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A novel fructosyltransferase (AoFT) capable of synthesizing sucrose 6-acetate (S6A) from sucrose and glucose 6-acetate has been purified to homogeneity from Aspergillus oryzae ZZ-01. Its molecular mass was ~50 kDa by SDS-PAGE; optimal activity was at 45 °C and it was stable from pH 4.5 to 7.5 with an optimum pH of 6. Mg(2+), K(+) (5 mM), propanol, toluene (50%, v/v), Tween 20 or Triton X-100 (1%, w/v) increased the transfructosylation activity by 20, 17, 17, 10, 25 and 20%, respectively. An overall conversion of 32% was achieved under optimal conditions over 24 h. This is the first report that the purified and characterized the fructosyltransferase from Aspergillus capable of synthesis of S6A from sucrose and glucose 6-acetate.

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Before being subjected to the aging process, raw tobacco leaves (TLs) must be threshed and redried. We propose that threshing and redrying affect the bacterial communities that inhabit the TL surface, thereby influencing the aging process. However, these effects remain unclear. In this study, Illumina sequencing was applied to analyze the bacterial communities on both raw and redried TLs. Shannon's diversity value decreased from 3.38 to 2.52 after the threshing and redrying processes, indicating a large reduction in TL bacterial diversity. The bacterial communities also largely differed between raw TLs and redried TLs. On unaged raw TLs, Proteobacteria was the most dominant phylum (56.15%), followed by Firmicutes (38.99%). In contrast, on unaged redried TLs, Firmicutes (76.49%) was the most dominant phylum, followed by Proteobacteria (21.30%). Thus, the dominant genus Proteobacteria, which includes Sphingomonas, Stenotrophomonas, and Pantoea, decreased after the threshing and redrying processes, while the dominant genus Firmicutes, which includes Bacillus and Lactococcus, increased. Changes in the bacterial communities between raw and redried TLs were also noted after 1 year of aging. The relative abundance of dominant Proteobacteria taxa on raw TLs decreased from 56.15 to 16.92%, while the relative abundance of Firmicutes taxa increased from 38.99 to 79.10%. However, small changes were observed on redried TLs after 1 year of aging, with a slight decrease in Proteobacteria (21.30 to 17.64%) and a small increase in Firmicutes (76.49 to 79.10%). Based on these results, Firmicutes taxa may have a higher tolerance for extreme environments (such as high temperature or low moisture) than Proteobacteria bacteria. This study is the first report to examine the effects of threshing and redrying on bacterial communities that inhabit TLs.

We have expressed the pqqABCDE gene cluster from Gluconobacter oxydans, which is involved in pyrroloquinoline quinone (PQQ) biosynthesis, in Escherichia coli, resulting in PQQ accumulation in the medium. Since the gene cluster does not include the tldD gene needed for PQQ production, this result suggests that the E. coli tldD gene, which shows high homology to the G. oxydans tldD gene, carries out that function. The synthesis of PQQ activated d-glucose dehydrogenase in E. coli and the growth of the recombinant was improved. In an attempt to increase the production of PQQ, which acts as a vitamin or growth factor, we transformed E. coli with various recombinant plasmids, resulting in the overproduction of the PQQ synthesis enzymes and, consequently, PQQ accumulation--up to 6 mM--in the medium. This yield is 21.5-fold higher than that obtained in previous studies.

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The Chrysanthemum morifolium flower is widely used in China and Japan as a food, beverage, and medicine for many diseases. In our work, two new caffeoylquinic acid derivatives (1, 2), a new flavanone glycoside (3), and six reported flavanones (4–9) were isolated and identified from the flowers of C. morifolium. The chemical structures of all isolates were elucidated by the analysis of comprehensive spectroscopic data as well as by comparison with previously reported data. The isolated constituents 1–8 were evaluated for their neuroprotective activity, and compounds 3 and 4 displayed neuroprotective effects against hydrogen peroxide-induced neurotoxicity in human neuroblastoma SH-SY5Y cells.