Volatile bromocarbons produced by Falkenbergia stages of Asparagopsis spp. (Rhodophyta)

Abstract

Volatile halocarbons released by 12 Falkenbergia phase isolates of Asparagopsis taxiformis and Asparagopsis armata collected from widely scattered geographical locations were identified using a purge and trap technique and gas chro‐matography/mass spectrometry. Production of the compounds under normal and high irradiance was quantified where possible. Bromoform (CHBr 3 ), dibromomethane (CH 2 Br 2 ), 1,2‐di‐bromoethylene (C 2 H 2 Br 2 ), dibromochloromethane (CHBr 2 Cl), and tribromoethylene (C 2 HBr 3 ) were identified as algal products. C 2 H 2 Br 2 and C 2 HBr 3 have not previously been recorded as natural products. Considerable qualitative and quantitative differences existed between isolates in the halocarbons released. The rates of CHBr 3 and C 2 H 2 Br 2 production were negatively correlated. Increased irradiance invariably resulted in higher rates of release of halocarbons. Initial rates of production ranged between <8 and 866 ng g −1 fresh weight (FW) h −1 for CHBr 3 , <3 and 59 ng g −1 FW h −1 for CH 2 Br 2 , and <0.4 and 17 ng g −1 FW h −1 for C 2 H 2 Br 2 .