Lysine Production of Microbacterium lacticum by Submerged Fermentation Using Various Hydrocarbon, Sugar and Nitrogen Sources

Abstract Bacterial isolation from oil-contaminated and uncontaminated soil was screened for hydrocarbon utilizer which was also capable of producing lysine. Microbial production of lysine by Microbacterium lacticum was investigated in submerged fermentations using various concentrations of hydrocarbon, sugar sources and nitrogen. Of the nine sugar and five nitrogen sources tested, glucose/ammonium sulphate proved optimum for lysine production. Effect of varying concentration of carbon and nitrogen sources on lysine accumulation showed that glucose (4%) ammonium sulphate (1%) respectively increased lysine production. A gram positive rod bacterium identified as Microbacterium lacticum was identified. Optimizing the cultural conditions of Microbacterium lacticum in submerged medium gave a methionine yield of 2.99 mg/ml lysine in the broth culture after 96 h

Isolation, Growth and Identification of Chlorpyrifos Degrading Bacteria from Agricultural Soil in Anambra State, Nigeria

Abstract The extensive use of pesticides is one of the major causes of pollution of soil and water environments. The current method for removing such contaminants from the environment through biodegradation has been shown to be more effective than any other method. Three pesticide degrading bacteria were isolated and identified through cultural and biochemical tests as strains of Pseudomonas aeruginosa, Serretia marcescens and Klebsiella oxytoca. Their growth in mineral salt medium supplemented with 20mg/l of Chlorpyrifos was monitored at optical density of 600nm. The result showed that Pseudomonas aeruginosa had maximum growth in ten days, while Serretia marcescens and Klebsiella oxytoca recorded highest growth after six days of incubation. HPLC analysis of the residual Chlorpyrifos after 14 days incubation showed that Pseudomonas aeruginosa was able to degrade 60% of the pesticide; Klebsiella oxytoca degraded 54%, while Serretia marcescens had 53% reduction of the pesticide concentration in the mineral salt medium. The results of this research indicated that the isolated bacteria can be used for bioremediation of Chlorpyrifos contaminated soil and water ecosystems

Microbial Assessment of Yoghurts Sold in Amawbia, Nigeria

Abstract Five brands yoghurts designated A, B, C, D and E were obtained and used for assessing their microbial quality. A ten-fold serial dilution was carried out and appropriate dilution used to inoculate duplicate plates of SDA, Eosin methylene blue, MacConkey and Nutreint agars. Discrete colonies that developed were purified and stored on agar slant at 4 o C. The pH of the samples ranged from 5.6 to 6.0. In the total coliform count, sample A recorded no count while others had count from 2.0 to 5.0 x 10 2 cfu/ml. The total viable bacterial and fungal counts were 6.0 to 18.0 x 10 4 and 1.0 to 6.0 x 10 3 cfc/ml, respectively. Five fungal genera were obtained as Aspergillus, Penicillium, Fusarium, Mucor, Geotricum, Neurospora and Absidia. Mucor species occurred in all the samples while Fusarium species occurred only in sample B. Among the samples, yoghurt sample B harbored a greater percentage of the fungal isolates. Samples C and D had the least number of fungal of thre