KLebsilla ASP-15根圈促生菌发酵工艺配方及复合菌株的性能研究

采用L9（34）正交设计筛选ASP-15菌发酵工艺培养基配方,结果表明,处理5效果最佳,活菌数达1.2×1010cfu/ml,高于其它处理64.4%～621.5%。所取的因素水平为饴糖2.0%,玉米浸汁0.5%,无机盐0.1%,接种量0.5%。氮源对ASP-15菌的生长影响最大,无机盐影响最小。由ASP-15菌、根瘤菌、细黄链霉菌等组成得复合菌剂能促进根瘤菌在大豆根部的定殖,与单独接种根瘤菌相比,根瘤数量增加了94.2%;复合菌剂的解磷能力较单独接种ASP-15菌明显增加,土壤速效磷含量较ASP-15菌处理组提高了28.6%、46.6%。

南阳盆地花生圈绒泡菌的发生规律及防治措施

河南省是全国花生的主产区,面积和总产居第1位。南阳市常年花生种植面积23.33万hm2以上,平均产量4 800 kg/hm2左右,是全国种植面积和总产居第一的地级市。针对近年南阳盆地花生圈绒泡菌发生的问题,从发病症状、诊断、发生特点入手进行了探讨,提出了切实有效的防治措施,对河南省花生生产具有很好的指导意义。

南阳首次发现圈绒泡菌(Physarum gyrosum Rostaf)危害谷子

2020年6月16日,在河南南阳卧龙区安皋镇首次发现圈绒泡菌侵染谷子植株,此后又陆续在新野县湍口社区、社旗县大冯营乡等地发现该菌侵染谷苗,这是国内首次发现该菌在谷子上侵染危害。2021年6月,该病菌在部分谷子田块上仍有零星发生。通过田间调查、取样分析、室内检测,明确了该黏菌的为害特征及其在谷子田间的发生规律,并提出了相应的防控策略。

抗菌肽与抗生素的体外抗菌效果比较

应用由 Hancock实验室改进的微量肉汤稀释法测定了 cecropin P1、cecropin A、magainin 2、defensin 1、bactenecin、lactoferricin和 indolicidin等 7种抗菌肽和盐酸金霉素、去甲万古霉素、土霉素、强力霉素等 4种抗生素的体外抗菌活性 ,并且使用薄层琼脂糖孔穴扩散法比较了抗菌肽中 cecropin P1和 cecropin A与土霉素和呋喃唑酮对大肠杆菌 K88的抑菌效果。结果发现 ,抗菌肽与抗生素一样对几种革兰氏阳性菌和阴性菌都有不同程度的抗菌效果。其中 cecropin A、cecropin P1和 defensin1对大肠杆菌的 2个菌株 ATCC2 5 92 2和 K88的抗菌活性高于抗生素 ,defensin1是各种抗菌肽中对金黄色葡萄球菌抗菌效果最好的。抗生素对试验用金黄色葡萄球菌的抑制活性总体上要好于抗菌肽。与抗生素相比 ,cecropin A、cecropin P1和 indolicidin对猪霍乱沙门氏菌和鼠伤寒沙门氏菌具有更好的抗菌效果。另外 ,抗菌肽的抑菌圈边缘十分清晰 ,而抗生素的整个抑菌圈都比较模糊且界线不明。因此 ,从抗菌效果方面考虑 。

大蒜、生姜水浸液对体外细菌抑制的对比研究

大蒜水浸液对四种细菌抑制试验结果表明:大蒜对这四种细菌都有非常强的抑制,并且抑制的效果随着浓度降低逐渐降低;其中大蒜对蜡样芽孢杆菌是杀菌作用,对痢疾杆菌受抑制时间最长,金黄色葡萄球菌次之;大肠杆菌最短;大蒜与生姜抑菌效果有显著性差异,大蒜的抑菌效果比生姜强得多。

肺炎克雷伯菌耐药性分析

超广谱β-内酰胺酶(ESβ-Ls)是大多数细菌对β内酰胺类抗生素耐药的主要机制.本文通过对168株肺炎克雷伯菌产ESβ-Ls情况及耐药特点进行分析,旨在更合理使用抗生素.……

两种女性洁护用品的抑菌效果观察

女性柔爽洁护液和日常清洁护理液抑菌主要成分为洗必泰、乳酸,笔者在实验室用抑菌环法对这两种女性洁护用品的抑菌作用进行了实验观察,现将结果报告如下:

贵州紫铜色松乳菇生态环境的调查

紫铜色松乳菇与橙色松乳菇在形态上基本相似,只是在颜色、乳汁、气味、口感有些区别;紫铜色松乳菇发生的环境和伴生植物与橙色松乳菇完全相同,都是在马尾松和栎树混交林中,并且在松林不太高,散射光较强的环境发生较多;但两者发生的温度有差别,紫铜色松乳菇原基的形成要求的温度低一些。

磺胺药的实验及临床研究

近年来新的磺胺药不断出现,其中许多品种具有高效、长效而副作用较少等优点。自从甲氧苄胺嘧啶(TMP)发现后,使磺胺药的抗菌作用显著增强,临床疗效大为提高。因此,进一步开展对磺胺药的药理特性的研究,以促进其合理使用,使之发挥更大的治疗作用,具有重要意义。

Lactobacillus plantarum B7 inhibits Helicobacter pylori growth and attenuates gastric inflammation

AIM:To determine the anti-Helicobacter property of Lactobacillus plantarum B7(L.plantarum)B7 supernatants in vitro and the protective effects of L.plantarum B7 on serum tumor necrosis factor-alpha(TNF-?),gastric malondialdehyde(MDA)level,apoptosis,and histopathology in Helicobacter pylori(H.pylori)-induced gastric inflammation in rats. METHODS:In vitro,the inhibition of H.pylori growth was examined using L.plantarum B7 supernatants at pH 4 and pH 7 and at the concentration of 1×,5×and 10×on plates inoculated with H.pylori.The inhibitory effect of H.pylori was interpreted by the size of the inhibition zone.In vitro,male Sprague-Dawley rats were randomly divided into four groups including group 1(control group),group 2(H.pylori infected group), group 3(H.pylori infected with L.plantarum B7 106 CFUs/mL treated group)and group 4(H.pylori infected with L.plantarum B7 1010 CFUs/mL treated group).One week after H.pylori inoculation,L.plantarum B7 106 CFUs/mL or 10 10 CFUs/mL were fed once daily to group 3 and group 4,respectively,for one week.Blood and gastric samples were collected at the end of the study. RESULTS:In vitro,at intact pH 4,mean inhibitory zone diameters of 8.5 mm and 13 mm were noted at concentrations of 5×and 10×of L.plantarum B7 supernatant disks,respectively.At adjusted pH 7, L.plantarum B7 supernatants at concentrations of 5 ×and 10×yielded mean inhibitory zone diameters of 6.5 mm and 11 mm,respectively.In the in vitro study, in group 2,stomach histopathology revealed mild to moderate H.pylori colonization and inflammation.The level of gastric MDA and epithelial cell apoptosis were significantly increased compared with group 1.The serum TNF-??level was significant decreased in group 3 compared with group 2(P<0.05).In addition,L.plantarum B7 treatments resulted in a significant improvement in stomach pathology,and decreased gastric MDA level and apoptotic epithelial cells. CONCLUSION:L.plantarum B7 supernatant inhibits H.pylori growth.This inhibition was dose-dependent and greater at pH 4.Moreover,L.plantarum B7 attenuated H.pylori-induced gastric inflammation.

The Effect of Mixture of Alpinia Galanga, Eurycoma Longifolia Jack and Syzygium Aromaticum Crude Extract on the Growth of Saccharomyces Cerevisiae and Escherichia Coli

Alpinia galanga, Eurycoma longifolia Jack and Syzygium aromaticum have been widely used in traditional medicine for decades. Antimicrobial activities for individual crude extract were well established. Crude methanolic extracts of Alpinia galanga, Eurycoma longifolia Jack and Syzygium aromaticum and the combination for all extracts were tested using well diffusion techniques against Saccharomyces cerevisiae （ATCC 9763） and Escherichia coli （ATCC 25922）. The mixed extracts were prepared based on the concentration ratio of 50 μg/μL which are 1：1, 1：1：1 and 1：2：2. Single Syzygium aromaticum extract showed higher inhibition zone on Saccharomyces cerevisiae compared to Escherichia coli. There is reduction in diameter of inhibition zone for single extract and mixture extracts either in combination of two or three extracts tested on Saccharomyces cerevisiae and Escherichia coli growth but they are not significant. In conclusion, Syzygium aromaticum showed highest activity against Saccharomyces cerevisiae and Escherichia coli. Reduction in diameter of inhibition zone indicated that Alpinia galanga and Eurycoma longifolia Jack extracts had antagonistic effect with Syzygium aromaticum.

Isolation and identification of symbiotic bacteria from the skin, mouth, and rectum of wild and captive tree shrews

Endosymbionts influence many aspects of their hosts’ health conditions, including physiology, development, immunity, metabolism, etc. Tree shrews(Tupaia belangeri chinensis) have attracted increasing attention in modeling human diseases and therapeutic responses due to their close relationship with primates. To clarify the situation of symbiotic bacteria from their body surface, oral cavity, and anus, 12 wild and 12 the third generation of captive tree shrews were examined. Based on morphological and cultural characteristics, physiological and biochemical tests, as well as the 16 S rDNA full sequence analysis, 12 bacteria strains were isolated and identified from the wild tree shrews: body surface: Bacillus subtilis(detection rate 42%), Pseudomonas aeruginosa(25%), Staphlococcus aureus(33%), S. Epidermidis(75%), Micrococcus luteus(25%), Kurthia gibsonii(17%); oral cavity: Neisseria mucosa(58%), Streptococcus pneumonia(17%); anus: Enterococcus faecalis(17%), Lactococus lactis(33%), Escherichia coli(92%), Salmonella typhosa(17%); whereas, four were indentified from the third generation captive tree shrews: body surface: S. epidermidis(75%); oral cavity: N.mucosa(67%); anus: L. lactis(33%), E. coli(100%). These results indicate that S. epidermidis, N. mucosa, L. lactis and E. coli were major bacteria in tree shrews, whereas, S. aureus, M. luteus, K. gibsonii, E. faecalis and S. typhosa were species-specific flora. This study facilitates the future use of tree shrews as a standard experimental animal and improves our understanding of the relationship between endosymbionts and their hosts.

Determination of Antimicrobial Activity of Methyl Cellulose Films Enriched with Some Essential Oils on Listeria innocua

Essential oils are effective antimicrobials on important some pathogenic bacteria and can be added packaging materials due to absorb various surfaces. In this study, the aim is to determinate of antimicrobial effects of methyl cellulose films with containing various proportions thyme, rosemary, coriander, basil and pimento berry oils （1%, 2%, 3% and 4% g/cc） against important bacteria as a surface contaminant Listeria innocua by in vitro. For this purpose, 1 cm diameter discs were cut from methyl cellulose films containing essential oils and inhibition zone diameter which were measured by the agar diffusion method. As the results of these analyses, all prepared active edible methyl cellulose films were antimicrobial effects on Listeria innocua. The most powerful antimicrobial effect achieved with methyl cellulose film including coriander oil on Listeria innocua. And also the weakest antimicrobial effect achieved with methyl cellulose film including rosemary oil on Listeria. All results were significant by statistically （p 〈 0.01） and all analyses were replicated in three times.

Soil Microbial Activity and Functional Diversity in Primeval Beech Forests

Virgin forests are unique ecosystems, which can be used as etalon for basic biocoenotic investigation. Soil microorganisms are very sensitive reagents on influence of biotical factors, and at the same time are the active producers of phytotoxic and phytostimulating exometabolites. Studies of soil microbiota were conducted in virgin beech forests of Shyrokoluzhansky massif of the Carpathian Biosphere Reserve. It was found the ratio and the number of different ecological-trophic groups of soil microorganisms changes with altitude. So the number of ammonificators with increasing of altitude above sea level was reduced. The soil at altitude of 1,100 meters above sea level was characterized by minimum content of organotrophes -1.22 × 10^6 （CFU-colony forming units/lg.a.d.s.）. At the altitude of 500 meters content of ammonificators increased at six times and was 7.07 ×10^6 CFU/lg.a.d.s., which indicates to accumulation of the soil organic matter. Similar changes occurred with the number of bacteria which are using mineral forms of nitrogen for their nutrition. Their maximum quantity （4.32 × 10^6 CFU/lg.a.d.s.） was in the soil of biotope disposed at altitude of 500 meters above sea level. Fluctuations in the number of soil micromycetes of virgin forest ecosystems have not been as significant as the bacterial microbiota （within 17 ×10^3-28 × 10^3 CFU/lg.a.d.s.）. Among a wide spectrum of bacterial microbiota were isolated strains with high phytostimulating action.

Sulfur metabolism by marine heterotrophic bacteria involved in sulfur cycling in the ocean

Sulfur cycling in the biosphere is tightly interwoven with the cycling of carbon and nitrogen,through various biological and geochemical processes.Marine microorganisms,due to their high abundance,diverse metabolic activities,and tremendous adaptation potential,play an essential role in the functioning of global biogeochemical cycles and linking sulfur transformation to the cycling of carbon and nitrogen.Currently many coastal regions are severely stressed by hypoxic or anoxic conditions,leading to the accumulation of toxic sulfide.A number of recent studies have demonstrated that dissimilatory sulfur oxidation by heterotrophic bacteria can protect marine ecosystems from sulfide toxicity.Sulfur-oxidizing bacteria have evolved diverse phylogenetic and metabolic characteristics to fill an array of ecological niches in various marine habitats.Here,we review the recent findings on the microbial communities that are involved in the oxidation of inorganic sulfur compounds and address how the two elements of sulfur and carbon are interlinked and influence the ecology and biogeochemistry in the ocean.Delineating the metabolic enzymes and pathways of sulfur-oxidizing bacteria not only provides an insight into the microbial sulfur metabolism,but also helps us understand the effects of changing environmental conditions on marine sulfur cycling and reinforces the close connection between sulfur and carbon cycling in the ocean.

Potential natural exposure of endangered red-crowned crane(Grus japonensis) to mycotoxins aflatoxin B_1, deoxynivalenol, zearalenone, T-2 toxin, and ochratoxin A

A survey was conducted to determine whether mycotoxins were present in the foods consumed by red-crowned cranes（Grus japonensis） in the Yancheng Biosphere Reserve, China. Collected in the reserve＇s core, buffer, and experimental zones during overwintering periods of 2013 to 2015, a total of 113 food samples were analyzed for aflatoxin B1, deoxynivalenol, zearalenone, T-2 toxin, and ochratoxin A using high performance liquid chromatography（HPLC）. The contamination incidences vary among different zones and the mycotoxins levels of different food samples also presented disparity. Average mycotoxin concentration from rice grain was greater than that from other food types. Among mycotoxin-positive samples, 59.3% were simultaneously contaminated with more than one toxin. This study demonstrated for the first time that red-crowned cranes were exposed to mycotoxins in the Yancheng Biosphere Reserve and suggested that artificial wetlands could not be considered good habitats for the birds in this reserve, especially rice fields.

Evaluation of the heat transfer performance of helical coils of non-circular tubes

This study addresses heat transfer performance of various configurations of coiled non-circular tubes, e.g., in-plane spiral ducts, helical spiral ducts, and conical spiral ducts. The laminar flow of a Newtonian fluid in helical coils made of square cross section tubes is simulated using the computational fluid dynamic approach. The effects of tube Reynolds number, fluid Prandtl number, coil diameter, etc., are quantified and discussed. Both constant wall temperature and constant heat flux conditions are simulated. The effect of in-plane coil versus a cylindrical design of constant coil, as well as a conical coil design is discussed. Results are compared with those for a straight square tube of the same length as that used to form the coils. Advantages and limitations of using coiled tubes are discussed in light of the numerical results.

Assembly and features of secondary metabolite biosynthetic gene clusters in Streptomyces ansochromogenes

A draft genome sequence of Streptomyces ansochromogenes 7100 was generated using 454 sequencing technology. In combination with local BLAST searches and gap filling techniques, a comprehensive antiSMASH-based method was adopted to assemble the secondary metabolite biosynthetic gene clusters in the draft genome of S. ansochromogenes. A total of at least 35 putative gene clusters were identified and assembled. Transcriptional analysis showed that 20 of the 35 gene clusters were expressed in either or all of the three different media tested, whereas the other 15 gene clusters were silent in all three different media. This study provides a comprehensive method to identify and assemble secondary metabolite biosynthetic gene clusters in draft genomes of Streptomyces, and will significantly promote functional studies of these secondary metabolite biosynthetic gene clusters.