Abstract: Plastic disposal is among the utmost problems threatening the environment at present, as enormous quantities of synthetic plastics are non-degradable. A constant exploration for bioplastic degraders is needed due to increasing demands for sustainable waste treatments. Bioplastic (Polycaprolactone) degradation potential of microorganisms isolated from soil was assessed. Soil sample was collected from a plastic dump site in Trans-Amadi, Port Harcourt, Nigeria. Isolation of Polycaprolactone (PCL) degrading bacteria and fungi were carried out via enrichment procedure and clear zone technique. Morphological, biochemical and molecular characteristics were used for strain identification of isolates. The optimal conditions for PCL degradation by bacterial and fungal strains were evaluated by growing the isolates at different temperatures (25, 30, 35 and 40°C), medium pH (ranging from pH 4 to 8) and salinities (5, 10, 15 and 20 ppt.) for 15 days. PCL residual weight in the culture was measured and used for PCL degradation assessment. Three PCL degrading bacterial strains (Bacillus megaterium, Alcaligenes aquatilis and Shewanella haliotis) and one fungal strain (Filobasidium uniguttalatum) were isolated. PCL maximum degradation rate of 59%, 56% and 53% respectively for bacterial strains and 62% for fungal strain were observed at 30°C. PCL maximum degradation rate of 63% for Filobasidium uniguttalatum were observed at pH 5 while the maximum degradation rate of 60% for Bacillus megaterium, 54% for Alcaligenes aquatilis and 57% for Shewanella haliotis were observed at pH 7. PCL maximum degradation rate of 58% for Bacillus megaterium, 55% for Alcaligenes aquatilis, 52% for Shewanella haliotis and 62% for Filobasidium uniguttalatum were observed at salinity of 5 ppt. It is concluded that the potential of the isolated indigenous microbial strains to degrade PCL qualifies them for use as compost cultures in waste treatment of bioplastic.Abstract: Plastic disposal is among the utmost problems threatening the environment at present, as enormous quantities of synthetic plastics are non-degradable. A constant exploration for bioplastic degraders is needed due to increasing demands for sustainable waste treatments. Bioplastic (Polycaprolactone) degradation potential of microorganisms isolated fr...Show More
Abstract: The study evaluated the water qualities of Ntawogba creek by utilizing the benthic macroinvertebrates diversity as well as physical-chemical parameters data, to give us an indication of the biochemical condition and health of the river. The research was carried out for twelve (12) months, firstly by establishing three (3) main sampling stations and their co-ordinates along the stretch of the creek based on ecological niche of the stream and human activities on the study area. The physical-chemical parameters measured and analysed include, Temperature, pH, Electrical Conductivity, Salinity, Turbidity, Total Dissolved Solids, Dissolved Oxygen and Biochemical Oxygen Demand, according to APHA 1998 standard methods. Sediment particle size was determined by hydrometer method. Replicate samples of benthic macroinvertebrates were collected from each station randomly with Eckmann’s grab. The results of the physical-chemical data were subjected to 2-way analysis of variance and differences among means where separated by Turkey-Honest significant difference at 95% probability. Percentage occurrence and relative numerical abundance of macroinvertebrates were calculated using excel descriptive statistical tool. Diversity of the benthos was determined using Shannon Wiener index hequitability of species. The results showed that pH values ranged from mild acidic to alkalinity (6.42 to 7.63). The values of turbidity, TDS, BOD and DO exceeded limits of World Health Organization in most of the sampling stations. The sediment particles of the stream were significantly dominated by sand fractions with the highest mean recorded in station three (74.08±0.71). The total number of benthic macroinvertebrates individuals in the sampled stations was 28,730 and total number of species was 40. The diversity, taxa richness and evenness recorded at station one were 0.823, 1.934 and 0.683, while station two had 0.605, 1.163 and 0.605 and station three had 0.301, 3.085 and 0.206. The results show that the human activities grossly polluted the stream, and constant monitoring is required to safeguard the waterbody and aquatic ecosystem in the study area.Abstract: The study evaluated the water qualities of Ntawogba creek by utilizing the benthic macroinvertebrates diversity as well as physical-chemical parameters data, to give us an indication of the biochemical condition and health of the river. The research was carried out for twelve (12) months, firstly by establishing three (3) main sampling stations and...Show More
