一株源自渤海海域高温酸败油井采出水的硫酸盐还原菌筛选与活性抑制

Isolation and activity inhibition of a sulfate-reducing bacterium in produced water from an offshore high-temperature soured oilfield in the Bohai Sea area, China

摘要:

【背景】海域油藏环境中硫酸盐还原菌(sulfate-reducing prokaryotes，SRP)的生长和代谢能够产生大量H2S，引发酸败(souring)及微生物腐蚀等多方面的问题。但有关油藏生境中SRP的微生物多样性与生理活性及其危害控制的认识仍十分有限。【目的】深入了解我国渤海海域某高温酸败油藏中SRP的生理特点，探究SRP危害的控制策略。【方法】采用Hungate厌氧纯培养技术从渤海海域某高温酸败油井采出水中分离筛选SRP，并考察优势菌株的生理特点，综合16S rRNA基因序列比对分析菌株系统发育地位，着重评价不同杀菌剂及使用剂量对优势菌株产H2S活性的抑制效力。【结果】酸败采出井的采出水中优势SRP菌株WJ1的细胞呈长杆状，菌体长度为2.0?5.5 μm，有运动性。WJ1与解糖泽恩根氏菌(Soehngenia saccharolytica)模式菌株BOR-YT的16S rRNA基因序列一致性达99%。WJ1最适生长温度约为37 °C，能够耐受60 °C高温；最适pH值约为8.0 (范围5.0?10.0)，最适盐度约为0%?3%，盐度高于5%不能生长。WJ1可利用丙酸钠、乳酸钠、乙酸盐等多种碳源，能以硫酸盐、亚硫酸盐、硫代硫酸盐为唯一电子受体产生H2S，不能利用单质硫。次氯酸钠(600 mg/L)、苄基三甲基氯化铵(600 mg/L)对WJ1产H2S活性无明显抑制效果。戊二醛(30 mg/L)、溴硝醇(10 mg/L)或四羟甲基硫酸磷(120 mg/L)可抑制WJ1产H2S活性达30 d以上。【结论】渤海海域某高温酸败油井采出水中优势SRP菌株WJ1与S. saccharolytica BOR-YT的16S rRNA基因序列一致性最高，但两者生理特性差异明显；溴硝醇、戊二醛、四羟甲基硫酸磷是控制该酸败油井的潜在有效杀菌剂。

Abstract:

[Background] The growth and activity of sulfate-reducing prokaryotes (SRP) that reside in petroleum reservoirs could generate large amount of H2S, resulting in various problems such as microbial souring and microbially-influenced corrosion. Unfortunately, knowledge on the diversity, physiology, and activity control of SRP therein is quite limited. [Objective] In order to further understand the phenotypic characteristics of SRP residing in the offshore high-temperature oilfield in the Bohai Sea area, China, and to explore the potential methods for addressing the SRP-mediated problems. [Methods] We first isolated, using Hungate techniques, SRP strains from the production water, and then evaluated the phenotypic features of the dominant strain. We also investigated the efficacy of each of five biocides in suppressing the sulfidogenic activity of the selected SRP strain. [Results] Cells of the isolated dominant SRP strain WJ1 are motile, rod-shaped, and approximately 2.0?5.5 μm in length. WJ1 exhibits a sequence identity of 99% for 16S rRNA gene with Soehngenia saccharolytica BOR-YT. Isolate WJ1 could survive at 60 °C (optimum at 37 °C), pH 5.0?10.0 (optimum pH 8.0), and in the presence of 0%?3% NaCl. Isolate WJ1 utilized a wide range of carbon substrates, including propionate, lactate, and acetate. Sulfate, sulfite, and thiosulfate could be utilized as electron acceptors, but not sulfur. Neither sodium hypochlorite (600 mg/L) or benzyltrimethylammonium chloride (600 mg/L) could inhibit H2S production by WJ1. By contrast, glutaraldehyde (30 mg/L), bronopol (10 mg/L), or THPS ((bis[tetrakis(hydroxymethyl)phosphonium] sulfate solution, 120 mg/L) could inhibited H2S production by WJ1 for at least 30 days. [Conclusion] The dominant SRP strain WJ1, isolated from the soured production water from this specific high-temperature offshore oilfield in the Bohai Sea area, shares the highest sequence identity of 16S rRNA gene with S. saccharolytica BOR-YT but presents distinct phenotypic traits from this phylogenetically close relative; bronopol, glutaraldehyde, or THPS could serve as potent agents for the mitigation of microbial souring by WJ1.