Anaerobic Degradation of the Plant Sugar Sulfoquinovose Concomitant With H2S Production: Escherichia coli K-12 and Desulfovibrio sp Strain DF1 as Co-culture Model
Anaerobic Degradation of the Plant Sugar Sulfoquinovose Concomitant With H2S Production: Escherichia coli K-12 and Desulfovibrio sp Strain DF1 as Co-culture Model
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DOI：
10.3389/fmicb.2018.02792
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发表时间：
2018-11-27
影响因子：
5.2
通讯作者：
Schleheck, David
中科院分区：
文献类型：
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作者：
Burrichter, Anna;Dengerl, Karin;Schleheck, David
磺基葡萄糖（SO，6-脱氧-6-磺基葡萄糖）由植物和其他光养生物产生，其生物降解是地球化学碳和硫循环的相关组成部分。已知SQ被好氧细菌聚生体以两个层级降解，通过C-3-有机磺酸盐作为CO2、水和硫酸盐的瞬时中间体。在这项研究中，我们提出了第一个实验室模型厌氧降解SO的细菌财团在两个层次的乙酸和硫化氢（H2S）。对于第一层，使用SO降解大肠杆菌K-12。它催化SO发酵生成2，3-二羟基丙烷-1-磺酸盐（DHPS）、琥珀酸盐、乙酸盐和甲酸盐，是一种新型的混合酸发酵。它采用表征的SQ EmbdenMeyerhof-Parnas途径，如突变和蛋白质组学分析所证实。对于第二层，使用来自厌氧污水污泥的降解DHPS的脱硫弧菌属分离物，菌株DF 1。它催化另一种新的发酵，DHPS到乙酸和H2S。它的DHPS磺化途径通过差异蛋白质组学鉴定，并通过异源产生的酶证明：DHPS通过两种NAD（+）依赖性脱氢酶（DhpA，SlaB）经由3-磺基乙醛氧化为3-磺基乳酸（SL）; SL被已知来自好氧细菌的SL亚硫酸盐裂解酶（SuyAB）裂解为丙酮酸盐和亚硫酸盐。丙酮酸被氧化成乙酸，而亚硫酸盐在呼吸作用中被用作电子受体并被还原成H2S。总之，厌氧产硫SQ降解被证明是一个新的环节，在土壤地球化学硫循环。SQ也是食草动物和杂食动物绿色蔬菜饮食的组成部分，肠道微生物组中的H2S产生对人类健康和疾病有许多公认的和潜在的贡献。因此，重要的是要检查细菌SO降解也在人类肠道微生物组中，与H2S的生产，饮食条件和人类健康。
Sulfoquinovose (SO, 6-deoxy-6-sulfoglucose) is produced by plants and other phototrophs and its biodegradation is a relevant component of the biogeochemical carbon and sulfur cycles. SQ is known to be degraded by aerobic bacterial consortia in two tiers via C-3-organosulfonates as transient intermediates to CO2, water and sulfate. In this study, we present a first laboratory model for anaerobic degradation of SO by bacterial consortia in two tiers to acetate and hydrogen sulfide (H2S). For the first tier, SO-degrading Escherichia coli K-12 was used. It catalyzes the fermentation of SO to 2,3-dihydroxypropane-1-sulfonate (DHPS), succinate, acetate and formate, thus, a novel type of mixed-acid fermentation. It employs the characterized SQ EmbdenMeyerhof-Parnas pathway, as confirmed by mutational and proteomic analyses. For the second tier, a DHPS-degrading Desulfovibrio sp. isolate from anaerobic sewage sludge was used, strain DF1. It catalyzes another novel fermentation, of the DHPS to acetate and H2S. Its DHPS desulfonation pathway was identified by differential proteomics and demonstrated by heterologously produced enzymes: DHPS is oxidized via 3-sulfolactaldehyde to 3-sulfolactate (SL) by two NAD(+)-dependent dehydrogenases (DhpA, SlaB); the SL is cleaved by an SL sulfite-lyase known from aerobic bacteria (SuyAB) to pyruvate and sulfite. The pyruvate is oxidized to acetate, while the sulfite is used as electron acceptor in respiration and reduced to H2S. In conclusion, anaerobic sulfidogenic SQ degradation was demonstrated as a novel link in the biogeochemical sulfur cycle. SQ is also a constituent of the green-vegetable diet of herbivores and omnivores and H2S production in the intestinal microbiome has many recognized and potential contributions to human health and disease. Hence, it is important to examine bacterial SO degradation also in the human intestinal microbiome, in relation to H2S production, dietary conditions and human health.