Production of PHB by a Bacillus megaterium strain using sugarcane molasses and corn steep liquor as sole carbon and nitrogen source

Faculty of Science, Alexandria University, Al Iskandarīyah, Alexandria, Egypt
Microbiological Research (Impact Factor: 2.56). 02/2001; 156(3):201-7. DOI: 10.1078/0944-5013-00104
Source: PubMed


Poly(hydroxybutyric acid) (PHB) and other biodegradable polyesters are promising candidates for the development of environment-friendly, totally biodegradable plastics. The use of cane molasses and corn steep liquor, two of the cheapest substrates available in Egypt, may help to reduce the cost of producing such biopolyesters. In this work, the effect of different carbon sources was studied. Maximum production of PHB was obtained with cane molasses and glucose as sole carbon sources (40.8, 39.9 per mg cell dry matter, respectively). The best growth was obtained with 3% molasses, while maximum yield of PHB (46.2% per mg cell dry matter) was obtained with 2% molasses. Corn steep liquor was the best nitrogen source for PHB synthesis (32.7 mg per cell dry matter), on the other hand, best growth was observed when ammonium chloride, ammonium sulphate, ammonium oxalate or ammonium phosphate were used as nitrogen sources.

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    • "Author reported, that even 2.5 g/L of P(3HB) can be synthesized by A. vinelandii UWD on a beet molasses-based medium. Accordingly to Gouda et al. (2001) B. megaterium is able to accumulate up to 46.2% of P(3HB) when 3% (w/v) sugar cane molasses was supplied. In other works, genetically recombinant bacteria were also employed to PHA, production using molasses. "
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    ABSTRACT: The development of processes for the production of biopolymer materials is being stimulated by a combination of factors. These factors include the negative effects of petrochemical-derived plastics on the global environment, depletion of global fossil fuel supplies, and the growing demands of an ever-increasing population for the products deemed necessary for an affluent modern lifestyle. In particular, polyhydroxyalkanoates have attracted attention as environmentally friendly alternatives to the synthetic polymers that are commonly used. Polyhydroxyalkanoates are polyesters produced and accumulated in intracellular granules by many microorganisms. Because they are biodegradable and biocompatible and can be produced by fermentation of renewable feedstocks, they are considered attractive substitutes for petroleum-derived polymers. To create bacterial polyesters, crude and waste plant oils, which can be difficult to dispose of, can be recovered and used as feedstock. This paper gives an overview of the potential for the production of polyhydroxyalkanoates with useful physicochemical properties by bacteria grown on renewable resources such as plant oils.
    Full-text · Article · Oct 2015 · Journal of Cleaner Production
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    • "Chaijamrus and Udpuay (2008), obtained 43% w/w of B. megaterium, (after 45 h of growth), when 4% of molasses was used. Gouda et al. (2001), cited by Bello et al. (2009) found that the greater accumulation of PHB with respect to cell dry weight, was obtained with substrate supplemented with molasses 0.5% (w/v). Similar results were obtained by Waranya et al. (2011), which evaluated the juice of sugar cane to produce PHB with A. eutrophus. "

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    • "3.9 x 106 Da) and the lower degree of crystallinity (60% XC).Thus, the present data indicate that molasses and CSL could be alternatively used for PHB production by this bacterium with high PHB content and adequate properties of biopolymer from a low cost process. Gouda et al. (2001) used cane molasses and corn steep liquor, two of the cheapest substrates available in Egypt to reduce the cost of producing such biopolyesters. The effect of different carbon sources was studied and maximum production of PHB was obtained with cane molasses and glucose as sole carbon sources (40.8, 39.9 per mg cell dry matter, respectively). "
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    ABSTRACT: In recent years, there has been a marked increase in interest in biodegradable materials for use in packaging, agriculture, medicine, and other areas. Polyethylene, polyvinylchloride, polystyrene are largely used in the manufacture of plastics which are not degradable for several hundred years. But the point is that even though they take thousands of years, they are eventually decomposed which means that there exist some microbes which can degrade plastic. If these microbes are genetically manipulated and made to degrade polythene (plastic) at a faster rate, it would be a novel technique to solve the global waste crisis. Example: Streptomyces sps. While these are various techniques to degrade the synthetic plastics, there are some methods to produce biodegradable polymers which can be easily decomposed by microbes on disposal. These polymers are made out of naturally occurring materials such as starch, cellulose, lactic acid and fiber, extracted from various types of plants. Biopolymers limit carbon dioxide emissions during creation, and degrade to organic matter after disposal but this does not mean that all the biopolymers should be completely biodegradable. However, microbial consumption of polymers is available through addition of hydrophilic type additives onto the surface of the polymer chains. These types of additives are readily available and are used worldwide. For example, Polylactic acid (PLA) is a 100% compostable biopolymer which can fully degrade above 60°C in an industrial composting facility. Biodegradable plastics are scientifically sound, and a novel idea, but the infrastructure needed to commercially expand their use is still costly, and inconvenient to develop. Time is of the essence for biodegradable polymer development, as society's current views on environmental responsibility make this an ideal time for further growth of biopolymers.
    Full-text · Article · Sep 2014
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