Exploring soil bacterial isolates for the production of biopolymers

Savitha, S. (2010) Exploring soil bacterial isolates for the production of biopolymers. [Student Project Report]

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Abstract

This Dissertation / Report is the outcome of investigation carried out by the creator(s) / author(s) at the department/division of Central Food Technological Research Institute (CFTRI), Mysore mentioned below in this page.

Item Type:	Student Project Report
Additional Information:	The increase in the demand of plastic has accelerated in the production of the petrochemical plastics. The plastics are being used in various industries. The increase in the demand of plastic as been correlated the increase in environmental pollution, which has become a threat of life and atmosphere. Various steps have been taken to over come this problem. Among which biodegradable plastics have become a boon of the life and atmosphere. The bioplastics are being used in various parts of the world, but due to its high production cost, the demand is being decreased commercially. Bioplastics are nothing but polyhydroxyalkanotes (PHA) produced by various microorganisms. The microorganisms produce PHA under nutritional depletion conditions, which occur under limiting supplement of N, P, S, O and Mg, but with excess supplement of carbon sources. Polyhydroxyalkanotes are polyester of 3-, 4-, 5-, 6- hydroxyalkanoic acid synthesized by numerous bacteria as intracellular carbon and energy storage compound, in the present work Rhizobium spp. which were maintained in Food Microbiology department, CFTRI, Mysore were used In the present study experiments were conducted for optimization of various media, effect of temperature and pH on PHA and EPS production by Rhizobium cultures. In this experiment, cheaper carbon sources were tested to enhance the PHA and EPS production. Among which culture number 2228 produced good yield of PHA (90.90%) and culture number 2 produced good amount yield of EPS (80%) in sucrose medium and hence sucrose was selected as carbon source. Temperature is one of the parameters to be critical for the growth of microorganisms. The production of PHA and EPS is also temperature dependent. The effect of temperature on PHA and EPS production was studied by incubating the medium with different temperatures like 30C and 37C. Finally it was concluded that temperature 30C favours in production of more amount of PHA (11.36%) and EPS (62.5%) by Rhizobium cultures. The pH is also one of the parameter to be critical for growth of microorganisms. The production of PHA and EPS is also pH dependent. The effect of pH on PHA and EPS production was studied by incubating the medium with different pH like 6, 7 and 8. The initial pH of the sucrose medium was adjusted to various levels of pH 6, 7and 8, individually, to optimize the pH for the production of PHA and EPS. At pH 7, culture number 2228 yielded about 13.15% of PHA and 100% of EPS and culture number 2 yielded about 6.11% of PHA and 79% of EPS comparatively which is higher than the result obtained with any other pH. Hence, pH 7 favors for the production of more amount of PHA and EPS. Hence, it was concluded that sucrose as the best carbon source, temperature 30C and pH 7 as the best condition which favors the production of more amount of PHA and EPS.
Uncontrolled Keywords:	polyhydroxyalkanotes; Biodegradable plastics; microbial bioplastics
Subjects:	500 Natural Sciences and Mathematics > 07 Life Sciences > 04 Microbiology > 02 Bacteriology 600 Technology > 05 Chemical engineering > 08 Plastics Technology
Divisions:	Food Microbiology
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	14 Jul 2010 09:15
Last Modified:	28 Dec 2011 10:16
URI:	http://ir.cftri.res.in/id/eprint/9553

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