Biodegradable Plastic Production from Polyhydroxybutyrate(PHB) Producing Bacteria and Its Impact on Environment (original) (raw)
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Plastics produced from petrochemical sources and known as polypropylene are now accumulating in our environment at rates of millions of tons per year creating severe problems. The present study aims to the production and isolation of PHB (polyhydroxy-buty rate ), a biodegradable plastic, from agro-industrial waste products (whey and date molasses) due to its high economic and industrial importance , taking into consideration many points that lead to produce PHB on large scale. The methodology of this study includes screening study for the isolation of a promising microbial producer of PHB , and optimization experiments to evaluate the best environmental and physiological factors that lead to maximum PHB production. Under the optimized conditions, Lactobacillus acidophilus has shown maximum production when grown for 4 days on date molasses supplemented with NB yielding 0.412g/50ml of PHB, followed by Bacillus thuringiensis (0.367g/50ml) grown for 4 days on the same medium, and Bacillus subtilis (0.337g/50ml) grown for 6 days on whey supplemented with glucose, yeast extract, and peptone. Eleven nutritional factors were examined for their significance on PHB production using a statistical design known as Plackette-Burman. Maximum PHB output of 43.1 g/l produced by Lactobacillus acidophilus was revealed by the statistical design, which represents about 7.04 fold increase in PHB production. Fedbatch fermentation was carried out using the optimized fermentation medium and PHB production has been increased to 27.5% as compared with batch closed process. PHB was detected by transmission electron microscopy and monitoring UV spectra of the sample by scanning the samples between 220 and 300nm compared with standard PHB. Lactobacillus acidophilus can be used for PHB production on large industrial scale, solving by this one of the problems of solid waste management that results from the accumulation of plastics and saving the environment from additional air pollution caused by its recycling.
Isolation, Screening and Extraction of Polyhydroxybutyrate(PHB) Producing Bacteria from Soil Sample
2018
Plastic and polyesters have wide spread use in today’s society because of their processability and amenability in providing a large variety of cost effective products that help to enhance comfort and quality of life. Synthesis of plastic and synthetic polymers from non renewable resources and after intended use ,resulting into environmental pollution.Therefore the value in developing biodegradable plastics such as poly hydroxyl butyrate (PHB), which consist of desirable chemical and physical properties similar to conventional synthetic plastics and are environment friendly too.In the present study an attempt was made to isolate efficient PHB producing bacteria from highly polluted soil.From the different colonies a single type of bacteria were isolated and found to be PHB positive based on the viable colony staining method using Sudan black B and the organism identified as B.cereus. Then Bacillus cereus found to be quite efficient PHB producer and exhibiting a potential for their ut...
European Journal of Biological Research, 2020
Among biodegradable plastics polyhydroxy alkanate and its polymers have received more attention than other biodegradable polymers because of their complete degradability, flexibility, water resistance and also the ease of production process. Polyhydroxybutyrate is one of the types of polyhydroxy alkanates that is seen as a storage granule in many microorganisms. In this study, Bacillus megaterium was prepared from Iranian microbial collection. Glucose and yeast extract were used as the main components of the medium in seed media 9 and 2.5 g/l and in fermentation medium 30 and 7.5 g/l respectively. GC-MASS and FTIR were used to identify the PHB produced. The results showed that the highest amount of biomass (0.221 g/l) and PHB (0.080 g/l) were obtained with glucose at 37°C and shaker speed of 150 rpm for 72 h incubation. The results of GC MASS and FTIR showed the production of PHB by Bacillus under investigation. Based on the mean of data on total cell growth conditions, the rate of cell biomass and PHB production in B. megaterium were 0.0869 and 0.0171 respectively. According to the results of the experiments, temperature had the greatest effect on biomass production and PHB production. The bioplastics produced by microbes are also highly degradable in the environment, and due to their specific chemical structure, they have been widely used in various fields of the food, pharmaceutical and chemical industries and are likely to replace today's plastics in the near future.
Poly-β-hydroxybutyrate (PHB) is the intracellular lipid reserve accumulated by many bacteria. The most potent terrestrial bacterium Bacillus cereus SE-1 showed more PHB accumulating cells (22.1 and 40% after 48 and 72 h) than that of the marine Bacillus sp. CS-605 (5 and 33% after 48 and 72 h). Both the isolates harbored phbB gene and the characteristics C=O peak was observed in the extracted PHB by Fourier transformed infrared spectroscopy analysis. Maltose was found to be the most suitable carbon source for the accumulation of PHB in B. cereus SE-1. The extracted PHB sample from B. cereus SE-1 was blended with a thermoplastic starch (TS) and an increased thermoplasticity and decreased crystallinity were observed after blending in comparison to the standard PHB. The melting temperature (T m ), melting enthalpy (ΔHf), and crystallinity (X c ) of the blended PHB sample were found to be 109.4°C, 64.58 J/g, and 44.23%, respectively.
Poly hydroxyl butyrate (PHB) can be used as an effective thermoplastic, and has many characteristics similar to those of standard commercial plastics like polypropylene. PHB-based plastic substitutes are less flexible than traditional plastics, they are completely biodegradable and leave behind no residue. In this present study high PHB producing strains were isolated from sewage soil sample. Six strains were showing PHB granules with Sudan Black B staining. The six strains were named as strain 2, 4, 5, 9, 11 and 16. The six strains were morphologicall and biochemically characterized. Growth profiles have been studied for all the strains and the polymer was produced after 48 hrs at 37°C. PHB producing growth medium was used for production of PHB. Strain 11 was showed high PHB production among the six strains. The medium used for PHB production showed high yield of the product was of less cost effective.
Production of Bioplastic from some selected Bacterial strains
Polyhydroxybutyrates are biodegradable polyesters synthesized by many bacteria Biodegradable polymer plays a predominant role as a biodegradable plastic due to their hydrolysable ester bonds. In the present study fromthirty two bacterial isolates collected from clay soil rhizopher of maiz, wheat and trefoil eighteen PHB producers.PHB is highly produced from microorganisms under optimum conditions such as physical conditions (pH, temperature, incubation times),Nutritional conditions(Carbon, Nitrogen sources and C/N ratio and Biochemical conditions. Due to their biological origin it is an advantage of PHB is, they are degraded naturally and completely to carbon dioxide and water under natural environment by the enzymatic activities of microbes. The present study reports the isolation and screening of soil bacteria and subsequent PHB production under normal conditions. It was observed that clay soil was able to produce maximum yield of PHB.
Biodegradable Plastic (PHB) from Bacteria Collected from Gopalpur Beach, Bhubaneswar
International Journal of Current Pharmaceutical Research, 2020
Objective: Environmental concerns have prompted research into the development of biodegradable polymer as an alternative to petroleum-based plastics. Polyhydroxybutyrates (PHBs) are good alternatives to produce biodegradable plastics. Some bacteria are found to be producing PHB. The aim of this work was to isolate potential PHB producing bacteria and screen them for their ability to produce PHB. Methods: Contaminated water sample from Gopalpur beach, Bhubaneswar was the source of bacteria. Three colonies were isolated from the water sample. The samples were named as C1, C2 and C3. The colonies were first identified by colony morphology. The sudan black screening test was done to screen for the production of (PHB) polyhydroxy butyrate by bacterial isolates. Results: The bacterial isolates C1 and C2 showed a positive result for the production of polyhydroxy butyrate (PHB). Presence of PHB granules in Cocobacillus and Rod shaped bacillus was confirmed. Conclusion: Polyhydroxybutyrate (...
Isolation and Screening of Poly β-Hydroxybutyrate Producing Microbes
2019
Poly-3-hydroxybutyrate (PHB) is a natural biopolymer produce by wide range of microbes which is a storage granule used by microbes as an energy as well as carbon source. PHB exhibit stiffness, brittle to rubber like, biodegradable, environment friendly properties. In present work we were isolated 34 bacteria and 10 fungi at 37°C, 30°C for 3-5 and 5-7 days incubation respectively by using nutrient agar medium and potato dextrose agar medium from cardboard industry waste water and sugarcane farm soil. Among which 25 bacteria and 4 fungi shown PHB accumulation which was confirmed by Sudan Black B staining.
Nepal Journal of Biotechnology, 2019
Polyhydroxybutyrates (PHBs) are energy reserves synthesized by different micro-organisms such as Alcaligenes, Pseudomonas, Staphylococcus, Algae, in excess of carbon and limitation of nutrients like nitrogen. These biopolymers are suitable alternate to synthetic carbon-based polymers. However, the high production cost limits their commercialization. The aim of this study was thus, focused on optimization of culture condition for maximum PHB production in an attempt to reduce the production cost. The micro-organisms for this purpose were isolated from 4 different soil samples and screened for PHB production. Culture conditions for these organisms were optimized by changing the parameters, viz., incubation time, pH, carbon source and NaCl concentration. Thus, optimized culture condition was used to culture the isolates for extraction of PHB and its analysis. The extracted compounds on FTIR-analysis gave characteristic C=O peak of PHB, thus, confirming the seven isolates to be PHB prod...