Advances in metabolic engineering for vitamins production / 生物工程学报

Vitamins are organic substances that are essential for the maintenance of life activities. Generally, vitamins need to be obtained from the diet or from some synthetic source as the body cannot synthesize vitamins, or the amounts of the synthesized vitamins are insufficient. At present, vitamins are widely used in medicine, food additives, feed additives, cosmetics and other fields, and the global demand for vitamins is constantly growing. Vitamins can be produced from chemical or microbial synthesis. Chemical synthesis usually requires harsh reaction conditions, produces serious wastes, and creates great potential safety hazard. In contrast, microbial synthesis of vitamins is greener, safer, and requires much less energy input. This review summarizes the advances in metabolic engineering for vitamins production in the past 30 years, with a focus on production of water-soluble vitamins (vitamins B1, B2, B3, B5, B6, B7, B9, B12 and vitamin C precursors) and lipid-soluble vitamins (vitamin A, precursors of vitamin D, vitamin E and vitamin K). Moreover, the bottlenecks for fermentative production of vitamins are discussed, and future perspectives for developing next generation vitamins producing strains using synthetic biotechnology are prospected.

Clinical features of chronic obstructive pulmonary disease in women / 中国医师杂志

Objective:To investigate the risk factors, severity of symptoms, acute exacerbations, and pulmonary function in women with chronic obstructive pulmonary disease (COPD).Methods:A total of 4 204 COPD patients, including 533 female COPD patients and 3 671 male COPD patients, were investigated from January 2017 to December 2019 in Second Xiangya Hospital of Central South University, Hunan Prevention and Treatment Institute for Occupational Disease, affiliated Hospital of Guilin Medical College and Guilin Second People's hospital. The risk factors, severity of symptoms, risk of acute exacerbation and clinical characteristics of pulmonary function in patients with COPD were comprehensively analyzed.Results:There was no statistical difference in age between male and female COPD patients ( P>0.05). There were statistically significant differences in smoking history, occupational exposure history and biofuel exposure history ( P<0.001), among which smoking history and occupational exposure history were significantly higher in males than in females ( P<0.001), and exposure history of biofuels was significantly higher in females than in males ( P<0.001). The COPD assessment test (CAT) score of male and female patients was statistically different ( P<0.05), and the mean CAT score of female patients was higher than that of male patients. The modified medical research council dyspnea scale (mMRC) grading results of male and female patients were statistically different ( P<0.05), and the mMRC grading of female patients was higher than that of male patients. There was no statistical difference in the risk of acute exacerbation between male and female patients ( P>0.05). There were statistically significant differences between male and female patients in first second exertional volume as a percentage of predicted value (FEV 1%) and forced expiratory volume in one second/forced vital capacity (FEV 1/FVC) mean value ( P<0.001), and FEV 1% predicted value and FEV 1/FVC of female patients were better than that of male patients. Conclusions:The risk factors, symptom severity and pulmonary function of female patients with COPD are different from those of male patients, providing reference for the individualized treatment of female patients with COPD.