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1.
科技是云南草地畜牧业可持续发展的关键因素 总被引:2,自引:0,他引:2
针对云南草地资源的现状及面临的问题,进行了草地畜牧业持续发展综合配套技术的研究,试验、示范、推广效果突出、效益明显,从而提出了科技是草地畜牧业可持续发展的基础和关键因素,以及加快科技推广的一系列建议。 相似文献
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温湿度调控对番茄灰霉病菌产生的细胞壁降解酶的影响 总被引:6,自引:0,他引:6
番茄灰霉病菌在致病过程中能够产生4种细胞壁降解酶,以PMG酶活性最高,其次是β-葡萄糖苷酶和PG酶,Cx最少。灰霉病菌在不同温度下侵染番茄叶片时产生的致病酶活性不同,4种酶在20℃时表现了最高的活性,15℃次之,当温度达到25℃时,各种酶的活性都急剧下降,随着温度的再升高,酶活更低。随着湿度的增高,病菌产生的细胞壁降解酶的活性也增加,当相对湿度达到90%以上时,4种酶的活性也达到最高。温湿度对番茄灰霉病菌产生细胞壁降解酶的影响趋势,与其对发病的影响趋势是一致的。 相似文献
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Fungal N2O production results from a respiratory denitrification that reduces NO3−/NO2− in response to the oxidation of an electron donor, often organic C. Despite similar heterotrophic nature, fungal denitrifiers may differ from bacterial ones in exploiting diverse resources. We hypothesized that complex C compounds and substances could favor the growth of fungi over bacteria, and thereby leading to fungal dominance for soil N2O emissions. Effects of substrate quality on fungal and bacterial N2O production were, therefore, examined in a 44-d incubation after soils were amended with four different substrates, i.e., glucose, cellulose, winter pea, and switchgrass at 2 mg C g−1 soil. During periodic measurements of soil N2O fluxes at 80% soil water-filled pore space and with the supply of KNO3, substrate treatments were further subjected to four antibiotic treatments, i.e., no antibiotics or soil addition of streptomycin, cycloheximide or both so that fungal and bacterial N2O production could be separated. Up to d 8 when antibiotic inhibition on substrate-induced microbial activity and/or growth was still detectable, bacterial N2O production was generally greater in glucose- than in cellulose-amended soils and also in winter pea- than in switchgrass-amended soils. In contrast, fungal N2O production was more enhanced in soils amended with cellulose than with glucose. Therefore, fungal-to-bacterial contribution ratios were greater in complex than in simple C substrates. These ratios were positively correlated with fungal-to-bacterial activity ratios, i.e., CO2 production ratios, suggesting that substrate-associated fungal or bacterial preferential activity and/or growth might be the cause. Considering substrate depletion over time and thereby becoming limited for microbial N2O production, measurements of soil N2O fluxes were also carried out with additional supply of glucose, irrespective of different substrate treatments. This measurement condition might lead to potentially high rates of fungal and bacterial N2O production. As expected, bacterial N2O production was greater with added glucose than with added cellulose on d 4 and d 8. However, this pattern was broken on d 28, with bacterial N2O production lower with added glucose than with added cellulose. In contrast, plant residue impacts on soil N2O fluxes were consistent over 44-d, with greater bacterial contribution, lower fungal contribution, and thus lower fungal-to-bacterial contribution ratios in winter pea- than in switchgrass-amended soils. Real-time PCR analysis also demonstrated that the ratios of 16S rDNA to ITS and the copy numbers of bacterial denitrifying genes were greater in winter pea- than in switchgrass-amended soils. Despite some inconsistency found on the impacts of cellulose versus glucose on fungal and bacterial leading roles for N2O production, the results generally supported the working hypothesis that complex substrates promoted fungal dominance for soil N2O emissions. 相似文献
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角蛋白的微生物降解与利用 总被引:6,自引:0,他引:6
本文对角蛋白、角蛋白酶、角蛋白降解菌的研究和应用状况作了系统的综述,现代化的家禽养殖产生大量角蛋白废物(如羽毛和毛发),若加以合理利用,它们是一种新的蛋白质来源。多种角蛋白降解菌和角蛋白酶已被分离并得到深入研究。在强调可持续发展的今天,角蛋白酶的研发和角蛋白废的利用不失为一个经济有效的环保举措。 相似文献
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[目的]研究添加麸皮与纤维素酶对笋壳青贮后氰甙含量的影响。[方法]采用异烟酸—吡唑啉酮比色法研究添加麸皮与纤维素酶对笋壳青贮后氰甙含量的影响。[结果]添加麸皮与纤维素酶均可降低笋壳青贮后的氰甙含量。麸皮添加水平越高,青贮笋壳毒性越低,当麸皮添加水平为15%时笋壳青贮后氰甙含量最低。[结论]该研究可为笋壳饲料的资源化利用提供理论依据。 相似文献
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洪永聪 《青岛农业大学学报(自然科学版)》2009,26(3):181-183
在大田甘蓝地中,以从菜园土壤和菠菜叶片分离得到的氯氰菊酯降解菌株T-1和菌株Y-3为研究对象,采用气相色谱法检测,对降解菌降解氯氰菊酯的残留动态进行研究。结果表明:与对照相比,降解菌对氯氰菊酯的降解有促进作用;菌株Y-3和菌株T-1在土壤中对氯氰菊酯的降解动态基本类似,半衰期均为10d;具有内生性的菌株Y-3在甘蓝植株体内对氯氰菊酯降解效果较好,半衰期为7d。 相似文献
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