Abstract
Polyhydroxyalkanotes (PHAs), the eco-friendly biopolymers produced by many bacteria, are gaining importance in curtailing the environmental pollution by replacing the non-biodegradable plastics derived from petroleum. The present study was carried out to economize the polyhydroxybutyrate (PHB) production by optimizing the fermentation medium using corn steep liquor (CSL), a by-product of starch processing industry, as a cheap nitrogen source, by Bacillus sp. CFR 256. Response surface methodology (RSM) was used to optimize the fermentation medium using the variables such as corn steep liquor (5–25 g l−1), Na2HPO4 2H2O (2.2–6.2 g l−1), KH2PO4 (0.5–2.5 g l−1), sucrose (5–55 g l−1) and inoculum concentration (1–25 ml l−1). Central composite rotatable design (CCRD) experiments were carried out to study the complex interactions of the variables.
The optimum conditions for maximum PHB production were (g l−1): CSL-25, Na2HPO4 2H2O-2.2, KH2PO4 − 0.5, sucrose − 55 and inoculum − 10 (ml l−1). After 72 h of fermentation, the amount of PHA produced was 8.20 g l−1 (51.20% of dry cell biomass). It is the first report on optimization of fermentation medium using CSL as a nitrogen source, for PHB production by Bacillus sp.
References
Lee YL (1996) Bacterial polyhydroxyalkanoates. Biotechnol Bioeng 49:1–14
Son H, Park G & Lee S (1996) Growth-associated production of poly-β-hydroxybutyrate from glucose or alcoholic distillery wastewater by Actinobacillus sp. EL-9. Biotechnol Lett 18:1229–1234
Rusendi D & Sheppard JD (1995) Hydrolysis of potato processing waste for the production of poly-beta-hydroxybutyrate. Bioresour Technol 54:191–196
Page WJ (1992) Production of poly-beta-hydroxybutyrate by Azotobacter vinelandii UWD in media containing sugars and complex nitrogen sources. Appl Microbiol Biotechnol 38:117–121
Hunter JS (1996). Determination of optimum conditions by experimental methods. Ind Qual Control 15:6–16
Triveni R, Shamala TR & Rastogi NK (2001) Optimized production and utilization of exopolysaccharide from Agrobacterium radiobacter. Process Biochem 36:787–795
Kshama L, Rastogi NK & Shamala TR (2004) Simultaneous and comparative assessment of parent and mutant strain of Rhizobium meliloti for nutrient limitation and enhanced polyhydroxyalkanoate (PHA) production using optimization studies. Process Biochem 39:1977–1983
Patnaik PR (2005) Perspectives in the modeling and optimization of PHB production by pure and mixed cultures. Crit Rev Biotechnol 25:153–171
Cochran WG & Cox GM (1977) Experimental designs, 2nd edn, Asia publishing House, Bombay
Saxena DC & Rao PH (1996) Optimization of ingredients and process conditions for the preparation of tandoori roti using response surface methodology. Int J Food Sci Technol 31:345–351
Law JH & Slepecky RA (1961) Assay of poly-beta-hydroxy butyric acid. J Bacteriol 82:33–36
Williamson DH & Wilkinson JF (1958) The isolation and estimation of poly-β-hydroxy-butyrate inclusions of Bacillus species. J Gen Microbiol 19:198–200
Wilkinson JF & Munro ALS (1967) The influence of growth limiting conditions on the synthesis of possible carbon and energy storage polymers in Bacillus megaterium. In: Microbial physiology and continuous culture, (Powell EO, Evans CGT, Strange RE & Tempest DE eds). H.M.S.O., London, pp 173–185
Cho CH, Jeong SJ & Kim JW (1994) Stimulation of poly (3-hydroxybutyrate) degradation by nitrogen nutrient in Alcaligenes eutrophus H16. Korean Biochem J 27:316–322
Borah B, Thakur PS & Nigam JN (2002) The influence of nutritional and environmental conditions on the accumulation of poly-beta-hydroxybutyrate in Bacillus mycoides RLJ B-017. J Appl Microbiol 92:776–783
Fouchet P, Jan S, Courtois J, Courtois B, Frelat G & Barbotin JN (1995) Quantitative single cell detection of poly (β-hydroxybutyrate) accumulation in Rhizobium meliloti by flow cytometry. FEMS Microbiol Lett 126:31–36
Tombolini R & Nuti MP (1989) Poly(β-hydroxyalkanoate0 biosynthesis and accumulation by different Rhizobium species. FEMS Microbiol Lett 60:299–304
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Vijayendra, S.V.N., Rastogi, N.K., Shamala, T.R. et al. Optimization of polyhydroxybutyrate production by Bacillus sp. CFR 256 with corn steep liquor as a nitrogen source. Indian J Microbiol 47, 170–175 (2007). https://doi.org/10.1007/s12088-007-0033-7
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12088-007-0033-7