1.Characterization of lignocellulolytic bacterial strains associated with decomposing wood residues in the Lagos lagoon, Nigeria
Olanike Maria Buraimoh ; Matthew Olusoji Ilori ; Olukayode Oladipo Amund
Malaysian Journal of Microbiology 2015;11(3):273-283
Aims: The presence of lignocelluloses, especially sawdust in the Lagos lagoon and the attendant ecological problems
warranted studies on their degradation. This study aimed to isolate and identify the indigenous bacterial strains capable
of utilizing lignocellulosic wastes under the prevalent tropical estuarine conditions.
Methodology and results: Nine bacterial species were obtained by elective culture from decomposing wood residues
in the lagoon. They were identified on the basis of morphology, biochemical characteristics and analysis of their 16S
rRNA gene sequences as Streptomyces, Bacillus and Paenibacillus species. They were cultured on various ligninrelated
lignocellulosic substrates over a period of 7 to 12 days. All the isolates showed moderate to very good growth on
sugarcane baggase. Streptomyces albogriseolus strain AOB and Paenibacillus sp. ROB showed good growth on grass
while on sawdust, only Streptomyces AOB, and Bacillus megaterium strain NOB showed good growth. High
performance liquid chromatographic analysis showed that the Streptomyces species completely utilized coniferyl
alcohol, B. megaterium strain NOB utilized 90-100% of all the lignin- related aromatic compounds. All the bacterial
species utilized less than 40% of sinapyl alcohol, Bacillus sp. OOB and Paenibacillus sp. strain ROB failed to utilize
vanillic acid.
Conclusion, significance and impact of study: The isolates degraded lignocellulosic wastes and lignin-related
compounds. The role of fungi in the breakdown of lignocellulose in the Lagos lagoon had been the subject of previous
research considerations whilst the role of bacteria spp was unreported. Autochthonous bacterial species may equally
play a role in the bio-rehabilitation of the sawdust-polluted water of the Lagos lagoon.
Keywords: Lignocellulose, Streptomyces, Bacillus, Paenibacillus, pollution
Alcoholic Beverages
;
Fermentation
;
Phoeniceae
2.Influence of pH, temperature and nutrient addition on the degradation of atrazine by Nocardioides spp. isolated from agricultural soil in Nigeria
Ayodele Elizabeth Omotayo ; Matthew Olusoji Ilori ; Oluwafemi Sunday Obayori ; Olukayode Oladipo Amund
Malaysian Journal of Microbiology 2016;12(4):270-278
Aims: To effectively exploit the atrazine degrading capabilities of Nocardioides spp. isolated from agricultural soil
samples in Nigeria and ascertain the effect of pH, temperature and nutrient addition on the degradation process.
Methodology and results: Isolates were cultivated on atrazine mineral salts medium at a temperature range of 4 °C -
45 °C and a pH range of 3-10. An optimum atrazine degrading activity was observed in the isolates between
temperatures of 25 °C and 37 °C and between pH 5 and 8. Different carbon sources (glycerine, glucose, chitin, cellulose
and sodium citrate) and nitrogen sources (urea, biuret, cyanuric acid, potassium nitrate and ammonium chloride) were
also added to the medium. The addition of carbon and nitrogen sources did not increase degradation rates although
urea and glycerine repressed the degradation ability of the isolates. Statistical analyses of variance at P < 0.05 showed
no significant differences in the growth and degradation rates by both bacterial isolates under these conditions.
Conclusion, significance and impact study: Atrazine degradation by Nocardioides spp. is pH and temperature
dependent, and requires no additional sources of carbon and nitrogen. Hence, its use in bioremediation of atrazine
contaminated agricultural soil should be explored.
Atrazine