Metabolic pathway for poly(3-hydroxybutyrate-co-3-hydroxyvalerate) formation in Nocardia corallina: inactivation of mutB by chromosomal integration of a kanamycin resistant gene

Article Abstract:

The methylmalonyl-CoA pathway allows the preparation of the 3-hydroxyvalerate (3HV) units of the Nocardia corallina poly (3-hydroxybutyrate-co-3HV). The mutB gene encodes the methylmalonyl-CoA mutase and is inactivated by a kanamycin resistant gene block. Cells with the mutant mutB gene lack a methylmalonyl-CoA mutase activity. The mutants produce a polyester that differs from the polyhydroxyalkanoates, produced by the wild type. The mutants grow on even-chain fatty acids, glucose and succinate, but fail to grow on odd-chain fatty acids in the presence of kanamycin.

Analysis, Observations, Gene expression, Microbial mutation, Nocardia corallina, Serratia

New pulp biobleaching system involving manganese peroxidase immobilized in a silica support with controlled pore sizes

Article Abstract:

Researchers have developed a chlorine-free pulp bleaching process by immobilizing manganese peroxide from Phanerochaete chrysosporium in FSM-16, a mesoporous material with a pore size close to the diameter of the enzyme. The enzyme retained 80% of its activity after 10 days of continual reaction.

Bleaching, Wood-pulp, Wood pulp

Application of a propionyl coenzyme A synthetase for poly(3-hydroxypropionate-co-3-hydroxybutyrate) accumulation in recombinant Escherichia coli

Article Abstract:

The properties of a propionyl coenzyme A synthetase from Salmonella enterica serovar typhimurium that was expressed in E. coli. When coexpressed with the polyhydroxyalkanoate genes from Ralstonia eutropha, 3-hydroxypropionate was converted to a PHA copolymer containing 3HP units.

Biopolymers