PDF(Pubmed)
Abstract：
This study demonstrates that Lactobacillus can produce exopolysaccharides (EPSs) using alternative carbon sources, such as sugarcane molasses and glycerol. After screening 22 strains of Lactobacillus to determine which achieved the highest production of EPS based on dry weight at 37 °C, the strain Ke8 (L. casei) was selected for new experiments. The EPS obtained using glycerol and glucose as carbon sources was classified as a heteropolysaccharide composed of glucose and mannose, containing 1730 g.mol-1, consisting of 39.4% carbohydrates and 18% proteins. The EPS obtained using molasses as the carbon source was characterized as a heteropolysaccharide composed of glucose, galactose, and arabinose, containing 1182 g.mol-1, consisting of 52.9% carbohydrates and 11.69% proteins. This molecule was characterized using Size Exclusion Chromatography (HPLC), Gas chromatography-mass spectrometry (GC-MS), Fourier-transform infrared spectroscopy (FTIR), and proton nuclear magnetic resonance spectroscopy (1H-NMR). The existence of polysaccharides was confirmed via FT-IR and NMR analyses. The results obtained suggest that Lacticaseibacillus casei can grow in media that use alternative carbon sources such as glycerol and molasses. These agro-industry residues are inexpensive, and their use contributes to sustainability. The lack of studies regarding the use of Lacticaseibacillus casei for the production of EPS using renewable carbon sources from agroindustry should be noted.
摘要：
这项研究表明，乳酸杆菌可以使用替代碳源产生胞外多糖（EPS），如甘蔗糖蜜和甘油。在筛选22株乳杆菌以确定在37°C下基于干重获得最高的EPS产量后，菌株Ke8(L.casei)被选为新实验。使用甘油和葡萄糖作为碳源获得的EPS被归类为由葡萄糖和甘露糖组成的杂多糖，含有1730g.mol-1，由39.4%的碳水化合物和18%的蛋白质组成。使用糖蜜作为碳源获得的EPS被表征为由葡萄糖组成的杂多糖，半乳糖,和阿拉伯糖,含有1182g.mol-1，由52.9％的碳水化合物和11.69％的蛋白质组成。使用尺寸排阻色谱法(HPLC)表征该分子，气相色谱-质谱(GC-MS),傅里叶变换红外光谱(FTIR),和质子核磁共振波谱(1H-NMR)。通过FT-IR和NMR分析证实了多糖的存在。获得的结果表明，干酪乳杆菌可以在使用甘油和糖蜜等替代碳源的培养基中生长。这些农业工业残留物价格低廉，它们的使用有助于可持续性。应注意，缺乏有关使用干酪乳杆菌生产EPS的研究。
