Combinatorial optimization of CO2 transport and fixation to improve succinate production by promoter engineering.

To balance the flux of an engineered metabolic pathway to achieve high yield of target product is a major challenge in metabolic engineering. In previous work, the collaborative regulation of CO2 transport and fixation was investigated with co-overexpressing exogenous genes regulating both CO2 transport (sbtA and bicA) and PEP carboxylation (phosphoenolpyruvate (PEP) carboxylase (ppc) and carboxykinase (pck)) under trc promoter in Escherichia coli for succinate biosynthesis. For balancing metabolic flux to maximize succinate titer, a combinatorial optimization strategy to fine-tuning CO2 transport and fixation process was implemented by promoter engineering in this study. Firstly, based on the energy matrix a synthetic promoter library containing 20 rationally designed promoters with strengths ranging from 0.8% to 100% compared with the widely used trc promoter was generated. Evaluations of rfp and cat reporter genes provided evidence that the synthetic promoters were stably and had certain applicability. Secondly, four designed promoters with different strengths were used for combinatorial assembly of single CO2 transport gene (sbtA or bicA) and single CO2 fixation gene (ppc or pck) expression. Three combinations, such as Tang1519 (P4 -bicA + pP19 -pck), Tang1522 (P4 -sbtA + P4 -ppc), Tang1523 (P4 -sbtA + P17 -ppc) with a more than 10% increase in succinate production were screened in bioreactor. Finally, based on the above results, co-expression of the four transport and fixation genes were further investigated. Co-expression of sbtA, bicA, and ppc with weak promoter P4 and pck with strong promoter P19 (AFP111/pT-P4 -bicA-P4 -sbtA + pACYC-P19 -pck-P4 -ppc) provided the best succinate production among all the combinations. The highest succinate production of 89.4 g/L was 37.5% higher than that obtained with empty vector control. This work significantly enhanced succinate production through combinatorial optimization of CO2 transport and fixation. The promoter engineering and combinatorial optimization strategies used herein represents a powerful approach to tailor-making metabolic pathways for the production of other industrially important chemicals. Biotechnol. Bioeng. 2016;113: 1531-1541. © 2016 Wiley Periodicals, Inc.

Childhood maltreatment profile in a clinical population in China: a further analysis with existing data of an epidemiologic survey.

To determine the lifetime prevalence and diverse profiles of types of childhood maltreatment (CM) in a high-risk clinical sample using standardized assessment tools (Child Trauma Questionnaire, CTQ) in China, Shanghai, 2090 subjects were sampled from the Shanghai Mental Health Centre. Personality disorder (PD) was assessed using the Personality Diagnostic Questionnaire (PDQ-4+) and subjects were interviewed using the Structured Clinical Interview (SCID-II). CTQ was used to assess CM in five domains (emotional abuse, EA; physical abuse, PA; sexual abuse, SA; emotional neglect, EN; and physical neglect, PN). The prevalence estimate of EA in the sample is 22.2%, followed by 17.8% of PA, and 12.5% of SA. The prevalence estimate was more frequent in PN (65.0%) and in EN (34.0%) than in childhood abuse (EA, PA and SA). It seems that males reported more PA and females reported more SA, the older subjects reported more neglect and the younger subjects reported more abuse. There was a higher prevalence of EA and SA in borderline PD patients (44.4%, 22.5%), PA in antisocial PD patients (38.9%). Multi-PD patients reported more forms of CM in childhood. Additionally, factor analysis of CTQ items confirmed factorial validity by identifying a five-factor structure that explained 50% of the total variance. These findings support the view that prevalence of CM was commonly experienced in clinical population during their childhood, especially for subjects with PDs. Factorial validity in PN needs to be further improved, and can in part be culturally explained.

[A cross-sectional survey on personality disorder in mental disorder outpatients in Shanghai].

OBJECTIVE: To study the prevalence and risk factors for personality disorder (PD) outpatients attending in for psychiatric and psychological counseling in Shanghai. METHODS: 3075 subjects were sampled by systematic sampling method from outpatients in psycho-counseling clinics and psychiatric clinics in Shanghai Mental Health Center. Based on DSM-IV criteria, personality disorders were assessed by both questionnaires (personality diagnostic questionnaire, PDQ-4+) and interviews (structured clinical interview for DSM-IV Axis II, SCID-II). Logistic regression analysis was performed to determine the significant independent contributor to PD. RESULTS: 71.3% of the outpatients were found having pathological personality by using questionnaire of self rating PD scale. 982 outpatients (31.9%) met criteria for at least one personality disorder by using structured clinical interview. Younger age (OR = 1.8, 95%CI: 1.5 - 2.1), single or divorced (OR = 1.6, 95%CI: 1.4 - 1.9), psychological counseling outpatients (OR = 1.2, 95%CI: 1.1 - 1.3), mood and outpatients with neurosis disorders (OR = 1.7, 95%CI: 1.4 - 2.0) were more frequently assigned as personality disorders. Data from logistic regression analysis showed that patients of tender age, not nurtured and raised by their parents, with introvert characters were related risk factors of PD. CONCLUSION: High prevalence rate of PD was found in this sample of Chinese outpatients, especially in those psychological counseling outpatients with mood or neurosis disorders. More attention should be paid to the recognition and intervention of PD in outpatients with mental disorders.