Isolation and characterization of synthetic detergentdegraders from wastewater

The biodegradability of the principal component of synthetic detergent products known as linear alkylbenzene sulphonate (LAS) has been contentious, hence the need to evaluate its primary biodegradation by indigenous microorganisms in wastewater ecosystem. The native microbial consortium of a wastewater ecosystem found to utilize detergent components were characterized using standard and conventional methods. The organisms identified were Enterococcus majodoratus, Klebsiella liquefasciens, Enterobacter liquefasciens, Klebsiella aerogenes, Escherichia coli, Enterobacter agglomerans, Staphylococcus albus, Pseudomonas aeruginosa, Proteus sp., Klebsiella oxytoca, Brevibacterium sp., Myceliophthora thermophila, Geomyces sp., Alternaria alternata, Verticillium alboatrum, Aspergillus flavus, Trichoderma sp. and Aspergillus oryzae. Alkaline pH andmesophilic temperature range (33.9 – 34.3oC) was found to be supportive of the metabolic activities of the detergent-degraders in the tropical wastewater ecosystem. The bacterial detergent-degraders weremore of gram-negative than gram-positive. Fungal detergent-degrader activities were abruptly terminated as the pH shifted to the alkaline range probably due to production of alkaline intermediates.The biodegradation of the synthetic detergent components that occurs in wastewaters, sewage treatment plants and in the ultimate open-water receiving ecosystems is primarily the result of microbial activities

Influence of composting techniques on microbial succession, temperature and pH in a composting municipal solid waste

Composting of urban wastes was carried out using both passive aeration technique (PACT) and conventional pit method. Feacal coliforms, Pseudomonas, Streptococcus, Proteus , Seratia and Bacillus species as well as fungi were isolated at mesophilic stage of degradation. A number of these microorganisms did not grow at the thermophilic stage but grew at cooling down stage. The trends in microbial succession in the composting wastes in pot and pit were somewhat similar. There was, however, repeated re-heat after turning the wastes in the pit until about 5 months later. Each time the waste was turned in the pit, there was an increase in temperature until the 21st week. Temperature however, stabilized at the 7th week in the pot. pH also stabilized as the composting process progressed in the pit. Good quality compost was obtained in 5 weeks when PACT was used. Conventional pit method lasted over several weeks. Key Words: Municipal wastes; passive aeration; pit composting; temperature; microbial succession. African Journal of Biotechnology Vol. 3 (4), 2004: 239-24

Effect of two commonly used herbicides on soil microflora at two different concentrations

The effect of two commonly used herbicides (atrazine and atrazine + metolachlor) on non-target soil microflora was investigated over a period of 8 weeks. One kilogram soil samples each from maize farm were treated with the herbicides separately at company recommended and one and half (X1.5) recommended rates. Effects of the herbicides on soil pH and percentage organic matter were also investigated. Significant changes in soil pH and percentage organic matter were observed only in atrazine treated soils (P < 0.05). Herbicide treatments at both recommended and X1.5 recommended rates resulted in decreases in microbial counts. Higher concentrations of herbicides treatments resulted in much lower microbial counts compared to soils treated with recommended herbicide does. Herbicide treatments also resulted in the elimination of some microbial species. Pseudomonas sp. and Bacillus sp. were the most frequently isolated bacteria from herbicide treated soils. While A. niger, A. Flavus, Penicillium sp and Trichoderma sp were the most frequently isolated fungi from herbicide treated soils.Keywords: herbicides, microflora, atrazine, metolachor, concentration

Effect of organic amendments on microbial biomass of a tropical soil treated with some herbicides

Studies were carried out on the impact of organic amendments on microflora of soils treated with 2,4- dichlorophenoxy-acetic acid, atrazine, atrazine + metolachlor and paraquat herbicides applied at one and half doses of the recommended rates. Poultry manure-0.05%, urea-0.1 M and glucose–0.1 M of herbicide-treated soils resulted in significant (

L-Glutamic acid production by Bacillus spp. isolated from vegetable proteins

22 isolates of Bacillus species were obtained from “Dawadawa”, “Ugba” and “Ogiri” (fermented vegetable proteins) in Nigeria. The isolates were identified as Bacillus subtilis (6), (27.3%), Bacillus pumilus (5), (22.7%), Bacillus licheniformis (5), (27.3%) and Bacillus polymyxa (6), (22.7%). Four species of the Bacillus isolates were selected based on their ability to grow and produce L- glutamic acid in a synthetic medium and their comparison with the reference strain Corynebacterium glutamicum ATCC 13032. The four Bacillus species were B. subtilis (UGI). B. pumilus (DD4), B. licheniformis (0G4) and B. polymyxa (OG7) isolated from “Ugba”. “Dawadawa” and “Ogiri”, respectively. All the 22 Bacillus species isolated produced L- glutamic acid with B. subtilis (UGI) from “Ugba” recording the highest (8.5 mg/ml), while B. licheniformis (OG4) from “Ogiri” had the lowest value (5.0 mg/ml). L-Glutamic acid produced by B. subtilis (UGI) from “Ugba” (8.5 mg/ml) compared favourably with that produced by the reference strain C. glutamicum ATCC 13032, (10.2 mg/ml). All the isolates were able to utilize a range of carbon sources with glucose been the best, giving a yield of 8.4 mg/ml, while galactitol was least utilized. Ammonium nitrate was the best nitrogen source (6.5 mg/ml), while asparagine was least utilized (3.40 mg/ml) by the test isolates.Key words: L-Glutamic acid, bacteria strains, fermented vegetable proteins, fermentation

Biodegradation of synthetic detergents in wastewater

A total of 76 wastewater samples were randomly collected from pharmaceutical, textile, and detergentmanufacturing industries as well as the Agbara Sewage Treatment Plant (STP). Thirty-eight sampleseach in 2-L plastic containers were collected for morning and evening effluent used for this study. Composite samples were later developed and the physico-chemical properties of these samples determined. The physico-chemical properties of the composite wastewater influenced the selected microbial population adapted to utilization of detergent components. The optimum temperature range of the composite wastewater was 33.9 – 34.3oC while the mean optimum pH ranged from 6.9 – 8.8 for the laboratory simulated biodegradation of test detergents. Although, the fungal consortium was eliminated as the medium approached the alkaline pH, this is as a result of the metabolites produced. The macroelements, the BOD and the hydrocarbon concentration of the composite effluent were above the EU andFEPA limits for discharged effluent. The composite effluent was thereafter spiked with test detergents (Elephant, Omo, Klin, Ariel Persil, Teepol, and SDS) at 0.01% (w/v) and its progressive degradationmonitored for 30 days. The microbial detergent-degraders population changed between Day 0 and 15, thereafter it stabilized. The heterotrophic bacterial count from the seventy-six randomly collectedeffluent samples was 42.9 x 106 cfu/ml, while the mean bacterial detergent-degrader population was 20.94 x 106 cfu/ml. The mean fungal population from the randomly collected effluent sample was 4.5 x106 cfu/ml. The bacterial detergent-degraders characterized and identified include Pseudomonas aeruginosa, Escherichia coli, Enterococcus majodoratus, Klebsiella liquefasciens, Enterobacterliquefasciens, Klebsiella aerogenes, Enterobacter agglomerans, Staphylococcus albus, Proteus sp., Klebsiella oxytoca and Brevibacterium sp., while the fungal detergent-degrader included;Myceliophthora thermophila, Geomyces sp., Alternaria alternata, Fusarium sp., Aspergillus flavus and Asperigillus oryzae. The primary biodegradability of synthetic detergent was confirmed by theMethylene Blue–Active Substance (MBAS) method. Gas chromatography (GC) provided the convincing evidence of synthetic detergent mineralization within the 30 day period in a sewage treatment plant. The detection of unusual peaks in the GC profiles provided the scientific evidence of inclusion of certain hydrocarbons in detergent formulation outside that of industry specifications. The unusual peaks are attributable to inclusion of certain chemical optical brighteners (C17–C24). Linear alkyl benzene sulphonates (LAS) which is the principal synthetic detergent component are thus biodegradable and itsuse in detergent formulation is environment - friendly

Isolation and antibacterial activity of triterpenes from Euphorbia kamerunica Pax

Two known compounds, friedelin and epifriedelinol were isolated from Euphorbia kamerunica Pax. The compound’s structures were established on the basis of spectral analysis. The antibacterial activities of these compounds and the ethyl acetate extract were established on Pseudomonas aeruginosa, Salmonella typhii and Staphylococcus aureus. The extract displayed higher inhibition activities on the bacteria than the isolated compounds. The zones of inhibition of the extracts were between 9.0 and 30.5 mm, with the highest extract activity on Staphylococcus aureus. The minimum inhibition concentration (MIC) values of the isolated triterpenes were between 7.5 - 10 μg/ml.© 2010 International Formulae Group. All rights reservedKeywords: Euphorbia kamerunica, friedelin, epifriedelinol, antibacterial activity, MIC