Microbial evaluation and deterioration of paints and paint-products.

The microbial quality of materials and final products of a reputable paint industry in Lagos area were analysed. The bacterial contaminants isolated in the paint-products included Bacillus brevis, B. polymyxa, B. laterosporus, Lactobacillus gasseri, L. brevis, Esherichia coli and Proteus mirabilis. The fungal contaminants detected in the paints were mainly Aspergillus niger, A. flavus and Penicillium citrinum. The microbial populations in the raw materials ranged from 1.0 x 106 – 9.5 x 106 cfu g-1 for bacteria and between 1.25 x 104 and 6.8 x 104 cfu g-1 for fungi while those present in packaging materials ranged from 3.45 x 106 – 7.65 x 106 cfu g-1 for bacteria and 2.4 x103 – 2.8 x 103 cfu g-1 for fungi respectively. The bacterial populations in the fresh paint samples monitored every two weeks from the time of production ranged from 1.6 x 101 – 4.7 x 105 cfu ml-1 while the fungal populations ranged from 1.0 x 101 – 5.5 x 103 cfu ml-1 over a ten-month study period. The optical density at 600 nm increased while transmittance, pH, specific gravity and viscosity of the paint samples decreased over the period suggesting gradual deterioration of the aesthetic qualities of the paint-products with time as indicated by the measured parameters.

Occurrence of Campylobacter species in poultry forms in Lagos area of Nigeria.

Samples of poultry droppings were collected from fifty poultry farms in Lagos area of Nigeria. Campylobacter species were isolated from serially diluted samples using Bolton selective enrichment medium under microaerophilic condition at 42 degrees C. Samples of water, both treated and untreated used in the farms were also analysed in the same manner. Fifteen Campylobacter strains were isolated from the droppings. All the strains were identified using biochemical characteristics differentiating Campylobacter species. They were identified as hippurate positive (C. jejuni) and negative species (C. coli). They were biotype' using the extended scheme described by Lior (1984). Campylobacter coli biotype 'I was the most prevalent (66.66%) followed by C. jejuni biotype 1 (20.00%). The biotype ii of the two species accounted for 6.67% each. The C. jejuni biotype III and IV were not isolated during the study. The preponderance of C. coli indicates that poultry can be a major reservoir for the spread of human campylobacteriosis. Poultry farmers, therefore, must ensure prompt and adequate means of disposal of waste materials as well as maintaining good sanitary conditions.

Biological treatments of textile industrial effluents in Lagos metropolis, Nigeria.

The assessment of the effluents from two textile industries in Ilupeju in Lagos metropolis, Nigeria showed that they were high in conductivity, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total dissolved solids (TDS) and contained traces of heavy metals like Ca, Zn but high concentrations of Cr and Pb. These wastewaters are normally discharged into neighbouring water bodies. Five bacterial groups, namely Micrococcus sp., Enterobacter sp., Alcaligens sp., Bacillus sp. and Acinetobacter sp. were isolated from these effluents. They were used individually for biotreatment and found to be able to utilize the components of the wastewaters for growth, Bacillus sp. and Acinetobacter sp. being the most efficient utilizers as they were able to reduce BOD to zero. The total viable count (TVC) increased significantly depicting growth of the bacterial population. The pH was regulated from 3.4-6.80 for NSF effluent and 12.2-10.29 for STI effluent. The work emphasises the level of industrial pollution in our environment as wastes are indiscrimately dumped into surrounding water bodies in urban areas, the textile industry being a case study. The treatment of any form of waste before disposal into the environment is important and ensures safety of the populace.

Environmental impact on the bacteriological quality of domestic water supplies in Lagos, Nigeria

OBJETIVO: Avaliar o impacto do planejamento urbano, da infra-estrutura, do saneamento e dos índices pluviométricos sobre a qualidade bacteriológica do abastecimento domiciliar de água. MÉTODOS: Foi realizada cultura de amostras de água obtida de poços superficiais e profundos, fossos e água corrente de bicas públicas para determinar o número mais provável de Escherichia coli e coliformes totais por meio da técnica de múltiplos tubos. Patógenos entéricos foram detectados pelo uso de meios diferenciais e seletivos. Amostras foram coletadas durante os períodos de seca e de chuvas intensas em municípios com características singulares de infra-estrutura, planejamento urbano e saneamento. RESULTADOS: A contaminaçäo de água tratada ou encanada esteve relacionada à distância do ponto de coleta com relaçäo à estaçäo de tratamento. Defeitos na canalizaçäo aumentaram o índice de contaminaçäo (p<0,5), principalmente em áreas densamente povoadas com infra-estrutura arruinada. Os despejos de bueiros representaram a principal fonte de contaminaçäo da água encanada. Houve maior contaminaçäo em poços superficiais do que em fossos e durante os períodos de chuvas intensas (p<0,05). E. coli e outros patógenos entéricos foram isolados de fontes de abastecimento contaminadas. CONCLUSOES: A falta de planejamento urbano, as más condiçöes de infra-estrutura e a localizaçäo indiscriminada de poços e fossos contribuíram para a baixa qualidade bacteriológica do abastecimento domiciliar de água. As águas das chuvas agravaram o impacto