Abstract:
This study was conducted to evaluate the potential production of
polyhydroxyalkanoate (PHA) by bacteria isolated from water sample of mangrove
environment in Bakau Tinggi, Kemaman, Terengganu. A total of 134 bacteria
colonies isolated anq screened using Nile red staining in order to observe the potential
PHA producer. A total of 15 colonies when glucose used as a carbon source and 6
colonies when fructose used as a carbon source was observed to emit pink
fluorescence when viewed under UV light. This indicates the probable present of
PHA granules in those bacteria. There are possibilities where the Nile red staining
was only indicates the present of fatty acid in bacteria cell. Shaken-flasks culture with
nutrient limitation and addition of excess carbon sources (glucose, fructose, cooking
oil, oleic acid) resulting on the growth of bacteria strain in medium supplemented
with glucose and fructose. However, no growth observed in medium supplemented
with cooking oil and oleic acid. This phenomenon probably occurred due to the
different ability of the bacteria to synthesize and utilize the carbon sources
supplement for growth or PHA production. The result of gas chromatography
indicates the production of MCL-PHA by strain R6(-6)50.1 using glucose as a carbon
source. MCL-PHA produced consist a monomer of 3-hydroxydodecanoate (C12) and
3-hydroxytetradecanoate (C14) with a total PHA content of 2.8 wt%. The strain was
tested as gram-negative by using Gram staining method. The complete identification
of bacteria species by using Polymerase Chain Reaction (PCR) is proposed on the
future study.
