No abstract

Ketogulonicigenium vulgare has been widely used in vitamin C two steps fermentation and requires companion strain for optimal growth. However, the understanding of K. vulgare as well as its companion strain is still preliminary. Here, the complete genome of K. vulgare Hbe602 was deciphered to provide insight into the symbiosis mechanism and the versatile metabolism. K. vulgare contains the LuxR family proteins, chemokine proteins, flagellar structure proteins, peptides and transporters for symbiosis consortium. Besides, the growth state and metabolite variation of K. vulgare were observed when five carbohydrates (D-sorbitol, L-sorbose, D-glucose, D-fructose and D-mannitol) were used as carbon source. The growth increased by 40.72% and 62.97% respectively when K. vulgare was cultured on D-mannitol/D-sorbitol than on L-sorbose. The insufficient metabolism of carbohydrates, amino acids and vitamins is the main reason for the slow growth of K. vulgare. The combined analysis of genomics and metabolomics indicated that TCA cycle, amino acid and nucleotide metabolism were significantly up-regulated when K. vulgare was cultured on the D-mannitol/D-sorbitol, which facilitated the better growth. The present study would be helpful to further understand its metabolic structure and guide the engineering transformation.

A series of novel guanidinium-based magnetic ionic liquids were synthesized. Among them, [TMG]­Cl/1.5FeCl3 exhibited a very strong paramagnetic strength with the value of magnetic susceptibility as great as 59.1 × 10–6 emu/g, which exceeded any other reported magnetic IL so far. By virtue of good physical and chemical properties, it was representatively selected to extract dibenzothiophene (DBT) and thiophene (T) from model oils with sulfur content of 900–1000 μg/g, which was compared with commonly reported imidazolium magnetic ionic liquid [BMIM]­Br/1.5FeCl3. The results revealed that [TMG]­Cl/1.5FeCl3 had perfect desulfurization efficiency (nearly 100%) with mass ratio of oil to MIL (g/g) of 1–4 within only 5 min at room temperature, and the method could easily meet the latest European sulfur emission standard (Euro 5). It showed significant selectivity for sulfur over toluene, as well as little pollution of the model oils, which were both better than [BMIM] Br/1.5FeCl3. Satisfactory desulfurization performance for 93 gasoline was further achieved by [TMG]­Cl/1.5FeCl3. Furthermore, it could be recycled at least 7 times without any noticeable decrease in desulfurization efficiency. The novel MIL demonstrates promise in practical application in the future.