Department of Molecular & Cellular Biology
University of Cape Town
Rondebosch, 7701, RSA
Ph: # (0)21 650 5070
The abalone Haliotis midae ingests a diversity of algae. We have found that the digestive tract of H. midae is colonized by highly active polysaccharolytic bacteria which assist in the digestion of seaweed ingested by the abalone. Our recent success in generating gnotobiotic (bacteria free) abalone has enabled systematic investigation of the role these bacteria play with regard to the well-being of H. midae. We have developed probiotics that enhance the growth rate and disease resistance of farmed abalone. Currently, we are elucidating the genetics of the abalone immune system with the use of microarray technology and qPCR.
The marine alga, Gracilaria gracilis, is an important source of agar which is incorporated as a solidifying agent in nutrient media used to cultivate microorganisms in the laboratory. Very little is known about the pathogens which contributed to the collapse of the Saldanha Bay population in 1989. This project involves characterisation of the bacterial epiphytes colonizing the surface of G. gracilis and the mechanisms which induce their pathogenicity towards the host plant. A second aspect of the project is concerned with the use of recombinant DNA technology to increase the resistance of farmed G. gracilis to disease. Thus, the synthesis and regulation of pathogenesis-related proteins produced by G. gracilis in response to infection is being investigated with the aim of expressing these constitutively in farmed G. gracilis in order to increase their resistance to disease.
- Iyer, R., Bolton, J.J. and Coyne, V.E. (2005). Gracilarioid species (Gracilariaceae, Rhodophyta) occurring in southern Africa, with the description of Gracilariopsis funicularis sp. nov. African Journal of Marine Science 27(1): 97-105.
- Macey, B.M. and Coyne, V.E. (2005) Improved growth rate and disease resistance in farmed Haliotis midae through probiotic treatment. Aquaculture 245: 249-261.
- Iyer, R., Tronchin, E.M., Bolton, J.J. and Coyne, V.E. (2005) Molecular systematics of the Gracilariaceae (Gracilariales, Rhodophyta) with emphasis on southern Africa. Journal of Phycology 41: 672-684.
- Macey, B.M. and Coyne, V.E. (2006) Colonization of the gastrointestinal tract of the farmed South African abalone Haliotis midaeby the probionts Vibrio midae SY9, Cryptococcus sp. SS1, and Debaryomyces hansenii AY1. Marine Biotechnology 8: 246–259.
- ten Doeschate, K.I. and Coyne, V.E. (2008) Improved growth rate in farmed Haliotis midae through probiotic treatment.Aquaculture Volume 284, Issues 1-4, Pages 174-179.
- Janse van Rensburg, M. and Coyne, V. E. (2008) The role of electron transport in the defence response of the South African abalone, Haliotis midae. Fish & Shellfish Immunology, doi: 10.1016/j.fsi.2008.09.01
Dr Kim ten Doeschate