环保型的生物农药--微生物杀虫剂

近年来,使用化学农药防治害虫,虽然在控制害虫危害和增加作物产量方面取得了一些显著的经济效益,但是随着害虫抗药性的增强,化学农药的使用浓度不断增大、用量增加,或不断开发新的化学农药,使害虫又出现了更大的或新的抗性,在这种恶性循环的情况下,化学农药防治害虫的经济效益已日益下降.……     

灯光诱杀在害虫无公害治理中的作用

１我国农业害虫防治现状６０年代末至今,我国农业害虫的治理主要以化学防治为主。化学农药在较长的一个时期内曾有效地控制住农业害虫的危害,为农业高产、稳产作出了巨大贡献。然而,长期使用农药已产生严重副作用：（１）使具有抗性基因的生理种群成为害虫优势种群,抗药性急剧上升,化学农药防治效果明显下降甚至无效。刘润玺等报道［１］,至１９９５年,棉铃虫对溴氰菊酯、对硫磷、久效磷、灭多威的抗性倍数分别为５９６１０．８、２５３５．２、１０３．３、２３９．９倍;（２）害虫抗性水平的剧增,加大了农药使用剂量及使用频率,…     

杀螟杆菌防治枣步曲

枣树最严重的虫害之一枣步曲(即枣尺蠖),它的幼虫期长,发生量大,防治不力时,常可将枣树的芽、叶、花蕾全部吃光。我县每年为防治这一害虫,需要大量的化学农药。由于连年使用化学农药,枣步曲产生了抗药性通常使用50—80倍的高浓度六六六、DDT混合液,仅有60％的杀虫     

鳞翅目昆虫中肠Bt杀虫蛋白受体研究进展

杀虫晶体蛋白(insecticidal crystal proteins,ICPs;含有Cry和Cyt 2大家族)和营养期杀虫蛋白(vegetative insecticidal proteins,Vips)等Bt杀虫蛋白可有效防治鳞翅目害虫,其中Cry应用最广泛。然而,一些地区的鳞翅目害虫已对Bt杀虫蛋白产生了抗性。目前,普遍认为鳞翅目昆虫中肠受体与Bt杀虫蛋白结合能力的改变是导致其对Bt杀虫蛋白产生抗性的最主要因素。在鳞翅目昆虫中,Cry受体是研究得最为透彻的Bt受体,已经被证实的有氨肽酶N、钙黏蛋白、碱性磷酸酶和ABC转运蛋白等。Vips杀虫蛋白类与鳞翅目昆虫中肠受体的结合方式与Cry杀虫蛋白相似,但结合位点与Cry杀虫蛋白不同。本文从结构特点、作用机制及不同鳞翅目昆虫间的表达差异等角度对以上4种鳞翅目昆虫中肠Bt受体进行了综述,并提出如下展望:(1)以棉铃虫或小菜蛾等鳞翅目昆虫为农业害虫模式生物进行深入研究,阐明其对Bt杀虫蛋白产生抗性的机制,为研究其他鳞翅目农业害虫对Bt杀虫蛋白产生抗性的机制提供理论借鉴;(2)鉴于在不同鳞翅目昆虫间,中肠Bt受体与Bt杀虫蛋白结合存在差异,且同一Bt杀虫蛋白与鳞翅目昆虫Bt受体并不专一性结合,Bt杀虫蛋白多基因组合策略是较为有效的田间鳞翅目昆虫防治策略,是今后一段时间内Bt杀虫蛋白应用的发展方向。     

营养型生物农药“杀鳞精”防治甘蓝夜蛾、斜纹夜蛾的试验

甘蓝夜蛾(Mamestra brassicae L．)、斜纹夜蛾(Spod op lilura Fabr．)是十字花科蔬菜的主要害虫。由于长期使用化学农药,害虫抗药性增强,防效下降,而且杀伤了天敌,污染了蔬菜和环境,影响了人类健康。作采用福建省绿十字生物工程联合发展中心,研制的新型营养型生物农药杀鳞精,防治这两种害虫,取得了较好的杀虫效果,同时促进了植株的生长,现将结果小结如下。     

芳香植物“防虫记”

正现代集约化农业生产模式,形成了单一化的农业景观,生物多样性的丧失必然引起害虫群落大爆发。化学农药的施用虽然达到了防控害虫、保障产量的目的,但过度依赖会造成环境污染、农药残留和食品安全等问题,直接威胁到农业、人类社会的可持续发展。随着国家农业可持续发展战     

昆虫病原线虫共生菌杀虫蛋白的研究进展

昆虫病原线虫共生菌杀虫蛋白对许多农业害虫都有很明显的毒杀作用,作为一种新型的具有开发潜力和应用前景的生物防治资源,已经引起科学家们的关注并成为国内外研究的热点之一.综述了昆虫病原线虫共生菌杀虫蛋白基因的结构和功能及其杀虫机制方面的研究进展.     

苏芸金杆菌在我国农业害虫防治中的作用

害虫对农作物的损失是十分巨大的,如果不采取有效措施防治害虫,就很难保证农作物增产。目前化学农药仍是防治农业害虫的重要制剂,但由于长期滥的结果,已出现了害虫产生抗药性、昆虫天敌减少、污染农副产品和环境等问题。因此许多植保工作者正探索防治害虫的新方法,新途径,并提出了综合防治害虫控制系统和     

微生物防治农林害虫的研究与进展

近十多年来,由于农业和林业上长期大量使用化学农药,破坏了大自然的生态平衡,污染了环境,给人类造成了灾难.所以世界上绝大多数国家对生物防治普遍重视起来.利用昆虫病原微生物防治农林害虫,是生物防治工作中的重要组成部分.昆虫病原微生物包括病毒、立克次氏体、细菌、真菌和原生动物等.目前国内外研究和应用的主要对象是细菌、真菌和病毒三大类.立克次氏体还在试验阶段. 细菌治虫目前,已分离到的昆虫病原菌的菌种和变种约有100种,其中研究最多、效果最好的是芽孢杆菌属的苏云金杆菌类和日本金龟子芽孢杆菌. 1.苏云金杆茵苏云金杆菌类是广谱杀虫细菌.1902年     

绿僵菌杀灭农业害虫

绿僵菌杀灭农业害虫法国科学家研制的生物杀虫剂,能够在数天内将蝗虫和蚱蜢种群尽数杀灭,其作用原理是,将农业害虫病原真菌黄绿僵菌（Ｍｅｔａｒｒｈｉｚｉｕｍｆｌａｖｏｒｉｖｉｄｅ）固定到蝗虫等害虫身体表面,使害虫像是患了一种癌症,最终导致死亡。其杀虫效率与...     

Production of mycelia and exo-biopolymer from molasses by Cordyceps sinensis 16 in submerged culture

The molecular weight of exo-biopolymer obtained from a submerged culture of Cordyceps sinensis 16 consisted of a main unit and a subunit of 126 and 68 kDa, respectively. The optimal medium for the production of mycelia and exo-biopolymer was determined to be molasses containing 2% sucrose, 0.9% yeast extract, 0.3% K2HPO4, and 0.4% CaCl2. Using optimized medium, maximum productions of mycelia and exo-biopolymer in shake-flask culture were 54.0 g/L and 28.4 g/L, respectively. This study suggests that large-scale production of mycelia and exo-biopolymer by C. sinensis 16 is possible in submerged culture.     

提高蛋白激发子产量的培养基及发酵条件的优化

为了进一步提高极细链格孢菌产蛋白激发子的产量,通过单因子和多因子试验与分析,筛选优化了适于极细链格孢菌产生蛋白激发子的培养基和培养条件,并检测了发酵过程中pH、还原糖、氨基氮和菌丝量变化以及与蛋白激发子产量的关系。结果表明,土豆淀粉和黄豆粉对蛋白激发子产量影响最大,其次是蛋白胨和无机盐。优化的发酵培养基主要成分（g／L）：碳源I 15、葡萄糖5、玉米淀粉5、土豆淀粉20、谷氨酸10、氮源I5、黄豆粉10、硫酸铵5。确定了优化的培养条件,调整培养基起始pH为7．0～7．5,将18h菌龄的种子培养液按10％接种量接种到装液量为75mL的500mL摇瓶中,在温度（28±1）℃、摇床转速180r／min下培养可获得理想的蛋白产量。在优化的培养基和培养条件下,发酵12～48h该菌进入对数生长期,48h进入稳定生长期,60h菌丝扣蛋白激发子产量达最高。蛋白产量与菌体生物量呈正相关,当还原糖、总糖量消耗到最低水平时,菌丝产量和蛋白激发子产量达最高。优化的培养基菌丝干重收率迭3．9g／100mL,蛋白激发子产量达到5．17g／L,比普通的土豆液体培养基提高近4倍。     

Phytase production byAspergillus ficuum on semisolid substrate

Summary Phytase production byAspergillus ficuum was studied using solid state cultivation on several cereal grains and legume seeds. The microbial phytase was used to hydrolyze the phytate in soybean meal and cotton seed meal. Wheat bran, soybean meal, cottonseed meal and corn meal supported good fungal growth and yielded a high level of phytase when an adequate amount of moisture was present. The level of phytase production on solid substrate was higher than that obtained by submerged liquid fermentation. Higher levels of phosphorus (more than 10 mg Pi/100 g substrate) in the growth medium (static culture) inhibited phytase synthesis, and the degree of phosphorus inhibition was less apparent in semisolid medium than in liquid medium. A static cultivation on semisolid substrate produced a higher level of phytase (2-20-fold) than that obtained by agitated cultivation. The minimal amount of water required for growth and enzyme production on those substrates was about 15%, while the optimum level for phytase production was between 25 and 35% and that for cell growth was above 50%. Optimum pH for phytase production was between 4 and 6.A ficuum grew well on raw (unheated) substrate containing a minimal amount of water and produced as much phytase as on heated substrate. About half of the phytic acid in soybean meal and cottonseed meal was hydrolyzed by treatment withA. ficuum phytase.     

Optimization of submerged culture requirements for the production of mycelial growth and exopolysaccharide by Cordyceps jiangxiensis JXPJ 0109

AIMS: The objective of the present study was to investigate the optimal culture requirements for mycelial growth and exopolysaccharide production by Cordyceps jiangxiensis JXPJ 0109 in submerged culture. METHODS AND RESULTS: The effects of medium ingredients (i.e. carbon and nitrogen sources, and growth factor) and other culture requirements (i.e. initial pH, temperature, etc.) on the production of mycelia and exopolysaccharide were observed using a one-factor-at-a-time method. More suitable culture requirements for mycelial growth and exopolysaccharide production were proved to be maltose, glycerol, tryptone, soya bean steep powder, yeast extract, medium capacity 200 ml in a 500-ml flask, agitation rate 180 rev min(-1), seed age 4-8 days, inoculum size 2.5-7.5% (v/v), etc. The optimal temperatures and initial pHs for mycelial growth and exopolysaccharide production were at 26 degrees C and pH 5 and at 28 degrees C and pH 7, respectively, and corresponding optimal culture age were observed to be 8 and 10 days respectively. According to the primary results of the one-factor-at-a-time experiments, the optimal medium for the mycelial growth and exopolysaccharide production were obtained using an orthogonal layout method to optimize further. Herein the effects of medium ingredients on the mycelial growth of C. jiangxiensis JXPJ 0109 were in the order of yeast extract > tryptone > maltose > CaCl2 > glycerol > MgSO4 > KH2PO4 and the optimal concentration of each composition was 15 g maltose (food-grade), 10 g glycerol, 10 g tryptone, 10 g yeast extract, 1 g KH2PO4, 0.2 g MgSO4, and 0.5 g CaCl2 in 1 l of distilled water, while the order of effects of those components on exopolysaccharide production was yeast extract > maltose > tryptone > glycerol > KH2PO4 > CaCl2 > MgSO4, corresponding to the optimal concentration of medium was as follows: 20 g maltose (food-grade), 8 g glycerol, 5 g tryptone, 10 g yeast extract, 1 g KH2PO4, and 0.5 g CaCl2 in 1 l of distilled water. CONCLUSIONS: Under the optimal culture requirements, the maximum exopolysaccharide production reached 3.5 g l(-1) after 10 days of fermentation, while the maximum production of mycelial growth achieved 14.5 g l(-1) after 8 days of fermentation. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report on the submerged culture requirements for mycelial growth and exopolysaccharide in C. jiangxiensis, and this two-step optimization strategy in this study can be widely applied to other microbial fermentation processes.     

Development of Commercially Acceptable Formulations of the Nematophagous FungusVerticillium chlamydosporium

Studies in shaken flasks and a 20-liter bioreactor showed that biomass ofVerticillium chlamydosporiumcould be produced in large quantities in liquid culture. The fungus grew readily in media containing commercially available, low-cost ingredients (e.g., cotton seed meal, soybean meal) and a volumetric productivity of about 0.3 g/h/liter was achieved in the bioreactor. Chlamydospores were not produced in submerged culture, the biomass consisting only of mycelia and conidia. When this biomass was mixed with a carrier (kaolin) and a binder (gum arabic) and the ingredients were granulated and then dried to a moisture content of less than 2%, a biologically active product suitable for application to soil was produced. The fungus grew vigorously from these granules when they were placed on agar and retained its viability when granules were stored in vacuum-sealed bags at 25°C for 12 months. Experiments on tomato in the glasshouse showed that when the formulated product was incorporated into field soil at 10 g granules/liter soil, population densities ofV. chlamydosporiumwere increased to about 10⁴colony-forming units/g soil after 7–14 weeks. Between 37 and 82% of the first generation egg masses produced byMeloidogyne javanicacontained parasitized eggs.     

古尼拟青霉液体发酵液有机粗提物产量的研究

目的:培养基成分对古尼拟青霉液体发酵液有机粗提物产量的影响。方法:采用正交设计方法,考察古尼拟青霉液体发酵培养基3种组分马铃薯、葡萄糖和蛋白胨对其菌丝体与发酵液有机粗提物量的影响。结果:在马铃薯300g/L,蛋白胨8g/L,葡萄糖30g/L时,古尼拟青霉液体发酵液有机粗提物产量可达到136.3mg/L。结论:培养基成分对古尼拟青霉液体发酵有机粗提物产量有显著影响,该文结果对指导古尼拟青霉液体的深层发酵具有参考价值。     

Culture medium improvement for Isaria fumosorosea submerged conidia production

Submerged conidia and blastospores of the entomopathogenic fungus Isaria fumosorosea are produced in several liquid culture media. However, yields and the ecological fitness of these propagules vary according to culture media composition. In most culture media, hyphae, blastospores and submerged conidia are white but we found that in some media they develop a brown pigmentation. A dark pigment was extracted from brown-pigmented propagules and analyzed by IR spectroscopy. Adsorption bands coincided to those characteristics of melanins.Hadamard's matrices were employed in order to increase submerged conidia yields and brown pigmentation of fungal propagules. Media containing 20–30 mg/l of FeSO₄·7H₂O and 6–12 mg/l of CuSO₄·5H₂O allowed reaching the highest pigmentation (9 in a hedonic scale). A maximal concentration of submerged conidia of 1.0 (±1.2) × 10¹² cell/l was achieved after 120 h of liquid culture in a improved culture medium, containing 25 ml/l of Polyethylene glycol (MW 200), substance which enhanced submerged conidia production, reducing free mycelia or mycelial pellets formation. In the improved medium, it was estimated that more than 60% of produced biomass corresponded to submerged conidia and blastospores, while in other media, mycelia were the main product (80–97%).     

桑木层孔菌液体培养条件的研究

对桑木层孔菌(Phellinus mori)液体发酵条件进行了研究,以生物量和胞外多糖为指标,通过L16(45)和L9(34)正交表进行了两次正交试验,筛选出桑木层孔菌最适液体培养条件为:麦芽糖30 g/L,酵母浸粉和蛋白胨15 g/L(质量比2 1),KH2PO4和CaCl25.5 g/L(质量比1 1),初始pH6.0;通过单因素试验筛选出最适装液量为120 mL/250 mL,最适接种量为10%。在此条件下液体发酵培养7 d后,桑木层孔菌生物量达到23.375 g/L,胞外多糖产量达到3.993 g/L。     

白蚁巢上生长的子囊菌——黑柄炭角菌的深层培养及其生理研究

黑柄炭角菌Xylaria nigripes(K1.)Sacc.是著名的滋补药用真菌,尤其是菌核部位生长在白蚁废弃的蚁巢中,生态条件特殊,资源稀少,研究和开发该菌具有重要意义。为了提高黑柄炭角菌菌丝体和多糖的产量,以便于组织工业化生产,本文探索了该菌的营养条件,测定其生长过程中菌丝体和多糖形成的动态变化,并研究了酯酶同工酶谱和多糖含量变化的相关性。结果表明:在深层培养时,碳源以葡萄糖、淀粉最佳;花生、黄豆、蛋白胨是适宜菌丝生长的良好氮源;Mg~(2+),Zn~(2+)等是其生长的必需元素;有机酸中仅柠檬酸对其菌丝生长有促进作用,在蚁酸影响下,pH值为4.0时,菌丝生长受抑制。在上述实验基础上,进行了产多糖和菌丝体的适宜培养基筛选试验,在适宜条件下,能培养出密集、白色、均匀的菌球和丰富的多糖,经4天培养的培养液中粗多糖量可达15.35g/L,菌丝干重为26.89g/L,符合了工业化生产要求。该菌的菌丝体酯酶同工酶谱较稳定,均为二条酶带,但它们的酶活性有所不同,与菌丝体生长的天数有关。并与多糖含量变化具有一定关系。     

飞虱虫疠霉液培菌丝的凝胶化及其杀蚜活性*

用丙烯酰胺淀粉凝胶包埋飞虱虫疠霉(Pandora delphacis)液培菌丝,制成含营养和不含营养的虫霉凝胶,并测试其产孢能力及对桃蚜(Myzus persicae)的侵染力。经持续9 d产孢观察,相同菌丝量条件下,含营养的虫霉凝胶的累计产孢量(1910.9 个/mm2）为不含营养的虫霉凝胶的3.14倍（608.5个/mm2）和对照（纯液培菌丝）的4.69倍（387.5个/mm2）。用虫霉凝胶的“孢子浴”接种桃蚜居群（成蚜与不同龄期若蚜的混合）,在2.23个/mm2的剂量下,接种后第7 d的死亡率达82.3%。结果表明,丙烯酰胺淀粉凝胶作为载体材料,与飞虱虫疠霉的基本生物学特性相容,对虫霉的剂型化具有重要意义