Effects of prebiotic activity of Ganoderma lucidum extracts on bifidobacterium species and faecal microflora in vitro

• Main Author: Shaari, Mohd Yamin
• Format: Thesis
• Language: English
• Published: 2012
• Online Access: http://psasir.upm.edu.my/id/eprint/20570/1/FBSB_2012_3_IR.pdf; http://psasir.upm.edu.my/id/eprint/20570/

Ganoderma lucidum is a fungus that has long history in Japan and China as traditional medicine with many claims about its health-stimulating properties. Many researches conducted by scientists have proven the medical significance of polysaccharides extracted from G. lucidum such as inhibition of tumour cell, effectiveness in hyperglycaemic and hypoglycaemia, and hypertension treatment. The polysaccharides were also reported to have potential to act as prebiotics to support the growth of probiotic bacteria. Thus, in this study, the effects of polysaccharides extracted from G. lucidum and its fraction were tested on selected Bifidobacterium strains and bacterial microflora from faeces in vitro. Three Bifidobacterium strains used were revived from stock cultures and confirmed as pure culture through microscopic test. Crude polysaccharides from G. lucidum (GLCP) were successfully obtained and fractionated into four types of fraction named as Polysaccharides fraction 1 (PF-1), Polysaccharides fraction 2 (PF-2), Polysaccharides fraction 3 (PF-3) and Polysaccharides fraction 4 (PF-4). PF-2 showed promising results in previous studies (Hamim, 2009) was selected for further test in this study. The growth rate of three types of Bifidobacterium strains was tested in pure culture fermentation. B. pseudocatenulatum G4 grew at the growth rate of 0.67 ± 0.09 h-1. B. breve ATCC 15700 and B. longum BB536 grew at 0.60 ± 0.09 h-1 and 0.64 ± 0.05 h-1, respectively. Glucose was served as control. In pure culture fermentation, 5 batch cultures of tryptone peptone yeast (TPY) medium were supplemented with different carbon sources namely glucose, fructooligosaccharides (FOS), inulin, GLCP and PF-2. The growth patterns of all Bifidobacterium strains increased in each carbon sources used with the highest growth was in FOS and followed by inulin, glucose, PF-2 and GLCP. In mixed culture fermentation, two prebiotic candidates (GLCP and PF-2) and commercial prebiotics (inulin and FOS) were tested to determine their impact to the bacterial microflora simulated using faecal culture. The increment pattern was shown in Bifidobacterium genus with the maximum growth at 24 h were 8.3 ± 0.3 log10 cells/ml for FOS. Meanwhile, maximum growth up to 8.3 ± 0.3, 8.0 ± 0.4, 7.9 ± 0.1 and 7.5 ± 0.2 log10 cells/ml were recorded for inulin, glucose, PF-2 and GLCP, respectively. Growth increase was also shown in Lactobacillus genus and higher than Bifidobacterium genus for FOS fermentation. However, the results were positive as Bifidobacterium and Lactobacillus genus were considered as beneficial bacteria for the host. For GLCP and PF-2, the increased growth showed promising result as the increases were 0.3 and 0.7 log10 cells/ml for Bifidobacterium genus and 0.7 and 1.0 log10 cells/ml for Lactobacillus genus at 24 h, respectively. On the other hand, the inhibition pattern could still be observed on Salmonella and E. faecalis when compared to glucose (control) in all tests conducted. HPLC result showed that the pattern of lactic acid and acetic acid production might directly result in antimicrobial action. From this research, it can be concluded that Ganoderma lucidum extracts (GLCP and PF-2) have prebiotic capability and can be considered for commercialization in the future.