Anguluri Kavitha, La China Salvatore, Brugnoli Marcello, De Vero Luciana, Pulvirenti Andrea, Cassanelli Stefano, Gullo Maria
Department of Life Sciences, University of Modena and Reggio Emilia, 42122 Reggio Emilia, Italy.
Polymers (Basel). 2022 May 13;14(10):2000. doi: 10.3390/polym14102000.
In this study, twelve strains of acetic acid bacteria (AAB) belonging to five different genera were tested for their ability to produce levan, at 70 and 250 g/L of sucrose concentration, respectively. The fructan produced by the bacterial strains was characterized as levan by NMR spectroscopy. Most of the strains produced levan, highlighting intra- and inter-species variability. High yield was observed for NBRC 101099 , DSM 14400 and DSM 9533 at 70 g/L of sucrose. A 12-fold increase was observed for NBRC 101099 at 250 g/L of sucrose concentration. Levan production was found to be affected by glucose accumulation and pH reduction, especially in DSM 14400 . All the strains showed a negative correlation with the increase in sucrose concentration. Among strains of genus, no clear effect of sucrose on levan yield was found. Results obtained in this study highlighted the differences in levan yield among AAB strains and showed interdependence between culture conditions, carbon source utilization, and time of incubation. On the contrary, the levan yield was not always related to the sucrose concentration.
在本研究中，分别在70 g/L和250 g/L的蔗糖浓度下，对属于五个不同属的12株醋酸菌（AAB）产生果聚糖的能力进行了测试。通过核磁共振光谱法将细菌菌株产生的果聚糖鉴定为果聚糖。大多数菌株都能产生果聚糖，这突出了种内和种间的变异性。在70 g/L蔗糖浓度下，NBRC 101099、DSM 14400和DSM 9533的产量较高。在250 g/L蔗糖浓度下，NBRC 101099的产量增加了12倍。发现果聚糖的产生受葡萄糖积累和pH降低的影响，尤其是在DSM 14400中。所有菌株都与蔗糖浓度的增加呈负相关。在该属的菌株中，未发现蔗糖对果聚糖产量有明显影响。本研究获得的结果突出了醋酸菌菌株在果聚糖产量上的差异，并表明培养条件、碳源利用和培养时间之间存在相互依赖性。相反，果聚糖产量并不总是与蔗糖浓度相关。
