Bacillus amyloliquefaciens-9 Reduces Somatic Cell Count and Modifies Fecal Microbiota in Lactating Goats

Subclinical mastitis is one of the major problems affecting dairy animals’ productivity and is classified based on milk somatic cell counts (SCC). Previous data showed that marine-derived Bacillus amyloliquefaciens-9 (GB-9) improved the immunity and the nonspecific immune defense system of the body. In this study, the potential role of GB-9 in improving subclinical mastitis was assessed with Radix Tetrastigmae (RT) as a positive control in subclinical mastitis Saanen dairy goats. The current data showed that GB-9 and RT significantly reduced the SCC in dairy goats. After being fed with GB-9 or RT, the decreased concentrations of malondialdehyde, IgA, IgM, IL-2, IL-4, and IL-6 were observed. The amplicon sequencing analysis of fecal samples revealed that GB-9 significantly altered the bacterial community. Bacteroides and Phascolarctobacterium were the major genera that respond to GB-9 feeding. The correlation analysis using weighted gene co-expression network analysis showed a MePink module was most associated with the serum concentrations of immunoglobulin and interleukin. The MePink module contained 89 OTUs. The feeding of GB-9 in decreasing the SCC was associated with the altered abundance of Bacteroides, which was correlated with the concentrations of immunoglobulins and chemokines. Collectively, the current data suggested that marine-derived GB-9 could be a helpful probiotic to control subclinical mastitis.     

中国土壤微生物组数据平台的构建与实现

近年来,高通量测序等新技术的快速发展,为大规模、快速、准确、全面认识土壤微生物多样性提供了技术保障。国际上已经建成了一些具有影响力的土壤微生物组数据管理及分析平台,但大多数已有平台聚焦于提供数据存储、管理、访问、注释等基础性服务,难以满足土壤微生物研究需求。借助空间数据库技术、网络地理信息系统(WebGIS)技术,设计并构建了包含土壤及微生物数据集成、数据可视化、知识发现和区域空间制图等功能的中国土壤微生物组数据平台,该平台将进一步推动我国土壤微生物组数据的标准化整合,并为整合数据的充分挖掘利用提供支撑。     

黄土高原旱地麦田26年免耕覆盖对土壤肥力及原核微生物群落多样性的影响

为明确黄土高原旱作麦田长期保护性耕作对土壤肥力和土壤原核微生物的效应,以位于山西省临汾市实施保护性耕作26年的小麦田为试验基地,采用Illumina Hiseq 2500高通量测序等手段,开展了不同耕作措施[免耕覆盖（NTS）、深松免耕覆盖（SNTS）和传统耕作（TT1）]对土壤理化性质和土壤原核微生物多样性的影响分析。研究结果表明：1）NTS和SNTS处理比TT1处理显著提高了土壤全氮、碱解氮、速效磷及速效钾的含量,降低了土壤pH,提高了土壤贮水能力和水分含量,降低了0~10 cm土层的土壤容重,但提高了10~20 cm土层的土壤容重;同时,SNTS处理显著增加了土壤的有机质含量。2）Illumina Hiseq高通量16S rRNA基因V4区测序结果表明：NTS和SNTS处理比TT1处理显著降低了绿弯菌门的相对丰度;NTS比SNTS处理显著降低了土壤中疣微菌门和绿弯菌门的相对丰度;NTS处理显著增加了土壤原核微生物群落的多样性,但未显著改变原核微生物群落的丰度;SNTS对原核微生物群落的多样性和丰富度均未有显著改变;NTS处理的显著性差异物种（Biomarker）高于其他2个处理;其他原核微生物门的相对丰度,在3个处理间尚未有明显差异。3）聚类分析可见：NTS和SNTS处理与TT1处理的微生物群落结构差异较大;NTS处理与SNTS处理间的微生物群落结构差异较小。4）CCA分析可知：土壤pH、有机质、速效氮、速效磷、速效钾含量对土壤原核微生物群落遗传多样性的变化起着重要作用;与TT1处理相比,NTS和SNTS处理在一定程度上改变了土壤原核微生物群落结构,但仍存在结构的相似性。综上所述,长期进行NTS和SNTS处理对黄土高原旱地麦田土壤微生物多样性、丰富度以及土壤肥力因子等的正效作用明显。     

Dietary fatty acids in gut health: Absorption,metabolism and function

In biological responses, fatty acids (FA) are absorbed and metabolized in the form of substrates for energy production. The molecular structures (number of double bonds and chain length) and composition of dietary FA impact digestion, absorption and metabolism, and the biological roles of FA. Recently, increasing evidence indicates that FA are essentially utilized as an energy source and are signaling molecules that exert physiological activity of gut microbiota and immune responses. In addition, FA could serve as natural ligands for orphan G protein-coupled receptors (GPCR), also called free fatty acid receptors (FFAR), which intertwine metabolic and immune systems via multiple mechanisms. The present review explores the recent findings on FA absorption and its impact on gut health, particularly addressing the mechanism by which dietary FA potentially influences intestinal microbiota and epithelial functions. Also, this work attempts to uncover research ideas for devising future strategies for manipulating the composition of dietary FA to regulate gut health and support a normal immune system for metabolic and immune disorders.     

北方吊笼养殖刺参肠道及其养殖环境菌群结构特征及其相关性分析

为探究北方吊笼养殖刺参(Apostichopus japonicus)肠道及其养殖环境菌群结构的关系,本研究基于高通量测序技术全面解析刺参肠道和养殖环境菌群结构和功能特征,并初步探讨刺参肠道及其养殖环境菌群相关性。结果显示,刺参肠道菌群丰度和多样性均显著高于养殖水体(P<0.05)。刺参肠道及养殖水体主要优势菌门均隶属于变形菌门(Proteobacteria)和拟杆菌门(Bacteroidetes),二者存在13个相对丰度大于0.1%的共有核心菌属。此外,肠道菌群具有一定的独立性,其特异性菌群主要隶属于厚壁菌门(Firmicutes)和绿弯菌门(Chloroflexi),以芽孢杆菌属(Bacillus)、乳酸杆菌属(Lactobacillus)、海泥海球菌属(Halioglobus)、Lutimonas和Woeseia为代表。基于KEGG代谢通路数据库,共注释到300条三级代谢通路,其中146条存在极显著差异(P<0.001)。刺参肠道菌群差异代谢通路主要表现在代谢方面,具体表现为碳水化合物消化吸收、蛋白质消化吸收和鞘脂类代谢。研究表明,刺参肠道菌群种类与其养殖水体呈高度相似性,但相对丰度存在显著性差异。本研究结果可为北方刺参吊笼健康养殖提供一定的理论依据。     

地衣芽孢杆菌A1在斑点叉尾鮰肠道的定植

为研究地衣芽孢杆菌A1(Bacillus Licheniformis, Bli)在斑点叉尾鮰(Ictalurus punctatus)肠道的定植规律,通过每周更换100%的循环水量以减少水体中的芽孢杆菌对实验的干扰,通过Co60 辐照灭菌杀灭饲料中的芽孢杆菌以消除其对实验的干扰。采用52℃高温选择性培养肠道Bli,研究外源Bli 在肠道内的消长规律。使用嗜热脂肪地芽孢杆菌(Geobacillus stearothermophilus)的芽孢作为惰性对照,通过洗涤肠壁去除非黏附菌,研究Bli 对肠粘膜的黏附。使用灭菌处理的肠内容物体外培养Bli,研究其在肠道的增殖潜能。结果显示,每周100%换水量使水体Bli 含量<1 cfu/mL。辐照灭菌使饲料Bli 含量由1.4×10^4 cfu/g 降至检出限以下。停止外源Bli 摄入后,在持续投喂无菌饲料的情况下, Bli 在斑点叉尾鮰肠内容物中的含量可维持3.3×10^2 cfu/g 左右至少42 天;在禁食情况下, 14 天后肠内容物中便无Bli 检出。Bli 对肠粘膜的黏附能力弱于惰性对照,但Bli 可以在肠内容物中生长至2.0×10^7 cfu/g。以上结果提示:在持续喂食情况下,地衣芽孢杆菌可以在斑点叉尾鮰肠道内长期定植,而禁食情况不能定植。其原因是由于地衣芽孢杆菌不能有效黏附于肠粘膜,但可以在肠内容物中增殖。     

Effect of a carbohydrase admixture in growing pigs fed wheat-based diets in thermoneutral and heat stress conditions

The efficacy of exogenous carbohydrases in pig diets has been suggested to depend on enzyme activity and dietary fiber composition, but recent evidence suggests other factors such as ambient temperature might be important as well. Therefore, we investigated the effect of heat stress (HS) on the efficacy of a multienzyme carbohydrase blend in growing pigs. Ninety-six (barrows: gilts; 1:1) growing pigs with initial body weight (BW) of 20.15 ± 0.18 kg were randomly assigned to six treatments, with eight replicates of two pigs per pen in a 3 × 2 factorial arrangement: three levels of carbohydrase (0, 1X, or 2X) at two environmental temperatures (20 °C or cyclical 28 °C nighttime and 35 °C day time). The 1X dose (50 g/tonne) provided 1,250 viscosimetry unit (visco-units) endo-β-1,4-xylanase, 4,600 units α-l-arabinofuranosidase and 860 visco-units endo-1,3(4)-β-glucanase per kilogram of feed. Pigs were fed ad libitum for 28 d and 1 pig per pen was sacrificed on day 28. There was no enzyme × temperature interaction on any response criteria; thus, only main effects are reported. Enzyme treatment quadratically increased (P < 0.05) BW on day 28, average daily gain (ADG) (P < 0.05), and average daily feed intake (ADFI) (P < 0.05) with the 1X level being highest. HS reduced the BW at day 14 (P < 0.01) and day 28 (P < 0.01), ADG (P < 0.01), and ADFI (P<0.001). There was a trend of increased feed efficiency (G:F) (P < 0.1) in the HS pigs. HS increased apparent jejunal digestibility of energy (P < 0.05) and apparent ileal digestibility of calcium (P < 0.01). At day 1, HS reduced serum glucose (P < 0.001) but increased nonesterified fatty acid (P < 0.01). In the jejunum, there was a trend of increased villi height by carbohydrases (P < 0.1), whereas HS reduced villi height (P < 0.05). HS increased the jejunal mRNA abundance of IL1β in the jejunum (P < 0.001). There was a trend for a reduction in ileal MUC2 (P < 0.1) and occludin (P < 0.1) by HS, and a trend for increased PEPT1 (P < 0.1). There was no effect of HS on alpha diversity and beta diversity of the fecal microbiome, but there was an increase in the abundance of pathogenic bacteria in the HS group. In conclusion, HS did not alter the efficacy of carbohydrases. This suggests that carbohydrases and HS modulate pig performance independently.     

Phytobiome metabolism: beneficial soil microbes steer crop plants' secondary metabolism

Crops are negatively affected by abiotic and biotic stresses, however, plant‐microbe cooperation allows prompt buffering of these environmental changes. Microorganisms exhibit an extensive metabolic capability to assist plants in reducing these burdens. Interestingly, beneficial microbes may also trigger, at the host side, a sequence of events from signal perception to metabolic responses leading to stress tolerance or protection against biotic threats. Although plants are well known for their vast chemical diversity, plant‐microbial interactions often stimulate the production of a rich and different repertoire of metabolites in plants. The targeted microbial‐plant interactions reprogramming plant metabolism represent potential means to foster various pest managements. However, the molecular mechanisms of microbial modulation of plant metabolic plasticity are still poorly understood. Here, we review an increasing amount of reports providing evidence for alterations to plant metabolism caused by beneficial microbial colonization. In addition, we highlight the vital importance of these metabolic reprograms for plants under stress erratic conditions. © 2019 Society of Chemical Industry     

植物根际微生物组的研究进展

根际微生物组(rhizosphere microbiome),是植物从其种子库土壤微生物组中有选择性地招募在根际聚集的动态微生物集群.随着近年来高通量测序技术、宏基因组学等的飞速发展,根际微生物组与植物宿主及土壤微生物组间的紧密联系引起了全球关注和研究热潮.根际微生物组被视作植物第二基因组,其与植物间的互作极为复杂,有...