一株端羟基聚丁二烯降解菌的筛选及降解机理研究

doi:10.11949/0438-1157.20250053

摘要/Abstract

摘要：

端羟基聚丁二烯（HTPB）是丁羟推进剂的重要组分，随着武器弹药的退役升级，废弃丁羟推进剂的处理对环境带来了重大的挑战。本研究从炼厂污泥中分离出一株以HTPB为唯一碳源的假单胞菌HM6。采用凝胶渗透色谱法测定了降解前后HTPB的分子量分布，采用傅里叶变换红外光谱、核磁共振氢谱和气相色谱-质谱联用法对降解产物进行了表征。HTPB降解后产生两种低分子量化合物，数均分子量由降解前的9523 g/mol分别降低至6809 g/mol和366 g/mol，中间代谢产物包括醛类、醇类和羧酸类等化合物。通过基因组和转录分析，发现编码铜氧化酶、醛脱氢酶、水解酶等基因且表达量均上调。基于化学表征和基因组分析，提出了菌株HM6对HTPB降解的途径。本研究为利用微生物降解废弃丁羟推进剂提供了理论依据。

关键词: 假单胞菌, 端羟基聚丁二烯, 降解, 生物技术, 聚合物

Abstract:

Hydroxyl-terminated polybutadiene (HTPB) is an important component of butyl hydroxy propellant. The disposal of waste butyl hydroxy propellant, resulting from the retirement and upgrading of weapons, poses notable environmental challenges. In this study, a Pseudomonas sp. HM6 was isolated from refinery sludge, which used HTPB as the sole carbon source. The molecular mass distribution of HTPB before and after degradation was determined by using gel permeation chromatography. The degradation products were characterized by using Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and gas chromatography-mass spectrometry. After degradation, the degradation products exhibit two distinct molecular mass,which decreased from an initial value of 9523 g/mol to 6809 g/mol and 366 g/mol. The degradation products contained aldehydes, alcohols, and carboxylic acid compounds. Through genomic and transcriptional analysis, genes encoding copper oxidase, aldehyde dehydrogenase, hydrolase and other genes were found, and their expression levels were upregulated. Based on chemical characterization and genomic analysis, a degradation pathway of HTPB by strain HM6 was proposed. This study provides a theoretical basis for the use of microorganisms to degrade waste butyl hydroxyl propellant.

Key words: Pseudomonas, hydroxyl-terminated polybutadiene, degradation, biotechnology, polymers

中图分类号:

TQ 319

张晓晨, 鲁中山, 郭腾, 桂恒, 宋红兵, 肖盟. 一株端羟基聚丁二烯降解菌的筛选及降解机理研究[J]. 化工学报, 2025, 76(8): 4205-4216.

Xiaochen ZHANG, Zhongshan LU, Teng GUO, Heng GUI, Hongbing SONG, Meng XIAO. Isolation and study of the degradation mechanism of hydroxyl-terminated polybutadiene-degrading strain[J]. CIESC Journal, 2025, 76(8): 4205-4216.

图/表 14

图1 菌株HM6的形貌图

Fig.1 Morphological picture of strain HM6

图2 菌株HM6基于16S rDNA序列的系统发育情况

Fig.2 Phylogenetic analysis of strain HM6 based on 16S rDNA sequence

图3 菌株HM6生长曲线(a)、不同温度(b)和pH(c)下的OD600值

Fig.3 Grow curve(a), OD600 values of strain HM6 at different temperatures(b) and pH (c)

图4 菌株HM6基因组图谱

Fig.4 Genome map of strain HM6

图5 COG数据库的基因组功能注释

Fig.5 Genome function annotation of COG database

图6 碳水化合物活性酶注释统计图

Fig.6 Carbohydrate-active enzyme annotation statistics

图7 实验组（HM6-T）和对照组（HM6-CK）差异表达基因的GO和KEGG富集分析

Fig.7 GO and KEGG enrichment analysis of differentially expressed genes between group HM6-T and group HM6-CK

图8 菌株HM6在不同碳源条件下表达差异的火山图

Fig.8 Volcano diagram of expression difference of strain HM6 under different carbon source conditions

表1 参与HTPB降解的基因

Table 1 Genes involved in HTPB degradation

KEGG	基因编号	名称	基因描述	显著性	上/下调情况
K01692	gene2244	paaF	crotonase/enoyl-CoA hydratase family protein	yes	up
K00059	gene1731	fabG	MULTISPECIES: 3-oxoacyl-ACP reductase FabG	yes	up
K00059	gene2659	fabG	MULTISPECIES: 3-oxoacyl-ACP reductase FabG	yes	up
K00249	gene0772	acd	acyl-CoA dehydrogenase family protein	yes	up
	gene2751	bcd	acyl-CoA dehydrogenase	yes	down
K22552	gene1654		copper oxidase	yes	up
K00257	gene2983	acd	acyl-CoA/acyl-ACP dehydrogenase	yes	up
K00128	gene0641	aldB	MULTISPECIES: aldehyde dehydrogenase	yes	down
	gene0924		MULTISPECIES: aldehyde dehydrogenase family protein	yes	up
	gene2891	aldB	MULTISPECIES: aldehyde dehydrogenase	yes	down
	gene4094	mmsA	MULTISPECIES: CoA-acylating methylmalonate-semialdehyde dehydrogenase	yes	up

表2 HTPB降解前后HTPB分子量分布

Table 2 Distribution of HTPB molecular mass before and after degradation

降解时间	组分1			组分2
降解时间	M_n/ (g/mol)	M_w/ (g/mol)	多分散性	M_n/ (g/mol)	M_w/ (g/mol)	多分散性
原样	9523	22364	2.350	—	—	—
对照组（28d）	9426	20882	2.220	—	—	—
5 d	9179	19808	2.160	682	784	1.150
10 d	8767	19406	2.210	716	806	1.330
14 d	6932	16141	2.328	383	652	1.701
21 d	6857	15968	2.329	394	648	1.644
28 d	6809	15795	2.320	366	617	1.685

图9 HTPB降解前后傅里叶变换红外光谱图a—HTPB原样;b—HTPB降解后样品

Fig.9 Fourier transform infrared spectra of HTPB before and after degradation

图10 HTPB降解前后的核磁谱图

Fig.10 Nuclear magnetic spectra of HTPB before and after degradation

表3 GC-MS检测结果

Table 3 Products detected by GC-MS

序号	保留时间/min	化学式	鉴定产物
1	2.518	CH₄O	甲醇
2	18.079	C₁₇H₃₄O₂	棕榈酸甲酯
3	19.665	C₁₉H₄₀O	十九烷醇
4	20.019	C₁₉H₃₈O₂	硬酯酸甲酯C18
5	20.758	C₂₂H₄₄O₂	正二十醋酸
6	21.575	C₂₀H₄₂	正二十烷
7	22.069	C₂₁H₃₈O₄	一亚油酸甘油酯
8	22.420	C₂₃H₃₂O₂	抗氧剂2246
9	23.990	C₃₆H₇₄	正三十六烷
10	25.465	C₃₄H₇₀	正三十四烷
11	26.917	C₄₄H₉₀	四十四烷

图11 菌株HM6对HTPB的降解途径

Fig.11 The degradation pathway of HTPB by strain HM6

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