Adaptive evolution of microorganisms based on industrial environmental perturbations / 生物工程学报

The development of synthetic biology has greatly promoted the construction of microbial cell factories, providing an important strategy for green and efficient chemical production. However, the bottleneck of poor tolerance to harsh industrial environments has become the key factor hampering the productivity of microbial cells. Adaptive evolution is an important method to domesticate microorganisms for a certain period by applying targeted selection pressure to obtain desired phenotypic or physiological properties that are adapted to a specific environment. Recently, with the development of technologies such as microfluidics, biosensors, and omics analysis, adaptive evolution has laid the foundation for efficient productivity of microbial cell factories. Herein, we discuss the key technologies of adaptive evolution and their important applications in improvement of environmental tolerance and production efficiency of microbial cell factories. Moreover, we looked forward to the prospects of adaptive evolution to realize industrial production by microbial cell factories.

Organic copper, iron, manganese and zinc: digestibility, production parameters and egg quality of layers / [Cobre, ferro, manganês e zinco orgânico: digestibilidade, parâmetros zootécnicos e qualidade dos ovos de poedeiras]

This study examined the replacement of the inorganic minerals (IM) Cu, Fe, Mn and Zn with their organic form (OM) in the diet of 67-week-old Dekalb White laying hens by comparing digestibility, production and egg quality. The experiment involved 240 birds, with 48 birds used per treatment and 12 per replicate. Isoenergetic and isonutrient diets were supplemented with 8mg Cu, 50mg Fe, 70mg Mn and 50mg Zn per kilogram of diet from an inorganic premix (IM100), from an organic premix (OM100), or the latter at the decreasing inclusion levels of 65% (OM65), 45% (OM45) and 35% (OM35). The following variables were evaluated: production, eggs per housed bird (EHB), viability, egg weight and mass, cracked and lost eggs, digestibility and egg physicochemical traits. Birds fed OM35 and OM45 showed lower production rates, and organic minerals provided the highest egg weights, regardless of their inclusion level. Accordingly, egg mass was similar between IM100, OM45 and OM35, and highest values were obtained with OM100 and OM65. Source or level had no influence on digestibility or egg quality. Supplementation with 2.8mg Cu, 17.5mg Fe, 24.5m g Mn and 17.5mg Zn per kilogram of diet (OM35) in the last third of the laying cycle provided relevant economic production indices (EHB, viability, egg weight or mass).(AU)

Estudou-se a substituição dos minerais inorgânicos (MI) Cu, Fe, Mn e Zn por minerais orgânicos (MO) na dieta de poedeiras Dekalb White com 67 semanas, comparando-se índices de produção, digestibilidade e qualidade dos ovos. Utilizaram-se 240 aves, 48 aves por tratamento e 12 por repetição. Dietas isoenergéticas e isonutrientes foram suplementadas com 8mg Cu, 50mg Fe, 70mg Mn e 50mg Zn por kg de ração MI100 e MO100 ou suplementações decrescentes MO65, MO45 e MO35. Avaliou-se produção, ovo por ave alojada (OAA), viabilidade, peso e massa dos ovos, trincados e perdidos, digestibilidade dos nutrientes e características físico-químicas dos ovos. Observaram-se menores índices de produção nas aves dos tratamentos MO35 e MO45 e maiores pesos dos ovos nos tratamentos com minerais orgânicos, independentemente da inclusão. Assim, massas de ovos foram semelhantes para os tratamentos MI100, MO45 e MO35 e maiores para MO100 e MO65. Fontes ou níveis de inclusões não influenciaram a digestibilidade e a qualidade dos ovos. Índices zootécnicos economicamente relevantes (OAA, viabilidade, peso e massa do ovo) foram obtidos com suplementação de 2,8mg Cu, 17,5mg Fe, 24,5mg Mn e 17,5mg Zn por kg de ração (MO35) em poedeiras brancas no último terço do ciclo de postura.(AU)

Effect of dietary nutrition on tail fat deposition and evaluation of tail-related genes in fat-tailed sheep

BACKGROUND: The effects of dietary nutrition on tail fat deposition and the correlation between production performance and the Hh signaling pathway and OXCT1 were investigated in fat-tailed sheep. Tan sheep were fed different nutritional diets and the variances in tail length, width, thickness and tail weight as well as the mRNA expression of fat-related genes (C/EBPα, FAS, LPL, and HSL) were determined in the tail fat of sheep at three different growth stages based on their body weight. Furthermore, the correlations between tail phenotypes and the Hedgehog (Hh) signaling pathway components (IHH, PTCH1, SMO, and GLI1) and OXCT1 were investigated. RESULTS: C/EBPα, FAS, LPL, and HSL were expressed with differences in tail fat of sheep fed different nutritional diets at three different growth stages. The results of the two-way ANOVA showed the significant effect of nutrition, stage, and interaction on gene expression, except the between C/EBPα and growth stage. C/EBPα, FAS, and LPL were considerably correlated with the tail phenotypes. Furthermore, the results of the correlation analysis demonstrated a close relationship between the tail phenotypes and Hh signaling pathway and OXCT1. CONCLUSIONS: The present study demonstrated the gene-level role of dietary nutrition in promoting tail fat deposition and related tail fat-related genes. It provides a molecular basis by which nutritional balance and tail fat formation can be investigated and additional genes can be identified. The findings of the present study may help improve the production efficiency of fat-tailed sheep and identify crucial genes associated with tail fat deposition.

Application of metabolic network model to analyze intracellular metabolism of industrial microorganisms / 生物工程学报

To quickly and efficiently understand the intracellular metabolic characteristics of industrial microorganisms, and to find potential metabolic engineering targets, genome-scale metabolic network models (GSMMs) as a systems biology tool, are attracting more and more attention. We review here the 20-year history of metabolic network model, analyze the research status and development of GSMMs, summarize the methods for model construction and analysis, and emphasize the applications of metabolic network model for analyzing intracellular metabolic activity of microorganisms from cellular phenotypes, and metabolic engineering. Furthermore, we indicate future development trend of metabolic network model.