Question

Isolation & screning of phb producing microorganisms

Answer 1

The characteristics of microbial mats within the waste stream from a seafood cannery were compared to a microbial community at a pristine site near a sandy beach at Puerto San Carlos, Baja California Sur, Mexico. Isolation of poly-beta-hydroxybutyrate (PHB)-producing bacteria, recognition of brightly refractile cytoplasmatic inclusions, lipophilic stains with Sudan Black and Nile Red, and chemical extraction of PHB were used as a culture-dependent strategy for the detection of PHB-producing bacteria. The culture-independent approach included denaturing gradient gel electrophoresis of phylotypes of 16S rRNA of microbial communities from environmental samples. Significant differences in community structure were found among the polluted and pristine sites. These differences were correlated with the physicochemical characteristics of the seawater column. At the polluted site, the seawater was rich in nutrients (ammonia, phosphates, and organic matter), compared to the pristine location. Partial sequencing of 16S rDNA of cultures of bacteria producing PHB included Bacillus and Staphylococcus at both sites; Paracoccus and Micrococcus were found only at the polluted site and Rhodococcus and Methylobacterium were found only at the pristine site. Bands of the sequences of 16S rDNA from both field samples in the denaturing gradient gel electrophoresis (DGGE) analyses affiliated closely only with bacterial sequences of cultures of Bacillus and Staphylococcus. High concentrations of organic and inorganic nutrients at the polluted site had a clear effect on the composition and diversity of the microbial community compared to the unpolluted site.

Answer 2

Answer:

PHB is a lipid reserve material that gets accumulated within the cell wall of micro organisms under stress conditions. ... Screening of PHB positive isolates was done by Sudan Black B and Nile blue A staining. Large scale production of PHB by the efficient bacterial strain was done by using wastewater as the substrate.