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We have identified three Microbacterium strains, A18JL200T, NY27T, and WY121T, that produce C50 carotenoids. Taxonomy shows they represent three novel species. These strains shared < 98.5% 16S rRNA gene sequence identity with each other and were closely related to Microbacterium aquimaris JCM 15625T, Microbacterium yannicii JCM 18959T, Microbacterium ureisolvens CFH S00084T, and Microbacterium hibisci CCTCC AB 2016180T. Digital DNA-DNA hybridization (dDDH) values and average nucleotide identity (ANI) showed differences among the three strains and from their closest relatives, with values ranging from 20.4% to 34.6% and 75.5% to 87.6%, respectively. These values are below the threshold for species discrimination. Both morphology and physiology also differed from those of phylogenetically related Microbacterium species, supporting that they are indeed novel species. These strains produce C50 carotenoids (mainly decaprenoxanthin). Among the three novel species, A18JL200T had the highest total yield in carotenoids (6.1 mg/L or 1.2 mg/g dry cell weight). Unusual dual isoprenoid biosynthetic pathways (methylerythritol phosphate and mevalonate pathways) were annotated for strain A18JL200T. In summary, we found strains of the genus Microbacterium that are potential producers of C50 carotenoids, but their genome has to be investigated further.

Background Menaquinones are constituents of prokaryote cell membranes where they play important functions during electron transport. Menaquinone profiles are strongly recommended for species classification when proposing a new Actinomycetes taxon. Presently, the most widely used methods to determine menaquinones are based on freeze-dried cells. Taxonomic research in our lab has revealed that menaquinone concentrations are low for some species of the genus Microbacterium, leading to difficulties in identifying menaquinones. Results Menaquinones extracted using the novel lysozyme-chloroform-methanol (LCM) method were comparable in quality to those obtained using the Collins method, the most widely used method. All tested strains extracted via the LCM method showed higher concentrations of menaquinones than those extracted via the Collins method. For some Microbacterium strains, the LCM method exhibited higher sensitivity than the Collins method, and more trace menaquinones were detected with the LCM method than the Collins method. In addition, LCM method is faster than the Collins method because it uses wet cells. Conclusion The LCM method is a simple, rapid and efficient technique for the extraction and identification of menaquinones from Actinomycetes.

In an environment that is tightly linked to humankind, how anthropogenic activity affects the quality and quantity of dissolved organic matter (DOM) in atmospheric depositions is not well understood. In this study, dissolved organic carbon (DOC), UV-vis spectra combined with molecular markers, including formic acid (FA), acetic acid (AA) and dissolved black carbon (DBC), were applied to track the temporal variation and influential factors of rainwater DOM at a coastal site. The ranges of DOC, light absorption at 254 nm (a

We have identified three Microbacterium strains, A18JL200

Plant-derived neutral oligosaccharides and pectic-oligosaccharides (POS) have been suggested as prebiotics based on their degree of polymerization (DP) and structural complexity. In the present study, neutral oligosaccharides without galacturonic acid were produced from commercial apple pectin using an optimized concentration of pectinase and degradation time. The crude oligosaccharide solution was refined by membrane separation using a DEAE-Sepharose CL-6B column, a graphite carbon column and an Xbridge C18 column, which resulted in the neutral oligosaccharides with DP 3–13. The monosaccharide composition of oligosaccharides primarily included glucose, arabinose, galactose and xylose without galacturonic acid. The structure of the oligosaccharides was analyzed using mass spectrometry with an electrospray ionization source by UPLC on an HILIC column and 1H NMR. The MS/MS spectra in positive ion mode and 1H NMR showed a main oligosaccharide structure corresponding to the connection of arabinogalactan with Galβ1→4Galβ1→4Galβ1→4Galβ1→α3Araf. The growth of the selected Lactobacillus. strains was improved by adding refined neutral oligosaccharides with DP = 3–13 compared with commercial inulin, and growth of Escherichia coli had not basically grown. Therefore, neutral oligosaccharides (DP = 3–13) can be considered effective prebiotics for potential application in functional food.

Phloroglucinol degradation at initial pH from 7.0 to 9.0 has been investigated in Fenton, UV-Fenton and nano-Fe3O4 catalyzed UV-Fenton (Hetero-Fenton). Within the reaction time given in this study (not more than 4 h), 150 mg·L−1 phloroglucinol was completely removed, while there was some difference in TOC removal efficiency: about 90% for UV-Fenton, nearly 60% for Fenton and Hetero-Fenton. Increasing initial pH from 7.0 to 9.0, there was an obvious decline in the degradation rate. The average values of H2O2 utilization efficiency were 0.65 ± 0.01 for Fenton, 0.66 ± 0.09 for UV-Fenton, and 1.35 ± 0.15 for Hetero-Fenton, suggesting Hetero-Fenton required less H2O2 consumption. Solution pH could decrease to strongly acidic conditions of pH