微生物源农用抗生素的研发与高产策略

开发高效、低毒、低残留的绿色农药是农药研发的发展趋势,其中微生物源农药抗生素占据了重要地位。随着基因组学、代谢工程、高通量筛选等技术的发展,新型微生物源农用抗生素的研究进入了新的阶段。文中简要总结了近10年来研发的新型微生物源农用抗生素的种类、农用抗生素产生菌株的高产育种与发酵研究策略等,为未来农用抗生素的研发提供参考。     

广州国家生物产业基地建设情况与发展思路

广州国家生物产业基地建设情况 近年来,在广州市委、市政府的高度重视下,广州生物产业发展迅速。2006年,广州生物产业总产值达到200亿元,约占全市高新技术产品产值的10％。目前广州具有各类生物企业300余家,其中上规模的70多家,年产值超过10亿元的有4家,年产值超过1亿元的有19家。     

广州国家生物产业基地建设情况与发展思路

广州国家生物产业基地建设情况 近年来,在广州市委、市政府的高度重视下,广州生物产业发展迅速。2006年,广州生物产业总产值达到200亿元,约占全市高新技术产品产值的10％。目前广州具有各类生物企业300余家,其中上规模的70多家,年产值超过10亿元的有4家,年产值超过1亿元的有19家。     

我国食品领域的发酵产业

生物技术产业涉及食品、医药、农业、化工、环境和海洋等领域,目前我国的生物技术产业主要在食品、医药和农业领域。根据国家有关部门的统计,2001年发酵工业(不包括酒类产品)264家生产企业统计,年产值为201.95亿元,占全国食品工业总产值的3.08％;年利税14.4亿元,其中利润5.56亿     

黄土高原草地畜牧业产业形成与发展的牧草生产力基础

在黄土高原197个区县土地利用方式重新规划的基础上,对黄土高原畜牧业产业形成与发展的牧草生产潜力进行了分析预测。结果表明：规划的牧、林、农、果用地占生产用地的比例分别是草地44％、林地22％、基本农田20％、果园14％;197个区县草地牧草生产、作物秸秆、草田轮作和果园种草预测的总牧草饲料生产潜力达104881028t／a(其中,草地牧草生产潜力约占45％,达47196462．7t／a),可载畜104881028个羊单位／a(其中草地可载畜47196462．7个羊单位／a)。按1999年不变价格计算,黄土高原预测畜牧业总产值将达到5244051万元RMB／a,是1999年畜牧业总产值的5．3倍,超过1999年黄土高原农业总产值14％。农业人口人均预测畜牧业产值大于l000元的区县占59％;小于l000元的区县占41％。此外,预测的农业总产值将达到l147．2234亿元RMB／a,其中畜牧业、果业、林业和农业产值占农业总产值的比重分别是46％、27％、14％和13％。随着畜牧业产业链的逐步建立与完善,产业发展布局的日趋合理,黄土高原畜牧业生产总值将有较大幅度的提高,黄土高原生态环境将有进一步的改善。黄土高原草地畜牧业蕴藏着巨大的发展潜力,有望成为黄土高原优化的生产一生态新产业带建制中的支柱产业。     

木聚糖的酶解和利用

<正> 木聚糖广泛存在于植物细胞壁中,是构成植物半纤维素组分的主要成分。在高等植物和农业废料中约占干重的20％。美每年有5亿吨植物纤维被废弃,其中含10～25％木聚糖形式的木糖,按最低估计也有5000万吨,若将这些木糖发酵,可产生1500万吨酒精。近年来,对于采取酶和微生物步序有效地利用木聚糖已受到了重视。很多微生物能够水解木聚糖,业已分离出真菌、细菌以及放线菌的木聚糖酶。很多微生     

发酵产品

据Frost & Sullivan(纽约州的纽约)的新报告,美国发酵产品的市场将由1989年预计的61亿美元增加到1992年的90.5亿美元,这几乎是1987年47.2亿美元的两倍。抗生素占市场的95％,并且是最大的产品种类。供销额可望从1989年的36.3亿美元增加到1992年的53.9亿美元。主要的抗生素类是头孢菌素,销售额从1989年的13.9亿美元将增加到1992年的23.4亿美元。发酵乙醇将可分享到20％的市场。这一需求的增加是因为其可用作未加四乙铅的煤     

黄土高原草地畜牧业产业形成与发展的牧草生产力基础

在黄土高原197个区县土地利用方式重新规划的基础上,对黄土高原畜牧业产业形成与发展的牧草生产潜力进行了分析预测.结果表明:规划的牧、林、农、果用地占生产用地的比例分别是草地44%、林地22%、基本农田20%、果园14%;197个区县草地牧草生产、作物秸秆、草田轮作和果园种草预测的总牧草饲料生产潜力达104 881 028 t/a(其中,草地牧草生产潜力约占45%,达47 196 462.7 t/a),可载畜104 881 028个羊单位/a(其中草地可载畜47 196 462.7个羊单位/a).按1999年不变价格计算,黄土高原预测畜牧业总产值将达到5 244 051万元RMB/a,是1999年畜牧业总产值的5.3倍,超过1999年黄土高原农业总产值14%.农业人口人均预测畜牧业产值大于1 000元的区县占59%;小于1 000元的区县占41%.此外,预测的农业总产值将达到1 147.223 4亿元RMB/a,其中畜牧业、果业、林业和农业产值占农业总产值的比重分别是46%、27%、14%和13%.随着畜牧业产业链的逐步建立与完善,产业发展布局的日趋合理,黄土高原畜牧业生产总值将有较大幅度的提高,黄土高原生态环境将有进一步的改善.黄土高原草地畜牧业蕴藏着巨大的发展潜力,有望成为黄土高原优化的生产-生态新产业带建制中的支柱产业.     

2000年新农药的设想——农用抗生素专题规划会议在杭州召开

由石油化工部组织召开的农用抗生素专题规划讨论会,于85年6月19日至6月22日在杭州召开。全国20多个研究单位以及生产工厂的专家和学者参加会议。会上广泛地总结和讨论了国内农药发展情况以及国外农药中抗生素农药的进展情况。专家们一致认为:农用抗生素不仅是一种低毒高效的新农药,而且,它是现代生物工程中发酵工程的新课题。由于它对人寿年丰有重要的贡献,因此,一些经济发达的国家十分重视农抗研究和开发。     

农用抗生素筛选模型的发展概述

农用抗生素是指微生物产生的,可用于防治农业有害生物的次级代谢产物。随着筛选模型的贫乏,发现新型农用抗生素的难度越来越大,同时农用抗生素的研究应用与筛选模型密切相关,并随筛选模型的不断改进而向前推进。近年来,随着新技术特别是现代生物技术在微生物研究中的应用,从微生物中筛选新的农用抗生素的几率逐渐加大。主要对传统筛选模型、特定筛选模型以及高通量筛选模型进行了阐述,并对我国未来农用抗生素筛选模型的发展方向提出了预测。     

我国主粮作物的化学农药用量及其温室气体排放估算

现代农业中化学农药在提高作物产量中发挥着重要的作用,但是我国普遍存在过量用药现象,导致环境污染和危害食品安全.基于2012年的全国性农户问卷调查,本研究分析了2011年我国水稻、小麦和玉米使用农药现状,并估算了它们的温室气体排放.结果表明: 这3种作物至少使用了54种杀虫剂、24种杀菌剂和50种除草剂,其中32%的水稻种植农户使用了生物农药.全国3种作物使用了30.8 kt杀虫剂、16.5 kt杀菌剂和58.3 kt除草剂,它们的温室气体排放总量为1.5 Tg Ce,杀虫剂、杀菌剂和除草剂的排放分别占23.8%、16.9%和59.3%.南方区的农药用量占全国用量的51%;全国水稻、小麦和玉米的单位产量农药用量分别是0.22、0.18和0.24 g·kg^-1粮食,3种作物用药总量分别为44.4、21.4和39.7 kt,温室气体排放分别为665.5、250.1和547.5 Gg Ce;在不同农药种类中,有机磷类杀虫剂占我国所用杀虫剂总量的69%,苯丙咪唑类、有机磷类、唑类和有机硫类等杀菌剂占杀菌剂总量的87%,酰胺类、有机杂环类和有机磷类等除草剂占除草剂总量的85%.因此,减少农药用量,对于我国粮食安全和环境安全及减少农业温室气体排放都具有重要意义.     

稻田水质模型研究和应用进展

水稻生产环境特殊、生产过程中病虫草害严重,导致农药使用品种多、频次高.部分农药会淋失到周围水体中,对水体的潜在污染风险较高.随着农药监测和田间试验成本的不断提高,数学模型已成为农药登记过程中不可或缺的一部分.稻田水质模型(RICEWQ模型)作为欧洲稻田农药暴露评估最可靠和应用最广泛的模型,主要用于预测淹水稻田土壤和积水中的农药浓度,在我国也得到了初步应用.本文简要介绍了RICEWQ模型的系统结构、农药归趋的主要过程、模型的输入输出,综述了国内外相关的研究进展,以期推进RICEWQ模型在我国的应用,并为相关研究提供参考.     

超声波在生物发酵工程中的应用

一定强度的超声波作用于发酵过程中缩短发酵时间,改善生物反应条件,提高生物产品的质量和产量,微弱超声可用于在线检测某些发酵过程参数,本简要介绍了超声波作用于生物发酵过程的基本原理,并详细讨论了超声波在遗传育种 ,改善发酵工艺有发酵产物的提取与分离,发酵产物浓度的在线检测等方面的主要应用。     

转基因抗虫水稻对生物多样性的影响

水稻是我国最重要的粮食作物,然而虫害造成的产量损失每年高达一千万吨以上。研究表明,转基因抗虫水稻对二化螟、三化螟和稻纵卷叶螟等水稻主要鳞翅目害虫具有高抗性,可以大幅度减少化学杀虫剂的使用。在不使用农药的情况下,在抗虫转基因水稻田中的害虫密度大幅度减少的同时,可以显著地增加中性昆虫及捕食性天敌数量和种类,显示出稻田生态系统和生物多样性的向良性发展的趋势。转基因水稻花粉向非转基因水稻品种的基因飘流实验表明,随着栽种距离的增大而显著减小,到间隔6.2 m时基因飘流频率已低于0.01%。转基因抗虫水稻的应用,对于保障我国粮食安全,保持农业可持续发展,保护生物多样性和生态环境尤其是在大幅度减少农药使用量方面具有重要意义。文章综述了转基因抗虫水稻研制进展及其对生物多样性的影响,并对农作物害虫防治的未来研究方向和发展趋势进行展望,以期为转基因抗虫水稻更好的应用提供借鉴。     

Farmers' management of cabbage and cauliflower pests in India and their approaches to crop protection

Cabbage (Brassica olearaceae var. capitata) and cauliflower (Brassica oleracea var. botrytis) are two major vegetables produced and consumed in India. Over the years, they have been cultivated more intensively. This has resulted in higher rates of pest infestation, especially by the diamondback moth (Plutella xylostella) and higher pesticide use. This, in turn, has contributed to insecticide resistance, environmental degradation, and human health impacts, which have triggered a growing interest in alternative management techniques. There is a dearth of knowledge on current pest management practices in cabbage and crucifer. Knowledge about pest management practices is necessary to develop appropriate strategies such as Integrated Pest Management. The main purpose of this study was to obtain comprehensive information on pest management practices among farmers growing cabbage and cauliflower in India.A survey was conducted in the states of Gujarat, West Bengal, and Karnataka from October 2006 through January 2007. Three hundred farmers were interviewed to obtain information on pesticide use in cabbage and cauliflower production, the cost of pesticide use, and socioeconomic characters that influence cabbage and cauliflower production.Farmers relied on pesticides as the major and often exclusive crop protection strategy. Ten of the active ingredients (16.4% of all pesticides reported by all farmers in this survey) were listed as extremely or highly hazardous (classes Ia and Ib) by the World Health Organization. The results confirmed that pesticide use differs between states of India, but that location alone does not determine pesticide spraying pattern. A regression model was used to identify determinants of pesticide application frequency and pesticide cost per hectare. After controlling for location, individual level variables, such as age, education and experience, had significant effects on how often farmers sprayed. Farmers also spent more for pesticides, and sprayed more frequently on cauliflower than on cabbage and on open-pollinated varieties than on hybrid varieties.Our findings highlight the excessive use of pesticides in cabbage and cauliflower, and the reliance on pesticides as the only pest management strategy. The results confirm the need for alternative management strategies. Bt vegetables may be one of these alternative strategies. However, it is questionable whether cultivation of Bt vegetables will reduce the strong reliance on pesticides. Small-scale farmers will need training in the identification of pests, natural enemies, basic ecology, and integrated pest management strategies to ensure sustainable and safe vegetable production.     

养殖排放农药和抗生素在红树林区中残留的初步研究

广西北海大冠沙红树林区是养殖废水的排放地,该文报道2008年10月农药和抗生素在该林区红树林滩、沙滩和潮沟三类生境的残留水、沉积物和底栖动物中的分布与含量。通过对103种农药和22种抗生素检测,发现该林区有16种农药,4种抗生素,其中甲氰菊酯、仲丁威和醚菌酯是主要的污染农药。在残留水中检出12种农药,它们在红树林滩、沙滩和潮沟中的总浓度分别是42.70、29.63和27.41ng/L。在沉积物中检出10种农药,它们在红树林滩、沙滩和潮沟中的总浓度分别是7.90、6.70和7.29μg/kg.DW。在底栖动物体内检出4种农药和3种抗生素。分析表明,红树林滩(残留水和沉积物)比底栖动物更易受到养殖废水的污染,底栖动物对抗生素的富集能力似乎高于对农药的富集能力,生境间污染相似度高于样品间的污染相似度。     

Five years of Bt cotton in China - the benefits continue

Bt cotton is spreading very rapidly in China, in response to demand from farmers for technology that will reduce both the cost of pesticide applications and exposure to pesticides, and will free up time for other tasks. Based on surveys of hundreds of farmers in the Yellow River cotton-growing region in northern China in 1999, 2000 and 2001, over 4 million smallholders have been able to increase yield per hectare, and reduce pesticide costs, time spent spraying dangerous pesticides, and illnesses due to pesticide poisoning. The expansion of this cost-saving technology is increasing the supply of cotton and pushing down the price, but prices are still sufficiently high for adopters of Bt cotton to make substantial gains in net income.     

Health risks of consuming apples with carbendazim,imidacloprid, and thiophanate-methyl in the Chinese population: Risk assessment based on a nonparametric probabilistic evaluation model

The pesticides carbendazim (CA), imidacloprid (IM), and thiophanate-methyl (TH) are used extensively in apple production. However, the presence of pesticide residues in apples has been associated with a wide range of human health hazards. To assess whether apples are safe to consume, evaluating their potential health risk is of great significance. We tested apples from two dominant apple-producing areas for the presence of pesticide residues and constructed a statistical model to evaluate their health risks. Of the three commonly used pesticides, thirty-two samples (11.3% of all tested samples) were residue-free and 231 (81.9%) contained CA residues, which was the most frequently detectable pesticide, followed by TH (52.1%) and IM (39.0%). All of the samples were below the maximum residue limits. The probabilistic assessment results indicated that the pesticide intake risks for kids (aged 2–6 years) and children (aged 7–13 years) were significantly higher than those of other groups, so that they were the vital monitoring objects. Our findings indicate that consumption of apples with these three pesticides does not pose a health threat for the population. Nevertheless, we recommend an investigation into continuous monitoring and stricter regulations on fruits' quality and safety throughout China.     

Dual-level toxicity assessment of biodegradable pesticides to aquatic species

The use of ecological models to assess the effects of pesticides on the structure and function of aquatic ecosystems is of growing interest. Of utmost concern is assessment of pesticides that have the potential to biodegrade into metabolites that are as toxic as the parent pesticide. In this work, a mathematical model to predict and evaluate the effect of two pesticides on the population of aquatic biospecies where both pesticides are bio-available in water and sediments with one of the pesticides capable of biodegrading into the other but not vice versa is formulated and analyzed. Conditions for nonlinear stability, instability and Hopf-bifurcation are obtained. The model undergoes a Hopf-bifurcation when the rate of discharge of pesticides crosses a critical value, so that the population of the aquatic species follows an oscillatory pattern. Four hypotheses involving the concentration of the pesticides and the population of the aquatic species where qualitatively investigated: the aquatic species will completely die out with time, the population of the aquatic biospecies will remain under certain conditions, the pesticide will continually remain in water and there will be a periodic variation in the population of the aquatic species over time. Results also indicate that the biodegradation potential of one of the pesticides had significant effect on the population dynamics of the aquatic species.     

广西苦丁茶的生产现状及无公害栽培技术探讨

广西苦丁茶生产区主要在大新县和天等县,种植面积约3 000 hm2,年产茶叶约700 t。生产过程中存在对农药和化肥的过份依赖、产品的重金属和农药超标等问题,需要通过无公害栽培来提高产品质量。该文从茶园选择、种植、土壤管理和施肥、茶树修剪和茶叶采摘、病虫害防治等方面对苦丁茶的无公害栽培技术进行了初步探讨。