จำนวน Repository ( 2 )
Antimicrobial activity of endophytic fungi isolated from myrtaceae at kuankreng peatlands
The purpose of this research was to study antimicrobial activity of endophytic fungi isolated from Myrtaceae ( Melaleuca cajeputi Malaleuca leucadendra Syzygium cumini L. and Rhodomyrtus tomentasa (Ait.) Hassk.) at Kuankreng Peatlands. A total of 124 isolates of endophytic fungi were obtained from all plant types. Three week old fermentation broths of endophytic fungi were tested for antimicrobial activity against pathogenic microorganisms using the agar well diffusion method. Forty- six isolates (37.1%) inhibited at least 1 type of pathogen. Fermentation broth and cells of active endophytes were further extracted with organic solvents and tested for MIC using the microdilution broth method. The results show that 156 of the total of 174 crude extracts (89.6%) produced MIC ? 200 g/mL. The lowest MIC for S. aureus ATCC25923 MRSA SK1 P. aeruginosa ATCC27853 C. albicans ATCC90028C. neoformans ATCC90012 and M. gypseum were 128 200 200 64 200 16 and 200 g/mL respectively.
Screening and identification of lactic acid bacteria with antimicrobial activity against food-borne pathogen
This study focused on screening and identification of lactic acid bacteria with antimicrobial activity against Escherichia coli from milk samples. There were 250 isolates showing different antimicrobial activities. Five isolates with predominant anti-E. coli efficiency were chosen for the study of bacteria identification bacterial growth as well as the stability in pH change heating and proteolytic treatment. The sequences of 16s rDNA indicated that selected isolates were Lactobacillus sp.. The antimicrobial efficiency described in the term of Antimicrobial Index (AI) ranged from 0.63 to 0.84. However the anti-E coli activity did not change when performing the test under proteinase-treated condition and high temperature-treated condition. Conversely the pH adjustment of cell-free bacterial culture to 7.0 demolished their antimicrobial activity. This data implied that their antimicrobial activities were results of acidic condition produced by lactic acid bacteria. From this study the selected lactic acid bacteria showed their potential as a starter culture for fermented foods.