The present invention relates to an environment friendly, safe, and
efficient four-step method of bio-bleaching Kraft pulp using the
following strains of bacteria: (a) Serratia marcescens, MTCC 5094, (b)
Pseudomonas aeruginosa, MTCC 5095, (c) Providencia rettgeri, MTCC 5096,
(d) Pseudomonas aeruginosa, MTCC 5098. The present invention also
provides a microbial consortium comprising a synergistic mixture of
ligninolytic bacterial isolates Serratia marcescens, MTCC 5094,
Pseudomonas aeruginosa, MTCC 5095, and Pseudomonas aeruginosa, MTCC 5098,
or comprising bacterial strains Providencia rettgeri, MTCC 5096, Serratia
marcescens, MTCC 5094, Pseudomonas aeruginosa, MTCC 5095, and Pseudomonas
aeruginosa, MTCC 5098, and a process for preparing an inoculum of the
bacterial isolate Providencia rettgeri, MTCC 5096. Also provided is a
process for the preparation of a consortium comprising the ligninolytic
bacterial isolates Serratia marcescens, MTCC 5094, Pseudomonas
aeruginosa, MTCC 5095, and Pseudomonas aeruginosa, MTCC 5098, as well as
a process for the preparation of a pulp suspension for bio-bleaching.