Anjali Mohan Nair1, Kanakalakshmi Annamalai1, Seralathan Kamala Kannan2 and Shanthi Kuppusamy1*
Author Address :
1Department of Environmental Science, PSG College of Arts and Science, Coimbatore 641014, Tamil Nadu, India
2Division of Biotechnology, Advanced Institute of Environment and Bioscience, College of Environmental and
Bioresource Sciences, Chonbuk National University, Iksan-570752, South Korea.
*For correspondence e-mail: firstname.lastname@example.org
Batch cultures of Bacillus subtilis AMN1 was screened for the production of polyhydroxyalkanoate (PHA) using sucrose as a carbon source. In subsequent experiments, sugarcane molasses was used as renewable carbon source since it was rich in sucrose (50%), leading to develop a low cost process of PHA production. The maximum PHA production (2.09 g/100 mL) and dry cell weight (DCW) production (1.5g/100 mL) was observed in the medium amended with 10% sugarcane molasses. The influence of pH on PHA production was also evaluated. It was found that pH 7.0 yielded a maximum DCW of 1.89 g/100 mL and PHA of 1.39 g/100 mL. The UV spectral analysis of PHA showed the presence of ester group (CH3-COO) by recording a sharp peak between 230-240 nm. The Fourier transform infrared spectrum of the synthesized PHA showed a transmission band at wave number 1726 cm-1 which is a characteristic of C=O stretching of carbonyl group of the polymer. The major compounds of PHA was detected and identified as aliphatic polymer esters using Gas chromatography mass spectrometry. The prominent peaks of proton and carbon Nuclear magnetic resonance spectra of the polymer depicted that it can be hydroxyl hexanoate.
Bacillus subtilis, biopolymer, fermentation, PHA, sugarcane molasses.
Article Info :
Received 18-Nov-2013, Revised 03-Apr-2014, Accepted 09-Dec-2013