一株DBP降解菌DNB-S1的降解特性及其摄食行为的研究

发布时间：2018-01-01 06:00

  本文关键词：一株DBP降解菌DNB-S1的降解特性及其摄食行为的研究　出处：《东北农业大学》2016年硕士论文　论文类型：学位论文

  更多相关文章： DBP降解菌 细菌细胞亚显微结构 细胞膜表面疏水性 细胞膜表面官能团 摄食机制

【摘要】：邻苯二甲酸二丁酯(DBP)是邻苯二甲酸酯(PAEs)的其中一种,作为塑料中的增塑剂被广泛应用于生产生活中,DBP很容易释放到环境中,对环境造成污染,威胁人类的生命健康。本研究以研究室前期筛选得到的DBP降解菌Novosphingobium aromaticivorans DNB-S1为研究对象,研究了DNB-S1的生长降解特性,并对其摄食行为进行初步探索,研究得到的主要成果如下:(1)菌株DNB-S1在不同营养条件下的生长速率不同,生长速率由快到慢的处理为:LBMSM-GluMSM-DBP+GluMSM-DBP。菌株DNB-S1对DBP的降解效果受pH及温度影响,在p H为7.0或温度为35℃时降解速率最高,48 h均可降解86.4%的DBP。(2)菌株DNB-S1对DBP、DMP、DEP和DEHP均有降解效果,以MSM培养基培养,在72 h内可分别将500 mg/L的DBP、DMP、DEP和DEHP降解95%、95%、84%和60%以上。使用4种PAEs混合的MSM培养基培养菌株DNB-S1,菌株生长情况良好,5天内对125 mg/L的DBP、DMP、DEP和DEHP的降解率可分别达到93%、88%、97%和71%以上,使500 mg/L的混合PAEs降解88%以上。(3)DNB-S1在各处理中生长状态均良好,细胞壁平滑,细胞外膜内膜结构完整,无溶膜现象细胞质饱满,核糖体延细胞内膜在细胞质中呈均匀分布状态,拟核形态正常,没有变异。当培养体系中存在DBP的条件下,DNB-S1细胞外部的肽聚糖层消失。(4)DNB-S1可根据不同环境及不同DBP的含量调节自身CSH,以MSM-DBP培养基或MSM-DBP+Glu培养基培养的菌株在培养初期CSH高达79.8%,在3天后稳定于50%左右;以MSM-Glu培养基培养的菌株在培养初期CSH为26.9%,3天后稳定于50%左右;以LB培养基培养的菌株CSH在7天内始终保持在9.3%-13.4%之间。培养的p H和温度对菌株DNB-S1的CSH均有一定影响,菌株DNB-S1在酸性环境或温度为30-35℃环境中CSH较高。(5)用100 mg/L的初始DBP浓度培养菌株72 h,整个降解体系及细胞外液中的DBP含量随时间呈逐渐下降趋势。而培养初期,菌体表面迅速积累DBP,积累量达到1.2 mg/L,之后菌体细胞表面积累的DBP含量随培养时间逐渐下降,72 h后降至0.3 mg/L以下;菌体细胞内部的DBP含量随培养时间不断增加,在48-72 h之内基本保持稳定状态,证明DBP能够顺利进入到菌体细胞内并被持续降解利用。(6)不论培养体系中是否存在DBP,DNB-S1亲水基团的种类都保持不变。当培养体系中存在DBP时,DNB-S1细胞膜表面会生成疏水性基团C-H和R-COOH;当培养体系中不存在DBP时,这些疏水性基团会相应消失。
[Abstract]:Dibutyl phthalate (DBP) phthalate two formic acid ester (PAEs) one, as the plasticizer is widely used in production and life in plastic, DBP is easily released into the environment, causing pollution to the environment, threat to human health. This study is based on the room before the screen of the DBP Degradation Strain Novosphingobium aromaticivorans DNB-S1 as the research object, studies the growth and degradation characteristics of DNB-S1, and makes a preliminary exploration on its feeding behavior, main research results are as follows: (1) the growth rate of strain DNB-S1 in different nutrition conditions, the growth rate from fast to slow: LBMSM-GluMSM-DBP+GluMSM-DBP. strain DNB-S1 effect on DBP the degradation effect of pH and temperature in P H 7 or the temperature is 35 DEG C when the degradation rate is highest, 48 h can degrade 86.4% DBP. (2) strain DNB-S1 on DBP, DMP, DEP and DEHP have the effect of degradation, In MSM medium, within 72 h respectively 500 mg/L, DBP, DMP, DEP and DEHP was 95%, 95%, 84% and more than 60%. The use of 4 kinds of PAEs hybrid MSM medium strain DNB-S1, strain DBP, good growth, to 125 mg/L DMP in 5 days, the degradation of DEP and the rate of DEHP can reach 93%, respectively, 88%, 97% and 71% above, the above mixed PAEs degradation of 88% 500 mg/L. (3) DNB-S1 well growth state in each treatment, cell wall smooth, endometrial cell membrane structure integrity, no film dissolution phenomenon of cytoplasmic ribosomal membrane was full, extended state of uniform distribution in the cytoplasm, the nuclear morphology was normal, no mutation. When the culture conditions of DBP exist in the system, the peptidoglycan layer DNB-S1 outside of the cell disappeared. (4) DNB-S1 according to the different environment and different content of DBP regulates its own CSH, with MSM-DBP medium or MSM-DBP+Glu medium strain at the beginning of culture C SH up to 79.8%, 3 days after the stable at around 50%; cultured with MSM-Glu strain in the early culture of CSH was 26.9%, 3 days after the stable at around 50%; with LB culture medium of strain CSH in 7 days is always maintained at between 9.3%-13.4%. The cultured P H and temperature of the DNB-S1 strain of CSH influence of strain DNB-S1 in acidic environment or high temperature environment. C CSH 30-35 (5) strain 72 h 100 mg/L with the initial concentration of DBP culture, DBP content of the whole system and the degradation of extracellular fluid decreased gradually with time. And the initial cultivation, cell surface rapid accumulation of DBP, accumulation up to 1.2 mg/L, the content of DBP after cell surface accumulation decreased gradually with incubation time, after 72 h below 0.3 mg/L; the content of DBP within the bacterial cells increased with incubation time, remained stable in 48-72 within h, proved that DBP can smoothly Into the cell and was sustained by degradation. (6) no matter whether culture exists in the DBP system, DNB-S1 type of hydrophilic group will remain unchanged. When the culture exists in DBP system, DNB-S1 cell membrane surface hydrophobic groups C-H and R-COOH; when the DBP does not exist in the training system, these hydrophobic the corresponding groups will disappear.

【学位授予单位】：东北农业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X172
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本文编号：1363205