Antifungal property of the essential oils and their constituents from Cinnamomum osmophloeum leaf against tree pathogenic fungi

This study compares the chemical constituents of leaf essential oils from various geographical provenances of Cinnamomum osmophloeum and investigates their antifungal activities against six tree pathogenic fungi. According to GC‐MS and cluster analyses, the leaf essential oils obtained from different geographical provenances and their relative contents were classified into six chemotypes: cinnamaldehyde type, cinnamaldehyde–cinnamyl acetate type, cinnamyl acetate type, linalool type, camphor type, and mixed type. Results from the antifungal tests show that the leaf essential oils of cinnamaldehyde type and cinnamaldehyde–cinnamyl acetate type have excellent inhibitory effect against Rhizoctonia solani, Collectotrichum gloeosporioides, Ganoderma australe and Fusarium solani. Furthermore, among the fourteen constituents of C osmophloeum leaf essential oils, Z‐cinnamaldehyde, eugenol, geraniol and citral display the best antifungal properties. Comparisons of the antifungal properties of Z‐cinnamaldehyde congeners reveal that Z‐cinnamaldehyde exhibits the best antifungal property of this group. Copyright © 2005 Society of Chemical Industry     

固载ClO2保鲜剂对米良猕猴桃腐败菌的抑菌活性

为考察固载Cl O2保鲜剂对米良猕猴桃腐败菌的抑菌效果,通过PDA平板培养法从米良猕猴桃病害组织中分离腐败菌,运用有伤和无伤接种法筛选最强致病力菌株,经形态学及分子生物学鉴定菌株,采用菌丝生长速率测定法考察固载Cl O₂保鲜剂对最强致病力菌株的抑菌效果。结果显示,从米良猕猴桃病害组织中分离出的7种腐败菌中,有3种致病力最强的菌株,经鉴定分别为漆斑菌属（Myrothecium sp.）、茎点菌属（Phoma sp.）和交链孢霉属（Alternaria sp.）;常温下固载Cl O₂保鲜剂对3株菌株均有抑制作用,但都不能完全抑制菌种的生长,抑制活性交链孢霉属>漆斑菌属>茎点菌属;2℃下固载Cl O₂保鲜剂几乎能使3株菌株完全受到抑制。结果表明,固载Cl O₂对米良猕猴桃腐败菌有较好的抑菌效果,可以作为米良猕猴桃的保鲜剂用于降低腐败率。      

含氧硫醚类香料对常见致病菌的体外抑菌活性研究

对11种含氧硫醚类香料的抑菌活性进行研究,并探讨其构效关系。以副溶血性弧菌、金黄色葡萄球菌、大肠杆菌和单增李斯特菌为供试致病菌,通过测量抑菌圈直径考察硫醚类香料的抑菌活性,并通过统计分析探讨结构的影响。结果显示在浓度为5 mol/L的条件下,3-（甲硫基）丙醛（MTPD）、2-甲基-3-甲硫基呋喃（MMTF）、糠基异丙基硫醚（FIPS）和甲基糠基二硫醚（MFDS）对四种致病菌均有抑制作用,且抑菌能力为MTPD>MFDS>或≈FIPS>或≈MMTF。对比11种含氧硫醚类香料的抑菌活性,双（2-甲基-3-呋喃基）二硫醚（BMFDS）对金黄色葡萄球菌的抑制作用最强,MTPD次之,而BMFDS对其他三种致病菌无抑制作用。MTPD对副溶血性弧菌、大肠杆菌和单增李斯特菌的抑制作用均最强,且对副溶血性弧菌的作用效果最佳,其最低抑菌浓度为2.44 mmol/L。以上结果说明,醛基的存在对含氧硫醚类香料抑制副溶血性弧菌、金黄色葡萄球菌、大肠杆菌和单增李斯特菌具有重要作用。      

甜樱桃果实采后病原菌的分离鉴定及植物精油抑菌效果研究

旨在研究甜樱桃果实采后贮藏过程中的病原微生物及其防治技术。以甜樱桃品种‘拉宾斯’为试材,对低温贮藏中的病原菌进行分离鉴定,并研究植物精油及其处理方式对病原菌的抑制效果。根据病原菌形态学特征和18S r DNA序列分析将2个病原菌鉴定为毛霉菌目毛霉菌科毛霉属Mucor sp.和肉座菌亚纲小丛壳科炭疽菌属胶孢炭疽菌Colletotrichum gloeosporioides。筛选出百里香精油和丁香精油对2种病原菌具有较好的抑制效果。百里香精油对Mucor sp.的抑制效果与处理方式无明显关联,但对Colletotrichum gloeosporioides熏蒸处理的抑制效果优于直接接触,该油对2种病原菌直接接触的最小杀菌浓度(MBC)分别为2000μL/L和1000μL/L;丁香精油直接接触对Mucor sp.和Colletotrichum gloeosporioides的抑制效果优于熏蒸处理,该油对2种病原菌直接接触的MBC分别为500μL/L和1000μL/L。      

物理方法对病原真菌及其产毒的防控作用研究进展

农产品受病原真菌侵染发生腐烂变质,失去感官品质、营养品质、商用品质,进而造成严重的经济损失。虽然病原真菌生长和病原真菌产毒是两种不同的生理过程,但是有效的防控措施对两种生理过程均会产生抑制作用。物理防控方法是一种操作简单、无化学污染、绿色的防控手段,某些技术处理农产品后,不仅有效去除病原真菌,抑制其产毒,还可以增强农产品自身组织抗性,起到改善食品品质、贮藏保鲜、延长货架期的作用。本文就应用广泛的热处理、辐射处理、紫外处理等物理技术的应用现状进行综述,并重点阐述了三种物理技术对病原真菌生长及其产毒的防控作用,以期为该领域的研究者提供理论参考。      

野菊花茎叶挥发油的化学成分及其对植物病原真菌抑制作用

用水蒸气蒸馏法提取野菊花茎叶中的挥发油,采用GC-MS联用技术分析其挥发油中的化学成分,并用生长速率法检测其挥发油对5种植物病原真菌的抑菌活性。结果表明,从野菊花茎叶挥发油中分离和鉴定出32种化合物,其挥发油对实验的植物病原真菌均有抑制作用,特别是对油菜菌核病菌的抑制作用更加显著,野菊花茎叶挥发油的浓度为500μg/mL时抑制率高达81.63%。      

抗白色念珠菌海洋真菌的筛选及抑菌活性初探

实验以白色念珠菌为对象,对从渤海湾不同站位分离获得的55株海洋丝状真菌进行了抗真菌活性菌株的筛选。从中筛选得到了BH431、BH515、BH531和BH09721 4株抑菌活性较高的菌株,并进一步对不同浓度发酵液的抑菌活性及代谢物性质进行了检测。结果显示,4株海洋真菌对野生型白色念珠菌SC5314均具有较强抑菌活性,其最小抑菌浓度分别为 65 g/mL、19 g/mL、54 g/mL、23 g/mL;其中BH431和BH515菌株还显示出对基因敲除型菌株RM1000的抑菌活性,最小抑菌浓度分别为 32 g/mL、39 g/mL。4株海洋真菌所产生的活性代谢物具有较好的酸碱适应性,活性物质分子质量＜6 000 u;其中BH431菌株的活性代谢物还具有良好的热稳定性。     

Antifungal activity of plant extracts against Colletotrichum lagenarium, the causal agent of anthracnose in cucumber

BACKGROUND: Colletotrichum lagenarium is an important plant‐pathogenic fungus that causes anthracnose of cucumber, a disease that is widespread under both greenhouse and field cultivation. To find a promising method for the control of this disease, extracts of eight plants from China were screened in the study presented here. RESULTS: The results showed that the extract of Cinnamomum camphora (L.) Presl had significantly greater inhibitory activity against C. lagenarium than the other seven plant extracts tested in vitro. At 5 days after inoculation in a potted seedling experiment, C. camphora extract demonstrated 95% control of C. lagenarium at a concentration of 16 mg mL^?1, and the MIC₅₀ was 2.596 mg mL^?1. Microscopic observation showed that this extract had a significant impact on the morphology of the fungus, leading to shorter hyphae that were more branched; this observation was associated with the inhibition of mycelial growth. Stability assays revealed that the extract was relatively stable at 80 °C, under acidic conditions and when exposed to light and short periods of UV radiation. CONCLUSION: These results demonstrated that the extract from C. camphora could be used as a potent phytochemical fungicide. Copyright © 2012 Society of Chemical Industry     

Chemical,antioxidant and antifungal activities of volatile oil of black pepper and its acetone extract

GC and GC‐MS analysis of volatile oil obtained from Piper nigrum L resulted in the identification of 49 components accounting for 99.39% of the total amount, and the major components were β‐caryophyllene (24.24%), limonene (16.88%), sabinene (13.01%), β‐bisabolene (7.69%) and α‐copaene (6.3%). The acetone extract of pepper showed the presence of 18 components accounting for 75.59% of the total amount. Piperine (33.53%), piperolein B (13.73%), piperamide (3.43%) and guineensine (3.23%) were the major components. The oil was found to be 100% effective in controlling the mycelial growth of Fusarium graminearum in inverted petriplate technique. The acetone extract retarded 100% mycelial growth of Penicillium viridcatum and Aspergillus ochraceus in food‐poisoning technique. Volatile oil and acetone extract were identified as a better antioxidant for linseed oil, in comparison with butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). Copyright © 2004 Society of Chemical Industry     

天然植物粗提物对蓝莓贮运病菌的抑制效果

为了筛选出对蓝莓鲜果贮运有较好应用保鲜效果的天然保鲜剂,采用牛津杯法开展21种植物粗提物对蓝莓贮藏中分离的3种病原真菌和物流中常见2种食源性致病细菌的抑菌活性的研究,并确定其最低抑菌浓度(MIC)和最低杀菌浓度(MBC),研究提取液浓度变化对病原菌抑制率的影响和进行提取液复配抑菌实验。结果表明:丁香提取物对真菌的抑制能力表现最强,对灰霉、链格孢霉和青霉的平均抑菌圈直径分别为47.58、39.68和40.54 mm,对这3种真菌的MIC分别为15.63、31.25、31.25 mg/m L,MBC分别为31.25、62.5和62.5 mg/m L;五味子提取物对金黄色葡萄球菌和大肠杆菌的抑菌效果最强,对这2种细菌的平均抑菌圈直径分别为42.08、28.49 mm,MIC分别为31.25、62.5 mg/m L,MBC分别为62.5、125 mg/m L。丁香和五味子提取液浓度梯度的变化对不同病原菌抑制率的影响存在差异,高浓度变化影响较大,丁香和五味子复配液比例大于5∶5可作为较佳的蓝莓贮运保鲜复配应用参考。      

In vitro and in vivo antifungal activity of a water-dilutable cassia oil microemulsion against Geotrichum citri-aurantii

BACKGROUND: Recently, food‐grade microemulsions have been of increasing interest to researchers and have shown great potential in industrial applications. In this study a food‐grade water‐dilutable microemulsion system with cassia oil as oil, ethanol as cosurfactant, Tween 20 as surfactant and water was developed and its antifungal activity in vitro and in vivo against Geotrichum citri‐aurantii was assessed. RESULTS: The phase diagram results confirmed the feasibility of forming a water‐dilutable microemulsion based on cassia oil. One microemulsion formulation, cassia oil/ethanol/Tween 20 = 1:3:6 (w/w/w), was selected with the capability to undergo full dilution with water. The average particle size was 6.3 nm. The in vitro antifungal experiments showed that the microemulsion inhibited fungal growth on solid medium and prevented arthroconidium germination in liquid medium and that cassia oil had stronger activity when encapsulated in the microemulsion. The in vivo antifungal experiments indicated that the water‐dilutable microemulsion was effective in preventing postharvest diseases of citrus fruits caused by G. citri‐aurantii. CONCLUSION: The results of this study suggest a promising utilisation of water‐dilutable microemulsions based on essential oils for the control of postharvest diseases. Copyright © 2012 Society of Chemical Industry     

Stimulating effect of sorbitol and xylitol on germination and growth of some xerophilic fungi

Sorbitol and xylitol are polyols often used in foods as naturally occurring sugar substitutes. They provide sweet taste and reduced calories in products of intermediate moisture. This type of food is susceptible to spoilage by xerophilic molds which affect shelf life of foods and produce significant losses. The aim of the present work was to study the effect of glycerol, sorbitol and xylitol on the germination and growth of four xerophilic fungi at different temperatures and water activity levels. Penicillium chrysogenum, Wallemia sebi, Eurotium chevalieri and Eurotium repens were cultivated on malt extract agar with the addition of the respective polyols and a_w adjusted to 0.85, 0.88, 0.90 and 0.93. Incubation was made at 25, 30 and 35 °C. Results of the present study demonstrated that sorbitol and xylitol affect the growth kinetics of the four fungal species. The observed tendency was that these solutes shortened the germination times and increased the growth rates. The effect of each solute depended on the fungal species and the a_w/temperature combinations. At lower a_w the influence was more evident on the germination times while the effect on growth rates was more pronounced at higher a_w levels.     

Cow and camel milk-derived whey and casein protein hydrolysates demonstrated effective antifungal properties against selected Candida species

Bioactive peptides derived from milk proteins are widely known to possess antibacterial activities. Even though the antibacterial effects of milk-derived peptides are widely characterized, not much focus is given to their antifungal characterization. Therefore, in this study, we investigated the antifungal properties of camel and cow whey and casein hydrolysates against various species of pathogenic Candida. The hydrolysates were produced using 2 enzymes (alcalase and protease) at differing hydrolysis durations (2, 4, and 6 h) and tested for their antifungal properties. The results showed that intact cow whey and casein proteins did not display any anti-Candida albicans properties, whereas the alcalase-derived 2 h camel casein hydrolysate (CA-C-A2) displayed a higher percentage of inhibition against Candida albicans (93.69 ± 0.26%) followed by the cow casein hydrolysate generated by protease-6 h (Co-C-P6; 81.66 ± 0.99%), which were significantly higher than that of fluconazole, a conventional antifungal agent (76.92 ± 4.72%). Interestingly, when tested again Candida krusei, camel casein alcalase 2 and 4 h (CA-C-A2 and CA-C-A4), and cow whey alcalase-6 h (CO-W-A6) hydrolysates showed higher antifungal potency than fluconazole. However, for Candida parapsilosis only camel casein alcalase-4 h (Ca-C-A4) and cow casein protease-6 h (Co-C-P6) hydrolysates were able to inhibit the growth of C. parapsilosis by 19.31 ± 0.84% and 23.82 ± 4.14%, respectively, which was lower than that shown by fluconazole (29.86 ± 1.11%). Overall, hydrolysis of milk proteins from both cow and camel enhanced their antifungal properties. Camel milk protein hydrolysates were more potent in inhibiting pathogenic Candida species as compared with cow milk protein hydrolysates. This is the first study that highlights the antifungal properties of camel milk protein hydrolysates.     

蜂胶乙酸乙酯提取物对意大利青霉菌的抑制作用及稳定性研究

本实验以青霉属的意大利青霉菌(Penicillium italicum)为研究材料,研究蜂胶不同溶剂提取物对意大利青霉菌的抑制作用及其对温度和pH 值的稳定性的影响。结果表明,乙酸乙酯提取物和乙醇提取物活性最高,氯仿提取物次之,石油醚提取物和水提取物活性最弱。提取物的抑菌活性与提取物中的黄酮含量和总酚呈显著正相关。乙酸乙酯提取物对意大利青霉的孢子萌发具有同样的抑制作用。蜂胶乙酸乙酯提取物溶液分别经过25、35、50、70、100℃的温度处理后其抑菌活性没有明显差异;在pH3.6～7.6 的范围内,随着pH 值的升高,提取物的抑菌活性先升高后降低,于pH5.2 时抑制率最高,pH4.4 时次之。这表明该蜂胶提取物能够有效的抑制意大利青霉的生长,在采后柑橘的防腐保鲜中具有良好的应用前景。     

三种海藻内生真菌的分离及其抑菌活性研究

从烟台浅海处采集到的鼠尾藻、裙带菜、海带三种海藻表面消毒后用PDA培养基将内生真菌进行分离纯化,将纯化的内生真菌进行液体培养7d后离心,菌丝体烘干研磨后用无水乙醇提取,分别测定发酵液和菌丝体乙醇提取物对七种植物病原真菌的抑菌活性。结果表明:三种发酵液都至少对三种病原菌有大于50%的抑菌活性,裙带菜发酵液对六种病原菌都有大于50%的抑菌率,最高为78.8%,说明它们能产生广谱高效的胞外代谢产物;而菌丝体提取物的抑菌活性并不明显,说明三种海藻内生真菌产生的胞内代谢产物无明显的抑菌活性。     

In vitro and in vivo antifungal properties of cysteine proteinase inhibitor from green kiwifruit

BACKGROUND: Higher plants possess several mechanisms of defense against plant pathogens. Proteins actively synthesized in response to those stresses are called defense‐related proteins which, among others, include certain protease inhibitors. It is of particular relevance to investigate plant natural defense mechanisms for pathogen control which include cystatins—specific inhibitors of cysteine proteases. RESULTS: In this study, a cysteine proteinase inhibitor (CPI), 11 kDa in size, was purified from green kiwifruit to homogeneity. Immuno‐tissue print results indicated that CPI is most abundant in the outer layer of pericarp, near the peel, and the inner most part of the pulp—sites where it could act as a natural barrier against pathogens entering the fruit. The purified protein (15 µmol L^?1) showed antifungal activity against two phytopathogenic fungi (Alternaria radicina and Botrytis cinerea) by inhibiting fungal spore germination. In vivo, CPI (10 µmol L^?1) was able to prevent artificial infection of apple and carrot with spore suspension of B. cinerea and A. radicina, respectively. It also exerted activity on both intracellular and fermentation fluid proteinases. CONCLUSION: Identification and characterization of plant defense molecules is the first step towards creation of improved methods for pathogen control based on naturally occurring molecules. Copyright © 2012 Society of Chemical Industry     

抗食源性病原菌细菌素的筛选及特性研究

目的 筛选一种抗食源性病原菌的细菌素,并对其稳定性进行研究.方法 以食源性病原菌Bacillus cereus ATCC 14579、Listeria monocytogenes LM201、Listeria monocytogenes LM605为指示菌,采用琼脂扩散法筛选细菌素产生菌,通过离子交换树脂法和高效液相色...