Kouitcheu Mabeku Laure Brigitte, Ngue Samuel, Bonsou Nguemo Idris, Leundji Hubert
Microbiology and Pharmacology Laboratory, Department of Biochemistry, Faculty of Science, University of Dschang, P. O. Box 67, Dschang, Cameroon.
Gastroenterology Department, Laquintinie Hospital of Douala, P. O. Box 4035, Douala, Cameroon.
BMC Res Notes. 2020 Feb 10;13(1):64. doi: 10.1186/s13104-020-4923-7.
The present study was designed to evaluate the inhibitory effect of lactic acid bacteria (LAB) isolates from the fermented cocoa juice and their cell-free culture supernatants (CFS) against Helicobacter pylori strains and their potential as good probiotic. Isolation of lactic acid bacteria (LAB) was performed by culture and subculture of sample on MRS agar. Morphological characteristics, Gram staining and catalase reaction were used to identify the isolates. The antagonistic activity of LAB was tested using the agar spot-on-lawn method and the inhibitory effect of CFS using well diffusion assay. Acid tolerance and resistance to antibiotics tests were used to evaluate the probiotic potential of LAB isolates.
Antagonistic effect was observed in 65.52% of isolated LAB. Isolate LAB19 showed the broader spectrum of antagonistic effect. The overall inhibitory activity was two to three folds reduced when CFSs were used instead of LAB isolates themselves. Our data showed that LAB19 controlled H. pylori growth using bacteriocins and that LAB4', LAB8, LAB11', LAB12, LAB13', LAB15, LAB16 and LAB17 were through organic acids. LAB9, LAB11' and LAB12 showed properties of probiotic tested. In this study, nine LAB isolates were found to possess anti-Helicobacter activity and some preliminary probiotic properties.
本研究旨在评估从发酵可可汁中分离出的乳酸菌(LAB)及其无细胞培养上清液(CFS)对幽门螺杆菌菌株的抑制作用及其作为优质益生菌的潜力。通过在MRS琼脂上对样品进行培养和传代培养来分离乳酸菌(LAB)。利用形态学特征、革兰氏染色和过氧化氢酶反应来鉴定分离株。采用琼脂点种法检测LAB的拮抗活性,采用打孔扩散法检测CFS的抑制作用。通过耐酸性和抗生素抗性试验来评估LAB分离株的益生菌潜力。
在分离出的LAB中,65.52%表现出拮抗作用。分离株LAB19表现出更广泛的拮抗作用谱。当使用CFS而非LAB分离株本身时,总体抑制活性降低了两到三倍。我们的数据表明,LAB19利用细菌素控制幽门螺杆菌的生长,而LAB4'、LAB8、LAB11'、LAB12、LAB13'、LAB15、LAB16和LAB17是通过有机酸发挥作用。LAB9、LAB11'和LAB12表现出所测试的益生菌特性。在本研究中,发现9株LAB分离株具有抗幽门螺杆菌活性和一些初步的益生菌特性。