Antimicrobial Activity Of Atratoxin From Local Sea Cucumber Holothuria atra (Jaeger)


Ibrahim Che Omar, Darah Ibrahim, Khaw Ai Guat dan Satheesh Nair


Simposium Sumber Alam Kebangsaan Pertama. Tema "Penggunaan Pengurusan Dan Pemuliharaan Alam Dalam Konteks Pembangunan Negara", Universiti Kebangsaan Malaysia, Kampus Sabah, Malaysia.




sea cucumber, Holothuria atra (Jaeger), antimicrobial agents, Atratoxin


At least 3 kinds of antimicrobial agents, namely Atratoxin A, B, and B2 have been isolated from the sea cucumber, Holothuria atra (Jaeger). In vitro, the agents exhibited high activity against various species of yeast and fungi. However bacterial species showed resistances against in vitro treatment with the agents. The toxicity effect of Atratoxin B1 was further investigated on the growth of Rhodotorula rubra and Aspergillus niger. The results revealed that Atratoxin B1 inhibited the development of yeast cells through the prevention of separation of daughter cell from the parent cell during budding. Cell Igsis occurred when the concentration of Atratoxin B, reached 4.6 ug/ml. Atratoxin B1 also prevented the development of fungal mycelium and its conidia. Nevertheless, the inhibition effect on spore germination could not be proven. Inhibitory mechanism can be related to the cell leakage which resulted the mycelium to become slender, flat and loss of rigidity. Tests on several dermatophytes gave the MIC values for Trichophyton rubrum, T. mentogrophytes, Microsporum gypseum and M. canis of 4.3, 1.4, 1.4 and 1.4 µg/ml Atratoxin Br respectively. Studies on some of the characteristics of atratoxin A, Bt and B2, revealed that the atratoxins were stable in the temperature range of 30 - 140°C and pH 3 -10. Addition of metal ions in the culture medium and treatment with trypsin did not show any significant inhibitory effect. Biochemical analysis of atratoxin B2 indicated that the agent is composed of carbohydrate, protein and steroid moiety, the later is absent in Atratoxin A and Br.