Poly-B-hydroxybutyrate (PHB): A Biodegradable Polymer of Microbial Origin - Natural Polymers, Biopolymers, Biomaterials, and Their Composites, Blends, and IPNs - page 48

Figure 1. Growth and PHB production in Pseudomonas sp. RZS1 at different time interval.
Figure 2. Growth curve and intracellular accumulation and mobilization of PHB in A. feacalis.
PhB ProduCtioN
Conditions and Nutrient sources
The PHB accumulation in cytoplasm is due to the unbalance of essential nutrients,
such as nitrogen, phosphate, potassium, iron, magnesium or oxygen. Feeding small
quantity of nitrogen promotes accumulation of PHB than without nitrogen. The higher
nitrogen leads to the intracellular degradation of PHB and also reduction of accu-
mulation. Sayyed and Chincholkar (2004) have reported maximum accumulation of
PHB in A. faecalis by providing nitrogen deficiency. Similar results were reported by
Sayyed and Gangurde (2010) for Pseudomonas sp.
Growth Phase
The PHB accumulation is the growth associated property of bacterium, the exponen-
tial phase of culture shows higher state of PHB accumulation. In addition, it provides