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Planococcus salinus sp nov., a moderately halophilic bacterium isolated from a saline-alkali soil
No full textA novel aerobic, Gram-stain-positive, motile, moderately halophilic and coccoid bacterial strain, designated LCB217(T),was isolated from a saline-alkali soil in north-western China and identified using a polyphasic taxonomic approach. Growth occurred with 3-15% (w/v) NaCl (optimum 3-5 %), at 10-45 degrees C (optimum 30 degrees C) and at pH 7.0-9.0 (optimum pH 9.0). Strain LCB217(T) contained MK-7 and MK-8 as the predominant menaquinones and anteiso-C-15 : 0, iso-C-14 : 0 and iso-C-16 : 0 as the major fatty acids. The polar lipids from strain LCB217(T) consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, one unidentified phospholipid, one unidentified aminophospholipid and one unidentified lipid. The peptidoglycan type was A4 alpha (L-Lys-D-Glu). Phylogenetic analysis of the 16S rRNA gene sequence showed that strain LCB217(T) belonged to the genus Planococcus and was closely related to the type strains Planococcus plakortidis AS/ASP6 (II)(T) (98.2% similarity), Planococcus maitriensis S1(T) (97.7 %) and Planococcus salinarum ISL-16(T) (97.2 %). The G+C content of the genomic DNA was 49.4 mol%. DNA-DNA relatedness values between strain LCB217(T) and Planococcus plakortidis AS/ASP6 (II)(T), Planococcus maitriensis S1(T) and Planococcus salinarum ISL-16(T) were 29.5, 38.1 and 39.5 %, respectively. On the basis of the phenotypic, phylogenetic and genomic data, strain LCB217(T) represents a novel species of the genus Planococcus, for which the name Planococcus salinus sp. nov. is proposed. The type strain is LCB217(T) (=CGMCC 1.15685(T) =KCTC 33861(T))
Analysis of DNA Methylation of Wheat in Response to Low Nitrogen Stress Based on Mathylation-Sensitive Amplified Polymorphisms
No full textAbiotic stress can induce considerable changes in the composition and quality of wheat grain and cause genomic DNA methylation. Here, methylation-sensitive amplified polymorphism (MSAP) was used to detect the effect of low nitrogen stress on the extent and patterns of DNA methylation in wheat grain at 5, 8, 11, 14, 16 and 21 days post-anthesis (DPA). First, our results showed that low nitrogen stress could reduce grain N content, sodium dodecylsulfate sedimentation (SDS) volume, the amounts of high-molecular-weight glutenin subunits (HMW-GS 2, 12 and 20) and total protein. Then, at 8, 11 and 21 DPA, the overall level of DNA methylation in low nitrogen group was higher than in control group with the maximum difference of 14.1% at 21 DPA. And, at 8 DPA, methylation / demethylation revealed the highest level under low nitrogen conditions, about 17.07% -30.99% of the CCGG sites. Thus, thirteen differentially displayed DNA fragments in MSAP profiles in samples at 8 DPA were further cloned for sequencing analysis. Homology analysis for these DNA fragments showed that most of them were involved in storage matter (protein, fatty acid), some engaged in stress signaling and physiological response regulation. Moreover, the relative expression levels revealed that the expression of a demethylated fragment was increased but the expressions of two other methylated fragments decreased. In conclusion, our results suggested that low nitrogen stress could decrease SDS volume, HMW-GS amount and total protein which might be associated with DNA methylation. (C) 2018 Friends Science Publisher
DETERMINATION AND ANALYSIS OF KINETIC PARAMETERS OF HETEROTROPHIC BACTERIA IN MATHEMATICAL SIMULATION
No full textThis paper studied the Anaerobic-Anoxic-Oxic (A(2)/O) process of a city sewage treatment plant in Sichuan Province, China. We established a mathematical model of sewage treatment plant. The yield coefficient of heterotrophic bacteria (YH) in A(2)/O process was 0.65; maximum specific growth rate (uH) of 8.6 d(-1); attenuation coefficient (bH) of 3.5 d(-1). Compared with the recommended values reported in the literature, the results showed that the yield coefficient of heterotrophic bacteria measured by this method was consistent with the recommended value and the maximum specific growth rate and attenuation coefficient were higher than the recommended value. Different water qualities of different processes and heterotrophic bacteria in the activity are not the same. So the determination of the results will be different. Using the Electrolytic Respirometer developed by Bioscience Incorporation (BI-2000), the microbial oxygen uptake rate (OUR) curve is more accurate, the sampling frequency is higher, the sampling point is more, the judgment of the logarithmic period is more accurate, the test result is more reliable and the sewage treatment plant of the upgrade and simulation to optimize the operation to provide a theoretical basis
A facile synthesis of molybdenum carbide nanoparticles-modified carbonized cotton textile as an anode material for high-performance microbial fuel cells
No full textA novel macroscale porous structure electrode, molybdenum carbide nanoparticles-modified carbonized cotton textile (Mo2C/CCT), was synthesized by a facile two-step method and used as an anode material for high-performance microbial fuel cells (MFCs). The characterization results show that the carbonized cotton textile modified with Mo2C nanoparticles offers a great specific surface area (832.17 m(2) g(-1)) for bacterial adhesion. The MFC using Mo2C/CCT anode delivers the maximum power density of 1.12 W m(-2), which is 51% and 116% higher than that of CCT and unmodified carbon felt anodes under the same conditions. The high power density is mainly due to the Mo2C nanoparticles with good biocompatibility and high conductivity and superior electrochemical activity, as well as the macroscale porous structure of carbonized cotton textile, which facilitate the formation of electroactive biofilm and improve the electron transfer. This paper introduces a feasible way to synthesize cost-effective and high-performance anode materials for MFCs
Cerebellum size is positively correlated with geographic distribution range in anurans
No full textThe 'cognitive buffer' hypothesis predicts that the costs of relatively large brains are compensated for later in life by the increased benefits of large brains providing a higher chance of survival under changing environments through flexible behaviors in the animal kingdom. Thus, animals that live in a larger range (with a higher probability of environmental variation) are expected to have larger brains than those that live in a restricted geographic range. Here, to test the prediction of the 'cognitive buffer' hypothesis that larger brains should be expected to occur in species living in geographic ranges of larger size, we analyzed the relationship between the size of the geographic range and brain size and the size of various brain regions among 42 species of anurans using phylogenetic comparative methods. The results show that there is no correlation between relative brain size and size of the species' geographic range when correcting for phylogenetic effects and body size. Our findings suggest that the effects of the cognitive buffer and the energetic constraints on brains result in non-significant variation in overall brain size. However, the geographic range is positively correlated with cerebellum size, but not with optic tecta, suggesting that species distributed in a wider geographic range do not exhibit larger optic tecta which would provide behavioral flexibility to allow for an early escape from potential predators and discovery of new food resources in unpredictable environments
A NEW SPECIES OF THE Gloydius strauchi COMPLEX (CROTALINAE: VIPERIDAE: SERPENTES) FROM QINGHAI, SICHUAN, AND GANSU, CHINA
No full textThe Hengduanshan Mountains have long been recognized as one of the evolutionary radiation centers of the genus Gloydius. Here we describe a new species of the Gloydius strauchi complex, Gloydius angusticeps sp. nov. Shi, Yang, Huang, Orlov et Li, 2018, which has been discovered in the adjacent areas of Sichuan, Qinghai, and Gansu Province, at the elevation of 3150 - 3653 m near the Yellow River. The new species is different from congeneric species by the following characteristics: (i) long and narrow head; (ii) grayish brown body coloration (few variations); (iii) 4 to 6 rows of discrete dark brown spots (or x-shaped patterns on the back); (iv) a pair of round spots on the parietal scales; (v) a pair of arched stripes on the occiput; (vi) up to 21 rows mid-body dorsal scales. This study preliminary clarified the distribution pattern of the Gloydius strauchi complex in Qinghai and Sichuan Province. The discovery of this new species verifies the importance of the Hengduanshan Mountains as a biodiversity hotspot
Plant biomass allocation strategies of the dominant species in an alpine meadow of northwestern Sichuan, China
No full text生物量分配是整个植株净碳获取的重要驱动因子,对植物未来的生长与繁殖具有直接的影响;川西北高寒草甸植物群落结构丰富、物种多样性高,研究高寒草甸不同类型植物的生物量分配格局对理解植物生活史对策有重要意义.对川西北高寒草甸中天然草地、干扰草地和冬季返青草地等3类样地中不同功能型和生活型的植物共72个物种进行调查,采用标准化主轴估计(SMA)和异速生长分析(Allometric scaling analysis)的方法,比较研究不同植物类群的生物量分配对策.结果显示:(1)不同功能型植物各构件生物量百分比差异显著,禾草的茎生物量百分比最高(60.60 % 3.07%),莎草的根生物量百分比较高(37.49 % 11.86%),杂草类植物(Forb)的叶生物量百分比更高(26.37 % 1.64%),各构件生物量之间的异速生长斜率在各功能型间无显著差异且均呈显著的同速生长关系;(2)生活型影响植物各构件生物量百分比大小,一年生植物对茎和繁殖构件投入的生物量比例相对更高,多年生植物则将更多生物量投资到根部;(3)样地类型对杂草类植物各构件的生物量具有显著影响,天然草地植物和返青植物的叶片与繁殖分配比更高,而干扰草地植物的茎生物量分配比更高.本研究表明植物功能型和生活型决定植物各构件生物量分配固有的异速生长关系,而人为干扰则显著影响植物的生物量大小,这对加强草地应对人类干扰和气候变化的响应研究以及高寒草甸生态系统的科学管理都有重要的理论与实践意义
Mapping loci that control lateral spike development in Tibetan barley by bulked segregant analysis (BSA)
No full text大麦侧小穗结实与否导致了二棱/六棱性状的分化,从而显著影响其籽粒产量,因此大麦二棱到六棱的变化具有显著驯化特征.青藏高原野生和栽培大麦资源丰富,被认为是栽培大麦的驯化和遗传多样性中心之一.为进一步了解大麦棱数调控的遗传基础以及西藏栽培大麦驯化的过程,以西藏野生二棱大麦和六棱大麦地方品种为亲本构建遗传分离群体,遗传分析发现二棱性状受单个显性基因位点控制.通过集群分离法(Bulked segregant analysis,BSA)分别建立含有22个F2单株的二棱混池和六棱混池,基于SLAF-seq(Specific-locus amplified fragment sequencing)技术共获得456 691个SLAF标签,通过SNP-index和ED两种关联算法交集得到3个与棱数性状相关的侯选区域,总长度为53.84 Mb,包含536个基因,其中能分别被3个数据库GO、KEGG和COG注释的基因有413、189和160个基因.上述研究实现了对控制西藏大麦侧小穗发育性状相关基因的初步定位,结果可为后续目标基因的精细定位和克隆提供理论参考
Advances in chemical compounds and pharmacological effects of Dendrobii Caulis
No full text石斛属Dendrobium Sw.是兰科重要的属之一,同具观赏价值与药用价值.石斛属植物的茎作为中药材石斛,已被广泛使用达千年,其主要有滋补、止痛、解热、抗炎等功效.近几十年来,国内外学者从40多种石斛属植物的药用部位中分离鉴定出约100种化合物,包括多糖、生物碱、黄酮、酚、萜、氨基酸、香豆素、鞣质、甾醇、微量元素等类化合物.综述近10多年从石斛中发现的化学成分及其在增强免疫、缓解糖尿病及其并发症、抑制肿瘤、抗氧化、延缓衰老、护肝、抗炎、保护神经系统、保护心血管、改善肠胃功能、抗血管生成、改善过敏性皮肤炎体征、缓解疲劳、抗血小板凝集等方面的药理作用,并提出了下一步研究的重点方向
Carbon:nitrogen ecological stoichiometry of the alpine steppe between the aboveground and belowground parts of plants and relevant impact factors in the Qiangtang Plateau
No full text研究高寒草地的植物生态化学计量特征对认识极端气候背景下的草地生态系统功能与服务具有重要的意义.选择羌塘高原高寒草地作为研究区,分析东西走向60个样点植物地上、地下部分的碳(C)、氮(N)含量与C:N的分布特征,及其各自的主要驱动因素.结果表明:高寒草地植物地上部分C、N含量(38.22%、1.82%)均高于地下部分(31.11%、1.15%),但C:N(22.08)却小于地下部分(28.88),且地上部分C含量、C:N与地下部分存在显著性差异(P < 0.05).干燥指数与植物地上部分C含量(R~2 = 0.072,P < 0.05)以及C:N(R~2 = 0.15,P < 0.005)呈负相关关系,却与植物地下部分C:N(R~2 = 0.53,P < 0.001)呈正相关关系;此外,年均降水量(R~2 = 0.13,P < 0.005)与地上部分C含量呈负相关关系,总生物量(R~2 = 0.13,P < 0.01)及植被总盖度(R~2 = 0.12, P < 0.01)与地下部分C含量呈正相关关系;海拔与地上部分C:N亦呈正相关关系(R~2= 0.15,P < 0.005),而年均温却与地下部分C:N呈负相关关系(R~2 = 0.31,P < 0.001).可见,水热条件是影响羌塘高原植物地上、地下C含量以及C:N差异的主要因素,而干燥指数可以作为较好的度量指标