抗生菌剂在缓解大豆重迎茬根际微生态障碍中的作用

重迎茬问题是造成大豆减产、品质下降的主要原因之一,而施用适宜的抗生菌剂能够改善根际微生态环境,促进大豆正常地生长发育,从而缓解甚至消除重迎茬的危害。本研究对正茬和重茬区大豆进行了抗生菌剂处理,并以常规处理作对照,在不同生育时期分别测定大豆的氮素同化量及根际微生物区系状况。经连续两年小区试验,结果表明:在播种同时施用定向筛选的抗生菌剂,明显改变了重迎茬大豆根际微生物区系组成,在细菌、放线菌数量显著增加的同时,真菌数量明显减少,即提高了B/F、A/F值,增强土壤自净与保健能力。进而改善了重迎茬大豆结瘤固氮状况,促进植株生长发育,增加了单株籽粒重量,提高了籽粒的氮素同化量,缓解了重迎茬大豆的氮素同化生理性障碍。

抗生-促生多功能菌剂对稻田土壤微生物区系及氮素转化的影响

以抗生-促生多功能菌剂为供试肥料,探讨对稻田土壤微生态环境及氮素转化动态的影响。结果表明:抗生-促生菌剂明显改善了水稻根际微生物区系组成,B/F、A/F不同时期均有提高,从而使稻田土壤中有益微生物(细菌、放线菌、硝化细菌)一直成为微生物群落内的优势菌群;水稻根际土壤硝酸还原酶活性提高,促进了稻田土壤氮素养分的有效转化,提高水稻植株含氮量。

Research Progress on the Control of Ginseng Gray Mold

This review article describes the research progresses on the control of ginseng gray mold, summarizes domestic and international related experimental re-sults and literature data using chemical fungicide, plant extracts, microbial prepara-tion and antagonistic bacteria to control ginseng gray mold, and final y puts forward the existing problem and future research direction of the treatment and control of ginseng gray mold.

生物肥料的施用方法

生物肥料(即细菌肥料)、化肥、有机肥的施用方法有根本区别，现将几种常用的生物肥料的施用方法简介如下。

Is the Potential Interconnection between Antibiotic Susceptibility and Disinfectant Resistance a Threat to Food Safety?

The prevalence of antibiotic susceptibility and disinfectant resistance in bacterial pathogens causes a serious problem not only to food safety but also to public health, which directly or indirectly leads to treatment and disinfection failures. In this review, multidrug resistance, the mechanism of disinfectant resistance, the methods for detecting disinfectant resistance and the cross-resistance between an- tibiotics and disinfectants are summarized. More efforts should be devoted to explor- ing the professional guidance of using antibiotics and disinfectants, and to develop- ing the comprehensive detection with genetic and molecular methods is highly ex- pected.

Antibiotic susceptibility of strains in Chinese medical probiotic products

Objective： To investigate the susceptibility of strains separated from probiotic products for medical purpose to 14 antimicrobial agents. Methods：The single aerobic strains were isolated from these products respectively and disc agar diffusion assay was proceeded to determine the susceptibility. Results： Probiotics tested in the study mostly showed multiresistant to the agents. Lactobacillus acidophilus LAP, LAB, Lactobacillus bulgaricus LBJ and Streptococcus therrnophilus STJ were resistant to vancomycin. Conclusion： Drug resistance exists in most of commercial probiotics. The evaluation and monitoring of safety of probiotic products for medical purpose should be paid great attention.

Antimicrobial Activities of Some Plants from Ivorian Flora on Southern Blight in Cote d＇ivoire

This study aims at determining and comparing the in vitro antifungal activity of six EOs （essential oils） extracted from Monodora myristica, Melaleuca quinquenervia, Eucalyptus torelliana, Chenopodium ambrosioides, fresh Zingiber officinalis and dehydrated Zingiber officinalis with those of three synthetic fungicides （Callicuivre, Banko plus and Mancozeb） on Sclerotium rolfsii a pathogenic fungus of tomato in Cote d＇Ivoire. The products were added to PDA （potato dextrose agar） medium at various concentrations. The results showed different aspects of the mycelium, different activities on mycelium growth and sclerotia production depending on the explants （mycelium or sclerotia）. Depending on their IC and MGI （mycelium growth inhibition）, the oils stemming from Chenopodium ambrosioides and fresh Zingiber officinalis showed more inhibitory activities on mycelial growth （reduction rate of 100%） and sclerotia production at 250 ppm. These activities were close to or even greater than those of fungicides. The mancozeb fungicide showed stronger activity than the others by inhibiting mycelium growth and sclerotia production of mycelium explants at 250 ppm. This study offers the possibility of using EOs in the control strategies of Sclerotium rolfsii.

Application of Selected Natural Antimicrobial Formulations for the Control of Food Pathogens in Fresh-Cut Cauliflower

In recent years, research on biopolymer based-coating containing natural antimicrobial agents is developing significantly. The objective of this study was to evaluate the antimicrobial efficiency of six formulations containing pre-selected natural antimicrobial compounds against Listeria monocytogenes, Escherichia coli O 157：H7, Salmonella typhimurium, the total bacteria and total yeasts and molds in cauliflower. Each formulation was subjected to a sensory test in parallel to microbiological analysis and the efficiency during storage at 5 ℃ was evaluated for the two best formulations, based on their ability to eliminate the target microorganisms. Both formulations were able to reduce all pathogens and total flora below detectable levels after 24 h of storage at 5 ℃. Using washing or spraying treatments, the two formulations were able to reduce Listeria to undetectable levels for 3 d. This efficiency was extended to 7 d when the formulations were incorporated into an edible coating. Washing treatment with the two formulations was also able to limit the growth of yeast and molds at levels lower than 2 log, for more than 7 d. The population of E. coli was reduced to below the detection limit during 14 d of storage, after washing treatment with the two formulations. The spraying treatment of cauliflower with the formulations allowed the use of very small amounts of antimicrobials while maintaining a fairly good efficiency, greatly reducing the potential costs of implementing this method in the industry. Future research may focus on development of nanoemulsion of antimicrobial formulations based on the developed antimicrobial formulations in this study to improve the better coating efficiency.

Development of Chitosan Film Incorporating Garlic Oil or Potassium Sorbate as an Antifungal Agent for Garlic Bread

Chitosan is a biopolymer material. Mechanical, physical and barrier properties of different chitosan films incorporating garlic oil at 25, 50 and 100 μL/g chitosan or potassium sorbate at 25, 50 and 100 mg/g chitosan as antifungal agents were studied. Addition of garlic oil or potassium sorbate into the films did not alter their color except at the highest concentration of garlic oil which resulted in a more yellowish film. Garlic oil reduced film strength and elongation but it had no effect on water vapor transmission rate. Potassium sorbate reduced film strength and water vapor transmission rate, but it increased oxygen transmission rate. Films containing garlic oil or potassium sorbate was used to wrap around garlic bread to evaluate its shelf life. The development of mold on the bread surface was observed daily. The results showed that garlic bread wrapped in chitosan film incorporating garlic oil had 23 days shelf life, compared with only 7 days shelf life of garlic bread without wrapping. Garlic bread wrapped by film containing potassium sorbate had 13 days shelf life. Garlic breads wrapped by the films incorporating either garlic oil or potassium sorbate were acceptable in terms of sensory evaluation.

Optimizing production ofasperolide A,a potential anti-tumor tetranorditerpenoid originally produced by the algal-derived endophytic fungus Aspergillus wentii EN-48

The marine algal-derived endophytic fungus Aspergillus wentii EN-48 produces the potential anti-tumor agent asperolide A, a tetranorlabdane diterpenoid active against lung cancer. However, the fermentation yield of asperolide A was very low and only produced in static cultures. Static fermentation conditions of A. wentii EN-48 were optimized employing response surface methodology to enhance the production of asperolide A. The optimized conditions resulted in a 13.9-fold yield enhancement, which matched the predicted value, and the optimized conditions were successfully used in scale-up fermentation for the production of asperolide A. Exogenous addition of plant hormones （especially 10 pmol/L methyl jasmonate） stimulated asperolide A production. To our knowledge, this is first optimized production of an asperolide by a marine-derived fungus. The optimization is effective and valuable to supply material for further anti-tumor mechanism studies and preclinical evaluation of asperolide A and other norditerpenoids.

Isolation, Characterization and Bio-Control Activities of Bacillus Subtilis from the Fermented Soybean in Cambodia

The objective of this study was to isolate Bacillus subtilis produced Bacteriocin from Khmer traditional fermented soybean to control the growth of pathogenic bacteria from 120 SIENG samples from 9 different local open markets in Phnom Penh, 1 local open market and 2 local producers in Kandal province in Cambodia. 119 out of 120 samples were positive with Bacillus subtilis strains. Fifteen of these isolated strains exhibited antimicrobial activity to Lactobacillus plantarum by agar well diffusion assay and one of them （CeM6-7 strain） exhibited strongest antimicrobial activity. The filtered supernatant of this strain also suppressed the growth of several Gram-positive pathogens （such as Staphylococcus aureus） or lactic acid bacteria in broth. The filtrate could also suppress the growth of L. plantarum inoculated into soymilk. Antimicrobial B. subtilis strain CeM6-7 is thought to be applicable for making a starter culture to produce much safe fermented soybean foods by suppressing the growth of naturally contaminated B. cereus or S. aureus during production. In addition, the use of this starter culture may contribute to prevent spoilage or quality loss of soybean products caused by the over growth lactic acid bacteria or other Gram-positive bacteria.

日粮添加卡巴氧对断奶仔猪氨基酸表观消化率的作用

本试验的目的是测定在日粮中添加卡巴氧对保育舍猪群氨基酸表观消化率的作用。方法:给15头断奶去势猪(初重:9.6kg)通过外科手术在其回肠末端插入一根T形插管。把这些仔猪随机分为3个日粮处理组,每组5头,试验期6周。每周为1个试验阶段。日粮处理组包括:(1)基础日粮(BD),主要含玉米、豆粕;(2)添加卡巴氧的量为27.5mg/kg日粮;(3)日粮添加卡巴氧55.0mg/kg日粮。第2～4阶段供应处理日粮;第1、5、6阶段供应基础日粮,每阶段最后2d收集回肠试样。结果:全部试验期只供应基础日粮的仔猪,其粗蛋白和多种氨基酸的表观消化率第2～4阶段显著(P<0.05)高于第1阶段,表明在试验期前几周粗蛋白和氨基酸的表观消化率提高了。分析显示,供应卡巴氧含量为55.0mg/kg日粮的仔猪在从第1到第2～4阶段,其粗蛋白和多种氨基酸的表观回肠消化率显著高于(P<0.05)供应其他日粮的仔猪。给仔猪日粮补充卡巴氧27.5mg/kg日粮或55.0mg/kg日粮,在第5、6阶段,一些氨基酸的表观回肠消化率显著(P<0.05)低于第2～4阶段。此观察结果表明卡巴氧对氨基酸消化率无残留作用。结论:断奶仔猪日粮中添加卡巴氧55.0mg/kg日粮可使其氨基酸的表观回肠消化率提高,但未观察到日粮中卡巴氧的残留作用。

Antimicrobial Activity of Probiotics on Swiss Mice

Salmonella enterica serovar typhimurium is the first cause identified of food poisoning in humans; new data indicate that the resistant strains of Salmonella sp. can be inhibited by a bacterial population present in foods have been called probiotics. Our study was conducted on Swiss albino mice in order to know the effect of probiotics or biotherapeutic agents, and suggest the different therapeutic possibilities of intestinal complications related to the presence of Salmonella enterica serovar typhimurium; Reference strains, Lactobacillus delbrueckii subsp, bulgaricus, Lactobacillus acidophilus and Lactobacillus paracasei in combination with Bifidobacterium sp. were tested for their health benefits. The number of Salmonella enterica serovar typhimurium decreases in intestine, in the stomach and in the liver for group 2, 3 in case of preventive treatment and group 4, 5 in case of a therapeutic treatment due to the use of a cuRure of probiotics, in comparison with group 1 where we recorded a high number. The bio-therapeutic treatment was finally confirmed by macroscopic and microscopic observations of different target organs before and after treatment for the experiment period.

Prevalence of Antibiotic Resistant Bacteria on Tomato Surfaces and Effectiveness of Disinfectants in Reducing the Microbial Load

This study was conducted to isolate and identify antibiotic resistant bacteria in fresh tomato sold in three different local markets of Dhaka city. On an average 〉 5.0 log CFU/g of natural microbial populations and coliform bacteria was present in the samples. Prevalence of Salmonella spp., E. coli, Listeria spp., and Yersinia spp., were recorded through cultivation dependent assay of tomato samples of different markets. Almost all of the isolates were uniformly resistant to rifampicin, erythromycin, clindamycin and oxacillin （100%）, vancomycin （93%）, amoxicillin （87%）, whereas 60% of the isolates were found to be resistant to ampicillin and cephalexin. Antibiotic sensitivity test of the presumptive E. coli and Salmonella spp. and corresponding plasmid profiling indicated a correlation of plasmid mediated multidrug resistance （MDR） of these environmental bacteria. Washing with sanitizing agents such as acidified sodium chlorite （ASC） and 200 ppm chlorinated water was able to reduce _〈 2.0 log CFU/g of natural microflora and coliform bacteria. In contrast, ASC was able to reduce 〈 2.0 log CFU/g of other food borne pathogens and, chlorinated water was able to reduce up to undetectable level. Therefore, washing of tomato with 200 ppm chlorinated water could be useful in reducing the pathogen populations on tomatoes.

一种植物生长调节剂及其制备方法

本发明给出一种含有活菌孢子的活性全营养植物生长调节剂及其制备方法。即由培养繁殖“5406”抗生菌剂产生并用水浸提的滤液，腐殖化发酵及霉曲发酵后，先用强碱碱解浸提的滤液和再用硝酸酸解、氧化硝基化处理所得的滤液三液混合调pH值7．5～9后再辅加微肥调配而成。本发明产品为含抗生菌活菌孢子和大量生化活性有机物，

Synthesis and biological activities of thio-triazole derivatives as novel potential antibacterial and antifungal agents

A series of novel thio-triazole derivatives including thiols, thioethers and thiones as well as some corresponding triazolium compounds were conveniently and efficiently synthesized from commercially available halobenzyl halides and thiosemicarbazide. All the new compounds were characterized by 1 H NMR, 13 C NMR, FTIR, MS and HRMS spectra. Their antibacterial and antifungal activities in vitro were evaluated against four Gram-positive bacteria, four Gram-negative bacteria and two fungi by two-fold serial dilution technique. The preliminary bioassay indicated that some prepared triazoles exhibited effective antibacterial and antifungal activities. Especially, 3,4-dichlorobenzyl triazolethione and its triazolium derivatives displayed the most potent activities against all the tested strains.

Novel berberine derivatives:Design,synthesis,antimicrobial effects,and molecular docking studies

A series of berberine derivatives were synthesized by introducing substituted benzyl groups at C-9.All these synthesized compounds（4a–4m）were screened for their in vitro antibacterial activity against four Gram-positive bacteria and four Gram-negative bacteria and evaluated for their antifungal activity against three pathogenic fungal strains.All these compounds displayed good antibacterial and antifungal activities,compared to reference drugs including Ciprofloxacin and Fluconazole;Compounds 4f,4g,and 4l showed the highest antibacterial and antifungal activities.Moreover,all the synthesized compounds were docked into topoisomerase Ⅱ-DNA complex,which is a crucial drug target for the treatment of microbial infections.Docking results showed that H-bond,π-πstacked,π-cationic,andπ-anionic interactions were responsible for the strong binding of the compounds with the target protein-DNA complex.

Discovery of ferrocene-carborane derivatives as novel chemical antimicrobial agents against multidrug-resistant bacteria

Antimicrobial resistance has now become a very serious global public health problem. New drug discovery and development are urgently needed to combat the growing threat of multidrug-resistant (MDR) bacteria. The aim of this study was to explore the potential application of three ferrocene-carborane derivatives as new promising agents to confront the problem of increasing antibiotic resistance. The results of agar diffusion bioassay, minimal inhibitory concentrations (MIC) testing and time-kill assay illustrate their broad-spectrum antimicrobial activities to both American Type Culture Collection (ATCC) control strains and MDR clinical isolates. It is evident that the relevant antimicrobial properties are all in a dose-dependent manner and gradually transform into a bactericidal effect from a bacteriostatic effect with the increasing of the drug concentration. Furthermore, these ferrocene-carborane derivatives have no/little toxic effect on normal cells like HELF cells and lead to little hemolysis at their MICs. This raises the possibility to develop novel antimicrobial drugs using these new ferrocene carborane derivants.

Endophytes from medicinal plants and their potential for producing indole acetic acid, improving seed germination and mitigating oxidative stress

Medicinal plants have been used by marginal communities to treat various ailments. However, the potential of endophytes within these bio-prospective medicinal plants remains unknown. The present study elucidates the endophytic diversity of medicinal plants（Caralluma acutangula, Rhazya stricta, and Moringa peregrina） and the endophyte role in seed growth and oxidative stress. Various organs of medicinal plants yielded ten endophytes, which were identified as Phoma sp.（6 isolates）, Alternaria sp.（2）, Bipolaris sp.（1）, and Cladosporium sp.（1） based on 18 S rD NA sequencing and phylogenetic analysis. The culture filtrates（CFs; 25%, 50%, and 100% concentrations） from these endophytes were tested against the growth of normal and dwarf mutant rice lines. Endophytic CF exhibited dose-dependent growth stimulation and suppression effects. CF（100%） of Phoma sp. significantly increased rice seed germination and growth compared to controls and other endophytes. This growth-promoting effect was due to the presence of indole acetic acid in endophytic CF. The gas chromatography/mass spectrometry（GC/MS） analysis showed the highest indole acetic acid content（（54.31±0.21） μmol/L） in Bipolaris sp. In addition, the isolate of Bipolaris sp. exhibited significantly higher radical scavenging and anti-lipid peroxidation activity than the other isolates. Bipolaris sp. and Phoma sp. also exhibited significantly higher flavonoid and phenolic contents. The medicinal plants exhibited the presence of bio-prospective endophytic strains, which could be used for the improvement of crop growth and the mitigation of oxidative stresses.