State Key Lab Food Sci & Technol, Wuxi 214122, Jiangsu, Peoples R China.;[Liu, Zhenmin] Bright Daily & Food Co Ltd, State Key Lab Dairy Biotechnol, Shanghai Engn Res Ctr Dairy Biotechnol, Dairy Res Inst, Shanghai 200436, Peoples R China.;[Zhou, Yonghua] Jiangsu Inst Parasit Dis, Key Lab Natl Hlth & Family Planning Commiss Paras, Jiangsu Prov Key Lab Parasite & Vector Control Te, Wuxi 214064, Jiangsu, Peoples R China.;[Chen, Xiaohua] Hengyang Normal Univ, Coll Life Sci & Environm, Hengyang 421008, Peoples R China.;[Chen, Wei; Zhao, Jianxin; Wang, Gang; Zhang, Hao] Jiangnan Univ, Sch Food Sci & Technol, Wuxi 214122, Jiangsu, Peoples R China.
通讯机构：
[Wang, Gang; Zhou, Yonghua] J;[Liu, Zhenmin] B;Jiangnan Univ, State Key Lab Food Sci & Technol, Wuxi 214122, Jiangsu, Peoples R China.;Bright Daily & Food Co Ltd, State Key Lab Dairy Biotechnol, Shanghai Engn Res Ctr Dairy Biotechnol, Dairy Res Inst, Shanghai 200436, Peoples R China.;Jiangsu Inst Parasit Dis, Key Lab Natl Hlth & Family Planning Commiss Paras, Jiangsu Prov Key Lab Parasite & Vector Control Te, Wuxi 214064, Jiangsu, Peoples R China.
摘要：
Caenorhabditis elegans (C. elegans) is increasingly used as a model organism to screen probiotics for ageing research. In this study, a C. elegans lifespan analysis model exposed to H2O2 and juglone (for chronic and acute assays) was used to preselect lactic acid bacteria (LAB) with resistance to oxidative stress. The mechanism of oxidative stress protection was analyzed. Seven out of ten LAB strains screened for namely 427, X13, 9-5, 422, Z5, G14 and H29M-8M demonstrated higher levels of protection to C. elegans, ranging from 70% to 85% survival rate, in comparison to the inactive strains 408, 13-7 and 430 (35% to 45% survival rate). The survival rates of the seven oxidative stress tolerant strains were correlated to increase in catalase (CAT), superoxide dismutase (SOD) and malondialdehyde (MDA) levels and decrease in reactive oxygen species (ROS) expression in C. elegans during H2O2 and juglone exposure. In addition, the transcription of mitogen-activated protein kinase (MAPK) and Nrf2-Keap1-ARE pathway related genes was elevated in the oxidative stress protection of LAB isolates. Finally, a significant correlation was found between the ability of these LAB strains to protect C. elegans from H2O2 or juglone exposure and their antioxidative ability in Campylobacter jejuni-infected mice. Thus the results indicated that the oxidative stress-based lifespan model of C. elegans is useful for screening of LAB with antioxidant efficacy in pathogen-infected mammals.
