Taxonomic and Bioactivity Characterizations of Mameliella alba Strain LZ-28 Isolated from Highly Toxic Marine Dinoflagellate Alexandrium catenella LZT09

Microalgae host varied microbial consortium harboring cross-kingdom interactions with fundamental ecological significance in aquatic ecosystems. Revealing the complex biofunctions of the cultivable bacteria of phycosphere microbiota is one vital basis for deeply understanding the mechanisms governing these dynamic associations. In this study, a new light-yellow pigmented bacterial strain LZ-28 was isolated from the highly-toxic and harmful algal bloom-forming dinoflagellate Alexandrium catenella LZT09. Collective phenotypic and genotypic profiles were obtained to confidently identify this strain as a new Mameliella alba member. Comparative genomic analysis showed that strain LZ-28 shared highly similar functional features with other four marine algae-derived M. alba strains in spite of their distinctive isolation sources. Based on the bioactivity assaying, the mutual growth-promoting effects between bacterial strain LZ-28 and algal strain LZT09 were observed. After the culture conditions were optimized, strain LZ-28 demonstrated an extraordinary production ability for its bioflocculanting exopolysaccharides (EPS). Moreover, the portions of two monosaccharides glucose and fucose of the EPS were found to positively contribute to the bioflocculanting capacity. Therefore, the present study sheds light on the similar genomic features among the selected M. alba strains, and it also reveals the potential pharmaceutical, environmental and biotechnological implications of active EPS produced by this new Mameliella alba strain LZ-28 recovered from toxic bloom-forming marine dinoflagellate.     

Recent Discoveries on Marine Organism Immunomodulatory Activities

Marine organisms have been shown to be a valuable source for biologically active compounds for the prevention and treatment of cancer, inflammation, immune system diseases, and other pathologies. The advantage of studying organisms collected in the marine environment lies in their great biodiversity and in the variety of chemical structures of marine natural products. Various studies have focused on marine organism compounds with potential pharmaceutical applications, for instance, as immunomodulators, to treat cancer and immune-mediated diseases. Modulation of the immune system is defined as any change in the immune response that can result in the induction, expression, amplification, or inhibition of any phase of the immune response. Studies very often focus on the effects of marine-derived compounds on macrophages, as well as lymphocytes, by analyzing the release of mediators (cytokines) by using the immunological assay enzyme-linked immunosorbent assay (ELISA), Western blot, immunofluorescence, and real-time PCR. The main sources are fungi, bacteria, microalgae, macroalgae, sponges, mollusks, corals, and fishes. This review is focused on the marine-derived molecules discovered in the last three years as potential immunomodulatory drugs.     

利用QuantStudioTM 3D数字PCR分析转基因玉米MON863含量

QuantStudioTM 3D数字PCR (QuantStudioTM 3D digital PCR,3D-dPCR)是一种基于超高密度亲疏水微孔芯片实现数字PCR分液原理的新型核酸绝对定量平台,在转基因生物定量领域具有极大的应用前景.本研究基于3D-dPCR平台,以转基因玉米(Zea mays)MON863混合样品为例,建立基于单重和双重数字PCR体系的转基因生物(genetically modified organisms,GMOs)含量分析方法.与传统qRT-PCR比较发现,在缺乏样品纯度、纯合度信息的情况下,数字PCR能够较好地排除这些因素的影响,测定准确的量值.研究结果表明,QuantStudioTM 3D数字PCR是一种适用于转基因生物含量分析的精确定量方法,还可反映转基因玉米种子的基因型.本研究基于3D-dPCR建立的转基因玉米MON863单重和双重定量方法为转基因检测提供了新的方法和参考.     

寒冷地区草原有毒有害牧草监测与防治

草原是内蒙古地区草食畜牧养殖产业健康发展的基础,同时也是优质牧草的主要来源。有毒有害牧草生长扩散预示着草场退化,对当地草食畜牧养殖产业健康发展会造成毁灭性打击。有毒有害植物生长发育,不仅会危害牲畜健康且还会严重消耗土壤的水分和养分,妨碍优良牧草繁殖生长,使草场产量和质量显著下降。在长时间草场利用过程中,很多农牧民群众只注重索取,不注重生态环境保护,使草场生产能力和抵抗能力逐渐变差,给有毒有害牧草繁殖生长提供了条件。因此需要加强寒冷地区草原有毒有害牧草的监测,并采取针对性措施进行防控,降低发病率。该文主要探讨内蒙古呼伦贝尔市寒冷地区草原有毒有害牧草的种类,并提出相应的防治措施。     

滑县花生新黑地蛛蚧的发生与防治技术

花生新黑地蛛蚧是近年来滑县花生田新发现的一种地下害虫,对花生造成危害,影响花生的 品质和产量。本文主要介绍新黑地蛛蚧的形态特征、发生规律、生活习性、为害症状及防治措施。     

土壤微塑料和农药污染及其对土壤动物毒性效应的研究进展

微塑料和农药可能会在土壤中长期共存,塑料制品的种类和结构差异导致其对化学污染物有不同的亲和力和吸附行为。因此,微塑料可作为农药的载体,与农药形成复合污染,对生物体产生联合毒性效应,进而对食物链乃至人类产生健康危害。本文归纳了微塑料和农药对土壤环境的影响,阐述微塑料吸附农药的机理与研究现状,分析了微塑料和农药对土壤动物的联合毒性效应,指出当前研究存在的问题并对未来研究方向进行展望,为未来研究微塑料与农药在土壤中的环境行为提供重要参考。     

港口疏浚淤泥悬浮物对2种海洋生物的急性毒性试验研究

从上个世纪开始,人们对于海洋悬浮物就予以了高度重视。悬浮物作为海洋中最普遍的污染,对海洋生物造成了很大危害。本文用海洋疏浚淤泥悬浮物对卤虫无节幼体和梭鱼幼鱼进行了急性毒性试验。结果显示,半致死浓度随着时间的延长而逐渐降低;不同密度的海洋生物半致死浓度相差不大。不同水温条件下的梭鱼幼鱼试验表明,水温为24℃时其半致死浓度比21℃时要低,其安全浓度也呈现相同的趋势。     

水产生物基因组研究进展与趋势

本文综述了水产生物基因组研究相关技术的发展历程和关键技术的应用。以二代测序技术的出现为分界点,首先回顾了早期水产养殖生物在遗传学和分子生物学方面的研究结果,以及为开展全基因组测序所做的相关基础研究,然后重点介绍了二代测序技术应用于水产生物全基因组测序和经济性状遗传基础解析的研究进展,最后展望了水产生物基因组研究发展趋势。水产生物经济性状遗传机制高度复杂,从全基因组角度阐明其遗传机制仍有很多难题,但基因决定性状是生物学法则之一,探索这一过程的奥秘引人入胜。     

动物饲料中有害微生物的快速检测方法

饲料中有害微生物病原体的污染影响着饲料全球化自由贸易的发展和动物食品的安全,并成为关注的焦点。主要介绍了饲料中有害微生物的危害及其快速检测方法,为了更好地控制饲料生产和销售全过程的安全,从饲料生产的源头控制有害微生物对动物的危害,进而减少有害微生物通过动物进入人的食物链。     

大豆深加工产品定性PCR检测影响因素分析

以大豆内源基因（Lectin）、筛选基因35S启动子（Cauliflower mosaic virus 5S,CaMV35S）、NOS终止子（Nopaline synthase,Nos）和外源基因（CP4 EPSPS）为检测对象,对大豆深加工产品的DNA提取方法、PCR扩增条件的退火温度、引物浓度进行探讨,得出不同DNA提取方法、退火温度、引物浓度对大豆加工产品PCR检测的影响,建立了大豆加工食品中转基因成分定性检测体系。检测结果表明,退火温度60℃、引物浓度0．4μM时所建立的定性PCR检测方法能有效检测出大豆加工产品中的转基因成分,而且方法简单、快速有效。