光、温、激素对烟草种子萌发和幼苗生长的影响

本文以4个烟草品种为材料,研究了激素、光、温对烟草种子萌发和幼苗生长的影响。光能明显加速烟草萌发,但对最终发芽率影响不大;红光、蓝光均能明显加速烟草萌发;光抑制烟草幼苗茎伸长,促进根伸长。烟草种子萌发的适宜温度为20~25℃;在10~30℃范围内,提高温度会促进幼苗生长。低浓度的茉莉酸甲酯(1×10-7mol/L~1×10-6mol/L)能明显加速烟草种子萌发,10-4mol/L以上浓度抑制种子萌发;适宜浓度的24-表油菜素内酯(0.01~0.1mg/L)也能促进烟草种子萌发,赤霉酸能明显促进烟草幼苗生长,其对茎伸长的促进效应明显强于对根伸长的促进效应,K346对GA₃最敏感。      

Control of meatborne Listeria monocytogenes and Brochothrix thermosphacta by a bacteriocinogenic Brochothrix campestris ATCC 43754

The effect of a bacteriocinogenic Brochothrix campestris ATCC 43754 upon the growth of Brochothrix thermosphacta and a 4 strain mixture of Listeria monocytogenes was determined in All Purpose Tween (APT) broth and on pork adipose tissue discs at 4 degrees C. Inocula were prepared to give initial numbers of B. campestris of 6-7 log cfu/ml or cm(2) and 3-4 log cfu/ml or cm(2) of B. thermosphacta and L. monocytogenes. Adipose tissue discs were evaluated by a sensory panel to determine the intensity and acceptability of any off-odours produced during the growth of B. campestris. During co-culture in APT broth with B. campestris the growth of B. thermosphacta or L. monocytogenes was 4 log cycles less than growth in its absence. B. campestris showed limited growth on inoculated pork adipose tissue, increasing from initial numbers of about 6 log cfu/cm(2) to a maximum of 7 log cfu/cm(2) within 7d. B. campestris at numbers of 7 log cfu/cm(2) produced slight off-odours but these were not perceived by the panel as unacceptable. When co-inoculated on adipose tissue discs with B. campestris the numbers of B. thermosphacta or L. monocytogenes was limited to about 2-3 log units less than the numbers attained in its absence. B. campestris ATCC 43754 may be useful for meat preservation because it can inhibit B. thermosphacta and L. monocytogenes in situ while producing little change in the sensory properties of the product.     

不同高粱品种酿造酱香型白酒发酵特性的研究

通过模拟发酵实验,选用米曲霉（Aspergillus oryzae）XJDJQM03作为糖化菌株,考察菌株XJDJQM03在发酵过程对不同高粱品种淀粉的降解、利用产葡萄糖的效果,并探讨了酿酒酵母（Saccharomyces cerevisiae）YM1、YM2的发酵特性及对不同高粱品种发酵的利用。结果表明,米曲霉XJDJQM03在酿造过程对糯高粱淀粉的利用不如粳高粱,其在粳高粱样品发酵中的生物量（3.65～4.11 g/L）明显高于糯高粱样品（3.12～3.45 g/L）,贵州仁怀产红缨子糯高粱B2发酵样中的葡萄糖产量最高（168.78 mg/L）,代谢分泌水解糖化酶较多。酿酒酵母YM1对贵州仁怀产红缨子糯高粱B2发酵更具有优势,更利于酿酒酵母生长（0.80×108 CFU/mL）和代谢产乙醇（39.2 g/L）。     

Riboflavin and lumichrome in Dalmatian sage honey and other unifloral honeys determined by LC-DAD technique

Riboflavin (vitamin B(2)) and its metabolite lumichrome were quantified in 117 samples from 11 unifloral honeys types (Arbutus unedo L., Asphodelus microcarpus Salzm. et Viv., Citrus spp., Eucalyptus spp., Hedysarum coronarium L., Castanea sativa L. honeydew, Mentha spp., Paliurus spina-christi., Salix spp., Salvia officinalis L., Satureja spp.). The quantification of these two compounds was performed by LC-DAD method which does not require sample purification. The proposed method in our study has low limits of detection and quantification, very good linearity in a large concentration range and very good precision. It allows simultaneous determination of 5-hydroxymethylfurfural (HMF) and known chemical biomarkers of unifloral honeys such as abscisic acid diastereomers, homogentisic acid, methyl syringate and kynurenic acid. No statistical correlation was observed between riboflavin and lumichrome content. Although, the concentration of vitamin B(2) in honey may be too low (<6.1mg/kg) to generate interest in the field of nutrition, the presence of its main metabolite lumichrome may be useful to determine the botanical origin of certain unifloral honeys. In fact, the analysis of 11 unifloral honey types showed that Dalmatian sage (S. officinalis L.) honey is characterised by unusual high levels of lumichrome (20.2±2.6mg/kg). The botanical origin of lumichrome from sage flower was assessed by analysing bee-stomach extracts. Other analytical parameters, such as total phenols, antioxidant and antiradical activities, HMF and diastase activity were studied in Dalmatian sage honey.     

两种微生物水解脱淀粉小麦中蛋白效果的比较研究

为研究枯草芽孢杆菌（Bacillus subtilis）和米曲霉（Aspergillus oryzae）对脱淀粉小麦中蛋白质的水解效果,采用前发酵和后发酵获得发酵液,比较两种微生物培养过程中性蛋白酶活力和发酵液的pH值、可溶性无盐固形物、氨基酸态氮含量、氨基酸组成,并对其发酵液进行感官评价。结果表明,在最适前发酵工艺的条件下,枯草芽孢杆菌和米曲霉中性蛋白酶活力分别为1 060.82 U/g和908.02 U/g;两种微生物最终发酵液pH值为7.08和5.37,可溶性无盐固形物为15.60%和18.98%,氨基酸态氮含量为0.73 g/100 mL和0.75 g/100 mL,总游离氨基酸含量为4.35 mg/mL和9.04 mg/mL,蛋白质水解度为55.99%和59.71%。枯草芽孢杆菌发酵液中必需氨基酸的组成和比例更符合氨基酸模式谱,必需氨基酸与总游离氨基酸的比值（EAA/TAA）、必需氨基酸与非必需氨基酸（EAA/NEAA）的比值也高于米曲霉。感官评价结果显示,米曲霉发酵液好于枯草芽孢杆菌。     

Evaluation of Chenopodium ambrosioides oil as a potential source of antifungal, antiaflatoxigenic and antioxidant activity

Essential oil extracted from the leaves of Chenopodium ambrosioides Linn. (Chenopodiaceae) was tested against the aflatoxigenic strain of test fungus Aspergillus flavus Link. The oil completely inhibited the mycelial growth at 100 microg/ml. The oil exhibited broad fungitoxic spectrum against Aspergillus niger, Aspergillus fumigatus, Botryodiplodia theobromae, Fusarium oxysporum, Sclerotium rolfsii, Macrophomina phaseolina, Cladosporium cladosporioides, Helminthosporium oryzae and Pythium debaryanum at 100 microg/ml. The oil showed significant efficacy in inhibiting the aflatoxin B1 production by the aflatoxigenic strain of A. flavus. During in vivo investigation it protected stored wheat from different storage fungi for one year. Chenopodium oil also exhibited potent antioxidant activity when tested by ABTS method. All these observations suggest the possible exploitation of the Chenopodium oil as potential botanical fungitoxicant in ecofriendly control of post harvest biodeterioration of food commodities from storage fungi.     

山茱萸总苷的分离及抑菌活性研究

实验探讨了大孔吸附树脂Diaion HP20富集纯化山茱萸总苷的工艺条件和山茱萸总苷的抑菌活性。结果表明,大孔吸附树脂Diaion HP20最优吸附条件为:上样液取自然pH值,盐离子浓度0.5mol/L、上样液浓度2.55mg/ml、上样量6BV。吸附完全后,用4BV去离子水以1.5ml/min的流速除去水溶性杂质,再用6BV30%乙醇解吸,可以较好地分离山茱萸总苷。通过抑菌实验,发现山茱萸总苷对金黄色葡萄球菌、绿脓杆菌、白菜软腐病菌、姜瘟病菌、柑桔溃疡病菌都有较明显的抑制效果。     

Assessment of contamination potential of lettuce by Salmonella enterica serovar Newport added to the plant growing medium

The capacity of Salmonella enterica serovar Newport to contaminate Romaine lettuce (Lactuca sativa L. cv. Nogal) via the root system was evaluated in 17-, 20-, and 33-day-old plants. Apparent internalization of Salmonella via the root to the above-ground parts was identified in 33- but not 17- or 20-day-old plants and was stimulated by root decapitation. Leaves of lettuce plants with intact and damaged roots harbored Salmonella at 500 +/- 120 and 5,130 +/- 440 CFU/g of leaf, respectively, at 2 days postinoculation but not 5 days later. These findings are first to suggest that Salmonella Newport can translocate from contaminated roots to the aerial parts of lettuce seedlings and propose that the process is dependent on the developmental stage of the plant.     

米曲霉液态发酵香菇残次品产蛋白酶条件优化

为了充分综合利用香菇资源，该研究以米曲霉（Aspergillus oryzae）为发酵菌种，对香菇残次品进行液态发酵，以蛋白酶活为响应值，采用单因素试验和响应面法优化米曲霉产蛋白酶发酵条件。结果表明，米曲霉产蛋白酶的最优发酵条件为发酵时间3 d、料液比1∶10（g∶mL）、初始pH值6.5、转速175 r/min，在此优化条件下，蛋白酶活力为1 182.48 U/mL。     

Dietary exposure to aflatoxin in Benin City, Nigeria: a possible public health concern.

A total of 100 samples of various foods comprising of 10 samples each of garri (Manihot utilis Pohl), beans (Phaseolus lunatus), yam flour (Dioscorea rotundata), cassava flour (Manihot esculentum), melon (Citrulus lunatus), onion (Allium cepa), rice (Oryza sativa), plantain (Musa paradisiaca), red pepper (Capsicum annuum L., Solanaceae) and eggs were screened for the presence of aflatoxins. Fifty percent of yam flour; 40% of cassava flour; 30% of garri; 20% of beans and melon and 10% of rice yielded aflatoxin. The implications of this incidence of aflatoxin in common foodstuff found in this community is discussed.     

薏苡仁在曲霉发酵过程中成分及抗氧化性变化的研究

研究以黑曲、米曲、红曲分别发酵薏苡仁,然后对发酵液中多肽、总糖、多酚、DPPH 自由基清除率进行测定,以考察不同曲霉发酵过程中,薏苡仁发酵液中的各种物质含量及抗氧化性变化。结果表明：发酵过程中多肽含量、总酚含量、蛋白质水解度、DPPH 自由基清除率都随着发酵时间的延长而不断增加。以黑曲霉发酵时各指标分别达到6.14mg/ml、0.10mg/ml、24.9%、10.2%;以米曲霉发酵时各指标分别达到2.58mg/ml、0.089mg/ml、31.1%、10.4%;以红曲霉发酵时各指标分别为2.93mg/ml、0.086mg/ml、14.7%、18.9%。发酵过程中总糖的含量黑曲霉组、米曲霉组均上升,各达到84.0mg/ml、76.1mg/ml;而红曲霉发酵后总糖含量下降明显,降至8.5mg/ml。     

米曲霉处理酒精废液积累菌丝体蛋白的工艺研究

以从酒精废液中筛选的米曲霉为特定微生物,进行了酒精废液处理的同时积累菌丝体蛋白的研究.结果表明:在酒精废液中添加0.25％葡萄糖,0.05％酵母膏,0.05％硫酸镁和0.05％磷酸二氢钾,pH值为5.0,接种量10％,转速160r/min发酵后COD达到142mg/mL,菌丝体干重达到26.5g/L.此方法可作为酒精废液资源化的处理工艺.     

柱前衍生-反相高效液相色谱法检测富硒米曲霉中有机硒形态

建立高效液相色谱法测定富硒米曲霉中有机硒形态的分析方法。采用6 mol/L HCl溶液,50 ℃水解富硒米曲霉48 h,提取样品中的有机硒,4-氯-3,5-二硝基三氟甲苯柱前衍生,C18反相色谱柱（4.6 mm×250 mm,5 μm）分离,以乙腈-水（1∶1,V/V）和pH 6.8乙酸-乙酸钠缓冲液为流动相进行梯度洗脱,紫外检测波长：240 nm,测得富硒米曲霉中有机硒化合物主要是硒代胱氨酸,检出限（RSN=3）为0.680 mg/L,定量限（RSN=10）为2.244 mg/L,线性范围为5.0～100 mg/L,加标回收率为94.8%～105.8%,硒代胱氨酸的含量为1.25 mg/g。本方法简单、灵敏、重复性好,可适用于富硒米曲霉及相关产品中有机硒形态的检测分析。     

花生根系分泌物自毒作用研究

采用连续收集法提取花生植株的根系分泌物,就其对花生种子发芽、幼苗生长、细胞膜的过氧化、抗氧化酶系统的影响等进行了研究,旨在探讨花生是否存在自毒作用。结果表明,花生根系分泌物的中性、酸性和碱性组分显著抑制了胚根的生长（P〈0.01）,随添加浓度的增加抑制作用逐渐增强,其中,中性组分的抑制作用最强。经过20d的处理,3种组分对花生幼苗的生长均表现出显著的化感抑制作用（P〈0.05）,作用规律与对胚根的抑制作用相似,在中性组分最高添加浓度30 mg/L处理下,株高、地上部鲜重、根系鲜重分别为对照的80%、73%和66%。叶片中SOD和POD的活性显著提高（P〈0.01）,MDA的含量也显著增加（P〈0.001）。3种组分中中性组分的化感促进作用最强,其次是酸性组分,碱性组分的作用相对最弱。研究结果证明了花生根系分泌物自毒作用的存在,是导致花生连作障碍的原因之一。     

根癌农杆菌介导的尖孢镰刀菌遗传转化体系构建

  背景和目的  尖孢镰刀菌（Fusarium oxysporum）可引起烟草镰刀菌根腐病（Fusarium root rot of tobacco）,为明确病原菌致病相关基因。  方法  以烟草强致病性尖孢镰刀菌菌株B-9-1的分生孢子为受体,利用携带潮霉素B（hygromycin B,hyg）质粒的根癌农杆菌（Agrobacterium tumefaciens）介导转化,获得能够稳定表达绿色荧光蛋白（green fluorescent protein, GFP）的尖孢镰刀菌转化菌株,构建烟草尖孢镰刀菌遗传转化体系。  结果  （1）尖孢镰刀菌的最优转化体系为:潮霉素B最适质量浓度50 μg/mL,在25℃条件下,以1 cm宽的条形硝酸纤维膜为载体,将携带有pCAM-GFP-hyg质粒的根癌农杆菌摇菌培养至OD₆₀₀=0.7,与震荡培养24 h获得的浓度为106个/mL的尖孢镰刀菌分生孢子悬浮液在含有200 μmol/L乙酰丁香酮的共培养基上共培养48 h。（2）转化子继代培养、PCR检测和荧光显微观察结果表明外源GFP基因成功整合到烟草尖孢镰刀菌基因组中并可以进行稳定遗传表达。（3）Sourthern blot分析结果进一步证明T-DNA成功整合到尖孢镰刀菌基因组中,且60%以上为单拷贝插入。  结论  本研究成功构建了根癌农杆菌介导的烟草尖孢镰刀菌遗传转化体系,为烟草尖孢镰刀菌基因功能及病原菌的致病机制研究提供基础。      

响应面法优化米曲霉液体发酵生产中性蛋白酶工艺

为提高米曲霉（Aspergillus oryzae）液体发酵生产中性蛋白酶的能力,采用单因素试验、Plackett-Burman（PB）试验筛选碳源、氮源和无机盐,并通过响应面法优化其最佳配比,提高米曲霉液体发酵生产中性蛋白酶的活性。结果表明,米曲霉液体发酵生产中性蛋白酶的最佳碳源、氮源和无机盐分别为玉米粉、牛肉膏和氯化钙,发酵的最优条件为玉米粉添加量17 g/L,牛肉膏添加量10 g/L,氯化钙添加量0.04 g/L,接种量5%,装液量60 mL/250 mL,于30 ℃条件下发酵84 h。在此优化条件下,产生的中性蛋白酶活性从最初的21.4 U/mL提高至110.5 U/mL。     

山茱萸总皂甙的抑菌作用研究

以山茱萸为原料,进行山茱萸总皂甙对几种常见的食品腐败菌和致病菌的抑菌作用进行了研究。试验结果表明,山茱萸总皂甙对细菌尤其是金黄色葡萄球菌的抑制效果明显,对酵母菌和霉菌的抑制效果较差;山茱萸总皂甙对金黄色葡萄球菌的最低抑菌浓度为24.82mg/ml;山茱萸总皂甙的最佳抑菌pH为3且山茱萸总皂甙的热稳定性好,在121℃,处理25min仍保持较好的抑菌活性。     

河南烟草镰刀菌的分子鉴定及致病性分析

为明确河南省不同烟叶产区危害烟草的镰刀菌种类,以河南省烟叶产区典型镰刀菌根腐病烟株及烟田土壤为供试样品,采用组织分离法和土壤分离法获得纯化菌株,根据菌株形态和rDNA-ITS序列分析对病原菌进行鉴定,并采用无创接种法测定病原菌对烟草的致病性。结果表明,获得的98个菌株在PDA培养基上均产生白色菌丝,大型分生孢子呈镰刀形或马特形,无色、多孢;小型分生孢子呈肾形、椭圆形或卵形,无色、多无分隔。序列比对结果显示,所分离的98株菌分属尖孢镰刀菌（Fusarium oxysporum）、茄病镰刀菌（Fusarium solani）、层出镰刀菌（Fusarium proliferatum）、木贼镰刀菌（Fusarium equiseti）和Fusarium nematophilum。致病性分析结果表明,尖孢镰刀菌、茄病镰刀菌、层出镰刀菌和木贼镰刀菌对烟苗具有致病性;48株致病菌中豫南烟区烟草镰刀菌根腐病致病性病原菌为尖孢镰刀菌、层出镰刀菌和木贼镰刀菌,以尖孢镰刀菌为主;豫中为尖孢镰刀菌;豫东、豫西为茄病镰刀菌和尖孢镰刀菌。因此,尖孢镰刀菌为全省烟区重点防控对象,豫南烟区还需加强层出镰刀菌和木贼镰刀菌的防控,豫东、豫西需防范茄病镰刀菌的发生。      

Antimycotoxigenic characteristics of Rosmarinus officinalis and Trachyspermum copticum L. essential oils

Aflatoxin B1 (AFB1) is a highly toxic and carcinogenic metabolite produced by Aspergillus species on food and agricultural commodities. Natural products may regulate the cellular effects of aflatoxins and evidence suggests that aromatic organic compounds of spices can control the production of aflatoxins. With a view to controlling aflatoxin production, the essential oils from Rosmarinus officinalis and Trachyspermum copticum L. were obtained by hydrodistillation. Antifungal activities of the oils were studied with special reference to the inhibition of Aspergillus parasiticus growth and aflatoxin production. Minimal inhibitory (MIC) and minimal fungicidal (MFC) concentrations of the oils were determined. T. copticum L. oil showed a stronger inhibitory effect than R. officinalis on the growth of A. parasiticus. Aflatoxin production was inhibited at 450 ppm of both oils with that of R. officinalis being stronger inhibitor. The oils were analyzed by GC and GC/MS. The major components of R. officinalis and T. copticum L. oils were Piperitone (23.65%), alpha-pinene (14.94%), Limonene (14.89%), 1,8-Cineole (7.43%) and Thymol (37.2%), P-Cymene (32.3%), gamma-Terpinene (27.3%) respectively. It is concluded that the essential oils could be safely used as preservative materials on some kinds of foods to protect them from toxigenic fungal infections.     

柑橘皮渣液态发酵制取曲酸工艺优化

以柑橘皮渣为原料,接种米曲霉,以液态摇瓶发酵的形式进行曲酸生产的研究。采用Box-Behnken中心组合设计,通过响应面法优化柑橘皮渣发酵的最佳工艺。结果表明,最佳发酵参数为米曲霉接种量4%、柑橘皮渣添加量13 g/100 mL、酵母膏添加量1.5 g/100 mL、MgSO4·7H2O添加量0.05 g/100 mL,在此条件下发酵制得的曲酸质量浓度最高,为（11.84±1.44） mg/mL。