Research Areas/Interest

 Malaysia produced high amount of lignocellullosic biomass which consisting of three types of polymers; cellulose, hemicelluloses and lignin that are strongly intermeshed and chemically bonded by non-covalent forces and by covalent cross-linkages. One of the abundant agricultural wastes which have high lignocellulose content is lemongrass leaves. Lemongrass leaves consisted of 58% of hemicelluloses, 65-86%% citral, volatile oil 0.2-04%, Myrcene 12-20% and 11% of lignin. Nowadays, more than 100 hectares of lemongrass farm in Malaysia produce about 200 tonne of dry bagasse (leaves) per year.  The waste of lemongrass leaves are partially dried in the fields and a fraction is burned to generate steam for stripping while the rest is left in the fields to naturally degrade. The usage as ruminant feedstock is however not a favor due to animal rejection against the residual sweet aroma and flavor.  Although the utilization of lemongrass leaves have been widely used in various fields, the biotechnology application of lemon grass leaves using microbial bioproccesing has not been study intensively. Due to high amount of lignocelluloses and citral content, it has potential use for vanillin production. Vanillin is the characteristic aroma component of the vanilla pod and frequently used for the production of flavors for foods and fragrances for perfumes. At present, “artificial” or “nature-identical” vanillin is mostly produced from petrochemicals like guaiacol and from lignin. Due to the increasing demand for healthy and natural food, there is a growing interest to produce vanillin from natural raw materials by biotransformation, which can then be regarded as a “natural” aroma chemical. This research will help to transform lemongrass leaves to commercial products as final yields (vanillin) with the use of potential fungi screened during preliminary study. Main work is to understand the biochemical pathways, the enzymes and the mechanism involved to obtain high yields of vanillin.

Several objectives are outlined below as precursors for the aims to be accomplished.

  • To study the effect of lemongrass leaves pretreatment (chemical, physical and enzymatic) method on ferulic acid recovery.
  • To isolate, screen and identify potential fungi that can convert ferulic acid to vanilin using one step conversion.
  • To screen factors influenced in vanillin production using two level factorial.
  • To optimize vanillin production in batch culture using response surface methodology (CCD).
  • To identify and characterize the profile of enzymes responsible in one step bioconversion of ferulic acid to vanillin
  • To conduct biostructural analysis of selected enzymes responsible in one step bioconversion of ferulic acid to vanillin.