Utilization of paddy straw as potential feedstock for PHB production.
•
PHB production by halophilic bacteria by using saccharified paddy straw leachate.
•
Effect of C:N ratio and bacterial growth stage on PHB production.
•
Alkali pretreatment and enzymatic saccharification of paddy straw.
Abstract
The halophilic bacteria Bacillus cereus LB7 and Burkholderia gladioli 2S4R1 were found utilizing mixed sugars which are released upon saccharification of paddy straw. The C:N ratio for growth and PHB production by LB7 and 2S4R1 was optimized at 30:1 and 38:1, respectively and a novel growth media (PMS-NaCl) containing saccharified paddy straw leachate as the sole C source was formulated. The PMS-NaCl was used for studying the growth kinetics and PHB production rate. At optimized parameters, B. cereus LB7 and B. gladioli 2S4R produced PHB @ 0.387 g L−1 h−1 and 0.309 g L−1 h−1, respectively which was statistically at par with the PHB yield obtained by utilizing pure glucose as the sole C source. Based on findings, it is suggested that paddy straw hydrolysates can be used as a substrate to produce PHB by halophilic bacteria and explored further for industrial-scale applications.
Graphical abstract
Bacterial production of Poly-β-hydroxybutyrate using saccharified paddy straw leachate as a substrate.
