pH对灵芝液态发酵代谢物及抗氧化活性的影响

已有研究报道灵芝栽培生长的最适pH在中性偏酸环境,在碱性范围的生长及代谢情况鲜见报道。本研究主要探究广泛pH对灵芝液态发酵代谢物及其抗氧化活性的影响。采用摇瓶液态培养后分析代谢物中灵芝三萜、胞内外多糖、菌丝体蛋白及抗氧化活性等指标,系统比较灵芝菌丝体在pH值2-11的生长和代谢情况。研究结果表明,灵芝菌丝体生长、合成灵芝三萜、胞内多糖、30E胞外多糖、菌丝体蛋白和菌丝体水解氨基酸的最适pH值分别为10、3、2、7、2和2。对应结果分别为17.13 g/L、33.86 mg/g、72.73 mg/g、7.86 g/L、71.42 mg/g和107.10 mg/g。比对照分别提高28.5%、77.3%、22.4%、96.5%、97.1%和70.8%。胞内多糖组分1和组分2最高分子量均在初始pH 4,分别为1.016×10⁸ g/mol和9.280×10⁴ g/mol,胞外多糖组分1最高分子量在初始pH 10,为4.946×10⁶ g/mol;对菌丝体的总抗氧化能力、1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2- picrylhydrazyl,DPPH)自由基清除能力、羟自由基清除能力分析结果表明最佳的初始pH分别为3、7、9。本研究为液态发酵方式下灵芝生长及其代谢物定向调控发酵的工艺优化提供参考依据,同时发现灵芝菌丝体中优质蛋白及抗氧化活性可在功能性食品和化妆品领域推广应用。     

Low genetic diversity and population connectivity fuel vulnerability to climate change for the Tertiary relict pine Pinus bungeana

Endemic species are important components of regional biodiversity and hold the key to understanding local adaptation and evolutionary processes that shape species distributions. This study investigated the biogeographic history of a relict conifer Pinus bungeana Zucc. ex Endl. confined to central China. We examined genetic diversity in P. bungeana using genotyping-by-sequencing and chloroplast and mitochondrial DNA markers. We performed spatial and temporal inference of recent genetic and demographic changes, and dissected the impacts of geography and environmental gradients on population differentiation. We then projected P. bungeana's risk of decline under future climates. We found extremely low nucleotide diversity (average π 0.0014), and strong population structure (global F_ST 0.234) even at regional scales, reflecting long-term isolation in small populations. The species experienced severe bottlenecks in the early Pliocene and continued to decline in the Pleistocene in the western distribution, whereas the east expanded recently. Local adaptation played a small (8%) but significant role in population diversity. Low genetic diversity in fragmented populations makes the species highly vulnerable to climate change, particularly in marginal and relict populations. We suggest that conservation efforts should focus on enhancing gene pool and population growth through assisted migration within each genetic cluster to reduce the risk of further genetic drift and extinction.     

肿瘤坏死因子α对白血病细胞作用的^31P核磁共振研究

木文用３１Ｐ核磁共振（ＮＭＥ）观察了人淋巴瘤白血病细胞系Ｍｏｌｔ－４和人早幼粒白血病细胞系ＨＬ－６０的细胞代谢。Ｍｏｌｔ－４和ＨＬ－６０细胞系的３１Ｐ谱主要由磷酸单酯、无机磷（Ｐｉ）、双磷酸双酯、ＡＴＰ的共振峰组成。３１Ｐ谱显示Ｍｏｌｔ－４细胞在受肿瘤坏死因子α（ＴＮＦ－α）作用后,ＡＴＰ／Ｐｉ比值降低。ＨＬ－６０细胞在受ＴＮＦ－α作用后,ＡＴＰ减少。３１Ｐ－ＮＭＲ提供了一种非损伤性研究细胞代谢的重要方法。     

Molecular markers of nuclear restoration gene Rf1 in sunflower using bulked segregant analysis-RAPD

Restoration of cytoplasmic male sterility (CMS) in sunflower was demonstrated to be controlled by polygenes by analysing 982 effective crosses among 109 self-crossed lines and 16 CMS lines. Two self-crossed lines and one CMS line with distinct genotypes were applied to creation of segregating populations for DNA bulks of the target gene Rfl. Bulked DNA was prepared in order to investigate single gene Rfl and its gene marker among polygenic characters at the same genetic background. Using 80 10-mer operon primers, 620 RAPD reactions were carried out between fertile and sterile DNA bulks. In about 800 loci, primary results showed that 8 were related to the restoration genes. Furthermore. 2 were confirmed as RAPD markers for gene Rfl by examining 9 maintenance and 7 restoration lines. This method is the improvement for bulked segregant analysis[1] with which markers of single gene of target can be identified rapidly among polygenic characters.     

野生猕猴声行为的研究

本文通过在华南四省区对四个野生种群猕猴声行为的观察和现场录音,对它们的叫声声学特性,行为模式和其它个体对其相应的行为反应进行了定量的分析研究,并得出１１种不同的声行为,这些声行为有相互不同的声学特性,不同的行为模式并引起其它个体相应的行为反应,从而起着通讯的作用。叫声在猕猴的声行为通讯中,一些借助视觉提示,至少以不同的刺激度来“表示”某一类事物,并得到个体间的“共识”有些甚至无需视觉提示而单独传递     

微生物产生的木聚糖酶的功能和应用

术聚糖是一种异质多糖,主要由木糖和阿拉伯糖组成。微生物产生的木聚糖酶来源广泛,能将木聚糖水解为木寡糖和D-木糖。该酶具有极大的应用价值,如可用于纸浆的漂白以减少环境污染,也可将造纸工业及农业废料中的木聚糖转化为D-木糖。