少动鞘氨醇单胞菌临床易感因素分析及药物治疗策略

目的:了解医院少动鞘氨醇单胞菌易感因素及耐药特点。方法:回顾性分析7例病原学检查提示少动鞘氨醇单胞菌患者的基础疾病、标本来源、抗菌药物用药史和药物敏感性试验。结果:少动鞘氨醇单胞菌对碳青霉烯类及复方新诺明的敏感性较好,对氨基糖苷类及氟喹诺酮类有一定敏感性,对氨曲南和三代头孢敏感性差。结论:少动鞘氨醇单胞菌宿主易感因素除了以往报道的免疫缺陷、肺部感染、广谱抗生素用药史,还可能存在低蛋白血症及乙型病毒性肝炎病史等因素。治疗用药应避免选择氨曲南及三代头孢。     

等离子体技术在鞘氨醇单胞菌脱硫废乳胶中的应用

采用等离子体技术对废乳胶进行预处理,利用鞘氨醇单胞菌对其进行脱硫,考察等离子体预处理前后废乳胶亲水性的变化,研究等离子体预处理对废乳胶脱硫效果的影响。结果表明:经等离子体预处理后,废乳胶表面亲水性明显改善;与直接脱硫的废乳胶相比,等离子体预处理后再脱硫的废乳胶表面的砜类基团明显增多,硫质量分数减小,氧质量分数显著增大,硫-氧键含量明显增大,且交联密度明显降低;等离子体预处理能够有效促进废乳胶的微生物脱硫,明显改善脱硫效果。     

Uptake of Cr (VI) by Sphingomonas paucimobilis Biomass from Aqueous Solutions

The Sphingomonas paucimobilis biomass has been successfully utilized to degrade several persistent organic pollutants (POPs). However, few studies have been conducted to use it to remove heavy metals from aqueous solutions. In the present study, biosorption experiments for Cr (VI) were investigated using nonliving biomass of S. paucimobilis isolated from activated sludge, Lianyungang Dapu sewage treatment plant, China. The effects of several parameters including solution pH, contact time, and ionic strength, etc. on Cr (VI) uptake were studied. The biomass was characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDS) and Fourier transform infrared spectrometer (FTIR). The applicability of the Langmuir and Freundlich models was tested. The correlation coefficients (R) of both models were greater than 0.95. The maximum adsorption capacities were found to be 28.5 mg/g for Cr (VI) at 20°C. The adsorption process was quick and found to follow the pseudo-second-order equation. The optimum adsorption was achieved at pH 2. The adsorption was also NaCl concentrations dependent.     

利用少动鞘氨醇单胞菌酶解制备棉籽壳低聚木糖

本文研究了利用自筛菌株酶法制备棉籽壳低聚木糖的基本工艺。低聚木糖是主要的功能性食品添加剂,棉籽壳是生产低聚木糖的良好来源。因此,如何有效的从棉籽壳中提取低聚木糖成为亟待解决的问题。本研究中通过筛选鉴定(法国梅里埃生物自动识别系统)得到一株新的产内切型木聚糖酶的菌株-少动鞘氨醇单孢菌。通过酶解木聚糖工艺的优化,结果表明:当酶解温度为30℃,酶解8 h,木聚糖酶的浓度15%,底木聚糖浓度为40 g/L时,低聚木糖的得率可达到53.20%,经HPLC分析,酶解野种木二糖和木三糖占低聚木糖总量的48.56%,低聚木糖占总糖的82%以上,以上研究可为工业生产低聚木糖工艺的优化提供依据。     

Pentachlorophenol contaminated groundwater bioremediation using immobilized Sphingomonas cells inoculation in the bioreactor system

Pentachlorophenol (PCP) has been used as a wood preservative for more than 100 years. The extensive use of PCP has widely contaminated soil and groundwater. PCP is toxic to living organisms. The main objective of this research was to inoculate the pure PCP-degrading bacterium strain Sphingomonas chlorophenolica PCP-1, isolated from PCP-contaminated soils, into PCP-contaminated groundwater for remediation purposes. The factors that influenced the bioremediation were explored with batch experiments using the inoculated immobilized and suspended cells as inoculation. A biological treatment system inoculated with immobilized cells was set up to estimate the microbial capability to degrade PCP. The results indicated that the suspended and immobilized cells could be inoculated into PCP-contaminated groundwater without adding other supplementary nitrogen and phosphate sources in batch conditions. Moreover, PCP decomposition was accompanied with released Cl- and decreasing pH value. The optimum HRT in the bioreactor system was 12.6h. PCP removal in the bioreactor remained stable and PCP removal efficiency was higher than 92% at this phase. Furthermore, PCP concentration in the biotreatment system effluent remained undetectable. It is possible to bioremediate PCP-contaminated groundwater using immobilized S. chlorophenolica PCP-1 cells in a bioreactor system. The proposed biological treatment system could be maintained for at least for 2 months.     

1例因生物膜导致饮料生产线污染的案例分析

生产企业因故停产数月,恢复生产后,多种产品连续出现微生物污染问题。经检测分析,污染菌鉴定为鞘氨醇单胞菌属Sphingomonas、土壤杆菌属Agrobacterium和栖稻黄色单胞菌Flavimonas oryzihabitans。这些微生物都具有产糖被的能力,加上设备管路拆洗中发现管路焊缝有片状成膜物质,更换相关管路后便根除了该污染。所以经过分析得出结论:污染原因是因管路连接粗糙,加上持续停产,多种环境中微生物形成生物膜,保护污染菌耐受高温短时蒸汽灭菌,导致多种细菌持续反复污染产品。     

Acinetobacter sp.XA05和Sphingomonas sp.FG03苯酚生物降解特性研究

从活性污泥和苯酚污染的土壤中分离出来两个菌株,分别编号为XA05和FG03.通过16S rRNA基因序列分析表明,XA05属于Acinetobacter sp.,而FG03属于Sphingomonas sp..将XA05和FG03在以不同浓度的苯酚作为唯一碳源的基础培养液中培养,结果显示,在初始苯酚浓度分别为800mg/L和1000mg/L时,作用45h和60h后,XA05和FG03对苯酚的去除率分别是99.5%、78.3%和97.6%、68.1%.两个菌株按1:1的体积比混合后,当苯酚的初始浓度分别为800mg/L和1000mg/L时,作用35h和60h后,苯酚去除率分别为99.8%,97.2%,XA05和FG03的苯酚降解动力学研究表明,在Haldane's模型中,XA05和FG03都有较高的KS和KSI值.     

Degradation of polybrominated diphenyl ethers by a sequential treatment with nanoscale zero valent iron and aerobic biodegradation

BACKGROUND: Polybrominated diphenyl ethers (PBDEs) are emerging persistent organic pollutants. Degradation of PBDEs is a significant challenge owing to their extreme persistence and recalcitrance nature. The objective of this study was to evaluate the effect of a sequential nano‐bio treatment using nanoscale zero‐valent iron (nZVI) and diphenyl ether degrading bacteria Sphingomonas sp. PH‐07 for degradation of PBDEs. RESULTS: In the bacterial tolerance test for determining the maximum endurable concentration of nZVI, the PH‐07 strain was able to grow in the presence of nZVI up to 5 g L^?1 in minimal salt medium by using non‐brominated diphenyl ether as growth substrate. Reductive debromination of decabrominated diphenyl ether (deca‐BDE; 1 mg) with nZVI (100 mg per vial) resulted in a 67% reduction of deca‐BDE and produced various intermediates ranging from nona‐BDEs to tri‐BDEs during a 20 day period. Additional experiments with 2,4,4′‐tri‐BDE and 2,4,6‐tri‐BDE as initial substrates revealed that both tri‐BDEs were further debrominated to mono‐BDEs. Following the reductive debromination process, reaction mixtures were aerobically treated with DE‐grown Sphingomonas sp. PH‐07 strain to mineralize the low brominated‐DEs (tri‐BDEs—mono‐BDEs) for additional 4 days. During bacterial treatment, the low brominated‐DEs were biologically degraded to bromophenols and other prospective metabolites. CONCLUSIONS: The nZVI‐biological sequential treatment method was found to be effective for degradation of PBDEs through reductive debromination followed by biological oxidation. This hybrid treatment method may lead to the development of a remediation strategy for highly halogenated environmental pollutants in contaminated sites. Copyright © 2011 Society of Chemical Industry     

Metabolism of PAHs and Methyl-Substituted PAHs by Sphingomonas paucimobilis Strain EPA 505

The ability of Sphingomonas paucimobilis strain EPA 505 (a soil bacterium capable of utilizing fluoranthene as the sole source of carbon and energy for growth) to metabolize 3-methyl-methylfluoranthene, 7-methlybenz[ a ]anthracene, 5-methylchrysene, and their corresponding unsubstituted parent hydrocarbons was investigated. The rate of degradation of 3-methylfluoranthene, 7-methylbenz[ a ]anthracene, and 5-methylchrysene by a resting cell suspension of S. paucimobilis grown on fluoranthene was 20.4, 6.2, and 2.7 nmole/mg of wet cells/hr, respectively. The rate of degradation of fluoranthene, benz[ a ]anthracene, and chrysene was 10.7, 3.4, and 1.4 nmole/mg of wet cells/hr, indicating that methylated PAHs are degraded at a higher rate than the corresponding unsubstituted analogs. Two major isolated metabolites of benz[ a ]anthracene were identified as 2-hydroxy-3-naphthoic acid, and 2-hydroxy-3-phenanthroic acid. Unlike benz[ a ]anthracene, 7-methylbenz[ a ]anthracene was metabolized to its cis -1,2-diol to a significant extent by S. paucimobilis suggesting that the presence of a methyl group at position 7 of benz[ a ]anthracene hinders the action of the enzymes (presumably dehydrogenases), which convert cis -1,2-diol to the corresponding catechol.