Torres Andrea Carolina, Vannini Verónica, Bonacina Julieta, Font Graciela, Saavedra Lucila, Taranto María Pía
Centro de Referencia para Lactobacilos (CERELA)-CONICET, San Miguel de Tucumán, Tucumán, Argentina.
BMC Microbiol. 2016 Oct 13;16(1):240. doi: 10.1186/s12866-016-0854-9.
Despite the fact that most vitamins are present in a variety of foods, malnutrition, unbalanced diets or insufficient intake of foods are still the cause of vitamin deficiencies in humans in some countries. Vitamin B (Cobalamin) is a complex compound that is only naturally produced by bacteria and archea. It has been reported that certain strains belonging to lactic acid bacteria group are capable of synthesized water-soluble vitamins such as those included in the B-group, as vitamin B. In this context, the goal of the present paper was to evaluate and characterize the production of vitamin B in Lactobacillus coryniformis CRL 1001, a heterofermentative strain isolated from silage.
Cell extract of L. coryniformis CRL 1001, isolated from silage, is able to correct the coenzyme B requirement of Salmonella enterica serovar Typhimurium AR 2680 in minimal medium. The chemical characterization of the corrinoid-like molecule isolated from CRL 1001 cell extract using HPLC and mass spectrometry is reported. The majority of the corrinoid produced by this strain has adenine like Coα-ligand instead 5,6-dimethylbenzimidazole. Genomic studies revealed the presence of the complete machinery of the anaerobic biosynthesis pathway of coenzyme B. The detected genes encode all proteins for the corrin ring biosynthesis and for the binding of upper (β) and lower (α) ligands in one continuous stretch of the chromosome.
The results here described show for the first time that L. coryniformis subsp. coryniformis CRL 1001 is able to produce pseudocobalamin containing adenine instead of 5,6-dimethlbenzimidazole in the Coα-ligand. Genomic analysis allowed the identification and characterization of the complete de novo biosynthetic pathway of the corrinoid produced by the CRL 1001 strain.
尽管大多数维生素存在于多种食物中，但在一些国家，营养不良、饮食不均衡或食物摄入不足仍是人类维生素缺乏的原因。维生素B（钴胺素）是一种复杂化合物，仅由细菌和古生菌天然产生。据报道，某些乳酸菌菌株能够合成水溶性维生素，如B族维生素中的那些，作为维生素B。在此背景下，本文的目标是评估和表征从青贮饲料中分离出的异型发酵菌株棒状乳杆菌CRL 1001中维生素B的产生情况。
从青贮饲料中分离出的棒状乳杆菌CRL 1001的细胞提取物能够在基本培养基中纠正鼠伤寒沙门氏菌AR 2680对辅酶B的需求。报道了使用高效液相色谱法和质谱法对从CRL 1001细胞提取物中分离出的类咕啉分子进行的化学表征。该菌株产生的大多数类咕啉具有腺嘌呤样的Coα配体，而非5,6-二甲基苯并咪唑。基因组研究揭示了辅酶B厌氧生物合成途径的完整机制。检测到的基因编码了在染色体的一个连续区段中参与咕啉环生物合成以及上（β）下（α）配体结合的所有蛋白质。
此处所述结果首次表明，棒状乳杆菌亚种棒状乳杆菌CRL 1001能够产生在Coα配体中含有腺嘌呤而非5,6-二甲基苯并咪唑的假钴胺素。基因组分析使得能够鉴定和表征CRL 1001菌株产生的类咕啉的完整从头生物合成途径。
