The definition of biodegradability

Biodegradability definition

According to

Towards Common Ground –

Meeting Summary of the International Workshop on Biodegradability,

Annapolis, MD, USA, 1992.

· For all practical purposes of applying a definition, material manufactured to be biodegradable must relate to a specific disposal pathway such as composting, sewage treatment, denitrification, or anaerobic sludge treatment.

· The rate of degradation of a material manufactured to be biodegradable has to be consistent with the disposal method and other components of the pathway into which it is introduced, such that accumulation is controlled.

· The ultimate end products of aerobic biodegradation of a material manufactured to be biodegradable are carbon dioxide, water and minerals and that the intermediate products include biomass and humic materials. (Anaerobic biodegradation was discussed in less detail by the participants).

· Materials must biodegrade safely and not negatively impact on the disposal process or the use of the end product of the disposal.

Aerobic biodegradation

CPOLYMER + O2 -------> CO2 + H2O + CRESIDUE + CBIOMASS

Anaerobic biodegradation

CPOLYMER ---------> CO2 + CH4 + H2O + CRESIDUE + CBIOMASS

Stuck @ dec 2010

E. coli Rosettagami2(DE3) with pET32 harbouring phaCcs gene

problem 1: Expression level of PhaC is very low compare to previous batches

(less than 10% , will be very difficult to be purified)

problem 2: Almost 100% of the expressed PhaC is insoluble

(not a native functional protein we want)

Troubleshoot:

1. IPTG is not functioning?

- trial: induce with IPTG from colleage which is functioning for their expression.