LeBlanc J G, Garro M S, Savoy de Giori G
Centro de Referencia para Lactobacilos (CERELA-CONICET), Chacabuco 145, San Miguel de Tucumán, 4000 Tucuman, Argentina.
Appl Microbiol Biotechnol. 2004 Jul;65(1):119-23. doi: 10.1007/s00253-003-1532-z. Epub 2004 Jan 16.
In this study, the behaviour of Lactobacillus fermentum CRL 722 and CRL 251 were evaluated under different pH conditions (pH 6.0, 5.5, 5.0, 4.5) and without pH control. Growth was similar under all conditions assayed except at pH 4.5. These microorganisms were able to eliminate raffinose, a nondigestible alpha-oligosaccharide (NDO) found in soy products, showing a consumption rate of 0.25 g l(-1) h(-1) (pH 6.0-5.0). The removal of raffinose was due to the high alpha-galactosidase (alpha-gal) activities of these lactic acid bacteria, which was highest at pH 5.5 (5.0 U/ml). The yield of organic acids produced during raffinose consumption was also highest at this pH. The results of this study will allow selection of the optimum growth conditions of L. fermentum with elevated levels of alpha-gal to be used in the reduction of NDO in soy products when used as starter cultures.
在本研究中，对发酵乳杆菌CRL 722和CRL 251在不同pH条件（pH 6.0、5.5、5.0、4.5）及无pH控制情况下的行为进行了评估。除pH 4.5外，在所有测定条件下生长情况相似。这些微生物能够消除棉子糖，棉子糖是一种存在于豆制品中的不可消化的α-低聚糖（NDO），在pH 6.0至5.0时显示出0.25 g l(-1) h(-1)的消耗速率。棉子糖的去除归因于这些乳酸菌的高α-半乳糖苷酶（α-gal）活性，其在pH 5.5时最高（5.0 U/ml）。在该pH下，棉子糖消耗过程中产生的有机酸产量也最高。本研究结果将有助于选择具有较高α-gal水平的发酵乳杆菌的最佳生长条件，以便在用作发酵剂时用于降低豆制品中的NDO。
