苯扎溴铵与艾叶水提物的协同杀菌效果

采用悬液定量杀菌试验,对苯扎溴铵与艾叶水提物的协同杀菌效果进行了实验室研究。研究发现,0.1%苯扎溴铵与艾叶水提物混合溶液对金黄色葡萄球菌、大肠埃希菌、枯草芽胞杆菌、白假丝酵母菌和黑曲霉均呈现出显著的协同杀菌作用。结果表明,苯扎溴铵与艾叶水提物具有良好的协同杀菌效果。     

香附水提液对小麦幼苗生理活性酶的影响

鉴于中草药在抗菌、杀菌,抑制细胞分裂等方面的作用,利用中草药来抑制小麦穗发芽或许是一种新的途径和方法。为了初步研究香附水提液在小麦种子萌发过程中对幼苗生理活性酶的影响,采用室内培养皿培养法,分析不同浓度的香附水提液浸种后对小麦幼苗的α-淀粉酶含量、叶绿素含量和过氧化氢酶活性的作用,结果表明α-淀粉酶含量、叶绿素含量随水提液浓度的增加而降低,过氧化氢酶活性含量则随之递增,并且以香附水提液浓度为120 g/L和150 g/L的处理差异显著,此为研究开发抑制小麦穗发芽的中草药生物抑制剂提供试验依据。     

艾叶提取物的杀菌效果

采用悬液定量杀菌试验,对艾叶提取物的杀菌效果进行实验室研究。研究发现,艾叶提取物对金黄色葡萄球菌、大肠埃希菌、枯草芽胞杆菌、白假丝酵母菌和黑曲霉均具有明显的杀菌作用。通过模拟现场试验,艾叶提取物有显著的杀菌效果。     

醋酸氯己定的杀菌效果

采用悬液定量杀菌试验,对醋酸氯己定的杀菌效果进行实验室研究。研究发现,0.1%醋酸氯己定对金黄色葡萄球菌、大肠埃希菌、枯草芽胞杆菌、白假丝酵母菌和黑曲霉均具有明显的杀菌作用。通过模拟现场试验,醋酸氯己定起到了显著的杀菌效果。     

醋酸氯己定与乙醇的协同杀菌效果

采用悬液定量杀菌试验,对醋酸氯己定与乙醇的协同杀菌效果进行了实验室研究。研究发现,0.1%醋酸氯己定与75%乙醇混合溶液对金黄色葡萄球菌、大肠埃希菌、白假丝酵母菌和黑曲霉均呈现出显著的协同杀菌作用。结果表明,醋酸氯己定与乙醇具有良好的协同杀菌效果。     

四种野生蕨类植物抑菌作用分析

研究了四种野生蕨类植物水提液和醇提液对五种常见微生物的抑菌情况,研究结果显示具有较好的抑菌效果。大多数情况下,其醇提液抑菌作用优于其水提液的,其中狗脊蕨表现了普遍较高的抑菌活性。     

洗必泰与新洁尔灭的协同杀菌效果

采用悬液定量杀菌试验,以协同系数T/E值作为评价指标,对洗必泰与新洁尔灭的协同杀菌效果进行了实验室研究。发现0.1%洗必泰与0.1%新洁尔灭协同作用2 min,对金黄色葡萄球菌、大肠埃希菌和白色念珠菌均起到了显著协同杀菌效果。     

当归水提液和醇提液体外抗脂质过氧化和红细胞溶血作用

研究当归水提液和醇提液对小鼠肝组织自发性过氧化酯质分解产物丙二醛（malondialdehyde,MDA）的生成和对红细胞膜脂质过氧化及红细胞溶血作用的影响。采用TBA比色法测定肝组织匀浆MDA生成,分光光度法测定过氧化氢诱导红细胞膜脂质过氧化和溶血。实验分为空白组、对照组、加药组。加药组分为25、50、100和200mg/mL四个浓度组。当归水提液和醇提液均在25～200mg／mL的浓度范围内,能够明显抑制小鼠肝组织匀浆自发性MDA的生成,具有抑制过氧化氢诱导红细胞膜脂质过氧化和溶血的作用,抑制效果随当归水提液和醇提液浓度的增大而逐渐增强,抑制率与药物浓度成良好的量效关系。当归水提液和醇提液具有抗脂质过氧化和红细胞溶血的作用。     

薇甘菊水提物的抑菌试验研究

以枯草芽孢杆菌、大肠杆菌和金黄色葡萄球菌为代表,分别探讨了薇甘菊水溶性提取物对上述3种细菌在培养24 h过程中的光密度、活菌数和最低杀菌浓度的影响。试验结果表明,在一定浓度范围内薇甘菊水提物对上述3种细菌均有不同程度的抑制作用。其中,枯草芽孢杆菌的抑制作用最强,其次是大肠杆菌和金黄色葡萄球菌。透射电镜观察结果表明,薇甘菊水提物可抑制金黄色葡萄球菌细胞壁的分离,因而抑制了细胞的分裂而达到抑菌效果。     

高蛋白豆浆超高压杀菌工艺研究

超高压杀菌技术是将已密封在最终包装内的产品放置在容器内,并对其施加由水传导的超高静水压力(300 MPa～600 MPa),以达到杀菌目的的冷杀菌技术。该技术既天然、环保,又不会影响食品的营养成分和风味。本文针对高蛋白豆浆超高压杀菌工艺开展了研究,从压力、保压时间和温度三个因素着手进行了单因素试验和正交优化试验,试验结果表明:在压力420 MPa,保压时间12 min,温度60℃条件下,可以达到最佳杀菌效果。     

清清爽牌湿巾的杀菌效果

采用载体定量杀菌试验,对清清爽牌湿巾的杀菌消毒效果进行了实验室研究。发现清清爽牌湿巾对金黄色葡萄球菌、大肠埃希菌和白假丝酵母菌作用2 min,杀菌率分别达到99.98%、99.76%和99.20%。模拟现场试验,清清爽牌湿巾对手自然菌杀菌率达到99.99%,起到了显著地杀菌消毒效果。     

Phylogenetic analysis of the <Emphasis Type="Italic">lux</Emphasis> operon distinguishes two evolutionarily distinct clades of <Emphasis Type="Italic">Photobacterium leiognathi</Emphasis>

The luminous marine bacterium Photobacterium mandapamensis was synonymized several years ago with Photobacterium leiognathi based on a high degree of phenotypic and genetic similarity. To test the possibility that P. leiognathi as now formulated, however, actually contains two distinct bacterial groups reflecting the earlier identification of P. mandapamensis and P. leiognathi as separate species, we compared P. leiognathi strains isolated from light-organ symbiosis with leiognathid fishes (i.e., ATCC 25521^T, ATCC 25587, lequu.1.1 and lleuc.1.1) with strains from seawater originally described as P. mandapamensis and later synonymized as P. leiognathi (i.e., ATCC 27561^T and ATCC 33981) and certain strains initially identified as P. leiognathi (i.e., PL-721, PL-741, 554). Analysis of the 16S rRNA and gyrB genes did not resolve distinct clades, affirming a close relationship among these strains. However, strains ATCC 27561^T, ATCC 33981, PL-721, PL-741 and 554 were found to bear a luxF gene in the lux operon (luxABFE), whereas ATCC 25521^T, ATCC 25587, lequu.1.1 and lleuc.1.1 lack this gene (luxABE). Phylogenetic analysis of the luxAB(F)E region confirmed this distinction. Furthermore, ATCC 27561^T, ATCC 33981, PL-721, PL-741 and 554 all produced a higher level of luminescence on high-salt medium, as previously described for PL-721, whereas ATCC 25521^T, ATCC 25587, lequu.1.1 and lleuc.1.1 all produced a higher level of luminescence on low-salt medium, a characteristic of P. leiognathi from leiognathid fish light organs. These results demonstrate that P. leiognathi contains two evolutionarily and phenotypically distinct clades, P. leiognathi subsp. leiognathi (strains ATCC 25521^T, ATCC 25587, lequu.1.1 and lleuc.1.1), and P. leiognathi subsp. mandapamensis (strains ATCC 27561^T, ATCC 33981, PL-721, PL-741 and 554).Electronic Supplementary Material Supplementary material is available for this article at .     

Phenotypic and biological properties of two antagonist <Emphasis Type="Italic">Bacillus subtilis</Emphasis> strains

Bacillus subtilis KB-1111 and KB-1122 were studied to illustrate their phenotypic and biological properties. Comparison of KB-1111 with KB-1122 in morphology was carried out by microscopy and agar plate assays. Biological assay of the test strains showed that they may possess different physiological pathways from those of reference strain ATCC6501. The assessment of antagonism against the indicator fungi showed that both test strains had broad antifungal characteristics against eight phytopathogenic fungi. Of those fungal species, Magnaporthe grisea P131, Sclerotinia sclerotiorum, and F. oxysporium exhibited high sensitivity to the test strains.     

Detection of Methicillin-Resistant Staphylococcus aureus Using mecA/nuc Genes and Antibiotic Susceptibility Profile of Malaysian Clinical Isolates

The aim of this study is to compare methicillin-resistant Staphylococcus aureus (MRSA) detection methods and to generate antibiogram profile of S. aureus clinical isolates from two teaching hospitals in Malaysia including three reference isolates from American Type Culture Collection (ATCC). The mecA/nuc gene PCR amplification, spot inoculation test and oxacillin disc diffusion test were applied to compare its MRSA detection abilities. No disagreement between the three methods was observed. From 29 bacterial isolates (including the ATCC strains) tested, 19 isolates were confirmed as S. aureus with 14 isolates exhibiting multidrug-resistance. All isolates are still susceptible to vancomycin as indicated by the E-test result. Current biochemical tests are comparable with the molecular detection method for MRSA used in this study while multidrug-resistance traits are present in both MRSA and MSSA clinical isolates. Presently, mupirocin seems to be the best alternative for vancomycin against multidrug-resistant S. aureus infections in Malaysia. Susceptibility profile of 19 S. aureus isolates acquired from two teaching hospitals and ATCC towards 16 selected antibiotics was analyzed and an antibiogram was generated. Findings also indicated resistance against many of the available antibiotics and thus an urgent need to search for alternative antibiotics.     

Xylitol production by Candida species grown on a grass hydrolysate

Xylitol was produced by selected species of the yeast Candida after growth on a medium containing a hydrolysate of the North American perennial prairie grass big bluestem. The grass was hydrolysed by a combination of dilute acid and enzymatic treatments. After growth on the medium for 120 h at 30 °C, Candida tropicalis ATCC 750 produced a 1.4-fold higher level of xylitol than did C. tropicalis ATCC 20215 while biomass production by C. tropicalis ATCC 750 was 1.7-fold higher than Candida guilliermondii ATCC 20216. The xylitol yields observed for C. tropicalis ATCC 750, Candida mogii ATCC 18364 and C. guilliermondii ATCC 20216 were at least 1.4-fold higher than the yield observed for C. tropicalis ATCC 20215 after growth for 120 h at 30 °C.     

肺囊康定产生菌Glarea lozoyensis线粒体基因组序列的再分析

[目的] Glarea lozoyensis是抗真菌药物卡泊芬净的产生菌,其突变菌株ATCC 74030的线粒体基因组已被报道。我们此前的研究发现诱变剂能引起该菌某些细胞核基因的突变,但诱变剂是否也能引起线粒体DNA序列的改变并不清楚。[方法] 组装野生型菌株ATCC 20868的线粒体基因组,并与发表的突变型菌株ATCC 74030的线粒体基因组进行比较。通过PCR验证野生和突变菌株线粒体基因组间表现差异之处,并利用正确的线粒体基因组序列进行新的分析。[结果] 我们成功组装出野生型菌株ATCC 20868的线粒体基因组,通过比较其与发表的ATCC 74030的线粒体基因组序列,发现存在6处单核苷酸变异位点和2处具有长度差异的区域。然而,随后的PCR验证和序列比较并没有发现2个菌株间存在这些差异。最初观察到的碱基差异是因为发表的ATCC 74030线粒体基因组存在序列错误。有趣的是,在Glarea lozoyensis的线粒体基因组中,我们发现存在3个具有内含子的tRNA基因和1个rnpB基因。同时,该菌线粒体基因组中存在多种重复序列,在其线粒体和细胞核基因组间也存在明显的DNA片段重复事件。[结论] 诱变剂没有引起G. lozoyensis线粒体DNA的任何改变;发表的ATCC 74030的线粒体基因组存在序列错误。我们报道G. lozoyensis正确的线粒体基因组序列,并且发现该菌线粒体和细胞核基因组间频繁的基因交流。