28

2 Integrated Approaches for the Production of Biodegradable Plastics and Bioenergy from Waste

substrates, such as glucose, lactose, propionate, acetate, malate, and lactate, and it

was found that the strain WP3-5 utilizes lactate, propionate, malate, and acetate

which lead to the production of H2, whereas it was able to synthesize PHB on

propionate and acetate. Under specific pH stress conditions, PHB synthesis can

also decrease the H2 production [39]. However, such a decrease was not observed

in R. palustris under limited amount of nitrogen. Under a nitrogen-limited growth

condition, R. palustris synthesized 40 mg/l/day of PHB and around 200 ml/l/day of

H2 was also produced when the studies were supplemented with 60 mg/l/day of

nitrogen [1].

2.7

Conclusions

Both biodegradable plastics and bioenergy were produced separately from differ-

ent wastes like food, dairy, starch wastes, and wastewater itself. However, separate

processes and systems should be set up for the production of plastics and bioen-

ergy which are cumbersome, not eco-friendly and not economical. Hence, integrated

production of bioenergy and bioplastics will be an advantageous process. However,

further improvement of microbial strains and more integrated studies on different

wastes or their derived products for the production of bioenergy and bioplastics will

definitely augment the existing processes for the economic production of both the

products at industrial level.

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