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Production of Bacterial Polyhydroxy-Alkanoates from Agro-Industrial Residues

Kalaivani, R. (2010) Production of Bacterial Polyhydroxy-Alkanoates from Agro-Industrial Residues. [Student Project Report]

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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: In the present study, the PHA production by Bacillus 67 was optimized by using various oil cakes in order to increase the elasticity of bioplastics by increasing the side chains of fatty acids with the help of lipids present in the oil cakes. Various oil cakes like GOC, TOC, COC, CsOC, SOC were used along with or without RB combination for the PHA production. Among those GOC, TOC shows promising results. In all cases, the combination of RB showed high PHA content. The PHA production medium was supplemented with crude oil cakes GOC and TOC and its hydrolysates in order to make the organism to utilize the lipids present in the oil cakes. GOC + RB (UH), TOC +RB (H) showed good results and hence they were taken for further optimization. The optimization parameters include the effect of initial pH, effect of temperature, effect of oil cake concentration, effect of inoculum concentration, effect of aeration, effect of incubation time. All these parameters show significant effect on the production of PHA by Bacillus 67. In case of GOC + RB (UH), the change in initial pH, affects the yield of PHA. The initial pH of 6 was found to be good which yields 0.29 g/l when supplemented with 2% of oil cake, 0.5% of RB. The effect of temperature also plays a vital role in production of PHA. In room temperature, the PHA content was found to be 3.09. If the temperature increases, the production of PHA decreases since the enzyme won’t work out at higher temperatures. The PHA content was high if the oil cake was used at 2% level. At higher concentration of oil cake concentrations, the PHA yield decreased which indicated that crude oil cake may hinder the growth and yield of PHA. The inoculum used at the concentration of 10% level showed the best result. The rate of oxygen supply also favours the yield of PHA. If the aeration increases, the biomass and the PHA yield also get increased. The effect of incubation time affects the growth of Bacillus 67. At 48 hours, the biomass, PHA yield was high while at 72 hours it gets decreased. 79 On testing the same optimization parameters with TOC + RB (H) samples, it also gave best results. The effect of initial pH on this supplement gave good result at the pH 6. The best yield was obtained when the Bacillus 67 culture grown at room temperature, it gave 4.83 g/l. On increasing the temperature, the biomass yield decreases. The oil cake supplements showed good result at 5% concentration i.e. 7.24 g/l. At higher concentration, there was great decrease in biomass. The addition of inoculum at 10% level leads to the production of increased biomass. The effect of aeration also favours the growth of Bacillus 67. At higher rpm, the yield was so high, since, the oxygen is responsible for metabolism. Incubation time affects the PHA yield. Unlike GOC + RB (UH), TOC + RB (H) supplemented samples produce high amount of PHA at 72 hours. Finally it can be concluded that, in case of GOC + RB (UH) supplemented samples, if the production medium was adjusted to the initial pH of 6, incubated at room temperature, supplemented with 2% of oil cake, 10% inoculums and kept at 250 rpm for 48 hours, the production of PHA will be high. While in TOC + RB (H) supplemented samples, if the pH was adjusted to 6, incubated at room temperature at 250 rpm for 78 hours, supplemented with 5% of oil cake, 10% of inoculum yields good results. The final product of GOC + RB (UH) shows high elasticity than TOC + RB (H) supplemented samples but yield wise TOC + RB (H) was considered as the best.
Uncontrolled Keywords: Polyhydroxyalkanoate; oil cakes; Bacillus
Subjects: 500 Natural Sciences and Mathematics > 04 Chemistry and Allied Sciences > 27 Polymer Chemistry
Divisions: Food Microbiology
Depositing User: Food Sci. & Technol. Information Services
Date Deposited: 08 Jul 2010 11:36
Last Modified: 28 Dec 2011 10:15
URI: http://ir.cftri.com/id/eprint/9481

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