体外试验中不同粗精比对山羊瘤胃细菌氨态氮利用效率的影响   总被引：4，自引：0，他引：4  

赵国琦  丁健  孙龙生  张艳云  刘大林  贾亚红  陈小连 《畜牧兽医学报》2004,35(6):640-645

利用体外发酵法研究了4种粗精比(10∶0、8∶2、6∶4和4∶6)底物对山羊瘤胃细菌产量、15NH3-N利用效率的影响。结果表明:混合培养液的pH值与氨态氮浓度在8h内急剧下降,而后至24h呈缓慢下降;经24h培养的细菌产量在8∶2、6∶4和4∶6组中差异不显著(P>0.05),但都极显著地高于10∶0组(P<0.01);细菌体15N丰度以8∶2及4∶6组较高,显著高于10∶0和6∶4组(P<0.05);细菌体15N富集量以8∶2组最高,底物547.43μg15N中有120.44μg被细菌体富集,显著高于10∶0组(P<0.05),但6∶4、4∶6组与10∶0组间差异均不显著(P>0.05)。细菌赖氨酸的相对百分组成随精饲料比例的增加而显著增加,胱氨酸在粗饲料组(10∶0)显著高于其它组,但各精饲料添加组间差异不显著,组氨酸以8∶2组为最高,显著高于10∶0组,但与其它精饲料添加组间差异不显著(P>0.05)。  相似文献   

添加不同酵母培养物对瘤胃纤维分解菌群和纤维素酶活的影响   总被引：14，自引：0，他引：14  

黄庆生  王加启 《畜牧兽医学报》2005,36(2):144-148

用3种酵母培养物(YC- 1、YC 2和YC- 3)分别饲喂4头带有永久性瘤胃瘘管的肉牛,研究培养物对瘤胃发酵、纤维分解酶活性和3种纤维分解菌数量的影响,结果表明:YC 2处理的乙酸、丙酸、丁酸和总 VFA浓度显著高于对照组(P<0 .05),YC 1和YC 3处理的乙酸/丙酸比例显著降低(P<0 .01);各处理均能显著提高瘤胃内羧甲基纤维素酶、水杨苷酶和木聚糖酶的活性(P<0 .01);各处理都显著提高黄化瘤胃球菌的相对比例(P<0 .01),16SrRNA特异性寡聚核苷酸探针杂交法分析测定结果表明 3 种纤维分解菌在瘤胃细菌中所占比例为 3. 80%±0 .2%。  相似文献   

Effects of concentrate‐to‐forage ratios and 2‐methylbutyrate supplementation on ruminal fermentation,bacteria abundance and urinary excretion of purine derivatives in Chinese Simmental steers          下载免费PDF全文

C. Wang  Q. Liu  G. Guo  W. J. Huo  C. X. Pei  S. L. Zhang  H. Wang 《Journal of animal physiology and animal nutrition》2018,102(4):901-909

This study evaluated the effects of dietary concentrate levels and 2‐methylbutyrate (2MB ) supplementation on performance, ruminal fermentation, bacteria abundance, microbial enzyme activity and urinary excretion of purine derivatives (PD ) in steers. Eight ruminally cannulated Simmental steers (12 months of age; 389 ± 3.7 kg of body weight) were used in a replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement. Moderate‐concentrate (400 g/kg diet [MC ]) or high‐concentrate (600 g/kg diet [HC ]) diets were fed with or without 2MB (0 g/day [2MB ?] or 15.0 g/day [2MB +]). Dry matter intake and average daily gain increased, but feed conversion ratio decreased with the HC diet or 2MB supplementation. Ruminal pH decreased, but total volatile fatty acid increased with the HC diet or 2MB supplementation. Molar proportion of acetate and acetate‐to‐propionate ratio decreased with the HC diet, but increased with 2MB supplementation. Propionate molar proportion and ruminal NH ₃‐N content increased with the HC diet, but decreased with 2MB supplementation. Neutral detergent fibre degradability decreased with the HC diet, but increased with 2MB supplementation. Crude protein degradability increased with the HC diet or 2MB supplementation. Abundance of Ruminococcus albus , Ruminococcus flavefaciens , Fibrobacter succinogenes and Bufyrivibrio fibrisolvens as well as activities of carboxymethyl cellulase, cellobiase, xylanase and pectinase decreased with the HC diet, but increased with 2MB supplementation. However, abundance of Prevotella ruminicola and Ruminobacter amylophilus as well as activities of α‐amylase and protease increased with the HC diet or 2MB supplementation. Total PD excretion also increased with the HC diet or 2MB supplementation. The results suggested that growth performance, ruminal fermentation, CP degradability and total PD excretion increased with increasing dietary concentrate level from 40% to 60% or 2MB supplementation. The observed diet × 2MB interaction indicated that supplementation of 2MB was more efficacious for improving growth performance, ruminal fermentation and total PD excretion with promoted ruminal bacteria abundance and enzyme activity in the MC diet than in the HC diet.  相似文献   

Effects of oral supplementation of probiotic strains of Lactobacillus rhamnosus and Enterococcus faecium on diarrhoea events of foals in their first weeks of life          下载免费PDF全文

Christina Ströbel  Elena Günther  Vladimir Urubschurov  Annette Zeyner 《Journal of animal physiology and animal nutrition》2018,102(5):1357-1365

Foal first diarrhoea is one of the most prominent problems in the early life of horses. Probiotics might have the potency to prevent or at least diminish neonatal diarrhoea. We hypothesised that the treatment of foals with probiotic strains of Lactobacillus rhamnosus and Enterococcus faecium starting early after birth and then daily over 2 weeks would prevent or mitigate foal heat diarrhoea. The influence of this probiotic treatment on diarrhoea incidence and growth and health performance of young foals was investigated. Thirty‐four foals were randomly allocated to two groups. From day 1 to 14 of life, the foals received either placebo (PG, n = 16) or the probiotic treatment (TG, n = 18). Clinical examination was performed, and the faeces consistency score (FCS, 1–5; with diarrhoea defined by ≤3) was recorded once per day in weeks 1 and 2 and once weekly in weeks 3–8 of life (WL). The body height was measured at birth and after two and eight WL. Diarrhoea occurred in the 1st WL in 19% and 61% of PG and TG foals respectively. In the 1st WL, diarrhoea lasted 0.3 ± 0.8 and 1.6 ± 1.4 days in PG and TG foals respectively. In the 2nd WL, diarrhoea occurred in 94% and 84% of PG and TG foals, respectively, and lasted for 3.0 ± 1.5 and 3.7 ± 1.6 days respectively. At least two periods of diarrhoea developed in 33% and 65% of PG and TG foals respectively. The TG foals grew slightly slower than the PG foals. The results indicated that the probiotic treatment of neonatal foals as performed in this study was not suitable to reduce diarrhoea within the first two WL, because contrary to the hypothesis, the TG foals suffered more frequently and for longer periods from diarrhoea than the PG foals.  相似文献   

大米草中耐盐乳酸菌的分离鉴定及对大米草青贮品质的影响     

陈堞  林凯程  林沁  陈霞  陈鑫珠 《草地学报》2020,28(2):565-570

本试验旨在研究大米草（Spartina anglica Hubb.）中耐盐乳酸菌的分离鉴定及对大米草青贮品质的影响，以期为大米草青贮利用提供技术支持和理论依据。试验采用传统培养法筛选出耐盐浓度为10%的乳酸菌菌株，通过生理生化及16S rDNA序列分析法综合鉴定筛选的菌株，并将其添加到大米草原料中进行青贮效果观察。结果表明：分离获得的42株乳酸菌菌株，耐盐溶度最高为10%的4株乳酸菌均为同型发酵的植物乳杆菌（Lactobacillus plantarum），命名为C1、C2、C3和C4。4株乳酸菌均能提高大米草的青贮发酵品质，其中C4显著提高青贮料的可溶性碳水化合物和粗脂肪含量（P<0.05），显著降低青贮料的氨态氮含量（P<0.05）；另外，C4处理组的干物质含量和乳酸含量显著高于其他3个菌株处理组（P<0.05），中性洗涤纤维、酸性洗涤纤维、半纤维素和丁酸含量显著（P<0.05）低于其他3个菌株处理组，青贮效果最佳。  相似文献   

Long-term fertilization effects on active ammonia oxidizers in an acidic upland soil in China     

《Soil biology & biochemistry》2015

The effects of long-term fertilization of acidic soils on ammonia-oxidizing archaea (AOA) and bacteria (AOB) communities and its ecological implications remain poorly understood. We chose an acidic upland soil site under long-term (27-year) fertilization to investigate ammonia oxidizer communities under four different regimes: mineral N fertilizer (N), mineral NPK fertilizer (NPK), organic manure (OM) and an unfertilized control (CK). Soil net nitrification rates were significantly higher in OM soils than in CK, N or NPK soils. Quantitative analysis of the distribution of amoA genes by DNA-based stable isotope probing revealed that AOA dominate in CK, N and NPK soils, while AOB dominate in OM soils. Denaturing gradient gel electrophoresis and clone library analyses of amoA genes revealed that Group 1.1a-associated AOA (also referred to as Nitrosotalea) were the most dominant active AOA population (>92%), while Nitrosospira Cluster 3 and Cluster 9 were predominant among active AOB communities. The functional diversity of active ammonia oxidizers in acidic soils is affected by long-term fertilization practices, and the responses of active ammonia oxidizers to mineral fertilizer and organic manure are clearly different. Our results provide strong evidence that AOA are more highly adapted to growth at low pH and low substrate availability than AOB, and they suggest that the niche differentiation and metabolic diversity of ammonia oxidizers in acidic soils are more complex than previously thought.  相似文献   

大豆GmNRT1.2a和GmNRT1.2b基因的克隆及功能探究     

LI Guo-Ji  ZHU Lin  CAO Jin-Shan  WANG You-Ning 《作物学报》2020,46(7):1025-1032

拟南芥中硝酸盐的吸收、转运和分配是通过硝酸盐转运蛋白(nitrate transporter, NRT)实现的。尽管之前的生物信息学分析推测大豆GmNRT1.2s可能参与共生固氮过程,但尚未开展相应的功能研究。本研究通过对其表达模式分析収现,GmNRT1.2a和GmNRT1.2b分别在根和叶中高表达,且受硝酸盐诱导,在接种根瘤菌与结瘤因子(nodfactors,NFs)后表达量明显升高。功能研究结果显示,过表达GmNRT1.2a或GmNRT1.2b后大豆根瘤数目显著增加。本研究为深入探究GmNRT1.2a和GmNRT1.2b调控大豆共生固氮过程的分子机制提供了一定的数据支持。  相似文献   

2株可培养细菌氮代谢特性的研究     

刘志新  姚娜  刘灵芝 《中国农学通报》2020,36(30):106-111

研究旨在分析土壤中可培养细菌菌株的氮代谢特征,并进一步探讨微生物在土壤氮素转化中的可能作用机制。以2株分离自苹果园土壤的细菌菌株SY5-4和SY11-10为试材,采用传统培养方法结合分子检测技术,分别测定菌株生长特性及其氮素转化能力。研究结果表明,异养条件下,菌株SY5-4和SY11-10的世代时间分别为243.5 min和202.7 min。菌株生长过程中,培养液中铵态氮浓度始终维持在较高水平,铵态氮、亚硝态氮和硝态氮浓度均表现出先升后降的趋势。硝化（amoA和hao）和反硝化（nosZ、norB、nirK和nap）基因检测结果表明,菌株SY11-10具有多种氮素转化潜能。综上,供试菌株培养过程中,培养液中氮素发生变化,并在菌体中检测到不同氮转化基因,表明菌株参与多种氮代谢途径。  相似文献   

Investigation of Interspecies Interactions within Marine Micromonosporaceae Using an Improved Co-Culture Approach     

Navid Adnani  Emmanuel Vazquez-Rivera  Srikar N. Adibhatla  Gregory A. Ellis  Doug R. Braun  Tim S. Bugni 《Marine drugs》2015,13(10):6082-6098

With respect to bacterial natural products, a significant outcome of the genomic era was that the biosynthetic potential in many microorganisms surpassed the number of compounds isolated under standard laboratory growth conditions, particularly among certain members in the phylum Actinobacteria. Our group, as well as others, investigated interspecies interactions, via co-culture, as a technique to coax bacteria to produce novel natural products. While co-culture provides new opportunities, challenges exist and questions surrounding these methods remain unanswered. In marine bacteria, for example, how prevalent are interspecies interactions and how commonly do interactions result in novel natural products? In an attempt to begin to answer basic questions surrounding co-culture of marine microorganisms, we have tested both antibiotic activity-based and LC/MS-based methods to evaluate Micromonosporaceae secondary metabolite production in co-culture. Overall, our investigation of 65 Micromonosporaceae led to the identification of 12 Micromonosporaceae across three genera that produced unique metabolites in co-culture. Our results suggest that interspecies interactions were prevalent between marine Micromonosporaceae and marine mycolic acid-containing bacteria. Furthermore, our approach highlights a sensitive and rapid method for investigating interspecies interactions in search of novel antibiotics, secondary metabolites, and genes.  相似文献   

不同补水方式下砂壤土渗滤系统对硝态氮去除效果   总被引：1，自引：0，他引：1  

潘维艳  黄权中  张子元  普薇如  黄冠华 《农业工程学报》2017,33(8):197-203

在水资源短缺的北京地区利用再生水回补城市河湖,一方面对于水资源的可持续利用有着十分重要的作用,另一方面也可能带来地下水环境的潜在污染风险.该文采用100 cm砂壤土柱模拟(河湖岸底)土地渗滤系统,设置定水头淹水、交替淹水落干、定流速补水和侧向补水4种不同再生水回补方式,研究再生水中硝态氮(NO3-N)在土地渗滤系统中的去除效果和迁移转化规律.结果表明,当水力负荷在0.25~2.65 cm/d范围内时,渗滤系统对NO3-N的去除率随着水力负荷的增大而减小;侧向补水方式下渗滤系统对NO3-N的去除效果最优,平均去除率高达96.1%.在定水头淹水和侧向补水方式下,系统对NO3-N的去除主要发生在土柱的上部,而交替淹水落干和定流速补水条件下,土柱中下部对NO3-N也有一定的去除作用.渗滤系统对NO3-N的去除主要取决于系统内部微生物的分布情况,土层中的反硝化细菌数量越大,该土层对NO3-N的去除率就越高.当水温在15~32℃范围内变化时,定水头淹水和交替淹水落干补水方式下,系统对NO3-N的去除率与温度分别呈指数和幂函数关系.该研究表明土地渗滤系统可实现再生水的进一步净化处理,可为再生水安全回补河湖提供参考.  相似文献