Design of a novel alkaliphilic bacterial system for triggering biopolymer gels

The use of microorganisms to trigger a delayed gelling reaction with curdla n biopolymer gelant was evaluated. The gel-triggering bacteria were strict alkaliphiles isolated from a soda lake. Using the alkaliphilic isolates to trigger gel formation, gelation time was inversely proportional to inoculum concentration and could be delayed up to 12 days after inoculation. The mi crobially triggered polymer system was injected into cores and then gelled in situ. Treatment of cores with the system decreased brine permeability by two to four orders of magnitude. Individual strains of the alkaliphiles ha d distinct effects on the polymer system, with respect to both gelling time and permanence of the polymer gel. These strain-specific traits may be exp loited to design gelled polymer systems with desirable performance properti es.