Evaluation of swollenin from <Emphasis Type="Italic">Trichoderma pseudokoningii</Emphasis> as a potential synergistic factor in the enzymatic hydrolysis of cellulose with low cellulase loadings

Swollenin is a novel plant expansin-like protein that has been proposed to have a cellulose disruption activity. In this study, the recombinant swollenin (SWO2) from Trichoderma pseudokoningii S38 was successfully produced and purified in Aspergillus niger with a final yield of up to 10 mg of purified protein from 1 l of fermentation supernatant. The recombinant protein was found to exhibit very low level of endoglucanase activity and caused a slight increase in the crystallinity when treating cellulose. Simultaneous incubation of SWO2 with low-dose cellulases resulted in a significant synergistic activity in cellulose hydrolysis. Specifically, an even greater increase in the synergistic activity was obtained when cellulose was pretreated with swollenin followed by cellulase hydrolysis. Our results, therefore, provide a novel approach for the potential application of swollenin in the efficient saccharification of cellulosic materials.     

工程菌种自动化高通量编辑与筛选研究进展

合成生物学(synthetic biology)与经典生物学研究的革命性区别之一是合成生物学能将生物实验的对象、方法、技术和流程高度标准化和模块化,创建出自动化与高通量的合成生物铸造模式。该模式通过复杂生物过程与自动化设施的结合,颠覆过往劳动密集型的研究范式,获得更高的技术迭代能力,极大促进了合成生物学的发展和产业化应用。值此天津工业生物技术研究所创立10周年之际,本文回顾了研究所在工业菌种自动化高通量编辑与筛选领域的系列重要工作进展,对基因克隆(gene cloning)、基因组编辑(genome editing)、编辑序列设计(editing sequence design)等生物技术的自动化实现,以及流式细胞、液滴微流控、全基因组规模扰动测序等高通量筛选技术进行了分析讨论,并展望了本领域未来的发展方向。望借此为创建具有自主知识产权的优秀菌种及其产业应用提供智能化、自动化和全链条覆盖的整体支撑能力。     

一株C3形态多重耐药大肠杆菌噬菌体生物学特性和基因组分析

【目的】多重耐药菌的出现对公共卫生安全构成严重威胁,本研究分离多重耐药大肠杆菌噬菌体,研究其生物学特性和基因组特征,为耐药菌的噬菌体疗法提供理论依据。【方法】使用双层平板法从污水样本中分离纯化大肠杆菌噬菌体;磷钨酸染色后通过透射电镜观察形态;测定其宿主范围,测定温度和pH稳定性、一步生长曲线和体外抑菌效果等生物学特性;体内抑菌试验评估噬菌体对多重耐药大肠杆菌N1203-1Af感染的大蜡螟幼虫的保护作用;基于全基因组测序对其基因组特点进行分析。【结果】本研究分离共得到5株大肠杆菌噬菌体,分别命名为pEC-S163-2.1、pEC-S163-2.2、pEC-M1167-5Ar.1、pEC-m1291-2Dr.1和pEC-N1203-2Af.1;电镜结果显示噬菌体pEC-N1203-2Af.1属于短尾噬菌体中罕见的C3形态型,头部较长,长是宽的2–3倍;pEC-N1203-2Af.1可裂解受试15株大肠杆菌中的3株;感染10 min后进入指数增长期,–20-50℃、pH值为4.0–10.0的环境下均能够保持稳定活性;大蜡螟幼虫感染大肠杆菌N1203-2Af后噬菌体pEC-N1203-2Af....     

气候变化下中国主要生物燃油树种分布与变迁

生物燃油树种是发展生物质能源,实现化石能源替代战略的重要物质基础,明确当前和未来气候变化下我国生物燃油树种适生区分布,对保护和利用生物燃油树种,促进林业生物能源产业发展,保障能源安全和实现“双碳”目标具有重要意义。基于我国10个主要生物燃油树种的1037条树种分布数据和20个环境变量,利用最大熵模型(MaxEnt)预测了各树种当前和未来气候情景下(2050年和2070年的RCP4.5情景)的潜在适生区,得到了影响各树种分布贡献率最大的环境因子,并对我国各区域主要种植树种进行了区划。结果表明：(1)MaxEent模型预测效果较好,各树种模拟结果AUC值均在0.9以上。(2)影响各种分布的贡献率较高的环境因子因树种而异,最暖季度降水量和温度季节性变化标准差的相对贡献率较高。(3)10个生物燃油树种极高适生区面积范围在43.38万km²—117.74万km²之间,可根据模拟结果将树种分布划分为北部、中东部、东南部和西南部4个亚区,北部亚区主要树种为文冠果(Xanthoceras sorbifolium)和欧李(Cerasus humilis),中东...     

2018-2019年中国流行性腮腺炎流行特征和病毒基因特征分析

阐明中国(未包括香港、澳门特别行政区和台湾地区,下同)2018-2019年流行性腮腺炎(流腮)流行特征和病毒基因特征。对2018-2019年中国流腮流行病学和病毒学监测数据进行描述流行病学和分子流行病学分析。2018-2019年中国流腮年报告发病率分别为18.65/10万和21.48/10万,15岁以下儿童和青少年是我国流腮的高发人群,分别占总病例数的85.30%和82.56%。流腮的流行具有明显的季节性特征。全国各省、自治区、直辖市份均有流腮病例报告,西部和中部地区发病率高于东部地区。2018-2019年共获得160条腮腺炎病毒(Mumps virus,MuV)SH基因序列,其中150条(93.75%)序列鉴定为F基因型MuV,在我国11个省份检测到;10条(6.25%)序列为G基因型MuV,2019年在广东、湖北和新疆3个省份检测到。和我国既往流行MuV代表株相比,2018-2019年流行的F基因型MuV代表株序列在基因亲缘性关系树上相对集中。现阶段我国流腮的流行病学特征未发生明显改变,仍呈现病毒自然流行模式;F基因型作为优势流行基因型,在我国大部分地区持续流行,但毒株的遗传多态性有所降低,这可能和我国实施1剂次腮腺炎疫苗常规免疫策略有关。G基因型MuV主要在我国局部地区流行,但流行范围在逐渐扩大。建议进一步加强两剂次腮腺炎疫苗接种工作,降低我国腮腺炎易感人群。同时持续性开展MuV流行学和病毒学监测工作,为鉴别病毒的来源,确定病毒传播途径和评估腮腺炎疫苗免疫策略奠定重要的基础。     

从国际非专利名称纵观全球生物药发展

生物药(bio-therapeutics)是指采用生物技术制备的、临床上用于疾病治疗的大分子生物制品,具有结构复杂、异质性高等特点,科学严谨的生物药通用名命名,是区分生物药物质基础的主要依据,也是药品生命周期管理的重要基础。世界卫生组织(World Health Organization,WHO)协调建立的国际非专利名称(International Nonproprietary Names,INN)是全球药物命名的标准化体系。从INN的起源,以及生物药INN的类别、发生与发展为主线,以较为详实的数据统计和分析,呈现了全球生物药的衍化进程,从不同的角度纵览生物药技术发展历程,对生物药的研发设计、技术标准及监管策略的考量均具有一定的参考意义。     

不同水肥一体化方式对苹果氮素吸收利用特性及产量和品质的影响

以‘嘎啦/八棱海棠’为试材,借助¹⁵N同位素示踪技术,研究了撒施(T₁)、滴灌施氮(T₂)和渗灌施氮(T₃)对嘎啦苹果氮素吸收利用、分配特性和产量品质的影响,以期进一步完善苹果园水肥一体化技术,挖掘提高氮素利用率的途径。结果表明: T₃处理苹果叶片的叶面积、叶绿素和氮含量显著高于T₁和T₂处理。各时期土壤矿化氮(N_min)含量在20~40 cm土层表现为T₃＞T₂＞T₁处理,在0~20 cm土层表现为T₂＞T₃＞T₁处理。同一器官的Ndff值(树体各器官从肥料中吸收到的¹⁵N占该器官全氮量的比例)在各时期均以T₃处理最高,T₂其次,T₁处理最低。果实成熟期的树体¹⁵N利用率表现为T₃＞T₂＞T₁处理,其中T₃处理的树体¹⁵N利用率为24.2%,分别是T₂和T₁处理的1.19和1.65倍。果实成熟期T₁处理的¹⁵N分配率在营养器官最高,T₂处理在贮藏器官最高,T₃处理在生殖器官最高。各处理的单果重、产量、可溶性固形物、硬度、可溶性糖及糖酸比均以T₃处理最高,T₂其次,T₁处理最低。渗灌施氮处理显著促进了嘎啦苹果树体叶片生长和氮素利用,并提高了果实产量和品质。     

Nicotinamide increases the sensitivity of chronic myeloid leukemia cells to doxorubicin via the inhibition of SIRT1

The NAD-dependent deacetylase Sirtuin 1 (SIRT1) plays a vital role in leukemogenesis. Nicotinamide (NAM) is the principal NAD⁺ precursor and a noncompetitive inhibitor of SIRT1. In our study, we showed that NAM enhanced the sensitivity of chronic myeloid leukemia (CML) to doxorubicin (DOX) via SIRT1. We found that SIRT1 high expression in CML patients was associated with disease progression and drug resistance. Exogenous NAM efficiently repressed the deacetylation activity of SIRT1 and induced the apoptosis of DOX-resistant K562 cells (K562R) in a dose-dependent manner. Notably, the combination of NAM and DOX significantly inhibited tumor cell proliferation and induced cell apoptosis. The knockdown of SIRT1 in K562R cells enhanced NAM+DOX-induced apoptosis. SIRT1 rescue in K562R reduced the NAM+DOX-induced apoptosis. Mechanistically, the combinatory treatment significantly increased the cleavage of caspase-3 and PARP in K562R in vitro and in vivo. These results suggest the potential role of NAM in increasing the sensitivity of CML to DOX via the inhibition of SIRT1.     

A set of Arabidopsis thaliana miRNAs involve shoot regeneration in vitro

Plant miRNAs, the critical regulator of gene expression, involve many development processes in vivo. However, the roles of miRNAs in plant cell proliferation and redifferntiation in vitro remain unknown. To determine better the molecular mechanism of these processes, we have recently reported that a set of miRNAs with different expression patterns between cells of totipotent and non-totipotent Arabidopsis calli. Some of these were specifically up- or downregulated during callus formation or shoot regeneration, and other development. Among them, miR160, and one of its target genes, ARF10, regulated Arabidopsis in vitro shoot regeneration via WUS, CLV3 and CUC1/2. The miR160-overexpressing, 35S transgenic lines, exhibited reduced shoot regeneration efficiency. The mARF10, a miR160-resistant form of ARF10, showed a high level of shoot regeneration ability. In the transgenic, expression of the above shoot meristem-specific genes was elevated, which is consistent with the improved shoot regeneration. In contrast, the ARF10 deficient knockout mutant produced fewer regenerated shoot. However, overexpressors of ARF10 were only marginally more efficient than the wild type with the respect to shoot regeneration. Our observation strongly supports that proper shoot regeneration from in vitro cultured cells requires the miR160-directed negative influence of ARF10. The enhanced expression of ARF10 is likely to have contributed to the improved regeneration ability.