NMR investigation of enzymatic coupling of sulfonamide antimicrobials with humic substances

Phenoloxidases mediate the oxidative transformation of soil phenolic constituents, contributing to the formation of humic substances and the chemical incorporation of some xenobiotic organic compounds into natural organic matter. We previously demonstrated phenoloxidase-mediated covalent coupling of sulfonamide antimicrobials with model humic constituents. Here, we investigate fungal peroxidase-mediated covalent coupling of 13C-sulfamethazine and 15N-sulfapyridine to humic substances. 1H-13C heteronuclear single quantum correlation (HSQC) nuclear magnetic resonance spectroscopy provided an initial indication of peroxidase-mediated covalent binding of 13C-sulfamethazine to humic acid. To confirm the role of the sulfonamide anilinic nitrogen in coupling to humic acid and to determine the nature of the covalent linkage, we incubated 15N-sulfapyridine with humic acid and peroxidase and examined reaction products in 1H-15N heteronuclear multiple bond (HMBC) experiments. The HMBC spectra revealed the presence of Michael adducts (i.e., anilinohydroquinones, anilinoquinones) and possibly other covalent linkages. No evidence for Schiff base formation was observed. Analogous experiments with the model humic constituent catechol provided corroborating evidence for these assignments. Michael adducts are expected to exhibit greater environmental stability than imine linkages that can form between sulfonamides and 2,6-dimethoxyphenols. Because the free anilinic nitrogen is required for the bioactivity of sulfonamide antimicrobials, nucleophilic addition occurring through this moiety could result in the biochemical inactivation of these compounds.     

Cross-coupling of sulfonamide antimicrobial agents with model humic constituents

The oxidative cross-coupling of sulfonamide antimicrobials to constituents of natural organic matter was investigated. Sulfonamide antimicrobials were incubated with surrogate humic constituents in the absence and presence of phenoloxidases (viz., peroxidase, laccase, and tyrosinase) or acid birnessite. Substituted phenols were chosen as simple model constituents to determine the structures in humic substances important for cross-coupling reactions. The extent of sulfonamide transformation was evaluated by the disappearance of the parent compound from solution. Incubation with phenoloxidases in the absence of substituted phenols resulted in little or no sulfonamide transformation. In contrast to this, direct oxidation of sulfonamides by acid birnessite was significant. Inclusion of o-diphenols and 2,6-dimethoxyphenols in reaction mixtures resulted in significant phenoloxidase-mediated transformation of sulfonamides and enhanced antimicrobial transformation in the presence of acid birnessite. Phenolic compounds with other substitution patterns were less effective in promoting sulfonamide transformation. Nuclear magnetic resonance spectroscopy experiments provided direct evidence of peroxidase-mediated covalent cross-coupling of sulfamethazine with syringic and protocatechuic acids. Our results indicate that sulfonamide antimicrobials may be chemically incorporated into humic substances. This may result in their diminished mobility, bioavailability, and biological activity.     

15N NMR investigation of the reduction and binding of TNT in an aerobic bench scale reactor simulating windrow composting

T15NT was added to a soil of low organic carbon content and composted for 20 days in an aerobic bench scale reactor. The finished whole compost and fulvic acid, humic acid, humin, and lignocellulose fractions extracted from the compost were analyzed by solid-state CP/MAS and DP/MAS 15N NMR. 15N NMR spectra provided direct spectroscopic evidence for reduction of TNT followed by covalent binding of the reduced metabolites to organic matter of the composted soil, with the majority of metabolite found in the lignocellulose fraction, by mass also the major fraction of the compost. In general, the types of bonds formed between soil organic matter and reduced TNT amines in controlled laboratory reactions were observed in the spectra of the whole compost and fractions, confirming that during composting TNT is reduced to amines that form covalent bonds with organic matter through aminohydroquinone, aminoquinone, heterocyclic, and imine linkages, among others. Concentrations of imine nitrogens in the compost spectra suggest that covalent binding by the diamines 2,4DANT and 2,6DANT is a significant process in the transformation of TNT into bound residues. Liquid-phase 15N NMR spectra of the fulvic acid and humin fractions provided possible evidence for involvement of phenoloxidase enzymes in covalent bond formation.     

N-15 NMR study of the immobilization of 2,4- and 2,6-dinitrotoluene in aerobic compost

Large-scale aerobic windrow composting has been used to bioremediate washout lagoon soils contaminated with the explosives TNT (2,4,6-trinitrotoluene) and RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) at several sites within the United States. We previously used 15N NMR to investigate the reduction and binding of T15NT in aerobic bench-scale reactors simulating the conditions of windrow composting. These studies have been extended to 2,4-dinitrotoluene (2,4DNT) and 2,6-dinitrotoluene (2,6DNT), which, as impurities in TNT, are usually presentwherever soils have been contaminated with TNT. Liquid-state 15N NMR analyses of laboratory reactions between 4-methyl-3-nitroaniline-15N, the major monoamine reduction product of 2,4DNT, and the Elliot soil humic acid, both in the presence and absence of horseradish peroxidase, indicated that the amine underwent covalent binding with quinone and other carbonyl groups in the soil humic acid to form both heterocyclic and non-heterocyclic condensation products. Liquid-state 15N NMR analyses of the methanol extracts of 20 day aerobic bench-scale composts of 2,4-di-15N-nitrotoluene and 2,6-di-15N-nitrotoluene revealed the presence of nitrite and monoamine, but not diamine, reduction products, indicating the occurrence of both dioxygenase enzyme and reductive degradation pathways. Solid-state CP/MAS 15N NMR analyses of the whole composts, however, suggested that reduction to monoamines followed by covalent binding of the amines to organic matter was the predominant pathway.     

Occurrence and sorption behavior of sulfonamides, macrolides, and trimethoprim in activated sludge treatment

The occurrence of sulfonamide and macrolide antimicrobials, as well as trimethoprim, was investigated in conventional activated sludge treatment. Average daily loads in untreated wastewater correlated well with those estimated from annual consumption data and pharmacokinetic behavior. Considerable variations were found during a day, and seasonal differences seem to occur for the macrolides, probably caused by a higher consumption of these substances in winter. The most predominant macrolide and sulfonamide antimicrobials were clarithromycin and sulfamethoxazole, respectively. In the case of sulfamethoxazole, the main human metabolite, N4-acetylsulfamethoxazole, was included as an analyte, accounting for up to 86% of the total load in untreated wastewater. The results obtained illustrate the importance of considering retransformable substances, for example human metabolites, when investigating the behavior and fate of pharmaceuticals. Average concentrations of sulfapyridine, sulfamethoxazole, trimethoprim, azithromycin, and clarithromycin in activated sludge ranged between 28 and 68 microg/kg of dry weight. Overall the sorption to activated sludge was shown to be low for the investigated antimicrobials, with estimated sorption constants for activated sludge below 500 L/kg. Elimination in activated sludge treatment was found to be incomplete for all investigated compounds. In final effluents, the median concentrations for sulfamethoxazole and clarithromycin were 290 and 240 ng/L, respectively.     

Reactions of a sulfonamide antimicrobial with model humic constituents: assessing pathways and stability of covalent bonding

The mechanism of covalent bond formation of the model sulfonamide sulfathiazole (STZ) and the stronger nucleophile para-ethoxyaniline was studied in reactions with model humic acid constituents (quinones and other carbonyl compounds) in the absence and presence of laccase. As revealed by high resolution mass spectrometry, the initial bonding of STZ occurred by 1,2- and 1,4-nucleophilic additions of the aromatic amino group to quinones resulting in imine and anilinoquinone formation, respectively. Experiments using the radical scavenger tert-butyl-alcohol provided the same products and similar formation rates as those without scavenger indicating that probably not radical coupling reactions were responsible for the initial covalent bond formation. No addition with nonquinone carbonyl compounds occurred within 76 days except for a slow 1,4-addition to the β-unsaturated carbonyl 1-penten-3-one. The stability of covalent bonds against desorption and pressurized liquid extraction (PLE) was assessed. The recovery rates showed no systematic differences in STZ extractability between the two product types. This suggests that the strength of bonding is not controlled by the initial type of bond, but by the extent of subsequent incorporation of the reaction product into the formed polymer. This incorporation was monitored for (15)N aniline by (1)H-(15)N HMBC NMR spectroscopy. The initial 1,2- and 1,4-addition bonds were replaced by stronger heterocyclic forms with increasing incubation time. These processes could also hold true for soils, and a slow nonextractable residue formation with time could be related to a slow increase of the amount of covalently bound sulfonamide and the strength of bonding.     

Addition of hydrogen sulfide to juglone

Evidence of the addition of hydrogen sulfide to 5-hydroxy-1,4-naphthoquinone (juglone) in aqueous solution was obtained by nuclear magnetic resonance spectrometry (NMR), electron paramagnetic resonance spectrometry (EPR), UV-visible absorbance spectroscopy, and kinetic measurements. Although numerous addition reactions of thiolated alkane and aromatic compounds to quinones have been previously reported, this study indicates that inorganic forms of S(-II) act as nucleophiles and electrophiles in addition reactions to the alpha,beta-conjugated system of the quinone. The results obtained are consistent with competing Michael and radical addition reactions, with radical addition favored with increasing pH. The simplest structure that simulated the NMR spectrum was a sulfur molecule containing sulfur bonded between two juglone molecules at C-2 or C-3, while EPR measurements of aqueous reaction solutions indicated the presence of a stable semiquinone that contained a sulfur substituent at C-2 or C-3. Quinones are present in trace amounts in natural organic matter, and the addition of S(-II) has important implications with respect to transport and transformation of a variety of compounds that react with natural organic matter.     

Transformation of sulfamethazine by manganese oxide in aqueous solution

The transformation of the sulfonamide antimicrobial sulfamethazine (SMZ) by a synthetic analogue of the birnessite-family mineral vernadite (δ-MnO(2)) was studied. The observed pseudo-first-order reaction constants (k(obs)) decreased as the pH increased from 4.0 to 5.6, consistent with the decline in δ-MnO(2) reduction potential with increasing pH. Molecular oxygen accelerated SMZ transformation by δ-MnO(2) and influenced the transformation product distribution. Increases in the Na(+) concentration produced declines in k(obs). Transformation products identified by tandem mass spectrometry and the use of (13)C-labeled SMZ included an azo dimer self-coupling product and SO(2) extrusion products. Product analysis and density functional theory calculations are consistent with surface precursor complex formation followed by single-electron transfer from SMZ to δ-MnO(2) to produce SMZ radical species. Sulfamethazine radicals undergo further transformation by at least two pathways: radical-radical self-coupling or a Smiles-type rearrangement with O addition and then extrusion of SO(3). Experiments conducted in H(2)(18)O or in the presence of (18)O(2)(aq) demonstrated that oxygen both from the lattice of as-synthesized δ-MnO(2) and initially present as dissolved oxygen reacted with SMZ. The study results suggest that the oxic state and pH of soil and sediment environments can be expected to influence manganese oxide-mediated transformation of sulfonamide antimicrobials.     

15N NMR investigation of the covalent binding of reduced TNT amines to soil humic acid,model compounds,and lignocellulose

The five major reductive degradation products of TNT-4ADNT (4-amino-2,6-dinitrotoluene), 2ADNT (2-amino-4,6-dinitrotoluene), 2,4DANT (2,4-diamino-6-nitrotoluene), 2,6DANT (2,6-diamino-4-nitrotoluene), and TAT (2,4,6-triaminotoluene)-labeled with 15N in the amine positions, were reacted with the IHSS soil humic acid and analyzed by 15N NMR spectrometry. In the absence of catalysts, all five amines underwent nucleophilic addition reactions with quinone and other carbonyl groups in the soil humic acid to form both heterocyclic and nonheterocyclic condensation products. Imine formation via 1,2-addition of the amines to quinone groups in the soil humic acid was significant with the diamines and TAT but not the monoamines. Horseradish peroxidase (HRP) catalyzed an increase in the incorporation of all five amines into the humic acid. In the case of the diamines and TAT, HRP also shifted the binding away from heterocyclic condensation product toward imine formation. A comparison of quantitative liquid phase with solid-state CP/MAS 15N NMR indicated that the CP experiment underestimated imine and heterocyclic nitrogens in humic acid, even with contact times optimal for observation of these nitrogens. Covalent binding of the mono- and diamines to 4-methylcatechol, the HRP catalyzed condensation of 4ADNT and 2,4DANT to coniferyl alcohol, and the binding of 2,4DANT to lignocellulose with and without birnessite were also examined.     

咖啡豆残渣有机肥对德阳雪茄根际土壤肥力及真菌群落的影响

【目的】咖啡豆残渣作为农业废弃物具有一定的资源化利用价值,为研究咖啡豆残渣有机肥在雪茄烟叶生产中的应用效果。【方法】以咖啡豆残渣有机肥为主设计3种配方有机肥、作基肥穴施,分析各处理对雪茄烟株生长、植烟土壤肥力及根际土壤真菌群落结构的影响。【结果】（1）3种配方有机肥处理下雪茄烟的株高、叶长和叶宽均有显著提升,其中“菜籽粕+酒糟+咖啡豆残渣”的配方有机肥处理（T2）效果最好。（2）各处理下的土壤有机质、富里酸、全氮、有效磷和速效钾含量较对照均增加。团棵期土壤的有效磷、速效钾、全氮、有机质、胡敏酸和富里酸含量,以及成熟期的土壤速效钾和碱解氮含量都显著影响根际真菌群落结构。（3）3种配方有机肥均可改变雪茄烟根际真菌的优势种群,降低α多样性,且各处理下团棵期α多样性均大于成熟期。T2处理可显著降低根际土壤中明梭孢属和镰刀菌属的相对丰度,显著提高圆酵母属、曲霉属和被孢霉属的相对丰度。LEfSe分析表明,在门水平下处理间差异物种为子囊菌门和被孢霉门;在属水平下处理间差异物种为镰刀菌属、曲霉属、明梭孢属和被孢霉属。【结论】咖啡豆残渣有机肥可提高雪茄植烟土壤肥力、影响根际土壤真菌群落和促进雪茄生长。本...     

Anti-Campylobacter, anti-aerobic, and anti-oxidative effects of roselle calyx extract and protocatechuic acid in ground beef

The inhibitory effect of roselle calyx extract and protocatechuic acid against susceptible and antibiotic-resistant Campylobacter jejuni, C. coli and C. fetus in agar plate and ground beef was examined. The minimal inhibitory concentrations of roselle calyx extract and protocatechuic acid against susceptible and antibiotic-resistant Campylobacter species were in the range of 96-152 and 20-44 mug/ml, respectively. Temperature treatments from 25 to 100 degrees C did not affect the anti-Campylobacter activity of protocatechuic acid. In ground beef stored at 15 degrees C for 6 days, roselle calyx extract and protocatechuic acid inhibited the survival and growth of aerobes, and susceptible and antibiotic-resistant Campylobacter species, in which protocatechuic acid exhibited dose-dependent effect. Both roselle calyx extract and protocatechuic acid decreased lipid oxidation levels in ground beef, in which protocatechuic acid also exhibited dose-dependent effect. The addition of roselle calyx extract or protocatechuic acid did not affect cooking loss, pH value, sensory attributes and content of fat, protein and moisture of beef samples during storage at 4 degrees C for 15 days. These data support that roselle calyx extract and protocatechuic acid may be used for muscle foods to prevent contamination from Campylobacter and aerobes, as well as delay lipid oxidation.     

瑰茄浸提及其发酵酒工艺优化及发酵前后有机酸和酚酸的比较

以云南产玫瑰茄干花萼为原料,在单因素试验基础上采用响应面法对玫瑰茄浸提工艺及其发酵酒工艺进行优化,确定玫瑰茄花萼浸提的最佳工艺条件为料液比1∶28（g/mL）、浸提温度84.0℃、浸提时间78min,在此条件下,花青素提取率为（0.060±0.009）%,多酚提取率为（0.201±0.05）%;玫瑰茄酒的最佳发酵工艺条件为发酵温度24.5℃、S4酵母接种量1.6g/L、加糖量22.5%,所得玫瑰茄酒风味独特,其乙醇体积分数为（10.6±0.12）%,花青素质量浓度为（121.25±0.35）mg/L,多酚质量浓度为（629.58±0.22）mg/L,氨基酸种类齐全,组成合理。检测出玫瑰茄浸提液中含有以柠檬酸和木槿酸为主的7种有机酸和以原儿茶酸为主的8种酚酸,玫瑰茄酒中的主要有机酸为乳酸和木槿酸,原儿茶酸仍是其主要的酚酸;在发酵过程中,柠檬酸、羟基柠檬酸和酒石酸含量降低,丙酮酸、乳酸和琥珀酸含量升高;原儿茶酸、龙胆酸和阿魏酸等酚酸含量降低,而没食子酸、香豆酸和丁香酸含量得到了提高。     

Solid-solution partitioning of organic matter in soils as influenced by an increase in pH or Ca concentration

Organic matter is an important component of soil with regard to the binding of contaminants. Hence, the partitioning of organic matter influences the partitioning of soil contaminants. The partitioning of organic matter is, among other factors, influenced by the ionic composition and ionic strength of the soil solution. This study focuses on the behavior of organic matter after a change in the ionic composition of the soil solution, particularly in Ca concentration and pH. Different amounts of Ca(NO3)2 and NaOH were added to soil suspensions. The dissolved organic carbon (DOC) concentration increased with increasing pH (addition of NaOH), whereas an increase in Ca (addition of Ca(NO3)2) had the opposite effect. A stronger increase in DOC was observed if a single dose of NaOH was added, compared to a gradual addition of the same amount of NaOH. Cation binding by organic matter in the supernatant was calculated using the NICA-Donnan model. The log DOC concentration appeared to be correlated to the Donnan potential, calculated under the assumption that all DOC equals humic acid. This correlation was found for all eight neutral to acidic soils used in this study, although the slopes and elevations of the regression lines varied. The slope varied by a factor of 2 and the elevation appeared to be strongly influenced by the DOC concentration in the untreated soils, which is related to the total organic matter in the soil. Finally, we predicted the Donnan potential on the basis of an extraction of untreated soil with 0.03 M NaNO3, and the total additions of Ca(NO3)2 and NaOH. Comparison of these predictions with speciation calculations in solution showed a good correlation, indicating that a combination of one batch experiment and the presented calculation procedure can provide good estimations of DOC concentrations after addition of chemicals.     

Isolation and characterization of Streptomyces sp. NL15-2K capable of degrading lignin-related aromatic compounds

Strain NL15-2K was isolated from soil by screening for bacteria capable of catabolizing lignin-related aromatic acids. This isolate was identified as a Streptomyces sp. on the basis of morphology and an analysis of its 16S rRNA gene sequence. NL15-2K utilized caffeic acid, coniferyl alcohol, ferulic acid, isovanillic acid, protocatechuic acid, vanillic acid, vanillin, and veratric acid as sole carbon sources.     

喀斯特山区不同种植方式下烟田土壤微生物特征分析

为明确喀斯特山区烤烟由常规种植转为有机种植方式后烟田土壤微生物特征的变化,在贵州省金沙县以常规种植方式为对照,选择连续3年进行有机种植的烟田为试验对象,研究了两种种植方式下烟田土壤基本性质、细菌和真菌群落结构特征及其关键影响因素。结果表明,喀斯特山区烤烟种植方式由常规种植转换为有机种植后,土壤有机质、微生物生物量碳显著增加,而全氮、全钾、速效磷、速效钾等养分含量(质量分数)显著降低(p<0.05);两种种植方式下,土壤微生物丰富度和多样性均以细菌高于真菌,土壤细菌和真菌多样性以及在“门”分类上的群落结构差异不大,细菌以变形菌门、放线菌门、酸杆菌门占优势(54.2%~62.0%),真菌以子囊菌门占绝对优势(74.4%);常规种植转为有机种植方式后,烟田土壤有益微生物类群数量增加。喀斯特山区烟田土壤微生物群落结构主要受土壤有机质、养分和容重的影响。      

Application of plant-based antimicrobials for the growth inhibition of clostridia in pressed beet pulp silage

BACKGROUND: In this study the inhibition of hop beta acids on the growth of clostridia in soil‐contaminated pressed sugar beet pulp silages was investigated. Hop beta acids are natural substances which display their effect at low concentrations. Fresh pressed beet pulp material was mixed with soil to artificially contaminate it with clostridia. Laboratory silos were filled with the substrate, stored at 25 °C and opened for sampling at 0, 2, 8, 15, 30, 60, and 90 days. The impact on clostridial growth during silage fermentation was monitored by determination of the pH value and dry matter content, as well as chemical analysis of the fermentation products. Throughout the experiments, the effect of a commercial silage inoculant based on lactic acid bacteria (LAB) and hop‐resistant LAB were examined with and without the combination of plant‐based antimicrobials. RESULTS: Results indicate that in contaminated silage samples without any additives high butyric acid contents occurred due to clostridial growth. This spoilage could not be suppressed by the application of LAB, whereas the combined application of LAB and hop beta acids significantly improved silage quality, which was reflected by favourable organic acid composition (P < 0.05). CONCLUSION: The experimental data indicate that the application of hop beta acids improves the preservation effect of LAB in suppressing clostridial growth in silages and thus demonstrates some potential for the combined use of plant‐based antimicrobials and LAB. Copyright © 2011 Society of Chemical Industry     

Natural organic matter as reductant for chlorinated aliphatic pollutants

Humic acids (HA) are ubiquitous redox-active compounds of natural aquatic and soil systems. Here we studied the potential of HA as reductants for chlorinated aliphatic pollutants. To avoid artifacts potentially involved when studying chemically reduced HA, we prepared electrochemically reduced soil, aquatic and synthetic HA, and anthrahydroquinone-2,6-disulfonic acid (AHQDS), a model compound for hydroquinone moieties in HA. Both reduced HA and AHQDS reduced hexachloroethane (HCE) at appreciable rates. Some reduction of HCE by HA, however, occurred even before electrochemical reduction of the humic acids. This indicates that a small fraction of reduced moieties in HA persists at oxic conditions for some time. The initial reaction followed pseudo-first-order reaction kinetics, and tetrachloroethylene was the only halogenated product. The relatively small variations in carbon-normalized rate constants, k(DOC), found indicate that despite inherent variations in concentration, accessibility, and reactivity of redox-active groups in HA of various origins their overall dechlorination activity is fairly constant. However, HCE transformation rate constants and reducing capacities of different HA did not correlate. Rate constants normalized to both carbon content and reducing capacity of HA clearly indicate that reduced functional groups in different HA exhibit different reactivities. Our results together with the fact that reduced HA can be formed by a variety of microbiological and chemical processes suggest that HA could play a significant role as reductants in the reductive transformation of subsurface contaminants and that such a process could potentially be enhanced at contaminated sites by addition of reducible natural organic matter.     

Optimization for biodegradation of 2,4,6-trinitrotoluene (TNT) by Pseudomonas putida

In this study, a strain of Pseudomonas putida KP-T202, isolated from the soil in a contaminated site, degraded 2,4,6-trinitrotoluene (TNT). In order to make this biodegradation process commercially feasible and reduce biodegradation time, optimal environmental factors are determined. At an initial concentration of 100 mg/l, TNT was totally degraded within 15 h under aerobic conditions. The optimal conditions for the biodegradation of TNT were found to be 30 degrees C, pH 7, 1% corn steep liquor (CSL), 0.025% NH,CI and 0.1% Tween 80; the reaction rate constant was 0.348 h(-1) These environmental conditions can be used to improve the efficiency of large-scale reactors for the treatment of TNT-contaminated wastewater and soil. In addition, the intermediates were identified as 2-amino-4,6-dinitrotoluene, 4-amino-2,6-dinitrotoluene, 2,4-dinitrotoluene and 2,6-dinitrotoluene.     

50种植物源化合物对阪崎克罗诺肠杆菌的抑菌活性评价

阪崎克罗诺肠杆菌（Cronobacter sakazkaii）是一种食源性条件致病菌,它能够引起菌血症、坏死性小肠 结肠炎和新生儿脑膜炎等多种疾病。本研究选取50 种植物源化合物,检测其在含C. sakazkaii培养基中抑菌圈直径 及最小抑菌浓度（minimum inhibitory concentration,MIC）,旨在评价植物源化合物对C. sakazakii的抑菌作用并筛 查优选高效抑菌剂。结果表明：使C. sakazakii ATCC 29544培养基产生可见抑菌圈的植物源化合物有40 种,其中 7 种（香芹酚、百里醌、百里酚、肉桂醛、柠檬醛、原儿茶醛和原儿茶酸）的抑菌圈平均直径不小于13 mm;在本 研究选取的50 种植物源化合物中,百里酚和香芹酚对C. sakazakii有着最强的抑制作用,对9 株C. sakazkaii的MIC均 为0.1～0.2 mg/mL;百里醌、肉桂醛、柠檬醛和原儿茶醛对C. sakazkaii有良好的抑菌效果,对C. sakazkaii的MIC为 0.30～1.25 mg/mL;阿魏酸、绿原酸、丁香酸、硫辛酸、原儿茶酸、表儿茶素、咖啡酸、丹皮酚和菊苣酸的MIC为 2.50～5.00 mg/mL。以上结果表明,部分植物源化合物对C. sakazakii有良好的抑菌作用,有潜力作为天然抑菌剂应 用于食品加工、流通、贮藏过程中,从而发挥其控制C. sakazakii的作用。