丁酸梭菌对蛋用仔公鸡肠道菌群、形态结构及黏膜免疫相关细胞的影响

本试验旨在探讨饲粮中添加丁酸梭菌对蛋用仔公鸡肠道菌群、形态结构及黏膜免疫相关细胞的影响。试验选择240只1日龄健康海兰褐蛋用仔公鸡,随机分为6组,每组4个重复,每个重复10只鸡,各组分别在基础饲粮中添加0(对照组)和150 mg/kg金霉素(抗生素组)以及250、500、750、1 000 mg/kg丁酸梭菌,试验期为42 d。结果表明:1)750 mg/kg丁酸梭菌组与1 000 mg/kg丁酸梭菌组的盲肠内大肠杆菌数与对照组和抗生素组相比显著降低(P<0.05),除250 mg/kg丁酸梭菌组外,其他各丁酸梭菌组盲肠内乳杆菌数量均显著高于对照组和抗生素组(P<0.05)。2)1 000mg/kg丁酸梭菌组小肠各肠段的绒毛高度显著高于对照组和抗生素组,绒毛长度/隐窝深度(V/C)值显著高于对照组(P<0.05),空肠的黏膜厚度显著高于其他各组(P<0.05)。3)1 000 mg/kg丁酸梭菌组的空肠与回肠上皮内淋巴细胞数量显著高于对照组(P<0.05),与抗生素组相比差异不显著(P>0.05),杯状细胞数量显著高于对照组与抗生素组(P<0.05)。1 000 mg/kg丁酸梭菌组的十二指肠和空肠的免疫球蛋白A(IgA)阳性物质有效数量显著高于对照组(P<0.05),与抗生素组相比差异不显著(P>0.05)。综上所述,丁酸梭菌能够促进生长发育,维持肠道健康,在本试验条件下,最适宜的添加水平为1 000 mg/kg。     

酪酸梭菌的作用机理及其在动物生产中的应用

本文综述了酪酸梭菌的作用机理及其在动物生产中的应用。     

水环境中2,4-D光降解、O_3/H_2O_2降解的研究进展

综述了水环境中2,4-D光降解、O_3/H_2O_2降解的理论依据。主要对水溶液中2,4-D的降解所涉及的影响因素(包括辐射强度、吸光物质、pH、温度)对降解产生的影响作用和机理作了介绍,并进行了展望。     

贵州赤水河流域10个暗色丝孢菌省级新记录种

对采自贵州赤水河流域的枯枝标本进行处理,鉴定出10个贵州省省级新记录种暗色丝孢菌,并对其进行形态学描述和图解。标本保存在遵义师范学院真菌学标本室（HMZNC）。     

辣木多糖酶促提取技术优化及不同部位含量研究

为研究辣木多糖的酶促提取工艺和辣木不同部位的多糖含量,在单因素试验的基础上,以多糖提取率为指标,选择纤维素酶用量、提取温度、提取时间、液料比为试验因素,采用二次回归正交旋转组合设计对纤维素酶辅助提取辣木多糖的工艺参数进行优化,并在此基础上研究辣木不同部位的多糖含量差异。4种因素对辣木多糖提取率的影响顺序依次为:纤维素酶用量>提取温度>液料比>提取时间。建立辣木多糖提取率(Y)与纤维素酶用量(X1)、提取温度(X2)、提取时间(X3)、液料比(X4)的二次正交回归模型:Y=18.6602+0.8134X1+0.7572X2–0.4312X3+0.6909X4–0.5181X12–0.4935X22–0.6277X42,该模型拟合度好,4个因素均对多糖提取率有显著影响(p<0.05)。通过回归模型获得优化的提取工艺为:纤维素酶用量1.60%,提取温度53℃,提取时间68 min,液料比52∶1,在此条件下辣木多糖提取率为19.83%,实际值与预测值一致。辣木不同部位的多糖含量结果表明,辣木根、花、嫩叶、茎中均含有丰富的多糖,其中根中含量最高且极显著高于其他部位(p<0.01),可进一步开发利用。采用二次回归正交旋转组合设计优化得到的辣木多糖酶促提取工艺条件准确可靠,可有效提高辣木多糖提取率并可在生产中推广应用。     

RETRACTED ARTICLE: The bioremediation of metolachlor in soil using Rhodospirillum rubrum after wastewater treatment

Purpose

Reliable and effective techniques for removing contaminants from soil are highly desirable. However, metolachlor residue bioremediation and soil fertility improvement by Rhodospirillum rubrum (R. rubrum) in effluent after wastewater treatment have not yet been investigated. The aims of this study were to investigate the feasibility of bioremediation of metolachlor residues in soil and soil fertility improvement by R. rubrum in effluent and to explain the mechanism that R. rubrum in effluent was induced to express the regulatory gene.

Materials and methods

Soybean processing wastewater was obtained from Harbin Soybean Products Machining Factory. Soil samples were the surface soil (0–30 cm) from campus (1.77 g/kg total N, 4.15 g/kg total P, 1.58 g/kg total K, 17 g/kg SOM, 0.07 g/kg SMBC). Cytochrome P450 monooxygenase regulatory gene, MAPKKKs gene, was measured by RT-PCR.

Results and discussion

Compared to control treatment, metolachlor was removed efficiently and soil fertility was remediated by effluent containing R. rubrum. The removal in concentrations reached 2.97 mg/L (99%). Soil organic matter (SOM) and SMBC were enhanced 42 times. Molecular analysis revealed that metolachlor induced cpm gene expression to synthesize cytochrome P450 monooxygenase through activating MAPKKKs gene in MAPK signal transduction pathway.

Conclusions

Bioremediation of metolachlor in soil and improvement of soil fertility using R. rubrum in effluent were feasible. Metolachlor, as environmental pressure, induced cpm gene expression to synthesize cytochrome P450 monooxygenase and to remove metolachlor through activating MAPKKKs, MAPKKs, MAPKs genes in MAPK signal transduction pathway.

     

Differentiation of nitrogen and microbial community in the littoral and limnetic sediments of a large shallow eutrophic lake (Chaohu Lake,China)

Purpose

Nitrogen (N) is one of the major elements causing eutrophication in freshwater lakes, and the N cycle is mainly driven by microorganisms. Lake littoral zones are found to be “hotspots” for N removal from both the basin and receiving waters. However, the environmental factors that drive the distribution of microorganisms are diverse and unclear. Here, we examined the differentiation of nitrogen and microbial community between the littoral and limnetic sediments to explore their interactions.

Materials and methods

Sediment samples were collected in the littoral and limnetic zones of Chaohu Lake in winter (ca. 7 °C) and autumn (ca. 22 °C). Abundances of the bacterial and archaeal genes amoA (ammoxidation), nirS and nirK (denitrification), hzsB (anaerobic ammonium oxidation; anammox), and nrfA (dissimilatory nitrate reduction to ammonium; DNRA) were measured via quantitative real-time polymerase chain reaction (qPCR). Clone libraries were constructed for further phylogenetic analysis to study the community composition.

Results and discussion

We observed significant higher concentration values in terms of sedimentary NH₄⁺-N and NO₃^?-N in the limnetic zone than littoral zone (p?<?0.05; n?=?12). In general, abundance values of the above six genes in the littoral zone were all higher than those in the limnetic zone, while higher in winter (7 °C) than in autumn (22 °C) (p?<?0.05; n?=?6). The spatial heterogeneity had the most significant effect on the distribution of ammonia-oxidizing archaea (AOA) and anammox bacteria abundance. Both temporal (temperature) and spatial heterogeneity affected the abundance of ammonia-oxidizing bacteria (AOB). The variation in the abundance of denitrifying bacteria and DNRA bacteria mainly reflected the temporal (temperature) heterogeneity.

Conclusions

The six N-cycle-related microorganisms were affected by different environmental factors and presented different distribution patterns. The lower nitrogen content and the higher microbial abundance and diversity showed that the littoral zone was the “hotspot” of N-cycling-related microorganisms in a large, eutrophic, and turbid lake. It is suggested that increasing the area and restoring the ecological function of the littoral zone was effective and significant in eutrophic lake management.

     

远安县建成区绿地栖凤园种植设计调查报告

植物生长并非一成不变,植物的动态性需格外注重,不同植物不同生长周期的养护手法(例如紫薇的修枝、红叶石楠的修枝情况)也不容忽视。植物景观作为一门多维度的艺术,包含了外形、色彩、嗅觉、触觉等不同的特征,同时又受到时间这一不确定因素影响颇深。针对不同时期植物的生长发育差异,应合理安排种植结构,加强季相搭配,延长观赏期,增加观赏角度。     

“一带一路”背景下中柬林业合作现状与展望

文中结合中国"一带一路"倡议、"三亚宣言""金边宣言"等中柬林业国际合作的大背景,对中柬开展的主要林业合作进行简要回顾;在此基础上,从发展目标、基本原则、工作构架、合作方向等方面,对中柬未来林业合作的前景进行了展望。     

土豆牛奶营养面包的研制

以小麦粉、土豆和牛奶为原料,采用正交试验优化土豆牛奶面包制作工艺。在单因素试验的基础上,以感官品质为考查指标,以土豆、鲜牛奶、白砂糖和酵母粉为正交试验的4个因素,筛选土豆牛奶面包的优良工艺参数。结果表明,土豆牛奶营养面包的优良配方为每100 g面粉用土豆泥30 g,牛奶25 g,白砂糖12 g,酵母粉1 g,鸡蛋10 g,饮用水9 g,面团发酵时间120 min。以此配方生产出的面包营养丰富、感官评分较高,可满足消费者需求。