Role of secondary metabolites as defense chemicals against ice-ice disease bacteria in biofouler at carrageenophyte farms

Charles Santhanaraju Vairappan, and Anangdan, Sangeetha Priya and Kai, Lee Tan and Shigeki, Matsunaga (2010) Role of secondary metabolites as defense chemicals against ice-ice disease bacteria in biofouler at carrageenophyte farms. Journal of Applied Phycology, 22 (3). pp. 305-311. ISSN 0921-8971


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Carrageenophyte farming is an expanding economical activity in North Borneo Island, Malaysia. During routine monitoring of "ice-ice" disease and epiphyte outbreak at commercial farms, it was apparent that culture lines were heavily (60-80%) infested with biofoulers, particularly Acanthophora spp. and Laurencia majuscula. However, only L. majuscula showed dominance and flourished even during "ice-ice" disease outbreak. Presence of chemical defense against seaweed pathogens was investigated in two populations of L. majuscula collected from three major carrageenophyte farms in two districts; (A) Lohok Butun, Selakan Island, and Bum-Bum Island, in Semporna district, and (B) Telutuh, Carrington Reef, and Balambangan Island, in Kudat district. The first population contained elatol (1), and iso-obtusol (2), and, second population contained (Z)-10,15-dibromo-9-hydroxy-chamigra-1,3(15),7(14)-triene (3) and (E)-10-15-dibromo-9-hydroxy-chamigra-1,3(15),7(14)-triene (4), as their antibacterial metabolites. All four metabolites showed highly selective inhibition against "ice-ice" disease bacteria compared to human pathogens at 30 μg disk-1. In addition, seasonal variation of these compounds at two representative farms (Selakan Island [P-1] and Balambangan Island [P-2]) revealed a 120-170% increase in concentration during "ice-ice" disease outbreak. Microscopy of fresh specimens showed the presence of corps en cerise, which is the synthesis and storage site of halogenated metabolites at superficial cortical cells, branch tips, and trichoblasts. This suggests the importance of these metabolites as defense chemicals against "ice-ice" disease bacteria in L. majuscula that grows on seaweed culture lines. © Springer Science+Business Media B.V. 2009.

Item Type: Article
Uncontrolled Keywords: Biofouler, Carrageenophyte, Chamigrenes, Defense chemicals, Ice-ice disease, Laurencia majuscula
Subjects: Q Science > QH Natural history > QH301 Biology
Divisions: SCHOOL > Institute for Tropical Biology and Conservation
Depositing User: Unnamed user with email
Date Deposited: 08 Mar 2011 02:33
Last Modified: 13 Oct 2017 01:33

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