瓜类作物枯萎病生防菌BS-2000和JK-2的分子鉴定

采用生理生化和16SrDNA两种不同的方法对生防菌BS-2000和JK-2进行鉴定。生理生化鉴定显示,BS-2000属于地衣芽孢杆菌,JK-2属于短短芽孢杆菌；16S rDNA基因的测定与分析表明,BS-2000与B．licheniformis(地衣芽孢杆菌)的同源性达99.9％,JK-2与B．brevis(短短芽孢杆菌)的同源性达99.9％,故推定BS-2000属于地衣芽孢杆菌,JK-2属于短短芽孢杆菌。     

Effects of Single and Dual Applications of Selected Trichoderma and Bacillus Isolates on Performance of Dry Bean Seedlings Grown in Composted Pine Bark Growth Medium under Shadehouse Conditions

A shadehouse pot trial was conducted to study the efficiency of single and dual inoculations with selected Trichoderma and Bacillus isolates on performance of dry bean plants (Phaseolus vulgaris L.) grown in composted pine bark (CPB) potting medium. All the plant treatments inoculated with Trichoderma spp. and/or Bacillus spp. had higher photosynthetic efficiency (Fv/Fm values). Of the treatments, only B. subtilis B69 showed a significant increase (P = 0.02) in Fv/Fm values over the growth period. The Trichoderma and Bacillus treated plants showed increase in dry shoot biomass. The greatest degree of nodulation was observed in Trichoderma and/or Bacillus treated plants. Increase in nitrogen concentrations were observed in leaves of plants inoculated with Trichoderma and Bacillus isolates. Only T. atroviride SY3A significantly increased phosphorus concentrations in leaves. These results depict and highlight the role these organisms can play in plant root-plant growth promoting rhizobacteria or plant growth promoting fungi (PGPR/PGPF) interaction in a nutrient-poor growth medium.     

LP3,LP5杆菌的防病作用及其对梨幼苗的促生效应

测定了内生芽孢杆菌LP3,LP5菌株对梨采收后果黑斑病的预防和治疗效果,并通过盆栽试验分析了这2个菌株对梨幼苗的促生效应。结果表明,LP3,LP5对9种病原菌的抑制率分别在42.3%～87.3%和45.6%～92.6%之间;其对梨黑斑病兼具预防和治疗作用,经LP3,LP5发酵液处理的梨果接病菌5 d后,防效分别为81.53%,88.92%;LP3,LP5处理病果3 d后,病斑扩展抑制率分别达65.64%和72.48%;LP3,LP5能促进梨树幼苗的生长,经这2个菌株处理的梨树幼苗初生枝长度分别比对照提高了50.48%和21.83%,鲜质量分别比对照增加35.67%,31.16%,干质量分别比对照增加29.24%,20.75%。     

高效固氮芽孢杆菌筛选及其生物学特性

 【目的】筛选高效固氮芽孢杆菌,研究固氮微生物固氮酶活性、竞争适应能力与接种固氮效能的关系,探讨接种固氮芽孢杆菌对根际细菌多样性的影响。【方法】采用无氮培养基富集、加热筛选固氮芽孢杆菌。乙炔还原法测定固氮酶活性,采用盆栽小白菜选育高效固氮芽孢杆菌、研究菌种竞争适应能力与接种固氮效能。通过形态、生理生化特征和16S rDNA序列分析鉴定菌种。【结果】筛选到了3株固氮酶活性相对较高、固氮能力较强的菌株GD062、GD082和GD282,初步鉴定为芽孢杆菌Bacillus spp.和类芽孢杆菌Paenibacillus sp.。进一步的研究结果表明菌株GD082竞争适应能力较强,在盆栽试验自然土壤条件下接种固氮效能与施用化肥试验处理效果相当,可望进一步研发用于生产固氮微生物肥料。试验结果同时显示,供试菌株的固氮酶活性与其接种固氮效能并不直接相关,菌株的竞争适应能力对接种固氮效能影响很大,接种固氮芽孢杆菌使小白菜根际土壤细菌多样性显著增加。【结论】接种固氮微生物为农作物提供氮素养分具有生产实践意义。高效固氮菌种的筛选是一个复杂的过程,菌株的固氮酶活性与其接种固氮效能并不直接相关,竞争适应能力对接种固氮效能影响很大。筛选到的芽孢杆菌GD082固氮酶活性较高、固氮能力较强、竞争适应能力很强,可望进一步研发成为优良的固氮微生物肥料生产用菌种。     

生防菌株TL2的菌剂研制及大田防病试验

本文以一株能在茶树体内内生定殖、对茶叶斑病防病效果好的枯草芽孢杆菌（Bacillus subtilis）菌株TL2为研究对象,优化该菌株的发酵条件和生产工艺,筛选它的适宜助剂,测定它在大田对茶叶斑病的防病效果。结果表明：该菌株的最佳产朊条件为氮源（蛋白胨）、培养温度（35℃）、碳源（蔗糖）、培养时间（72h）、初始pH（6.6）和250ml装液量（50ml）。它的最佳固态发酵工艺为氮源（豆饼粉）、碳源（麸皮)、含水量（25ml）、接种量（4%）、培养温度（35℃）和初始pH(7.0)。筛选得到该菌剂的4种良好载体,碳酸钙、高岭土、滑石粉和硅藻土等,1种良好的润湿分散剂,木质素磺酸钙,以及2种优良的紫外保护剂,腐植酸和糊精。该菌剂（孢子粉可湿性粉剂）在田间对茶叶斑病有较好的防治效果,防效达70%以上,与对照药剂多菌灵的防治效果相当。     

梅花鹿γ-干扰素在牛型结核病中的应用研究进展

梅花鹿γ-干扰素是细胞因子超家族中干扰素家族的特殊重要成员之一,具有广泛的生物学功能。其功能的多样性是通过诱导细胞表达多种蛋白质实现的。对梅花鹿γ-干扰素的诱导与产生、结核病特异性基因、梅花鹿γ-干扰素用于牛型结核病的检测原理及γ-干扰素优劣的研究进展进行综述。     

白僵菌可湿性粉剂防治玉米螟田间药效研究

2年药效试验结果表明,在黑龙江省选用白僵菌150亿孢子/g球孢可湿性粉剂防治玉米螟,可明显提高越冬幼虫僵死率。药剂对环境无污染,对人和牲畜安全。施药宜选择春季解冻后,幼虫刚从秸秆中爬出寻找水源的关键时段,进行喷粉封垛防治。推荐剂量以18.75~25g制剂/m3为宜。     

纳豆菌培养条件的初步研究

以OD600为指标,研究了培养条件对纳豆菌生长的影响。试验结果表明,该菌株最适培养条件为温度37℃,pH值6.0,接种量3%,培养时间9h,装液量1/5,摇床转数180r/min,最适碳源为葡萄糖,最适氮源为酵母浸粉。     

高压静电喷雾灭菌的试验

运用高压静电雾化技术和轴流风送输运技术设计了高压静电喷雾消毒试验装置,以适应各种不同环境下的卫生防疫消毒需要．在实验室内进行了喷雾特性试验,得到了雾滴的平均粒径、雾滴荷质比及雾滴的流量密度等．试验表明：药剂荷电后,雾滴表面张力下降,内外压强差增强,雾滴容易发生二次雾化;同时其表面活性增强,改善了液体的雾化性能及雾滴捕集粒子的能力．进行了现场灭菌试验,对比了静电喷雾与传统喷雾的灭菌效果．结果表明,荷电明显改善了传统灭菌方式中药液施用量过大、存在消毒死角等缺点,有效改善药剂喷洒的均匀性,细化雾滴,使雾滴能够有效地捕捉细菌,提高了灭菌效率,减少了对环境的二次污染．     

Improving productive performance and mitigating harmful emissions from laying hen excreta via feeding on graded levels of corn DDGS with or without Bacillus subtilis probiotic

An experiment that included some inclusions of corn distillers dried grains with solubles (DDGS) with or without supplementation of probiotic bacteria to Hi‐sex Brown laying hen diets was conducted to evaluate the impacts on performance, egg quality, blood metabolites and nitrogen and phosphorus excretion in the manure. A total of 216 twenty‐two‐week‐old Hi‐sex Brown laying hens were randomly divided into eight treatment groups in a factorial design (4 × 2) experiment, which included four levels of DDGS (0, 50, 100 and 150 g/kg diet) plus two levels of Bacillus subtilis probiotic (0 or 1000 mg/kg diet, with a concentration of 1.5 × 108 CFU/g of dried product). The experimental period extended from 22 to 34 weeks of age. The results showed that linear increase in DDGS level up to 150 g/kg improved (p ≤ 0.01) the values of feed consumption, egg shape index and yolk colour compared to the control and other treatment groups. Inclusion of dietary DDGS up to 150 g/kg in layer diets led to a significant decrease in egg mass and a significant increase in Haugh unit score compared to other groups. In the bacillus group, the values of feed conversion, egg weight and egg mass enhanced by 6.45, 3.27 and 7.60% respectively compared with the control diet. Total protein, albumin, triglycerides, cholesterol, calcium and ammonia in serum were significantly (p ≤ 0.01) influenced by DDGS inclusion. The excreted nitrogen decreased by 8.62 and 4.31% in hens fed 50 or 100 g/kg of DDGS respectively, while excreted phosphorous decreased by 3.33, 7.22 and 10.56% in hens fed 50, 100 or 150 g/kg of DDGS respectively as compared to the control group. It could be concluded that increasing DDGS inclusion level in the diet up to 10% and the supplementation of probiotic bacteria improved the productive performance of laying hens and mitigated the harmful emissions from chicken manure; this means better production within environmentally friendly conditions.