Studies on Lignin Degradation Activity by Pseudomonas aeruginosa Isolated from Kware Lake

Background: Wood is naturally degraded by wood degrading microorganisms and modified and partly degraded residual of lignin goes into soil. It is an amorphous and complex aromatic compound. In the plant cells, lignin can be converted via phenylalanine and tyrosine by transamination. Africa generates a huge amount of waste from agricultural and household activities. This huge amount of waste can be exploited as a sustainable raw material for many industrial processes other than just simply burning it as a solid fuel.

Aims: The study aimed at isolating and screening Pseudomonas aeruginoas for lignin degradation.

Methods: The bacterium was characterized and identified according to morphological and biochemical characteristics. The bacterial DNA was extracted using DNA isolation kit and used for molecular analysis. Four (4) dyes such as Methylene blue, Congo red, iodine and Malachite green were screened on bacterial isolate for its ability to decolorize the dyes. The effect of some growth parameters such incubation time, temperature, pH and agitation were studies on the isolate for lignin degradation as well as bacterial biomass production.

Results: The effect of some growth parameters such incubation time, temperature, pH and agitation were studies on the isolate for lignin degradation as well as bacterial biomass production. From the results, it was observed that the isolate showed higher zone of inhibition on Congo red (14.00 mm) and Methylene blue (10.00 mm), while no decolorization was observed on Malachite green. The growth parameters studied indicated the optimum condition required for both lignin degradation and bacterial biomass production as follows; 48 hours (65%, 0.41g), 40oC (77%, 0.31g), pH 7 (58%, 0.26g) and 100rpm (72%, 0.42). The FTIR revealed two peaks at 3375 cm-1 which attributed to O-H stretching while the second peak 1687.5 cm-1 corresponded to C=O stretching.

Conclusion: The results of GC-MS detected the presence of 2,5-Hexanediol, 2-Octynoic acid, n-Hexadecanoic acid and i-Propyl9,12-octadecenadienoate.