Inhibition of Chlamydospore Germination and Mycelial Growth of Trichoderma spp. by Chemical Fungicides

For exploring the influences of application and residue of chemical fungi- cides on chlamydospore preparations of Trichoderma spp., the effects of seven chemical fungicides on chlamydospore germination and mycelia growth of two bio- control fungi T. harzianum 610 and T. Iongibrachiatum 758 were studied. Carben- dazim, tebuconazole and difenoconazole showed strong toxicities, thiram and car- bexin showed moderate toxicities, and metalaxyl showed Mycelia growth of the two strains was more sensitive to most tested fungicides than those of chlamydospore germination. Chlamydospore germination of 610 was more sensitive to tested fungicides than those of 758, and mycelia growth of 758 was more sensitive to most tested fungi- cides than those of 610. Among the seven fungicides, 98% carbendazim had the strongest effects （ECru values were 1.64 and 0.05μpg/ml）, and 70% pentachloroni- trobenzene had the weakest effects （EC50 values were 1.64 and 0,05 μg/ml） for chlamydospore germination and mycelia growth of 610. As for 758, 98% carbendaz- im had the strongest inhibitory effects and 95% metalaxyl had the weakest inhibitory for chlamydospore germination of 756 （EC50 values were 0.62 and 1 108.61 μg/ml respectively）, whereas 96.2% tebuconazole showed the strongest inhibitory effects for mycelia growth of 758 （EC= value was 0.32μg/ml）, and 95% metalaxyl was the weakest （EC= value was 1 206.29 μg/ml）. According to the applied concentration of different fungicides in practice, we concluded that chlamydospore preparations of 610 and 758 could not be combined with carbendazim, tebuconazole, thiram and carboxin for controlling plant diseases, and the pesticide residues to the biocontrol effects should be kept in mind. Chlamydospore preparations of 610 and 758 can be and difenoconazole for controlling plant dis- eases, 758 chlamydospore preparations and germinated chlamydospore of 610 can be combined with metalaxyl for controlling plant diseases, and pesticide residue risk was not serious.

中西医结合治疗复发性口疮

1993年至1996年对门诊105例复发性口疮(RAu)应用中西医结合方法治疗,收到了满意的疗效,现报道如下。1 一般资料 本组男36例,女69例,年龄最大60岁,最小12岁;50～60岁22例,30～49岁53例,12～29岁30例。病程1～3天30例,4～6天56例,7天以上19例。均为浅表性口腔溃疡,再次复发。

Bactericidal and anti-adhesive properties of culinary and medicinal plants against Helicobacter pylori

AIM： To investigate the bactericidal and anti-adhesive properties of 25 plants against Helicobacter pylori （H pylon）. METHODS： Twenty-five plants were boiled in water to produce aqueous extracts that simulate the effect of cooking. The bactericidal activity of the extracts was assessed by a standard kill-curve with seven strains of H pylori. The anti-adhesive property was assessed by the inhibition of binding of four strains of FITC-labeled Hpylori to stomach sections. RESULTS： Of all the plants tested, eight plants, including Bengal quince, nightshade, garlic, dill, black pepper, coriander, fenugreek and black tea, were found to have no bactericidal effect on any of the isolates. Columbo weed, long pepper, parsley, tarragon, nutmeg, yellow-berried nightshade, threadstem carpetweed, sage and cinnamon had bactericidal activities against Hpylori, but total inhibition of growth was not achieved in this study. Among the plants that killed H pylori, turmeric was the most efficient, followed by cumin, ginger, chilli, borage, black caraway, oregano and liquorice. Moreover, extracts of turmeric, borage and parsley were able to inhibit the adhesion of H pylori strains to the stomach sections. CONCLUSION： Several plants that were tested in our study had bactericidal and/or anti-adhesive effects on Hpylori. Ingestion of the plants with anti-adhesive properties could therefore provide a potent alternative therapy for H pylori infection, which overcomes the problem of resistance associated with current antibiotic treatment.

Studies on characteristics of nanostructure of N-TiO_2 thin films and photo-bactericidal action

Pseudomonas aeruginosa strain （AS 1.50） and Bacillus subtilis strain （AS 1.439） from Ming lake were decomposed by photocatalytic nanostructure N-TiO2 thin films in a photo-reactor under UV irradiation. The different thickness nanostructure N-TiO2 thin films coated on mesh grid were prepared by sol-gel method and immobilized at 500 ℃ （films A） or 350 ℃ （films B） for 1 h in a muffle furnace. The results showed that N-TiO2 thin film B （8.18 nm thickness, 2.760 nm height and 25.15 nm diameter） has more uniform granular nanostructure and thinner flat texture than N-TiO2 thin film A （12.17 nm thickness, 3.578 nm height and 27.50 nm diameter）. The bactericidal action of N-TiO2 thin film A and film B for Pseudomonas aeruginosa strain （AS 1.50） and Bacillus subtilis varniger strain （AS1.439） were investigated in this work. More than 95% of photocatalytic bactericidal efficiency for Pseudomonas aeruginosa strain （AS 1.50） and 75% for Bacillus subtilis strain （AS 1.439） were achieved by using N-TiO2 thin films-B for 70-80 rain of irradiation during the photo-bactericidal experimental process. The results indicated that the photo-induced bactericidal efficiency of N-TiO2 thin films probably depended on the characteristics of the films.

Adsorption and Insecticidal Activity of Toxin from Bacillus thuringiensis on Rectorite

The adsorption and desorption of the toxin from Bacillus thuringiensis strain WG-001 on rectorite were studied at different toxin and/or rectorite concentrations, pH values and temperatures. The insecticidal activity of the adsorbed toxin was evaluated by determining the lethal concentration to kill 50% of the larvae of Heliothis armigera （LC50）. The adsorption of the toxin on rectorite in sodium carbonate buffer （pH 9） reached equilibrium within 0.5-1.0 h and the adsorption isotherm of the toxin followed the Langmuir equation （R^2 〉 0.99）. In the pH range from 9 to 11 （carbonate buffer）, the adsorbed toxin decreased with increasing pH. The adsorption amounts decreased with increasing rectorite：toxin ratio. The adsorption was not significantly affected by the temperature between 10 and 50 ℃. The X- ray diffraction analysis indicated occurrence of the intercalation of the rectorite by the toxin. The infrared absorption spectrum showed that the binding of the toxin did not alter its structure. The LC50 wlues of the adsorbed toxin were smaller than those of the free toxin. The rectorite protected the toxin from ultraviolet irradiation damage. The desorption of the adsorbed toxin in water ranged from 37.5% to 56.4% and from 27.4% to 41.8% in a carbonate buffer. The desorption percentage also decreased with increasing rectorite：toxin ratio.

The Biological Activity of Some Bacteria as Biocides to Protect Sesame Crop （Sesamum indicum） from Fungi Diseases

Two experiments were conducted during 2006-2007 in Complete Randomized Design （CRD） to test the biological activity of Pseudomonas bacteria as biocides to protect sesame crop from some fungi and to evaluate its efficiency as plant growth promoting First experiment investigated the effects of Pseudomonas putida2 and Pseudomonas fluorescens3 on germination and seedlings growth of sesame crop against Pythium, Alternaria and Fusarium under plastic house conditions. Second experiment conducted in large pots to investigate the effects of the two bacterial isolates on some morphological, productive and physiological characters of sesame plants against same fungi under normal conditions. Results showed very low germination and slowly seedlings growth in Pythium, Fusarium and Alternaria treatments respectively, but adding bacterial vaccine of Pseudomonas putida2 and Pseudomonas fluorescens3 as a Biocide to fungi treatments, increased the germination percent and seedlings growth of sesame crop significantly, 20 days after planting compared with control treatment. In the second experiment, control treatment scored germination by 52%, while vaccines of Pseudornonas putida2 and Pseudomonas fluorescence3 treatments increased germination percentage in Fusarium, Pythium and Alternaria treatments significantly in average more than 71%. Both isolates increased significantly Leaf number per plant, leaf area per plant, height of plant, branches number per plant, total dry weight of shoot per plant and chlorophyll content compared with other and control treatments. Similar significant effect for both isolates was recorded in seeds number per pod per plant, total weight of 1,000 seeds per plant and pods number per plant and percentage of N, P, K in total dry weight of shoot per plant and oil percentage in seeds per plant compared with other and control treatments. P. putida2 increased oil percentage in seeds by 43.3, 48.0 and 45.0% respectively while with P. fluorescens3 increased to 42.7, 44.0 and 43.7% respectively compared with control treatment （27.7%）. In general Pseudomonas putida2 increased most of growth characters much higher than Pseudomonas fluorescens3, it may related to siderophores compound and genetic factors.

Alternate Two Different Modes of Actions of Green Chemicals to Combat Batrachedra amydraula Meyrick and Cadra cautella Walk on Date Palm Fruit, Egypt

Alternate two different modes of actions of green chemicals： spinosad ＆ methoxyfenozide to combat the lesser date moth, Batrachedra amydraula and the Almond moth, Cadra cautella Walk on dates in Dakhla Oasis, New Valley, Egypt were done in 2010 and 201 I. Based on infestation of the early insect pest B. amydraula, the three-rotation program with basic 1st spray of spinosad 24 SC at 20 mL/100 L showed insignificant difference. Based on minimum effective rotation doses, alternating spinosad 24 SC at 20 mL/100 L, then methoxyfenozide 24 SC at 15 mL/100 L with two-week interval showed zero infestation and 1.8% at the last sample of 2010 and 2011, respectively. Based on infestation of the late insect pest, Cadra spp., tlhe same previous trend of the three-rotation results. Based on minimum effective rotation doses, alternating spinosad 24 SC at 20 mL/100 L, then methoxyfenozid 24 SC at 15 mL/100 L with three-week interval indicated less than 1% and 1% infestation during harvest for 2010 and 201 l, respectively. The last reflected important value when storing the fruit. Both products proved to be working under dry hot high temperatures.

Antibacterial Effect of Lavender （Lavandula） Flavor （Volatile）

The objective of this study was to test the essential oil-emitted flavor （volatile） of lavender by bacteria killing potency using Escherichia coli, methicillin-resistant Staphylococcus aureus （MRSA）, enterohemorrhagic E. coli O157：H7, Pseudomonas aeruginosa and Candida albicans. Antibacterial activity was assessed by creating of the bacterial growth curve in the liquid medium cultivation and the growth inhibition on the agar plate cultivation. Citronellal, one of compounds in Rosa rugose oil, was used as a positive control for comparison in activity. The results showed that lavender and citronellal flavor （volatile） or oil respectively demonstrated bacteria killing effect in both analytical manners. However, P. aeruginosa resisted bacteria killing potency of lavender （citronellal） oil or oil-emitted flavor. It could be concluded that both lavender oil-emitted flavor and oil showed bacteria killing potency. Lavender oil （or oil-emitted flavor） will be expected to apply for the patient waiting room to disinfect in air along with the mental relaxation of the patient.

Antibacterial applications of graphene oxides: structure-activity relationships, molecular initiating events and biosafety

Bacterial infections may lead to diverse acute or chronic diseases （e.g., inflammation, sepsis and cancer）. New antibiotics against bacteria are rarely discovered in recent years, which necessitates the exploration of new antibacterial agents. Engineered nanomatetials {ENMs） have been extensively studied for antibacterial use because of their long lasting killing effects in wide spectra of bacteria. Graphene oxide （GO） is one of the most widely studied ENMs and exhibit strong bactericidal effects. The physicochemical properties of GO play important roles in bacterial killing by triggering a cascade of toxic events. Many studies have explored the signaling pathways of GO in bacteria. Although molecular initiating events （MIEs） of GO in bacteria dominate its killing efficiency as well as toxicity mechanisms, they have been rarely reviewed. In this report, we discussed the structure-activity relationships （SARs） involved in GOinduced bacterial killing and the MIEs including redox reaction with biomolecules, mechanical destruction of membranes and catalysis of extracellular metabolites. Furthermore, we summarized the clinical or commercial applications of GO-based antibacterial products and discussed their biosafety in mammal. Finally, we reviewed the remaining challenges in GO for antibacterial applications, which may offer new insights for the development of nano antibacterial studies.