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The present study explored bacterial aerobic biodegradation of reduced carbon-contaminants (RCC) in a pilot system mimicking remediation of a saturated aquifer in a permeable reactive biobarrier (PRBB). Bioaugmentation was performed with a pure culture of Pseudomonas putida macro-encapsulated in a cellulose-acetate porous envelope and integrated transversely to the flow trajectory of the fluid in the biobarrier and compared with controls without capsules. The macro-encapsulation technique applied allowed the incorporation of a built-in nutrient core for the slow release of macronutrients, i.e. N, P, instead of exogenous nutrients supply. 3-Chlorophenol (3CP) at a concentration range of 350–500 mg/L was chosen as an RCC model compound. The findings indicate efficient 3CP biodegradation during the PRBB operation with a similar degree of transformation (76 ± 2% and 72 ± 2%) and mineralization (55 ± 4% vs. 49 ± 3%) for exogenous and built-in nutrients supply, respectively. The extent of dechlorination in both cases (54 ± 10% vs. 40 ± 2%, respectively) followed mineralization rather than transformation, suggesting that Cl− release took place in late transformation stages. Negligible decontamination was observed in the control system without bioaugmentation. Concluding, tailored PRBB with macro-capsules incorporating a built-in nutrient core to support bacterial growth presents a significant environmental advantage controlling excess nutrients release required in bioremediation of oligotrophic systems. [ABSTRACT FROM AUTHOR]

Research was conducted to examine the hypothesis that manganese deficiency can replace high oxygen levels needed for lignin peroxidase (LIP) formation by Phanerochaete chrysosporium. Shallow stationary cultures developed in the presence of limited or excess N were used to study the combined effects of Mn and oxygen on lignin peroxidase activity and isozyme composition. Results indicate that the trigger for LIP formation normally provided by a high oxygen concentration can be replaced by Mn deficiency and that the substitution can be effective under both N-limited and N-excess conditions.

An enzymatic fraction with extracellular lignin peroxidase (LIP) from Phanerochaete chrysosporium was analyzed to determine its enzymatic profile during enzymatic dephosphorylation. Analyis of an enzymatic fraction with LIP dephosphorylating (LpD) activity indicated the presence of unchanged LIP catalytic properties during dephosphorylation. Furthermore, LIP dephosphorylation is characterized by LpD-mediated postranslational modification.

The synthesis and isoenzyme composition of the ligninolytic system under nonlimiting nutrient conditions in Phanerochaete chrysosporium BKM-F-1767 were characterized using a nonimmersed liquid culture system and conditions close to those occurring in nature. The response of P. chrysosporium to any kind of starvation conditions may be controlled by a broad regulatory mechanism, but the factors that trigger overproduction of the individual components of the ligninolytic system may differ.