[Effect of enhanced recovery after surgery on surgical stress response in patients with gastric cancer complicated with type 2 diabetes mellitus].

Objective: To investigate the effect of enhanced recovery after surgery on the stress response of gastric cancer patients complicated with type 2 diabetes mellitus. Methods: We retrospectively analyzed the data of 49 patients with type 2 diabetes who underwent radical gastrectomy for gastric cancer in the Department of gastroenterology of the Affiliated Hospital of Jiangsu University from Jan to Dec 2020. They were randomly divided into experimental group and control group according to different perioperative management measures. The perioperative C-reactive protein (CRP), white blood cell (WBC), interleukin-6(IL-6), insulin resistance (HOMA-IR), blood glucose fluctuation and postoperative recovery were compared between the two groups. Results: A total of 49 patients were enrolled in the study (23 in the experimental group and 26 in the control group). The degree of stress reaction of the experimental group was lighter than that of the control group. The levels of CRP were significantly different on the 5th and 7th day after operation, IL-6 was significantly different on the 1st, 3rd, 5th and 7th day after operation, WBC and HOMA-IR were significantly different on the 1st day postoperatively. And the changes of HOMA-IR and blood glucose in experimental group were more gentle than those in control group. All the differences were statistically significant(P<0.05). In the experimental group, the time of first anal exhaust, indwelling time of drainage tube or nasointestinal tube and the total hospitalization time were significantly shorter than those of the control group(P<0.05). Conclusion: ERAS can reduce the degree of inflammatory stress and the postoperative IR level promote the early recovery of patients with gastric cancer complicated with type 2 diabetes mellitus.

Highly selective resolution of racemic 1-phenyl-1,2-ethanediol by a novel strain Kurthia gibsonii SC0312.

Chiral 1-phenyl-1,2-ethanediol (PED) performs vital effect for the preparation of pharmaceuticals, agrochemicals and cosmetics. In the study, a newly isolated strain Kurthia gibsoniiSC0312 with the ability to selectively oxidize racemic PED to achieve (S)-PED was evaluated in the aqueous reaction system. The strain showed excellent catalytic performances within the range of pH 5·5-8·5, temperature 25-45°C and the amount of cell 15 mg ml-1 to 30 mg ml-1 . Besides, 2-hydroxyacetophenone (HAP) as the oxidation product displayed a stronger inhibition to the catalytic activity of cell, only remaining <63% of catalytic activity after incubation at 40 mmol l-1 HAP for 6 h. For various metal ions, Cu2+ can obviously improve 1·7 times of the catalytic activity of cell at the concentration of 0·2 mmol l-1 . Acetone can stimulate the catalytic capacity of cell to improve the optical purity of (S)-PED at the PED concentration of 80 mmol l-1 , up to appropriately 94% from 85·4%; compared to the resting cell, growing cell exerted no positive effect in the yield and optical purity. Finally, a highly effective kinetic resolution system of racemic PED by the new strain was obtained, with the (S)-PED yield of 41% and optical purity of 94%. SIGNIFICANCE AND IMPACT OF THE STUDY: Biocatalyst is a vital component in the process of biotransformation. There are a growing number of studies of biocatalyst reporting the preparation of enantiomer of 1-phenyl-1,2-ethanediol. And the performance of this preparation reaction is also gradually improving. This study is the first to demonstrate that Kurthia gibsonii can efficiently and selectively oxidize racemic 1-phenyl-1,2-ethanediol, and we assess the effect of various factors on the catalytic performance of the strain. The work adds to a growing body of evidence for using biocatalytic method in the synthesis of chiral 1-phenyl-1,2-ethanediol and provides a probable approach to mine excellent properties of enzymes.

Efficient biocatalytic stereoselective reduction of methyl acetoacetate catalyzed by whole cells of engineered E. coli.

Asymmetric synthesis of chiral ß-hydroxy esters, the key building blocks for many functional materials, is currently of great interest. In this study, the biocatalytic anti-Prelog reduction of methyl acetoacetate (MAA) to methyl-(R)-3-hydroxybutyrate ((R)-HBME) was successfully carried out with high enantioselectivity using the whole cell of engineered E. coli, which harbored an AcCR (carbonyl reductase) gene from Acetobacter sp. CCTCC M209061 and a GDH (glucose dehydrogenase) gene from Bacillus subtilis 168 for the in situ regeneration of the coenzyme. Compared with the corresponding wild strain, the engineered E. coli cells were proved to be more effective for the bio-reduction of MAA, and afforded much higher productivity. Under the optimized conditions, the product e.e. was >99.9% and the maximum yield was 85.3% after a reaction time of 10 h, which were much higher than those reported previously. In addition, the production of (R)-HBME increased significantly by using a fed-batch strategy of tuning pH, with a space-time yield of approximately 265 g L-1 d-1, thus the issue in previous research of relatively low substrate concentrations appears to be solved. Besides, the established bio-catalytic system was proved to be feasible up to a 150 mL scale with a large-scale relatively high substrate concentration and selectivity. For further industrial application, these results open a way to use of whole cells of engineered E. coli for challenging higher substrate concentrations of ß-ketone esters enantioselective reduction reactions.

Efficient lipid production with Trichosporon fermentans and its use for biodiesel preparation.

Effects of medium components and culture conditions on biomass and lipid production of Trichosporon fermentans were studied. The optimal nitrogen source, carbon source and C/N molar ratio were peptone, glucose and 163, respectively. The favorable initial pH of the medium and temperature were 6.5 and 25 degrees C. Under the optimized conditions, a biomass of 28.1 g/l and a lipid content of 62.4% could be achieved after culture for 7 days, which were much higher than the original values (19.4 g/l and 50.8%) and the results reported by other groups. T. fermentans could grow well in pretreated waste molasses and a lipid yield of 12.8 g/l could be achieved with waste molasses of 15% total sugar concentration (w/v) at pH 6.0, representing the best result with oleaginous microorganisms on agro-industrial residues. Addition of various sugars to the pretreated molasses could efficiently enhance the accumulation of lipid and the lipid content reached as high as above 50%. Similar to vegetable oils, the lipid mainly contains palmitic acid, stearic acid, oleic acid and linoleic acid and the unsaturated fatty acids amount to about 64% of the total fatty acids. The microbial oil with an acid value of 5.6 mg KOH/g was transesterified to biodiesel by base catalysis after removal of free fatty acids and a high methyl ester yield of 92% was obtained.

Improvement of biodiesel production by lipozyme TL IM-catalyzed methanolysis using response surface methodology and acyl migration enhancer.

The process of biodiesel production from corn oil catalyzed by lipozyme TL IM, an inexpensive 1,3-position specific lipase from Thermomyces lanuginosus was optimized by response surface methodology (RSM) and a central composite rotatable design (CCRD) was used to study the effects of enzyme dosage, ratio of t-butanol to oil (v/v) and ratio of methanol to oil (mol/mol) on the methyl esters (ME) yield of the methanolysis. The optimum combinations for the reaction were 25.9U/goil of enzyme, 0.58 volume ratio of t-butanol to oil and 0.5, 0.5, 2.8 molar equivalent of methanol to oil added at the reaction time of 0, 2, and 4h, respectively, by which a ME yield of 85.6%, which was very close to the predicted value of 85.0%, could be obtained after reaction for 12h. Waste oil was found to be more suitable feedstock, and could give 93.7% ME yield under the optimum conditions described above. Adding triethylamine (TEA), an acyl migration enhancer, could efficiently improve the ME yield of the methanolysis of corn oil, giving a ME yield of 92.0%.

Kinetic resolution of organosilicon compounds by stereoselective dehydrogenation with horse liver alcohol dehydrogenase.

Stereoselective dehydrogenation of three isomers of trimethylsilylpropanol was carried out with horse liver alcohol dehydrogenase (HLADH, EC 1.1.1.1.) and optically active organosilicon compounds were obtained in a water-organic solvent two-layer system with coenzyme regeneration. Furthermore, we examined the effects of the silicon atom on stereoselectivity of HLADH compared to the corresponding carbon compounds. Substitution of the silicon atom for the carbon atom was found to improve the stereoselectivity of HLADH. For example, the optical purity of the remaining 1-trimethylsilyl-2-propanol was higher than 99% enantiomeric excess (ee) at 50% conversion, whereas that of the carbon analogue was 84% ee. This phenomenon was probably ascribable to the bulkiness of the organosilicon compounds derived from their longer Si-C bond. Kinetic analysis in an aqueous monolayer system demonstrated that the specific properties of the silicon atom greatly affected the reactivity of these substrate compounds.