Stenotrophomonas terrae应用于退化窖泥修复的初步研究

为修复退化窖泥,该研究将Stenotrophomonas terrae接种于退化窖泥,以正常窖泥及退化窖泥为对照,将不同窖泥进行模拟发酵实验,对发酵结束后的窖泥、糟醅、酒样理化指标及细菌菌群进行检测,并对不同窖泥样品细菌菌群进行主坐标分析(PCoA)及相关性网络分析。结果表明,与退化窖泥相比,修复后的窖泥pH、产酸能力、铵态氮含量、感官评分分别显著提升至4.82、185.83 mg/g、98.33mg/100 g、6.10分(P<0.05);对应糟醅的酸度显著降低至3.27(P<0.05),而水分及残余淀粉含量差异不显著(P>0.05);对应酒样总酯、己酸乙酯含量显著提升至1.00 g/L、0.56 g/L(P<0.05),总酸由0.49 g/L显著降低至0.27 g/L(P<0.05)。修复窖泥细菌菌群丰富度及多样性增加,基于属水平,乳杆菌属(Lactobacillus)相对丰度极显著降低(P<0.01),氢孢菌属(Hydrogenispora)、Clostridium_sensu_stricto_12、嗜碱菌属(Alkalibaculum)及产己酸菌属(Caproiciproducens)等功能微生物相对丰度极显著提高(P<0.01)。PCoA及相关性网络分析表明,退化窖泥接种Stenotrophomonas terrae后,可使其细菌菌群接近于正常窖泥,可增强窖泥细菌间的协同作用,提高微生物生态网络稳定性。

菌株Stenotrophomonassp．ZS-S-01去除菜心中残留高效氯氰菊酯和氰戊菊酯农药的作用

通过室内盆栽和田间小区试验,评价降解菌株Stenotrophomonas sp.ZS-S-01去除菜心中残留高效氯氰菊酯和氰戊菊酯农药的效果.室内盆栽试验结果表明,处理72 h后,菜心中高效氯氰菊酯和氰戊菊酯的降解率分别为71.1%和65.9%,残留量分别为0.28和0.35 mg/kg,降解半衰期(T1/2)分别为26.3和29.2 h,与对照相比,T1/2分别缩短了57.2和34.1 h.田间小区试验结果表明,处理72 h后,菜心中高效氯氰菊酯和氰戊菊酯的降解率分别为63.2%和54.0%,残留量分别为0.35和0.46 mg/kg,T1/2分别为27.7和32.1 h,与对照相比,T1/2分别缩短了34.2和15.4 h.可见,降解菌株ZS-S-01可有效去除菜心中高效氯氰菊酯和氰戊菊酯农药残留.处理72 h后,菜心中高效氯氰菊酯和氰戊菊酯残留量均低于国家叶菜类蔬菜中最大残留限量(MRLs),显示该菌具有进一步开发的潜力.

Isolation of Stenotrophomonas maltophilia from clinical samples: An investigation of patterns motility and production of melanin pigment

Objectives: To investigate possible sources of Stenotrophomonas maltophilia(S. maltophilia) in the clinical environment.Methods: Different samples were collected from Amol City of Iran. Steps for the identification of S. maltophilia included culturing, biochemical tests, polymerase chain reaction(PCR) of 16 S r RNA gene and 23 S r RNA gene. In addition, production of melanin pigment and patterns of motility of the bacteria, were also investigated.Results: In our study, 20 S. maltophilia strains were isolated from clinical sources,oxygen manometer apparatus of hospitals were 7/110(6.36%), blood was 1/777(0.13%),sputum was 4/40(4%), urine was 1/2 947(0.03%), tap water was 1/240(0.42%) and dental suction was 6/120(5%). The isolated bacteria showed production of melanin pigment with rates of strong, moderate, weak, and lack of pigment. Types of motilities were seen in isolates.Conclusions: The highest percentage of bacteria is isolated of oxygen manometer system and dental suction, yet has not been reported from oxygen manometer system. These bacteria have also been associated with patients who have respiratory problems, so it is essential for staffs of hospitals to draw attention to this source of bacteria.

AFB1 Bio-Degradation by a New Strain - Stenotrophomonas. sp

The paper was to find the bacteria to degrade aflatoxin B 1 （AFB 1） and realize the application of biological degradation on AFB 1. Using cumarin as the carbon source and energy on the first screening, then the ten strains which were first screened out were taken to degrade AFB 1 100 pg kg^-1. Strain NMO-3 was screened out of ten strains, the degradation ratio of AFB 1 reached 85.7%, which was more prominent than the others （P 〈 0.01）. With the analysis of colony morphology, physiological and biochemistry experiments, and 16S rDNA gene sequence, the strain NMO-3 was finally identified as Stenotrophomonas sp. Using cumarin as the carbon source and energy could screen out the AFB 1 degradation strains. Acute toxicity tests show that the viable number of NMO-3 lower than 3.12 × 10^10 cfu mL-1 is safety. The crude enzyme was obtained by 65% ammonium sulfate fractionation, and it could degrade AFB1. It is the first report for the strain＇s detoxi- AFB1.

Characterization of tricalcium phosphate solubilization by Stenotrophomonas maltophilia YC isolated from phosphate mines

The phosphate solubilizing characteristics of a strain YC, which was isolated from phosphate mines (Hubei, China), were studied in National Botanical Research Institute’s phosphate (NBRIP) growth medium containing tricalcium phosphate (TCP) as sole phosphorus (P) source. The strain YC is identified as Stenotrophomonas maltophilia (S. maltophilia) based upon the results of morphologic, physiological and biochemical characteristics and 16S rRNA sequences analysis. The results show that the strain S. maltophilia YC can solubilize TCP and release soluble P in NBRIP growth medium. A positive correlation between concentration of soluble P and population of the isolate and a negative correlation between concentration of soluble P and pH in the culture medium are observed from statistical analysis results. Moreover, gluconic acid is detected in the culture medium by HPLC analysis. It indicates that the isolate can release gluconic acid during the solubilizing experiment, which causes acidification of the culture medium and then TCP solubilization. S. maltophilia YC has a maximal TCP solubilizing capability when using maltose as carbon source and ammonium nitrate as nitrogen source, respectively, in NBRIP growth medium.

Characteristics of copper removal and ion release during copper biosorption by Stenotrophomonas maltophilia in presence of benzo[a]pyrene

The ability of Stenotrophomonas maltophilia was demonstrated to selectively remove Cu2+from Cu(NO3)2 solution under the circumstance that 1 mg/L benzo[a]pyrene(BaP) was either present or not. The removal ratios of 2 and 10 mg/L Cu2+by 0.25 g/L biosorbent are up to 80% and 49% at 10 min, respectively. The biosorption includes ion exchange, NO3 reduction, ion release, and cell oxidation by Cu2+. BaP does not significantly affect Cu2+removal and ion release. Although 2 mg/L Cu2+increases the release of PO4 3, K+, NH4 +and Ca2+, 10 mg/L Cu2+has strong oxidation on cell, and then decreases NO3 reduction and hinders the release of K+, NH4 +and Ca2+. Exogenous cations inhibit the Cu2+biosorption, while additional anions increase the removal ratios of 10 mg/L Cu2+from 52% to 88%.

海洋产几丁质酶菌株Stenotrophomonas nitritireducens CZW003的筛选、鉴定及酶学特性研究

关于海洋中产几丁质酶具有低温耐酸特性的研究报道极少,因此筛选出具有产低温耐酸特性的几丁质酶菌株具有现实意义。该研究从连云港连岛海域采集的海泥样品中,通过透明圈法筛选一株产几丁质酶的菌株CZW003,结合形态学特征观察、生理生化试验及16S rDNA扩增分析鉴定出菌株为还原亚硝酸盐寡养单胞菌(Stenotrophomonas nitritireducens)并作酶学特性研究。结果表明,该酶最适反应温度为35℃,且在5℃具有催化活性,在5~35℃之间酶活较为稳定;最适pH为6.0,在pH 5.0时酶活仍保持在95%以上,酸性环境下具有较好的稳定性;Mg^(2+)、Ca^(2+)、K^(+)对酶活具有促进作用,而Hg^(+)、Fe^(2+)、Ag^(+)及EDTA对酶活具有显著的抑制作用;用胶体几丁质为底物时酶活力最高。

<i>Stenotrophomonas maltophilia</i>Keratitis Related to Therapeutic Contact Lens Misidentified with an Automated Identification System

We present a case of keratitis caused by Stenotrophomonas maltophilia in a therapeutic contact lens user with trichiasis and symblepharon. This keratitis was initially diagnosed as caused by Achromobacter xylosoxidans, but the strain was sent for species confirmation and the isolate was finally identified as S. maltophilia by means of 16S rDNA sequencing. The patient rapidly improved on administration of fortified ceftazidime. Physicians should be aware that the definitive identification of the pathogenic agent and prolonged antimicrobial treatment according to culture sensitivities in keratitis are mandatory as treatment success depends greatly on them.

Comparative Study of the Mutant Prevention Concentrations of Sulfamethoxazole-Trimethoprim Alone and in Combination with Levofloxacin against <i>Stenotrophomonas maltophilia</i>

Objectives: To determine the mutant prevention concentration (MPC) of sulfamethoxazole-trimethoprim (SXT) alone and in combination with levofloxacin (LVX) against Stenotrophomonas maltophilia (S. maltophilia) and to determine if the combination may decrease the emergence of resistant mutants. Methods: The MPC with 20 S. maltophilia strains which were both susceptible to SXT and LVX were determined by inhibiting visible growth among 1010 CFU on four agar plates after 72 hours incubation at 37°C. Results: All except two strains (18/20) showed a mutant prevention concentration ≥ 152/8 μg/mL for SXT and the range of the mutant prevention concentration for the SXT in combination with LVX is 9.5/0.5~608/32 μg/mL, which demonstrates at least 2 fold reduction except one strain. There was a significant difference (P < 0.01) between SXT alone and in combination with LVX on the mutant prevention concentration and mutant prevention concentration/minimum inhibitory concentration values. Conclusions: The MPC/MIC values were narrowed for SXT by combining with LVX against the S maltophilia. The combination may decrease the enrichment of mutant bacterial populations. Much study is needed to verify whether the using of drug combinations may restrict or even block the selection of S. maltophilia mutants.

Stenotrophomonas maltophilia,an emerging pathogen in newborns:Three case reports and a review of the literature

BACKGROUND Stenotrophomonas maltophilia(S.maltophilia)is a rare cause of neonatal sepsis with significant morbidity and mortality and has extensive resistance to several antibiotics leaving few options for antimicrobial therapy.Only a few cases have been reported in neonates from developing countries.We report three cases of critically ill,extramural babies with neonatal S.maltophilia sepsis.All three babies recovered and were discharged.CASE SUMMARY All three cases were term extramural babies,who were critically ill at the time of presentation at our neonatal intensive care unit.They had features of multiorgan dysfunction at admission.Blood culture was positive for S.maltophilia in two babies and one had a positive tracheal aspirate culture.The babies were treated according to the antibiogram available.They recovered and were subsequently discharged.CONCLUSION Although various authors have reported S.maltophilia in pediatric and adult populations,only a few cases have been reported in the newborn period and this infection is even rarer in developing countries.Although S.maltophilia infection has a grave outcome,our three babies were successfully treated and subsequently discharged.

Degradation of poly(butylene adipate-co-terephthalate) by Stenotrophomonas sp. YCJ1 isolated from farmland soil

In recent years, poly(butylene adipate-co-terephthalate)(PBAT) has been widely used. However, PBAT-degrading bacteria have rarely been reported. PBAT-degrading bacteria were isolated from farmland soil and identified. The effects of growth factors on the degradation of PBAT and the lipase activity of PBAT-degrading bacteria were assessed. The degradation mechanism was analyzed using scanning electron microscopy, attenuated total reflection Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, Xray diffraction, and liquid chromatography-mass spectrometry. The results showed that Stenotrophomonas sp. YCJ1 had a significant degrading effect on PBAT. Under certain conditions, the strain could secrete 10.53 U/m L of lipase activity and degrade 10.14 wt.% of PBAT films. The strain secreted lipase to catalyze the degradation of the ester bonds in PBAT, resulting in the production of degradation products such as terephthalic acid, 1,4-butanediol, and adipic acid. Furthermore, the degradation products could participate in the metabolism of YCJ1 as carbon sources to facilitate complete degradation of PBAT, indicating that the strain has potential value for the bioremediation of PBAT in the environment.

黄曲霉毒素B1降解菌株的筛选及鉴定

【目的】筛选能降解黄曲霉毒素B1(AFB1)的细菌,以期在该毒素的生物脱毒中得到应用。【方法】以香豆素为惟一碳源和能源进行AFB1降解菌株的初筛,之后将初筛的10株菌分别降解浓度为100μg·kg-1的AFB1。【结果】筛选出的NMO-3菌株降解AFB1能力达85.7%,显著高于其它菌株(P<0.01)。从形态、生理生化反应以及16SrDNA序列比对等方面分析,最终确定NMO-3菌株为嗜麦芽窄食单胞菌(Stenotrophomonas sp.)。【结论】利用香豆素作为惟一碳源和能源筛选出了黄曲霉毒素降解菌株,后期试验证明活菌制剂在2.56×1010CFU/ml剂量以下不会引起急性毒性反应,用65%硫酸铵提取的蛋白(酶)具有AFB1降解能力。

低温石油降解菌LHB16的筛选及降解特性研究

目的:筛选、鉴定低温石油降解菌并对其降解特性进行研究。方法:富集分离低温石油降解菌;采用形态学、生理生化实验和分子生物学方法进行菌种鉴定;紫外分光光度法和GC-MS检测石油降解特性。结果:自盘锦油田低温环境土样中分离到1株低温菌,命名为LHB16,该菌能以石油烃为惟一碳源和能源。经鉴定为嗜麦芽窄食单胞菌(Stenotrophomonas maltophilia)。该菌生长温度范围0℃～35℃,最适生长温度15℃。在接种量为2%(V/V),原油浓度为0.5%(W/V),振荡培养10d时,降解率可达80.16%。石油中长链烷烃C15～C32被完全降解。传代培养数代,降解率为81.06%,降解性能稳定。结论:菌株LHB16在低温地区石油污染的生物治理中有良好的应用前景。

斑点叉尾嗜麦芽寡养单胞菌溶血素的分离、纯化与特性研究

采用硫酸铵沉淀、DEAE-Sephadex A50离子交换层析和Sephadex G100凝胶层析对嗜麦芽寡养单胞菌(Stenotrophomonas maltophilia)的溶血素进行了分离、纯化并对其生物学活性进行了研究。结果显示:嗜麦芽寡养单胞菌产生一种分子量为20.76 KD的单一多肽溶血素。该溶血素对斑点叉尾、云斑、鲫、人、小白鼠和兔等多种动物红细胞具有溶血活性;家兔肠袢试验显示其能致兔回肠积液,具有肠毒性;致Vero细胞形态改变,具有细胞毒性,对Vero细胞的TCID50为0.126μg。

嗜麦芽窄食单胞菌DHHJ角蛋白酶的纯化及酶解研究

对突变的嗜麦芽窄食单胞菌(Stenotrophomonas maltophilia)DHHJ产生的角蛋白粗酶液的酶解范围进行研究,发现该酶对实验选用的角蛋白底物均有不同程度的酶解作用,酶解范围广泛;对不同颜色鸡毛的酶解研究表明,鸡毛颜色对完整鸡毛的角蛋白酶解影响较大,但当鸡毛经过粉碎等处理之后,颜色对其角蛋白酶解的影响不大;对角蛋白粗酶进行纯化,首先用硫酸铵粗提,然后经过葡聚糖凝胶Sephadex G-100和陶瓷羟基磷灰石(CHT)层析,最后进行聚丙烯酰胺凝胶电泳,得到该酶分子量为35.2ku。

蛋白酶高产菌株的筛选鉴定与酶学特性研究

以酪蛋白水解圈为筛选标记,在以酪蛋白为唯一氮源的平板上,从土壤中分离筛选到3株高产蛋白酶的菌株,经形态学鉴定和16S rRNA分析,将其分别鉴定为Bacillus sp.G1、Bacillus sp.G2、Stenotrophomonas sp.V1。将这3株菌株的发酵液通过硫酸铵分级沉淀初步纯化后,其比酶活分别为22.21、19.10和16.03 U/mg。菌株Bacillus sp.G1和Bacillus sp.G2所产蛋白酶的最适反应温度和最适反应pH值均为40℃和7.0;菌株Stenotrophomonas sp.V1所产蛋白酶的最适反应温度为70℃,最适酶反应pH值为7.5。

低温石油烃降解菌LHB16的筛选及降解特性

自盘锦油田低温环境土样中分离到1株低温菌,该菌能以石油烃为唯一碳源和能源。经形态学、生理生化和16S rDNA序列鉴定:菌株LHB16为嗜麦芽窄食单胞菌(Stenotrophomonas maltophilia)。紫外分光光度法测定该菌在含石油0.5%(w/v)的无机盐培养基中,20℃,振荡培养10 d,降解率达80.16%。经传代培养数代,降解性能稳定。GC-MS分析表明烷烃C15～C32被完全降解。菌株LHB16在低温地区石油污染的生物治理中有良好的应用前景。

响应面法优化海洋细菌NTa产琼胶酶的发酵条件

利用Plackett-Burman试验、最陡爬坡试验和响应面法,对培养基组成、培养条件对Stenotrophomonas sp.NTa发酵产琼胶酶的影响进行分析并优化,研究该菌株发酵产酶的动态规律,并利用薄层色谱和MALDI-TOF MS进行酶解产物的鉴定。结果显示,在琼脂、酵母浸膏、CaCl_(2)、MgSO_(4)·7H_(2)O、培养基的初始pH值、装液量、接种量几个因素中,酵母浸膏和培养基初始pH值对菌株NTa产琼胶酶具有显著影响,在含有1.03%酵母浸膏、初始pH=8.0的基础发酵培养基(NaCl、KNO_(3)、MgSO_(4)·7H_(2)O、CaCl_(2)、K_(2)HPO_(4)、FeSO_(4)·7H_(2)O、琼脂的质量浓度分别为50,5.0,5.0,0.2,0.1,0.02,2.0 g/L)中可获得最高的琼脂酶活力。菌株在28℃、180 r/min条件下发酵时,对数生长中后期快速合成琼胶酶。发酵48 h,琼胶酶活力高达2.688 U/mL。酶解72 h的产物分析结果显示,菌株NTa琼胶酶水解琼脂主要产生四糖。

海洋细菌NTa发酵产琼胶酶条件的初步优化

利用选择性培养基从厦门红树林泥土样品中分离得到一株具有较高琼胶酶活力的海洋细菌NTa,通过16S rRNA分析,将该菌株归属为Stenotrophomonas sp.NTa.对该菌株发酵产琼胶酶的条件进行初步优化,结果表明:菌株NTa产琼胶酶的最佳碳源是琼脂,氮源是酵母浸膏,NaCl的质量分数为5%,在28℃发酵培养40 h,发酵液的酶活力达到1.98 U/mL,比优化前提高了37.35%.

氯氰菊酯降解菌DZS-3的分离鉴定及其特性

以氯氰菊酯为惟一碳源与氮源,从生产氯氰菊酯的农药厂污水曝气处理池的活性污泥样品中,通过富集驯化和划线分离,筛选出一株氯氰菊酯的高效降解菌DZS-3。经气相色谱检测,3d内其对氯氰菊酯的降解率为65.7%。形态学观察,该菌圆形,周边光滑,革兰氏染色鉴定为革兰氏阴性菌。通过16S r DNA序列分析及生理生化特性鉴定,将其初步鉴定为寡养单胞菌属的一种(Stenotrophomonas sp.)。