Antibacterial Activity Of Some Bryophytes

The bryophytes are the second largest group of green land plants after the flowering plants. Most bryophytes live in rugged environment, so they are able to produce abundant secondary metabolites. Bryophytes are regarded as one of the important sources of biologically active, naturally occurring compounds.This work aims to supply some theoretical knowledge about biological activity of bryophytes in order to attract scientists' interest and recognition. Some valuable species with distinct antibacterial activity are screened through this work, and the scientific evidence for the development of antibiotics is expected to be presented.The antibacterial activity of extracts of 67 bryophytes from some Chinese provinces (Anhui, Fujian, Guangxi, Hainan, Zhejiang, Shanghai, and Hong Kong) and Mongolia. These bryophytes include 45 liverworts belonging to 39 genera in 24 families, 21 mosses belonging to 17 genera in 16 families, and one hornwort.Disc diffusion assay was used to screen for antibacterial activity of extracts of 67 bryophytes against seven bacteria. The antibacterial activity of the alcoholic extracts of eight species (two liverworts and six mosses) further expressed as MICs (minimal inhibitory concentration) and MBCs (minimal bactericidal concentration), were compared with three reference antibiotic drugs. In addition, the curves of the number of surviving the bacteria were presented. The result indicated that out of 67 bryophytes, 60 species (89.6%) have detectable antibacterial activity against at least two of the selected seven bacteria, including four Gram positive (Bacillus megaterium, Bacillus subtilis, Bacillus thuringiensis, and Staphylococcus aureus) and three Gram negative (Escherichia coli, Pseudomonas aeruginosa, and Pseudomonas putida). Seventeen species (two mosses and 15 liverworts) are active against all seven selected bacterial species. Other seven species (two liverworts and five mosses) are inactive against all seven bacteria. Out of the seven bacteria tested, Staphylococcus aureus is most resistant to the extracts of both liverworts and mosses. Pseudomonas putida is most sensitive to the extracts of mosses, and Bacillus subtilis is most sensitive to the extract of liverworts.According to the result of this work and published literature, the conclusions are as follows:The ethanolic extracts of most tested bryophytes exhibited detectable and...