Environmental and Intestinal Phylum Firmicutes Bacteria Metabolize the Plant Sugar Sulfoquinovose via a 6-Deoxy-6-sulfofructose Transaldolase Pathway
Environmental and Intestinal Phylum Firmicutes Bacteria Metabolize the Plant Sugar Sulfoquinovose via a 6-Deoxy-6-sulfofructose Transaldolase Pathway
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DOI：
10.1016/j.isci.2020.101510
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发表时间：
2020-09-25
期刊：
影响因子：
5.8
通讯作者：
Schleheck, David
中科院分区：
文献类型：
--
作者：
Frommeyer, Benjamin;Fiedler, Alexander W.;Schleheck, David
细菌降解植物、藻类和蓝藻产生的6-脱氧-6-磺基葡萄糖（SQ，6-deoxy-6-sulfoglucose）是生物地球化学碳硫循环的重要组成部分。在这里，我们揭示了第三个生化途径的主要SQ降解好氧芽孢杆菌aryabhattai菌株。异构酶将SQ转化为6-脱氧-6-磺基果糖（SF）。一种新的转醛酶将SF切割成3-磺基乙醛（SLA），而非磺化的C-3-（甘油酮）-部分被转移到受体分子甘油醛磷酸（GAP），产生果糖-6-磷酸（F6 P）。肠厌氧菌如金黄色肠球菌、共生梭菌和直肠真杆菌菌株在与SQ发酵生长期间也表达转醛醇酶途径基因簇。目前已知的SQ催化剂的三种生化策略反映了对不同细菌的有氧或厌氧生活方式的适应。这些途径在肠（科）肠杆菌科和（门）厚壁菌门菌株中的出现进一步突出了绿色饮食SQ通过肠道微生物群落最终代谢为硫化氢的潜在重要性。
Bacterial degradation of the sugar sulfoquinovose (SQ, 6-deoxy-6-sulfoglucose) produced by plants, algae, and cyanobacteria, is an important component of the biogeochemical carbon and sulfur cycles. Here, we reveal a third biochemical pathway for primary SQ degradation in an aerobic Bacillus aryabhattai strain. An isomerase converts SQ to 6-deoxy-6-sulfofructose (SF). A novel transaldolase enzyme cleaves the SF to 3-sulfolactaldehyde (SLA), while the non-sulfonated C-3-(glycerone)-moiety is transferred to an acceptor molecule, glyceraldehyde phosphate (GAP), yielding fructose-6-phosphate (F6P). Intestinal anaerobic bacteria such as Enterococcus gilvus, Clostridium symbiosum, and Eubacterium rectale strains also express transaldolase pathway gene clusters during fermentative growth with SQ. The now three known biochemical strategies for SQ catabolism reflect adaptations to the aerobic or anaerobic lifestyle of the different bacteria. The occurrence of these pathways in intestinal (family) Enterobacteriaceae and (phylum) Firmicutes strains further highlights a potential importance of metabolism of green-diet SQ by gut microbial communities to, ultimately, hydrogen sulfide.