Genc Berna, Karatas Seyda Merve, Tunç Merve Tuğçe
Department of Genetics and Bioengineering, Gumushane University, Baglarbasi Road, 29100 Gumushane, Turkey.
Department of Food Engineering, Gumushane University, Baglarbasi Road, 29100 Gumushane, Turkey.
Food Technol Biotechnol. 2024 Dec;62(4):480-487. doi: 10.17113/ftb.62.04.24.8606.
Given the potential of microbial exopolysaccharides from lactic acid bacteria in various industrial processes, alternative sources for the isolation of lactic acid bacteria are highly topical. In this study, we used a traditional sourdough from einkorn ( L. ssp. ) as a source of lactic acid bacteria for the isolation, identification and determination of exopolysaccharide producers.
The sourdough was prepared from einkorn according to the traditional method. Lactic acid bacteria were isolated and purified using the single colony technique on MRS and M17 media. The isolates were characterised using matrix-assisted laser desorption ionization-time of flight mass (MALDI-TOF) spectrometry. All isolates were analysed for extracellular polysaccharide production and one isolate was selected for purification and characterisation of its polysaccharide.
The isolates were identified as , , , , and . The production of exopolysaccharides by all lactic acid bacteria was evaluated and it was found that all strains (except one) were capable of producing exopolysaccharides. One polysaccharide (EPS-SL70) was purified from the isolates of SL70. This anionic heteropolysaccharide had, in addition to the carbohydrate backbone, a protein structure that did not contain nucleic acid. The carbohydrate backbone consisted of mannose, glucose, rhamnose, arabinose, xylose and galactose.
The microbial flora of traditional einkorn sourdough has been identified in this study and represents the first report on the exopolysaccharide production by lactic acid bacteria in traditional einkorn sourdough. Additionally, from einkorn sourdough was identified as a new exopolysaccharide producer.
鉴于乳酸菌产生的微生物胞外多糖在各种工业过程中的潜力，寻找分离乳酸菌的替代来源成为当前热门话题。在本研究中，我们使用了来自单粒小麦（L. ssp.）的传统酸面团作为乳酸菌的来源，用于分离、鉴定和确定胞外多糖产生菌。
按照传统方法用单粒小麦制备酸面团。采用单菌落技术在MRS和M17培养基上分离和纯化乳酸菌。使用基质辅助激光解吸电离飞行时间质谱（MALDI-TOF）对分离菌株进行鉴定。分析所有分离菌株的胞外多糖产生情况，并选择一株进行多糖的纯化和特性分析。
分离菌株被鉴定为 、 、 、 、 和 。评估了所有乳酸菌的胞外多糖产生情况，发现所有菌株（除一株外）均能产生胞外多糖。从SL70分离株中纯化出一种多糖（EPS-SL70）。这种阴离子杂多糖除碳水化合物主链外，还具有不含核酸的蛋白质结构。碳水化合物主链由甘露糖、葡萄糖、鼠李糖、阿拉伯糖、木糖和半乳糖组成。
本研究鉴定了传统单粒小麦酸面团的微生物菌群，这是关于传统单粒小麦酸面团中乳酸菌产生胞外多糖的首次报道。此外，从单粒小麦酸面团中鉴定出 为一种新的胞外多糖产生菌。
