共查询到19条相似文献，搜索用时 78 毫秒
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葡萄球菌分类和鉴定的研究进展 总被引：1，自引：0，他引：1
潘培根 《微生物学免疫学进展》1989,(1):16-22
<正> 葡萄球菌常存在于空气、水、土壤、物品、人和动物中,是人体皮肤、呼吸道和胃肠道等的正常菌群。过去长期认为只是金黄色葡萄球菌才有致病作用,而凝固酶阴性葡萄球菌是人类无害的共栖菌。近些年来,由于葡萄球菌分类和鉴定的研究取得了突出的成就,临床上已承认凝固酶阴性葡萄 相似文献
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色泽鲜艳的羽毛,是大自然赋予鸟类最珍贵的礼物,当我们惊叹于眼前身着五彩羽毛的鸟儿时,也曾想过：数千万年前,原始鸟类的羽毛是什么颜色？ 相似文献
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采用以羽毛粉为唯一碳源和氮源的培养基,从自然界中分离到一株能够高效降解羽毛角蛋白的细菌,经形态学观察,生理生化实验和16SrRNA基因鉴定,初步确定该菌株为短小芽孢杆菌(Bacillus pumilus),且命名为短小芽孢杆菌WHK4。发酵48 h时,羽毛粉降解率达到85.76%。本研究为微生物降解羽毛角蛋白提供了优良的菌株,在蛋白饲料生产中具有潜在的广泛的应用前景。 相似文献
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【目的】从土壤中分离并鉴定羽毛降解菌,测定其生长最适温度及起始pH,并观察酶活动态。【方法】采用系列稀释法和选择培养基法筛选目的菌株,基于16S rRNA基因序列及Biolog方法鉴定其分类地位,利用全自动生长曲线分析仪监测菌株的最适生长条件,并通过测定蛋白水解活性观察其酶活动态。【结果】从混合羽毛的土壤样品中筛选到一株羽毛降解菌,命名为菌株GIMN1.015,初步判定该菌株属于芽孢八叠球菌属(Sporosarcina)。最适生长pH为9.0,温度为30°C。蛋白水解活性最高值出现在培养后96 h。【结论】菌株GIMN1.015在利用羽毛角蛋白资源中具有潜在的应用价值。这是芽孢八叠球菌在羽毛降解方面的首次报道。 相似文献
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CHRISTIAN SCHMIDT 《Zoological Journal of the Linnean Society》1997,121(2):129-244
The European species of Trachelipus Budde-Lund, 1908 are revised. The generic diagnosis is extended. The species T. aegaeus (Verhoeff, 1907), T. arcuatus (Budde-Lund, 1885), T. ater (Budde-Lund, 1896), T. camerani (Tua, 1900), T. dijfkilis (Radu, 1950), T. nodulosus (C. L. Koch, 1838), T. palustris (Strouhal, 1936), T. rathkii (Brandt, 1833), T. ratzeburgii (Brandt, 1833), T. razzautii (Arcangeli, 1913), T. rhinoceros (Budde-Lund, 1885), T. squamuliger (Verhoeff, 1907), T. trilobatus (Stein, 1859), (77 troglobius Tabacaru & Boghean, 1989) and 7T vespertilio (Budde-Lund, 1896) are recognized as valid. Except for T. troglobius , redesriptions, figures and distribution maps are given. A key to species is provided. Nineteen names are new synonyms of the above mentioned ones; nine names become nomina dubia. 相似文献
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Diagnoses of the cyst-forming genera of Heteroderidae (viz., Heterodera, Sarisodera, Globodera, Punctodera, Cactodera, and Dolichodera) and distribution and morphometrics of the 34 known cyst species in the Western Hemisphere are presented along with an illustrated key for the identification of these genera and species. The key is based mainly on cysts and larvae, and important morphological and diagnostic features are extensively shown by LM and SEM illustrations. The genus Bidera is placed as a new synonym under the genus Heterodera. 相似文献
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GREGORIO MORENO‐RUEDA 《Ibis》2011,153(1):195-198
This study assesses whether uropygial gland size is related to improved feather quality. To address this question, I analysed the relationship between uropygial gland size and feather wear in the House Sparrow Passer domesticus. The results show that birds with larger uropygial glands had less worn feathers, suggesting that uropygial gland secretions improve feather resistance to abrasion. 相似文献
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小孢子链格孢OPA2-1核苷酸序列分析及系统发育研究 总被引：4，自引：0，他引：4
本研究采用引物对OPA2-1L/OPA2-1R对供试小孢子链格孢菌株OPA2-1区段进行扩增,所有菌株都可获得PCR产物。核苷酸序列分析表明:不同小孢子链格孢种OPA2-1核苷酸序列存在明显差异。利用邻近结合法构建系统发育树,供试菌株被分为8个组,梨黑斑链格孢Alternaria gaisen、长柄链格孢A.longipes、树状链格孢A.arborescens明显被归于不同分支,显示OPA2-1核苷酸序列对这些种均具有区分能力;链格孢A.alternata的一些不同分离物被聚在不同组中,说明链格孢A.alternata存在明显遗传差异,可能为一个复合体。OPA2-1核苷酸序列富于变化,可作为小孢子链格孢系统发育研究的一种有用的手段。 相似文献
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Most beginners are introduced to plant diversity through identification keys, which develop differentiation skills but not species memorisation. We propose that mnemonics, memorable ‘name clues’ linking a species name with morphological characters, are a complementary learning tool for promoting species memorisation. In the first of two experiments, 64 adults in a group-learning environment were taught species identification using mnemonics, an educational card game and a text-based dichotomous key. In the second experiment, 43 adults in a self-directed learning environment were taught species identification using mnemonics and a pictorial dichotomous key. In both experiments, mnemonics produced the highest retention rates of species identification based on vegetative characters. The educational value of these findings is discussed for vegetative plant identification and broader applications. 相似文献
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《Animal : an international journal of animal bioscience》2020,14(5):1005-1013
Feathers play a critical role in thermoregulation and directly influence poultry production. Poor feathering adversely affects living appearance and carcass quality, thus reducing profits. However, producers tend to ignore the importance of feather development and do not know the laws of feather growth and development. The objective of this study was to fit growth curves to describe the growth and development of feathers in yellow-feathered broilers during the embryonic and posthatching periods using different nonlinear functions (Gompertz, logistic and Bertalanffy). Feather mass and length were determined during the embryonic development and posthatching stages to identify which growth model most accurately described the feather growth pattern. The results showed that chick embryos began to grow feathers at approximately embryonic (E) day 10, and the feathers grew rapidly from E13 to E17. There was little change from E17 to the day of hatching (DOH). During the embryonic period, the Gompertz function (Y = 798.48e−203 431exp(−0.87t), Akaike’s information criterion (AIC) = −0.950 × 103, Bayesian information criterion (BIC) = −0.711 × 103 and mean square error (MSE) = 559.308) provided the best fit for the feather growth curve compared with the other two functions. After hatching, feather mass and length changed little from the DOH to day (D) 14, increased rapidly from D21 to D91 and then grew slowly after D91. The first stage of feather molting occurred from 2 to 3 weeks of age when the down feathers were mostly shed and replaced with juvenile feathers, and the second stage occurred at approximately 13 to 15 weeks of age. The three nonlinear functions could overall fit the feather growth curve well, but the Bertalanffy model (Y = 116.88 × (1−0.86e−0.02t)3, AIC = 1.065 × 105, BIC = 1.077 × 105 and MSE = 11.308) showed the highest degree of fit among the models. Therefore, the Gompertz model exhibited the best goodness of fit for the feather growth curve during the embryonic development, while the Bertalanffy model was the most suitable model due to its accurate ability to predict the growth and development of feathers during the growth period, which is an important commercial characteristic of yellow-feathered chickens. 相似文献