Bacterial consortia

In this study, we isolated seven strains (termed BY1-7) from polluted soil at an oil station and evaluated their abilities to degrade total petroleum hydrocarbons (TPHs). Among 45 bacterial colonies one bacterial strain was identified based on the cultural, morphological and biochemical characteristics. The isolated bacterium was then subjected to a preliminary assessment of their crude oil after 48 hours of incubation on nutrient agar plates overlaid with 100 ML of petroleum crude oil, the zone of clearance was observed. The isolated bacteria showed 35% petrol degradation, whereas a relatively high oil degradation rate, almost 40% was observed when the bacterium was acclimatized. The selected bacterial strains crude oil resistance was analysed based on the growth ability on the crude oil containing mediums. This strain was identified as Brevibacterium brevis. After inoculation, growth ability was measured and the highest percentage of petrol degradation occurred at temperature 37 °C with the value 30.8%. Bacteria displaying such capabilities are often exploited for the bio-remediation of petroleum oil contaminated environments. Recently, microbial remediation technology has developed rapidly and achieved major gains. However, this technology is not omnipotent. It is affected by many environmental factors that hinder its practical application, limiting the large-scale application of the technology.

Recycling  of  sawdust  to  biomethane  using  bacterial  consortia  were  investigated.  The  Molecular identification of the bacterial and archaeal isolates based on 16S rRNA gene sequences showed that the  dominant  bacterial  species  were  the  Bacillus  and  Pseudomonas species while Methanosarcina and Methanobrevibacter were the dominant archaeal group. Four bacterial consortia (1, 2, 3 and 4) were formulated by combining the isolates in different ratios. One batch of the organic slurry was
biologically-pre-treated  with 1.0% broth culture of Phanarochaete chrysosporium for easy  hydrolysis of β-glycosidic and ether-ester bonds of lignocellulose while the other batch was not treated. The results  obtained  on  methane  production  from  1,600  ml  of  organic  slurry  containing  200  grams  of pre-treated  and  untreated  substrate  each  shows  that  consortium  4  containing  more  of  the Methanogens had  the highest methane-producing potential followed by consortia  3, 2 and the least
consortium  1  at  different  digestion  temperatures.  The  graphical  plot  of  methane  yield  against different  digestion  temperatures  using  the  consortia  showed  that  the  optimum  temperature  was 55oC with highest methane yield of 11.80 cm
/g VS and 7.38 cm3/g VS  produced by consortium 4 for pre-treated  and untreated substrate  respectively while the maximum temperature was 65oC with a decline  in  methane  production.  One-way  analysis  of  variance  of  the  results  obtained  from  biogas yield shows that methane production was significantly  (p ≤ 0)  dependent on the microbial consortia,nature of substrates and digestion temperature.