Regina Nogueira
Institute for Sanitary Engineering and Waste Management , Germany
Title: Cost effective production of Polyhydroxyalkanoates biopolymers using mixed microbial culture and industry waste water: An ecofriendly approach
Biography
Biography: Regina Nogueira
Abstract
Statement of the Problem: Plastic and plastic products have become integrated part of our daily life. Even after recycling 5.6 million tons of undegradable plastic waste is produced per year in India which will persist in landscapes. Polyhydroxyalkanoate (PHA) are biodegradable, biocompatible, and have thermoplastic features; and can substitute conventional plastics. PHA biopolymer cost is estimated to be ranging between US$2.25–2.75/lb which is significantly higher than the conventional plastics and is attributed to use of pure cultures, high price of high purity substrates, and usage of batch and fed-batch production modes, thus hampering the wide commercialization and industrialization. To make PHA production economical, cheap industrial waste water like yeast production industries, which are rich in volatile fatty acids can be used. This will serve purpose of reducing the cost of production and waste water conditioning to reduce VFA (volatile fatty acids) content. Use of PHA producing microorganism rich mixed microbial culture will allow bioreactor operation under non-sterile condition reducing costs further.
Objectives: The objective of current study is cost effective production of PHA namely PHB and PHV by using mixed microbial culture (MMC) by feeding yeast industry waste water.
Methodology: To produce MMC, activated sludge was subjected to ecological pressure of aerobic dynamic feeding, in sequencing batch reactor selecting the PHA accumulators. PHA accumulation capacity of MMC was evaluated using batch, fed batch and continuous mode of bioreactor operation using acetate and waste water as feed.
Results: Experiment with waste water produced 71.63 % PHA per dry cell weight (DCW) in batch mode and continuous mode produced 65.38 % PHA per DCW hence yielding 242.21 tons and 296.46 tons of theoretical possible production per year respectively.
Recommendation: We recommend using continuous reactor due to its simplicity and ease of operation and ability to handle large quantity of feed in very small reactor volume.