1.Anthocyanins from Clitoria ternatea Attenuate Food-Borne Penicillium expansum and its Potential Application as Food Biopreservative.
Chean Ring LEONG ; Muhammad Afif KAMARUL AZIZI ; Md Abu TAHER ; Suzana WAHIDIN ; Kok Chang LEE ; Wen Nee TAN ; Woei Yenn TONG
Natural Product Sciences 2017;23(2):125-131
Clitoria ternatea or Commonly known blue pea, is a perennial climber crop native to Asian countries. The current study was aimed to evaluate the antimicrobial activity C. ternatea extract on food borne microorganisms and its antifungal effect on Penicillium expansum. The extract showed significant antimicrobial activity against 3 Gram positive bacteria, 2 Gram negative bacteria and 1 filamentous fungus on disc diffusion assay. The extract also showed good biocidal effect on all Gram positive bacteria tested and P. expansum. However, the kill curve analysis revealed that the fungicidal activity of the extract against P. expansum conidia was depend on the concentration of the extract and the time of exposure of the conidia to the extract. The scanning electron micrograph of the extract treated P. expansum culture showed alterations in the morphology of fungal hyphae. The germination of P. expansum conidia was completely inhibited and conidial development was totally suppressed by the extract, suggesting the possible mode of action of anthocyanin. Besides, the extract also exhibited 5.0-log suppression of microbial growth relative to control in the rice model. The results indicate the potential use of the C. ternatea anthocyanin as food biopreservative.
Anthocyanins*
;
Asian Continental Ancestry Group
;
Clitoria*
;
Diffusion
;
Fungi
;
Germination
;
Gram-Negative Bacteria
;
Gram-Positive Bacteria
;
Humans
;
Hyphae
;
Peas
;
Penicillium*
;
Spores, Fungal
2.Antimicrobial activities of endophytic fungi residing in Aloe vera against diabetic wound pathogens
Md Abu Taher ; Tong Woei Yenn ; Leong Chean Ring ; Suzana Wahidin ; Mohd Azizan Mohd Noor ; Syarifah Ab Rashid ; Tan Wen-Nee
Malaysian Journal of Microbiology 2020;16(6):519-529
Aims:
Endophytic fungi are organisms that colonize living plant tissues without causing significant symptoms of
diseases. They are known as the repository of bioactive compounds. This study was aimed to isolate endophytic fungi
associated with Aloe vera and to assess their antimicrobial activity against the diabetic wound pathogens that result to
lower limb amputations.
Methodology and results:
In this study, 84 endophytic fungi were isolated from A. vera by using 5% sodium
hypochlorite and 70% ethanol as surface sterilants. On preliminary antimicrobial screening by agar plug assay, 12
(14.3%) isolates showed significant antagonistic activity on the test microorganisms. Two of the endophytes were
identified as Aspergillus flavus and Colletotrichum gloeosporioides through morphological and molecular techniques.
The fungal cultures fermented in shake flask were extracted subsequently with hexane, dichloromethane, ethyl acetate,
and n-butanol. Ethyl acetate and dichloromethane extracts of A. flavus and C. gloeosporioides inhibited all test bacteria.
The compounds in the extracts were seemed to be semi-polar in nature. On broth microdilution assay, minimal inhibitory
and minimal lethality concentration of ethyl acetate extracts of the fungi were found in the range of 0.63−2.50 and
1.25−5.00 mg/mL, respectively.
Conclusion, significance and impact of study
This study reveals that A. vera harbours a wide diversity of endophytic
fungi. A. flavus and C. gloeosporioides showing broad spectrum antimicrobial activity on wound pathogens may be
potential sources of bioactive compounds. Further investigations should be conducted to isolate and identify the
antimicrobial compound produced by these fungal isolates.
Endophytes--isolation &
;
purification
;
Aloe