High-throughput system for screening of high <Emphasis Type="SmallCaps">l</Emphasis>-lactic acid-productivity strains in deep-well microtiter plates

For strain improvement, robust and scalable high-throughput cultivation systems as well as simple and rapid high-throughput detection methods are crucial. However, most of the screening methods for lactic acid bacteria (LAB) strains were conducted in shake flasks and detected by high-performance liquid chromatography (HPLC), making the screening program laborious, time-consuming and costly. In this study, an integrated strategy for high-throughput screening of high l-lactic acid-productivity strains by Bacillus coagulans in deep-well microtiter plates (MTPs) was developed. The good agreement of fermentation results obtained in the MTPs platform with shake flasks confirmed that 24-well U-bottom MTPs could well alternate shake flasks for cell cultivation as a scale-down tool. The high-throughput pH indicator (bromocresol green) and l-lactate oxidase (LOD) assays were subsequently developed to qualitatively and quantitatively analyze l-lactic acid concentration. Together with the color halos method, the pH indicator assay and LOD assay, the newly developed three-step screening strategy has greatly accelerated the screening process for LAB strains with low cost. As a result, two high l-lactic acid-productivity mutants, IH6 and IIIB5, were successfully screened out, which presented, respectively, 42.75 and 46.10 % higher productivities than that of the parent strain in a 5-L bioreactor.     

Ubiquitin-specific protease 47 regulates intestinal inflammation through deubiquitination of TRAF6 in epithelial cells

Science China Life Sciences - Deubiquitinates (DUBs) alter the stabilities, localizations or activities of substrates by removing their ubiquitin conjugates, which are closely related to the...     

江苏省仓贮害虫的种类及分布（一）鞘翅目

江苏省仓贮鞘翅目害虫共有７７ 种, 分属２２ 科５４ 属, 其中２０ 种为江苏省新记录。并对该目害虫在江苏省的分布、种类组成及变化进行了初步分析。     

微生物谷氨酰胺转胺酶生产菌株的育种研究

在简要介绍微生物谷氨酰胺转胺酶的主要功能、应用和国外研究成果与目前状况后,指出该酶生产微生物菌种选育的重要性以及实际难度和艰巨性,阐述了进行初筛、复筛和常规诱变育种试验的关键技术手段及其成果效益。利用这些有效方法获得性能优良的高产酶突变菌株,进行规模化发酵工艺条件和酶制剂产品分离提纯技术研究,并在此基础之上,进一步开展通过“神舟”四号飞船搭载的微生物空间诱变育种研究强化产酶菌株的各种优良性能,说明了空间多种复合因素引发的综合搭载效果显著。     

植物代谢组学中几种重要的次生代谢物液质分析技术研究进展

代谢组学（metabolomics）主要是研究生物体、组织、细胞的代谢物组分及检测其动态变化过程,是继基因组和蛋白组学后新兴的一门组学技术。代谢物是细胞调节过程中的最终产物,其水平被视为生物系统对遗传或环境变化的最终反映。通过合适的分析平台,准确定性、定量在复杂的生物中具有化学多样性的次生代谢物是代谢组学的一项重要工作。液相色谱-串联质谱技术（liquid chromatography-tandem mass spectrometry,LC-MS/MS）是代谢物质检测平台最常用的方法,也为植物次生代谢物的广泛应用研究提供了基础。本文主要从植物激素类、叶酸类、黄酮类等次生代谢物方面进行阐述,结合液质联用技术,简要论述不同次生代谢物检测技术的研究进展。     

西安市青年学生胸骨长与身长的关系

本文对1980年测量的西安在校汉族青年学生1585名(男863,女722),年龄16-24岁,按年龄性别分组,计算了身长和胸骨长的均值、胸骨长占身长的百分数、身长与胸骨长的比值、身长、胸骨长指数,并提出了由胸骨长推算身长的回归方程。     

黄芪复合体（豆科）核型研究补充材料

本文首次报道了民和黄芪的染色体数目及核型。发现该种与黄芪复合体其它类群的染色体数目相同,但核型有别,其核型公式为２ｎ＝１６＝８ｍ（２ＳＡＴ）＋８ｓｍ。这种核型变异与它的形态变异一致。在黄芪复合体内,每一类群的染色体至少具１对随体,且附着在最后１对染色体的短臂上（除蒙古黄芪具２对随体外）,而Ｔｏｈ（１９７１）报道采自Ｋｙｕｎｇｉ和Ｍｔ．Ｈａｒｌａ膜荚黄芪和高山膜荚黄芪（新拟）的染色体不具随体,可能观察有误。     

一种非手术性小鼠胚胎移植技术

为了提高非手术性小鼠胚胎移植技术的成功率,利用塑料移植导管模拟非手术胚胎移植过程,通过观察染料在子宫角的分布而评估胚胎移植效果,并在此基础上将自然妊娠3.5 d的小鼠囊胚经子宫颈移植受体小鼠。结果表明:将CD-1小鼠囊胚移植假孕2.5 d小鼠单侧子宫角,平均70.9%的胚胎能够发育至成活新生仔鼠,建立了高效非手术性小鼠胚胎移植技术。该方法简便快捷、不易污染、费用低,无需专业的手术器械,且符合实验动物伦理原则,完全可以取代手术法胚胎移植技术,更重要的是,它为人类和其他大动物的胚胎移植提供了研究模型。     

NAD+ ameliorates endotoxin‐induced acute kidney injury in a sirtuin1–dependent manner via GSK‐3β/Nrf2 signalling pathway

Acute kidney injury (AKI) is a substantial worldwide public health concern with no specific and effective therapies in clinic. NAD⁺ is a pivotal determinant of cellular energy metabolism involved in the progression of AKI; however, its mechanism in kidney injury remains poorly understood. Sirtuin 1 (SIRT1) is an NAD⁺‐dependent deacetylase associated with renal protection and acute stress resistance. In this study, we have investigated the role of NAD⁺ in AKI and the potential mechanism(s) involved in its renoprotective effect. NAD⁺ was notably decreased and negatively correlated with kidney dysfunction in AKI, restoring NAD⁺ with NMN significantly ameliorates LPS‐induced oxidative stress and apoptosis and attenuates renal damage. We also found that the protection of NAD⁺ is associated with SIRT1 expressions and performs in a SIRT1‐dependent manner. Inhibition of SIRT1 blunted the protective effect of NAD⁺ and up‐regulated the activity of glycogen synthase kinase‐3β (GSK‐3β) that was concomitant with mitigated Nrf2 nuclear accumulation, thereby exacerbates AKI. These findings suggest that NAD⁺/SIRT1/GSK‐3β/Nrf2 axis is an important mechanism that can protect against AKI which might be a potential therapeutic target for the treatment of AKI.