BACKGROUND： Polyhydroxyalkanoates are a good substitute for synthetic plastic because they are highly biocompatible, ecofriendly, and biodegradable. Bacteria in freshwater bodies such as rivers, tube wells, and canal...BACKGROUND： Polyhydroxyalkanoates are a good substitute for synthetic plastic because they are highly biocompatible, ecofriendly, and biodegradable. Bacteria in freshwater bodies such as rivers, tube wells, and canals are exposed to alternating high and low concentrations of substrates that induce PHA production. METHODS： Fresh water samples were collected for isolation of bacterial strains. Screening of PHA in bacterial cells was performed with Sudan and Nile Red staining. Extracted PHA was characterized by FTIR. RESULTS： In this study, nine bacterial isolates were selected for PHA production on the basis ofphenotypic screening. Their ability to accumulate PHAs was determined using different monosaccharides and disaccharides. Two bacterial isolates Bacillus cereus T1 （KY746353） and Bacillus cereus R3 （KY746354） produced PHAs. Optimal growth of the bacterial strain （T1） was observed in the presence of glucose, followed by maximum production of PHAs （63% PHAs） during the logarithmic phase of growth. B. cereus R3 （KY746354） accumulated 60% PHAs by dry cell weight. CONCLUSION： PHA accumulation was relatively less with fructose, but both strains showed increased production （up to 50%） with sucrose. The polymer produced was characterized by Fourier-transform infrared spectroscopy （FTIR）, which showed that the compound contains short-chain PHAs.展开更多
文摘BACKGROUND： Polyhydroxyalkanoates are a good substitute for synthetic plastic because they are highly biocompatible, ecofriendly, and biodegradable. Bacteria in freshwater bodies such as rivers, tube wells, and canals are exposed to alternating high and low concentrations of substrates that induce PHA production. METHODS： Fresh water samples were collected for isolation of bacterial strains. Screening of PHA in bacterial cells was performed with Sudan and Nile Red staining. Extracted PHA was characterized by FTIR. RESULTS： In this study, nine bacterial isolates were selected for PHA production on the basis ofphenotypic screening. Their ability to accumulate PHAs was determined using different monosaccharides and disaccharides. Two bacterial isolates Bacillus cereus T1 （KY746353） and Bacillus cereus R3 （KY746354） produced PHAs. Optimal growth of the bacterial strain （T1） was observed in the presence of glucose, followed by maximum production of PHAs （63% PHAs） during the logarithmic phase of growth. B. cereus R3 （KY746354） accumulated 60% PHAs by dry cell weight. CONCLUSION： PHA accumulation was relatively less with fructose, but both strains showed increased production （up to 50%） with sucrose. The polymer produced was characterized by Fourier-transform infrared spectroscopy （FTIR）, which showed that the compound contains short-chain PHAs.
