光质对小球藻(Chlorella sorokiniana)生长和代谢机制的调控

为研究光质对小球藻(Chlorella sorokiniana)生长和代谢机制的影响,分析了不同光质下C. sorokiniana的生长情况,利用Illumina平台进行转录组测序.结果表明:红､蓝光是C. sorokiniana生长的有效光质,红､蓝光培养7d后藻细胞密度分别比白光对照组的高52.96%和61.11%.C. sorokiniana在不同光质下具有独特的生理特性,蓝光组Chl a､Chl b和Car最高,分别为(17.84±0.26), (8.39±0.19), (6.04±0.08) mg/L;红光培养7d后微藻的碳水化合物和脂质含量最高,分别达到了(115.60±1.81)μg/mg和(18.64±0.54)%.通过转录组测序分析,不同光质下C. sorokiniana的基因表达存在差异,红光下碳酸酐酶､乙酰辅酶A羧化酶和脂肪酸合成酶的基因表达量较高,差异表达的基因大部分参与了脂肪酸合成和碳固定过程;蓝光下RubisCO酶的基因表达量最高且光合系统中富集的差异基因均上调表达,光合速率和碳固定速率最快;绿光下微藻大部分的基因表达量较低,新陈代谢潜能较差;白光下C. sorokiniana的TCA循环活跃,不利于储存碳水化合物和脂质.     

Guidelines for genetic monitoring of translocated plant populations

Plant translocation is a useful tool for implementing assisted gene flow in recovery plans of critically endangered plant species. Although it helps to restore genetically viable populations, it is not devoid of genetic risks, such as poor adaptation of transplants and outbreeding depression in the hybrid progeny, which may have negative consequences in terms of demographic growth and plant fitness. Hence, a follow-up genetic monitoring should evaluate whether the translocated populations are genetically viable and self-sustaining in the short and long term. The causes of failure to adjust management responses also need to be identified. Molecular markers and fitness-related quantitative traits can be used to determine whether a plant translocation enhanced genetic diversity, increased fitness, and improved the probability of long-term survival. We devised guidelines and illustrated them with studies from the literature to help practitioners determine the appropriate genetic survey methods so that management practices can better integrate evolutionary processes. These guidelines include methods for sampling and for assessing changes in genetic diversity and differentiation, contemporary gene flow, mode of local recruitment, admixture level, the effects of genetic rescue, inbreeding or outbreeding depression and local adaptation on plant fitness, and long-term genetic changes.     

Martelella sp. AD-3强化活性污泥耐盐降解菲效能

基于嗜盐菌Martelella sp. AD-3优配市政活性污泥搭建耐盐高效降解菲的生物反应器,在3.0 %盐度,进水菲浓度20mg/L的运行条件下,菲去除率高达97 %.批次实验证明,盐度为3.0 %,pH值为7.5~8.5,底物浓度为20~200mg/L是菲降解的最佳环境条件,此时污泥比活性高于1.0mg/(gVSS×h).各共存底物的受试浓度下,酵母提取物和苯酚促进菲降解,镉和氰化物则抑制该过程,乙酸钠、铜、铬对该过程没有明显影响.16S rRNA基因高通量测序结果表明AD-3菌在反应器内具有长期稳定性,其相对丰度维持在1.5 %.Shinella、Microbacterium和Brevundimonas是反应器中的优势菌,其相对丰度分别为20.7 %,15.1 %和11.9 %.RT-qPCR结果显示接种AD-3菌后,编码PAHs双加氧酶RHDa的功能基因差异倍数从2.1提升至11.7.     

橡胶坝对河流沉积物氮转化功能基因丰度和营养盐的影响

沉积物氮转化功能微生物是河流脱氮和水体净化的重要生物因素.为探讨橡胶坝对沉积物氮转化功能基因丰度及氮营养盐的影响，本研究以沂河沂水城区蓄水段为研究对象，从橡胶坝前不同距离采集沉积物，利用实时荧光定量PCR（qPCR）方法研究了沉积物的反硝化功能基因（nirS、nirK、nosZ）、厌氧氨氧化功能基因（AMX）和反硝化型甲烷厌氧氧化功能基因（pmoA）的丰度及沉积物营养盐特征.结果表明：橡胶坝促进了沉积物中nirK、nirS、nosZ和pmoA基因的聚集，反硝化功能基因nirK、nirS、nosZ丰度在坝前120 ~330 m范围内较高；橡胶坝促进了沉积物NH4+、NO3-、TN、TP、TOC、有机质（OM）等营养盐的滞留，主要在120 ~360 m区域聚集，多元线性回归模型拟合度较高.相关分析表明，16S rRNA、nirK、nirS、nosZ、pmoA基因丰度与环境因子NH4+、NO3-、TN、OM、TOC、孔隙度呈正相关；PCA分析结果表明，随着沉积物环境因子主成分的增长，氮转化功能基因丰度主成分呈升高趋势.橡胶坝可促进沂河沉积物氮素等营养盐的滞留和氮转化功能微生物的聚集.