红色诺卡菌固体培养基配方的优化

应用响应面优化设计法优化固体培养基配方,增大红色诺卡菌的固体培养细胞生物量。首先用Plackett-Burman法从现有培养基组分中找到影响红色诺卡菌细胞生物量的关键因素,再通过最陡爬坡法确定细胞生物量最大的配方,用作中心组合设计(Central Composite Design, CCD)实验的基础起始值,拟合数学模型方程,最后找到最优组分的组合。优化的配方转移至企业实施放大实验,对结果进行验证和比较。试验结果表明,培养基各组分中影响红色诺卡菌细胞生物量的关键因素为蛋白胨、NaCl、牛肉膏;最优固体培养基配方:蛋白胨42 g/L、牛肉膏8 g/L、NaCl 1.2 g/L、甘油10 mL/L、Na_2HPO_4·12H_2O 0.3 g/L、琼脂20 g/L。在细胞生物量方面最优固体培养基配方比原配方高104%。响应面优化设计可用于提高红色诺卡菌细胞生物量固体培养基的优化,也为红色诺卡菌培养条件、液体发酵的优化研究提供参考。     

HIV-1 Neutralizing Antibody Signatures and Application to Epitope-Targeted Vaccine Design

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合成生物制造2022

本文对2022年《生物工程学报》发表的与合成生物制造相关的综述和研究论文进行了评述,重点讨论了DNA测序、DNA合成、DNA编辑、基因表达调控和数学细胞模型等底层技术,酶的设计、改造和应用技术,化学品生物催化、氨基酸及其衍生物、有机酸、天然化合物、抗生素与活性肽、功能多糖、功能蛋白质等重要产品的生物制造技术,一碳化合物和生物质原料利用技术以及合成微生物组技术,以帮助读者从一个侧面了解合成生物制造相关技术和产业的发展情况。     

Mixture design as a potential tool in modeling the effect of light wavelength on Dunaliella salina cultivation: an alternative solution to increase microalgae lipid productivity for biodiesel production

Abstract

For a feasible microalgae biodiesel, increasing lipid productivity is a key parameter. An important cultivation parameter is light wavelength (λ). It can affect microalgal growth, lipid yield, and fatty acid composition. In the current study, the mixture design was used as an alternative to model the influence of the λ on the Dunaliella salina lipid productivity. The illumination was considered to be the mixture of different λ (the light colors blue, red, and green). All experiments were performed with and without sodium acetate (4?g/L), as carbon source, allowing the identification of the impact of the cultivation regimen (autotrophic or mixotrophic). Without sodium acetate, the highest lipid productivity was obtained using blue and red light. The use of mixotrophic cultivations significantly enhanced the results. The optimum obtained result was mixotrophic cultivation under 65% blue and 35% green light, resulting in biomass productivity of 105.06 mgL^?1day^?1, a lipid productivity of 53.47 mgL^?1day^?1, and lipid content of 50.89%. The main fatty acids of the oil obtained in this cultivation were oleic acid (36.52%) and palmitic acid (18.31%).     

Synthesis and Activity Evaluation of Nasopharyngeal Carcinoma Inhibitors Based on 6‐(Pyrimidin‐4‐yl)‐1H‐indazole

Human nasopharyngeal carcinoma is a common head and neck malignancy with high incidence in Southeast Asia and Southern China. It is necessary to develop safe, effective and inexpensive anticancer agents to improve the therapeutics of patients with nasopharyngeal carcinoma. A series of small molecular compounds based on 6‐(pyrimidin‐4‐yl)‐1H‐indazole were synthesized and evaluated for antiproliferative activities against human nasopharyngeal carcinoma cell lines SUNE1. Compounds 6b , 6c , 6e and 6l showed potent antiproliferative activities similar to positive control drug cisplatin in vitro with lower nephrotoxicity than it. N‐[4‐(1H‐Indazol‐6‐yl)pyrimidin‐2‐yl]benzene‐1,3‐diamine ( 6l ) was selected for further study. It was found that 6l induced mitochondria‐mediated apoptosis and G₂/M phase arrest in SUNE1 cells. Furthermore, compound 6l at 10 mg/kg can suppress the growth of an implanted SUNE1 xenograft with a TGI% (tumor growth inhibition) value of 50 % and did not cause serious side effects in BALB/c nude mice. This study suggests that 6‐(pyrimidin‐4‐yl)‐1H‐indazole derivatives are a series of small molecule compounds with anti‐nasopharyngeal carcinoma activities.     

棉田优势天敌对棉铃虫种群的控制作用

采用二次正交回归旋转组合设计及其方程Ya=b0 ∑bixi ∑bijxij ∑biixi^2分别研究了棉田优势天敌类群小花蝽,异色瓢虫,龟纹瓢虫对棉铃虫卵,小花蝽,异色瓢虫,龟纹瓢虫,拟水涯狼蛛对棉铃虫1－2龄幼虫和三突花蛛,异色瓢虫,龟纹瓢虫,拟水涯狼蛛对棉铃虫3－6龄幼虫的捕食作用。通过对方程的失拟性检验和显著性检验以及对回归系数的显著性,分析了这些捕食性天敌与棉铃虫态之间的相互关系以及捕食性天敌之间的相互关系。     

Tertiary motifs as building blocks for the design of protein‐binding peptides

Despite advances in protein engineering, the de novo design of small proteins or peptides that bind to a desired target remains a difficult task. Most computational methods search for binder structures in a library of candidate scaffolds, which can lead to designs with poor target complementarity and low success rates. Instead of choosing from pre‐defined scaffolds, we propose that custom peptide structures can be constructed to complement a target surface. Our method mines tertiary motifs (TERMs) from known structures to identify surface‐complementing fragments or “seeds.” We combine seeds that satisfy geometric overlap criteria to generate peptide backbones and score the backbones to identify the most likely binding structures. We found that TERM‐based seeds can describe known binding structures with high resolution: the vast majority of peptide binders from 486 peptide‐protein complexes can be covered by seeds generated from single‐chain structures. Furthermore, we demonstrate that known peptide structures can be reconstructed with high accuracy from peptide‐covering seeds. As a proof of concept, we used our method to design 100 peptide binders of TRAF6, seven of which were predicted by Rosetta to form higher‐quality interfaces than a native binder. The designed peptides interact with distinct sites on TRAF6, including the native peptide‐binding site. These results demonstrate that known peptide‐binding structures can be constructed from TERMs in single‐chain structures and suggest that TERM information can be applied to efficiently design novel target‐complementing binders.