花椒不同部位提取物抑菌活性及果蔬发病率研究

以花椒壳、籽、叶三个部位提取物为供试材料,研究其抑菌活性及对果蔬发病率的影响。采用滤纸片法检测花椒不同部位提取液对大肠埃希菌、沙门氏菌、铜绿假单胞菌、金黄色葡萄球菌、枯草芽孢杆菌的抑菌活性,通过组织分离法从常见果蔬中分离得到4株病原菌,初步鉴定为曲霉属、青霉属和链格孢属,对分离所得病原菌进行花椒提取物抑菌活性检测。花椒壳提取液的抑菌效果明显高于花椒籽和叶,其中花椒壳提取液对沙门氏菌和金黄色葡萄球菌有良好的抑菌活性,MIC分别为125 mg/mL、62.5 mg/mL。花椒壳、籽、叶对曲霉属、青霉属和链格孢属均有明显的抑菌作用,花椒壳抑菌效果最强,平均抑菌率在90%以上,经过花椒壳提取液处理后,果蔬发病率显著降低。结果表明花椒三个部位提取物具有良好的抑菌作用,可作为候选天然植物抗菌剂资源。     

Bedding hygiene,cleanliness and lying behaviour for heifers housed on wood chip or straw deep bedding

The aim of this project was to compare the hygienic quality of the bedding, as well as the parasitic load, cleanliness and lying behaviour in heifers kept on either straw or wood chip deep bedding. Fourteen heifers kept in two pens were housed on straw or wood chip bedding for 43 days, after which the bedding material was switched for 43 additional days. Significantly more mould was found in wood chip than in straw and there was a tendency towards less yeast in wood chip. The heifers had a low faecal parasitic load. The results indicate that the wood chip treatment resulted in somewhat cleaner animals. The heifers had a significantly longer total lying time when kept on straw. In conclusion, wood chip deep bedding could be an option as bedding material, but the impact on hygiene of bedding material and lying behaviour needs to be further investigated.     

2株益生菌在鳗鲡消化道内的定植与演替

对鳗鲡分别人工灌喂含有益生菌A40209CDC4(枯草芽孢杆菌,Bacillus subtilis)和A31009NA(少动鞘氨醇单胞菌,Sphingomonas pauci mobilis)的饲料,于停止灌喂后的第1、2、3、4、5、7、9、15、20、30 d进行细菌的分离培养,研究试验菌株A31009NA和A40209CDC4在鳗鲡消化道内的定植与演替规律。结果显示:A40209CDC4能在鳗鲡胃内定植至少7 d,在肠道内定植至少17 d;A31009NA能在鳗鲡胃内定植至少4 d,在肠道内定植至少9 d;消化道细菌总数与益生菌数量同步变化。试验结果表明:试验用益生菌菌株A40209CDC4和A31009NA均能在鳗鲡消化道内定植,并具有从胃至肠的迁移规律;人为添加具定植能力的益生菌时,将对养殖动物消化道菌群数量产生显著影响。     

Microbial phytase activity and their role in organic P mineralization

Plants respond to their external environment to optimize their nutrition and production potential to minimize the food security issues and support sustainable agriculture system. Phosphorus (P) is an important nutrient for plants and is involved in plant metabolic processes. It is mostly available as orthophosphate and has a tendency to form complexes with cations. It has low mobility in soil, thus becoming unavailable for plant uptake that causes a reduction in plant growth and yield. Besides free P, phytate is the major form of organic P in soil and plant tissues. Phytases obtained from different sources, that is, plants, animals, and microorganisms, catalyze the hydrolysis of phytate and release available forms of inorganic P. The knowledge of mechanisms involved in catalytic activity of phytase obtained from microorganisms in soil is limited. This review summarizes the role of microbial phytase in releasing organic P by hydrolysis of phytate and factors affecting its activity in the soil.     

益科乐活力菌在育肥猪、肉鸡饲养中的应用效果研究

通过在饲料中添加2％的益科乐活力茵固体菌剂和液体茵剂稀释液喷洒圈舍的方法，对育肥猪和肉鸡分别进行效果对比试验，结果表明：在育肥猪试验中，试验组比对照组减少饲料用量14．27kg／头，饲料利用率提高了12％，成本降低了27．27元，降低了7．2％，有害气体氨气和硫化氢含量试验组和对照组的平均浓度分别降低了29．8％和12．7％。在肉鸡试验中，试验组和对照组平均每只出栏鸡耗料4．116kg和4．373kg，平均少耗料0．257kg，死淘率分别为8．8％和15．5％，试验组比对照组多出栏168只，提高出栏率7．95％；饲养成本降低了27．27元，降低了7．2％，圈舍内试验组和对照组氨气和硫化氢气体平均浓度为1．71mg／m3、2．78mg／m3和0．040mg／m3、0．057mg／m3，分别降低了38．5％和29．8％。     

土壤微生物介导植物抗盐性机理的研究进展

土壤盐渍化是农业可持续生产面临的严重威胁之一。利用高效、低成本和适应性强的方法对盐渍区进行修复是一个具有挑战性的目标。土壤微生物在调节植物根际环境、调控生长发育和提高系统生产力等方面具有重要作用。近年来,由微生物驱动的植物胁迫耐受性受到了广泛关注。通过识别和利用能与植物相互作用的土壤微生物来减轻盐胁迫,为盐渍区改良提供了一种新策略,也为与胁迫耐受相关新机制的发现开辟了新途径。了解不同微生物介导的胁迫耐受性的潜在生理机制对有效利用这些微生物促进农业可持续生产至关重要,本文从植物养分吸收、渗透平衡、激素水平、抗氧化功能等方面论述了国内外关于土壤微生物介导植物耐盐性的作用机理,评估了目前关于土壤微生物参与调节植物耐盐性相关研究的有益作用和不足之处,提出了未来研究的发展方向。目前通过提高养分及水分吸收效率维持盐胁迫下植物离子稳态,提高生长素的合成、降低乙烯的释放调控植物激素水平是土壤微生物改良植物耐盐性的目标过程,然而单个外源微生物接种时会与土著微生物组竞争,导致许多微生物菌株不能在土壤或植物根系中定殖或存活,致使微生物在大规模农业生产应用中仅取得了有限的成功。未来微生物介导植物抗盐性的研究应突破单一微生物接种的研究方式,进一步在群落水平上阐明植物-微生物的相互作用介导植物抗盐性的机制,解决农业微生物利用的关键问题。     

微生物资源的生物勘探

从传统资源研究方法和"meta-技术"两方面阐述了微生物勘探的必要性,介绍微生物勘探的主要内容与研究方法,讨论微生物勘探对微生物资源研究的意义与价值及其发展趋势。     

江苏草地贪夜蛾天敌资源调查及其在玉米田控害作用评价

江苏省是我国草地贪夜蛾入侵地之一，为明确本地潜在自然天敌资源及其在玉米田的控害作用，2020年8—9月，对江苏省8个市县主要玉米种植区的草地贪夜蛾为害及其天敌资源开展了实地调查和室内饲养观察。结果表明，草地贪夜蛾对各调查点玉米植株的为害率均在50%以上。天敌种类主要有寄生蜂（棉铃虫齿唇姬蜂；姬蜂科1种；小腹茧蜂亚科1种）、病原真菌（白僵菌、绿僵菌、莱氏野村菌）、瓢虫（异色瓢虫、黑襟毛瓢虫），另外还有寄生蝇、细菌、病毒等多种类群。寄生性天敌的寄生率在0%~24.55%，病原微生物的感染率在2.33%~56.41%，表现出良好的防控潜能。江苏玉米田草地贪夜蛾虽然发生为害严重，但也拥有丰富的自然天敌类群，能为利用本地天敌防控草地贪夜蛾提供可靠资源。     

Biological Control of Common Bunt (Tilletia tritici)

Summary

Common bunt (Tilletia tritici syn. T. caries) is a significant seed-borne plant disease in organic agriculture. General measures in ecological crop protection like crop rotation and manuring have in practice failed to control this disease, and direct seed treatment may be necessary to ensure yield and food quality. The present study indicates that biological control can be successfully used without negative effects on seed germination and vigor. A combination of biocontrol agents and milk powder improves the efficacy of biocontrol. Application of compost to the soil increases the frequency of this disease. The potential role of biocontrol within the principles of ecological disease management is discussed.     

Typical Microorganisms in Cold Marinated Anchovies (Engraulis anchoita) Filled with Corn Oil and Spices

Abstract

The aim of this work was to study the influence of microbiological load of spices in the microflora of anchovy marinades. Microorganisms were not detected in anchovy at the end of the marinating stage, previous to packaging the marinated fillet. In the spices used, the microorganisms found were Lactobacillus paracasei paracasei 1, Bacillus mycoides, and Monilia spp. in black pepper; L. cellobiosus and B. mycoides in bay leaves; L. acidophilus and B. mycoides in paprika; and L. acidophilus, B. mycoides and Micrococcus varians in milled red pep per. After three months of storage of marinated anchovy at 4°C and 18°C only L. paracasei paracasei 1, L. acidophilus 1, M. varias and B. mycoides were found. Several of these bacteria were from spices and were considered typical of marinades, since the homeostatic mechanisms were adaptable in the medium.