ABSTRACT
Carotenoids are secondary metabolite responsible for colored pigments in plants and microbes (Li et al., 2022). They are a class of C40 tetraterpenoids consisting of eight isoprenoid units, and can be classified into carotenes and xanthophylls on the basis of their functional groups (Saini et al., 2015). Carotenes can be linear (phytoene, phytofluene, and ζ-carotene) or branched (β-carotene and α-carotene). Xanthophylls comprise β,β-xanthophylls (β-cryptoxanthin, zeaxanthin, violaxanthins, and neoxanthin) and β,ε-xanthophylls (α-cryptoxanthin, α-carotene, and lutein). Citrus fruits are complex sources of carotenoids, which are the principal pigments responsible for the typical orange color of most types (Chen, 2020). The difference in total carotenoid content and the diversity of carotenoid isomer proportion also accounts for other colors of citrus fruits, such as yellow, red, and pink (Chen, 2020).
Subject(s)
Citrus/metabolism , Carotenoids , Xanthophylls , Lutein/metabolism , Zeaxanthins/metabolism , FruitABSTRACT
Objective@#To analyze the molecular characteristics of Listeria monocytogenes strains from ready-to eat food in China.@*Methods@#A total of 239 Listeria monocytogenes strains isolated from ready-to-eat food in 2017, all strains underwent whole-genome sequencing (WGS) , and comparisons uncovered population structure derived from lineages, clonal complex, serogroups, antimicrobial susceptibility and virulence, which were inferred in silico from the WGS data. Core genome multilocus sequence typing was used to subtype isolates.@*Results@#All strains were categorized into three different lineages, lineage Ⅱ was the predominant types in food, and IIa was the main serogroups. CC8, CC101 and CC87 were the first three prevalent CCs among 23 detected CCs, accounting for 49.4%. Only 4.6% (11 isolates) of tested strains harbored antibiotic resistance genes, which were mostly trimethoprim genes (7 isolates, 2.9%). All strains were positive for LIPI-1, and only a part of strains harbored LIPI-3 and LIPI-4, accounting for 13.8% (33 isolates) and 14.2% (34 isolates), respectively. ST619 carried both LIPI-3 and LIPI-4. 51.5% (123 isolates) of strains carried SSI-1, and all CC121 strains harbored SSI-2. Different lineages, serogroups and CCs can be separated obviously through cgMLST analysis, and 24 sublineages were highly concordant with CCs.@*Conclusion@#Ⅱa was the main serogroups in ready-to-eat food isolates in China; CC8, CC101 and CC87 were the prevalent CCs, and CC87 isolates was hypervirulent isolates, cgMLST method can be adopted for prospective foodborne disease surveillance and outbreaks detection.
ABSTRACT
Objective To isolate and identify the Sertoli′ cells, and the expression of FasL was examined immunohistochemically. Methods Testis were isolated from male Wistar rats and Sertoli′ cells were isolated. After culturing for 72 hours, Sertoli′ cells were morphologically observed by several ways and identified with transmission electron microscope. FasL was examined immunohistochemically. Results The yielded Sertoli′ cells accounted for over 90% of all the cells harvested. FasL was expressed in high level in the 72h cultured Sertoli′ cells. Conclusion Sertoli′ cells that we have isolated can be used for co-transplantation with other cells and offer immune privilege.