Biodegradation and detoxification of nicotine in tobacco solid waste by a Pseudomonas sp.

A Pseudomonas sp. grew with nicotine optimally 3 g l^–1 and at 30 °C and pH 7. Nicotine was fully degraded within 10 h. The resting cells degraded nicotine in tobacco solid waste completely within 6 h in 0.02 m sodium phosphate buffer (pH 7) at maximally 56 mg nicotine h^–1 g dry cell^–1.     

Biological treatment of the components of solid oligomeric waste from a nylon-6 production plant

On partial analysis of the solid oligomeric waste of a nylon-6 production plant, it was found to contain ε-caprolactam, 6-aminocaproic acid (6-ACA) and its linear and cyclic oligomers. Out of four bacterial isolates capable of utilizing caprolactam as the sole growth substrate, Alcaligenes faecalis was found to be the most potent and utilized 90% of caprolactam in 24 h. In shake flask experiments, when the solid waste after solubilization was treated with a consortium of bacteria of four different genera, except the cyclic oligomers, all the other constituents were found to be degraded. A reduction of the chemical oxygen demand (COD) of the solid waste to the level of 63–66% was obtained when it was treated with either a consortium of the bacterial isolates or only a single isolate, A. faecalis. Alcaligenes faecalis could bring about a decrease of 95% in the caprolactam content of the solid waste, while 6-ACA and its linear oligomers were almost completely degraded. Alcaligenes faecalis cells adapted on solid waste could degrade the linear oligomers at a faster rate as compared to cells adapted on caprolactam. However, cyclic oligomers could not be degraded in either case. When solid waste, partially hydrolysed with acid to yield 6-ACA as the major constituent, was treated with the consortium of bacterial isolates, a 95% reduction in the COD was achieved. This revised version was published online in November 2006 with corrections to the Cover Date.     

Biodegradation of Nitriles in Shale Oil

Enrichment cultures were obtained, after prolonged incubation on a shale oil as the sole source of nitrogen, that selectively degraded nitriles. Capillary gas chromatographic analyses showed that the mixed microbial populations in the enrichments degraded the homologous series of aliphatic nitriles but not the aliphatic hydrocarbons, aromatic hydrocarbons, or heterocyclic-nitrogen compounds found in this oil. Time course studies showed that lighter nitriles were removed more rapidly than higher-molecular-weight nitriles. A Pseudomonas fluorescens strain isolated from an enrichment, which was able to completely utilize the individual nitriles undecyl cyanide and undecanenitrile as sole sources of carbon and nitrogen, was unable to attack stearonitrile when provided alone as the growth substrate. A P. aeruginosa strain, also isolated from one of the enrichments, used nitriles but not aliphatic or aromatic hydrocarbons when the oil was used as a sole nitrogen source. However, when the shale oil was used as the sole source of carbon, aliphatic hydrocarbons in addition to nitriles were degraded but aromatic hydrocarbons were still not attacked by this P. aeruginosa strain.     

Biotechnological Potential of Bacillus salmalaya 139SI: A Novel Strain for Remediating Water Polluted with Crude Oil Waste

Environmental contamination by petroleum hydrocarbons, mainly crude oil waste from refineries, is becoming prevalent worldwide. This study investigates the bioremediation of water contaminated with crude oil waste. Bacillus salamalaya 139SI, a bacterium isolated from a private farm soil in the Kuala Selangor in Malaysia, was found to be a potential degrader of crude oil waste. When a microbial population of 10⁸ CFU ml^-1 was used, the 139SI strain degraded 79% and 88% of the total petroleum hydrocarbons after 42 days of incubation in mineral salt media containing 2% and 1% of crude oil waste, respectively, under optimum conditions. In the uninoculated medium containing 1% crude oil waste, 6% was degraded. Relative to the control, the degradation was significantly greater when a bacteria count of 99 × 10⁸ CFU ml^-1 was added to the treatments polluted with 1% oil. Thus, this isolated strain is useful for enhancing the biotreatment of oil in wastewater.     

The Geological Roles Played by Microfungi in Interaction with Sulfide Minerals from Libiola Mine,Liguria, Italy

The potential role played by fungi in the weathering of sulfide abandoned mines and waste rock dumps is scarcely investigated, yet. In particular microfungi may produce biofilms that work as sites of metals and minerals precipitation. This study aimed to investigate interactions, bioalteration, and biocorrosion between three microfungi (Trichoderma harzianum group, Penicillium glandicola, P. brevicompactum) isolated from the Libiola sulfide mine (Liguria, Italy) and pyrite-rich mineralizations occurring within the waste rock dumps. After six weeks of incubation, Environmental Scanning Electron Microscope (ESEM) analyses showed how single pyrite crystals were completely corroded and altered by all the selected species. These results represent the first step to establish that fungi play a central role in the biogeochemical cycles of extreme and contaminated sites such as sulfide mines, and that they actively contribute to the evolution of the degraded ecosystem to more harmonized scenery.     

Bacterial community dynamics during <Emphasis Type="Italic">in-situ</Emphasis> bioremediation of petroleum waste sludge in landfarming sites

In-situ bioremediation of petroleum waste sludge in landfarming sites of Motor Oil Hellas (petroleum refinery) was studied by monitoring the changes of the petroleum composition of the waste sludge, as well as the changes in the structure of the microbial community, for a time period of 14 months. The analyses indicated an enhanced degradation of the petroleum hydrocarbons in the landfarming areas. A depletion of n-alkanes of approximately 75–100% was obtained. Marked changes of the microbial communities of the landfarms occurred concomitantly with the degradation of the petroleum hydrocarbons. The results obtained from terminal restriction fragment length polymorphism (T-RFLP) analysis of polymerase chain reaction (PCR) amplified 16S rRNA genes demonstrated that bacteria originating from the refinery waste sludge and newly selected bacteria dominated the soil bacterial community during the period of the highest degradation activity. However, the diversity of the microbial community was decreased with increased degradation of the petroleum hydrocarbons contained in the landfarms. T-RFLP fingerprints of bacteria of the genera Enterobacter and Ochrobactrum were detected in the landfarmed soil over the entire treatment period of 14 months. In contrast, the genus Alcaligenes appeared in significant numbers only within the 10 month old landfarmed soil. Genes encoding catechol 2,3-dioxygenase (subfamily I.2.A) were detected only in DNA of the untreated refinery waste sludge. However, none of the genes known to encode the enzymes alkane hydroxylase AlkB, catechol 2,3-dioxygenase (subfamily I.2.A) and naphthalene dioxygenase nahAc could be detected in DNA of the landfarmed soils.     

Degradation of PrPSc by Keratinolytic Protease from Nocardiopsis sp. TOA-1

A keratinolytic alkaline proteae (NAPase) from Nocardiopsis sp. TOA-1 degraded a scrapie prion without any chemical or physical treatment. Optimal temperature and pH were 60 °C and above pH 10.0. The scrapie prion was completely degraded within 3 min under optimal conditions.     

Expression of sfp gene and hydrocarbon degradation by Bacillus subtilis

Bacillus subtilis C9 produces a lipopeptide-type biosurfactant, surfactin, and rapidly degrades alkanes up to a chain length of C₁₉. The nucleotide sequence of the sfp gene cloned from B. subtilis C9 was determined and its deduced amino acid sequence showed 100% homology with the sfp gene reported before [Nakano et al. (1992) Mol. Gen. Genet. 232: 313–321]. To transform a non-surfactin producer, B. subtilis 168, to a surfactin producer, the sfp gene cloned from B. subtilis C9 was expressed in B. subtilis 168. The transformed B. subtilis SB103 derivative of the strain 168 was shown to produce surfactin measured by its decrease in surface tension, emulsification activity, and TLC analysis of the surface active compound isolated from the culture broth. Like B. subtilis C9, B. subtilis SB103 containing sfp gene readily degraded aliphatic hydrocarbons (C_10–19), though its original strain did not. The addition of surfactin (0.5%, w/v) to the culture of B. subtilis 168 significantly stimulated the biodegradation of hydrocarbons of the chain lengths of 10–19; over 98% of the hydrocarbons tested were degraded within 24 h of incubation. These results indicate that the lipopeptide-type biosurfactant, surfactin produced from B. subtilis enhances the bioavailability of hydrophobic hydrocarbons.     

Aerobic degradation of a hydrocarbon mixture in natural uncontaminated potting soil by indigenous microorganisms at 20 °C and 6 °C

A hydrocarbon mixture containing p-xylene, naphthalene, Br-naphthalene and straight aliphatic hydrocarbons (C₁₄ to C₁₇) was aerobically degraded without lag phase by a natural uncontaminated potting soil at 20 °C and 6 °C. Starting concentrations were approximately 46 ppm for the aromatic and 13 ppm for the aliphatic compounds. All aliphatic hydrocarbons were degraded within 5 days at 20 °C, to levels below detection (ppb levels) but only down to 10% of initial concentration at 6 °C. Naphthalene was degraded within 12 days at 20 °C and unaffected at 6 °C. At 20 °C p-xylene was degraded within 20 days, but no degradation occurred at 6 °C. Br-naphthalene was only removed down to 30% of initial concentration at 20 °C, with no significant effect at 6 °C. The biodegradation was monitored with head space solid-phase microextraction and gas chromatography–mass spectrometry. Received: 5 October 1998 / Received revision: 4 December 1998 / Accepted: 5 December 1998     

Degradation of oily sludge from a flotation unit by free and immobilized microorganisms

Summary The degradation rate of hydrocarbons in oily sludge obtained from a flotation unit by free and immobilized cells in shaking flasks and in a stirred tank reactor was investigated. For the biodegration of 3.3% hydrocarbons free cells and cells immobilized on granular clay were used. Free cells needed 7–8 weeks to use 30% of the 3.3% hydrocarbons, whereas with immobilized cells the same result was obtained after 3–4 weeks only. In shaken flasks with high hydrocarbon concentrations (8%), immobilized Candida parapsilosis degraded 90% of the hydrocarbons in the oily sludge within 3 weeks, while free cells degraded only 27.5% in the same period. In degradation experiments with a bioreactor, free and immobilized cells of the isolate ISO-OS BÜ 20 showed better results compared to cultures in shaken flasks due to better aeration and mixing. Free cells degraded 50% of the 5% hydrocarbon-containing oily sludge in 7 weeks, whereas immobilized cells gave the same result after only 4 weeks.Offprint requests to: H.-J. Rehm     

Rhamnolipid production by a novel thermophilic hydrocarbon-degrading Pseudomonas aeruginosa AP02-1

Thermophilic bacterial cultures were isolated from a hot spring environment on hydrocarbon containing mineral salts media. One strain identified as Pseudomonas aeruginosa AP02-1 was tested for the ability to utilize a range of hydrocarbons both n-alkanes and polycyclic aromatic hydrocarbons as sole carbon source. Strain AP02-1 had an optimum growth temperature of 45°C and degraded 99% of crude oil 1% (v/v) and diesel oil 2% (v/v) when added to a basal mineral medium within 7 days of incubation. Surface activity measurements indicated that biosurfactants, mainly glycolipid in nature, were produced during the microbial growth on hydrocarbons as well as on both water-soluble and insoluble substrates. Mass spectrometry analysis showed different types of rhamnolipid production depending on the carbon substrate and culture conditions. Grown on glycerol, P. aeruginosa AP02-1 produced a mixture of ten rhamnolipid homologues, of which Rha-Rha-C₁₀-C₁₀ and Rha-C₁₀-C₁₀ were predominant. Rhamnolipid-containing culture broths reduced the surface tension to ≈28 mN and gave stable emulsions with a number of hydrocarbons and remained effective after sterilization. Microscopic observations of the emulsions suggested that hydrophobic cells acted as emulsion-stabilizing agents.     

Degradation of chlorinated lignin compounds in a bleach plant effluent by the white-rot fungus Trametes versicolor

Summary Chlorinated lignin derivatives in a combined bleach plant effluent from sulphite pulping were degraded by several white-rot fungi among which Trametes versicolor (Coriolus versicolor) strains were the most efficient. With glucose as co-substrate, about 90% colour reduction was achieved within 3 days. Simultaneously, the concentration of chloro-organic compounds measured as adsorbable organic halogens decreased by about 45%. As shown by gel chromatography, the high-molecular-weight fraction in the effluent was completely depolymerized while over 50% of total aromatic compounds were degraded. The presence of a co-substrate was necessary for all these activities of the fungus. The residue obtained after degradation was extremely recalcitrant and not further degradable. Offprint requests to: M. Bergbauer     

Biodegradation of nicotine by a newly isolated Agrobacterium sp. strain S33

Aims: To isolate and characterize bacteria capable of degrading nicotine from the rhizospheric soil of a tobacco plant and to use them to degrade the nicotine in tobacco solid waste. Methods and Results: A bacterium, strain S33, was newly isolated from the rhizospheric soil of a tobacco plant, and identified as Agrobacterium sp. based on morphology, physiological tests, Biolog MicroLog3 4·20 system and 16S rRNA gene sequence. Using nicotine as the sole source of carbon and nitrogen in the medium, it grew optimally with 1·0 g l^?1 of nicotine at 30°C and pH 7·0, and nicotine was completely degraded within 6 h. The resting cells prepared from the glucose‐ammonium medium or LB medium could not degrade nicotine within 10 h, while those prepared from the nicotine medium could completely degrade 3 g l^?1 of nicotine in 1·5 h at a maximal rate of 1·23 g nicotine h^?1 g^?1 dry cell. Using the medium containing nicotine, glucose and ammonium simultaneously to cultivate strain S33, the resting cells could degrade 98·87% of nicotine in tobacco solid waste with the concentration as 30 mg nicotine g^?1 dry weight tobacco solid waste within 7 h at a maximal rate of 0·46 g nicotine h^?1 g^?1 dry cell. Conclusions: This is the first report that Agrobacterium sp. has the ability to degrade nicotine. Agrobacterium sp. S33 could use nicotine as the sole source of carbon and nitrogen. The use of resting cells of the strain S33 prepared from the nicotine–glucose–ammonium medium was an effective method to degrade nicotine and detoxify tobacco solid waste. Significance and Impact of the Study: Nicotine in tobacco wastes is both toxic and harmful to human health and the environment. This study showed that Agrobacterium sp. S33 may be suitable for the disposal of tobacco wastes and reducing the nicotine content in tobacco leaves.     

Thiocyanate degradation by Acremonium strictum and inhibition by secondary toxicants

Acremonium strictum, capable of degrading 7.4 g thiocyanate l^–1, was isolated from wastewater condensate from coke-oven gas. Ammonia and sulfate were the final products from thiocyanate degradation with a stoichiometric ratio of near 1:1. The highest degradation activity was at pH 6. Although the degradation rate started to be inhibited above 4 g thiocyanate l^–1, thiocyanate was completely degraded up to 7.4 g l^–1 within 85 h in shake-flask cultures. The degradation of thiocyanate was inhibited by phenol above 625 mg l^–1, by cyanide above 16 mg l^–1, and by nitrite above 100 mg l^–1. However, ammonia and nitrate had negligible inhibition on thiocyanate degradation up to 3 g l^–1 and 1.5 g l^–1, respectively.     

Impact of incubation period on biodegradation of petroleum hydrocarbons from refinery wastewater in Kuantan,Malaysia by indigenous bacteria

This work studied the biodegradation of petroleum hydrocarbons (PHCs) extracted from refinery wastewater to produce industrially important by-products at different incubation periods. Two out of 13 bacterial isolates, KRD2 and KRA4 were isolated. Dichloromethane was used to extract the PHC, and gas chromatography-mass spectrometry (GC-MS) analysis revealed that the refinery wastewater PHC was successfully biodegraded using the selected bacterial isolates within 15 days of incubation. Both KRD2 and KRA4 isolates degraded all 13 initially extracted PHC compounds within 5 days, except C13BD and C9BD, which produced 6 and 4 compounds as secondary metabolites with peak area percentages of 1.58, 1.38, 0.85, 29.94, 7.59, and 11.16% and 3.55, 2.88, 52.31, and 6.14%, respectively. These metabolites have been reported in industrial and medical applications. After 10 days, only 6 and 8 compounds were degraded by both isolates, respectively, and C11PAD compound was produced, as well as C5PAD, C7PAD, and C13PAD. After 15 days, it was clear that all the initial PHC compounds have been completely degraded by both isolates. Metabolites C5PAD, C6PAD, C8PAD, and C13PAD were produced by KRD2, and metabolites C5PAD, C6PAD, C8PAD, and C9PAD were produced by KRA4 at different peak areas. The alignment revealed that the KRA4 isolate was included in the genus Chryseobacterium gambrini, while KRD2 isolate was successfully identified as Mycobacterium confluentis using the Biolog microbial identification system. The incubation period evidently affected biodegradation process by indigenous degraders. These effective bacteria were shown to be of great potential for further application in biodegradation technology of PHC contaminated refinery wastewater to produce industrially important by-products.     

Microbial degradation of high and low molecular weight polyaromatic hydrocarbons in a two-phase partitioning bioreactor by two strains of Sphingomonas sp.

A mixture of six polyaromatic hydrocarbons (naphthalene, phenanthrene, fluoranthene, pyrene, chyrysene and benzo[a]pyrene), varying in size from 2 to 5 rings, was dissolved in dodecane, and used as the delivery phase of a partitioning bioreactor. Two species of Sphingomonas were then used individually, and as a consortium, to determine which of the PAHs were degraded. Only low molecular weight PAHs (naphthalene, phenanthrene and fluoranthene) were degraded by the individual strains, but the consortium degraded all substrates either to completion or near completion.     

Tributyl phosphate degradation by <Emphasis Type="Italic">Rhodopseudomonas palustris</Emphasis> and other photosynthetic bacteria

Tributyl phosphate (TBP) is widely used in nuclear fuel processing and other waste generating chemical industries. Although TBP is bacteriostatic, some microbes are resistant to it and may degrade it. Under dark aerobiosis, purple non-sulfur photosynthetic bacteria degraded up to 0.6 mM TBP, initially present at 2 mm, within 3 weeks and under photosynthetic conditions, Rhodopseudomonas palustris degraded 1.6 mM TBP within 3 weeks. The curing of the Rhodopseudomonas palustris endogenous plasmid demonstrated that the genes involved in the TBP degradation are chromosomal.     

Variation in Petroleum Hydrocarbon Chain Lengths with Depth at a Former Crude Oil and Natural Gas ProductionFacility

An investigation was performed at a former crude oil and natural gas production facility to evaluate whether releases from the product flowlines, gathering lines or water injection lines had impacted soil beneath the site. Thirty-six trenches were initially excavated and sampled beneath the former piping runs to a maximum depth of 6?m. After the trenching investigation, nine soil boreholes were advanced and sampled to a depth of approximately 18?m to further delineate the lateral and vertical extent of impacted soil. Soil samples collected from the trenches and boreholes were analyzed for total petroleum hydrocarbons (TPH) in accordance with ASTM Method 2887. The results of the investigation indicated that TPH impacted soil was present within several areas of the 40-ha site. The petroleum hydrocarbons generally had chain lengths ranging from C₆ to C₃₅, characteristic of light crude oil. The impacted soil also contained condensate, the volatile portion of crude oil. Condensate consists of short-chain hydrocarbons (C₁ to C₁₂) and is characterized by low levels of aromatic volatile organic compounds (VOCs). The condensate typically was more prevalent at depths below 4.5?m than the less volatile, longer chain length hydrocarbons. Statistical analysis of TPH data collected during subsequent excavation activities showed that the mean percentage of condensate was significantly greater at depths below 4.5?m than in shallower samples. In contrast, the mean percentage of TPH compounds in the diesel range (C₁₄ to C₂₃) was significantly greater in samples collected at depths above 4.5?m. The difference in the mean percentage of heavier hydrocarbons (C₂₄ to C₄₄+) with depth was not statistically significant.     

Nicotine degradation by two novel bacterial isolates of <Emphasis Type="Italic">Acinetobacter</Emphasis> sp. TW and <Emphasis Type="Italic">Sphingomonas</Emphasis> sp. TY and their responses in the presence of neonicotinoid insecticides

Two novel nicotine-degrading bacterial strains were isolated from tobacco waste and identified as Acinetobacter sp. TW and Sphingomonas sp. TY based on morphology, physiological and biochemical tests, Biolog analysis and 16S rDNA sequencing. The 16S rDNA sequences have been deposited in GenBank under the accession numbers FJ753401 for TW and FJ754274 for TY. The best culture conditions for nicotine degradation were 25–37°C and pH 7.0–8.0 for strain TW and 25–30°C and pH 6.0–7.0 for strain TY. Under the best conditions, the cell growth and nicotine-degradation kinetics of the two isolates were assessed, and 1.0 g/l nicotine was completely degraded within 12 and 18 h for TW and TY, respectively. Moreover, the presence of four widely-used commercial neonicotinoid insecticides in the medium had no effects on nicotine degradation by TW; among the four tested neonicotinoids, only thiamethoxam significantly delayed nicotine degradation by TY. TW and TY were also able to degrade selected neonicotinoids. This is the first report of nicotine degradation by Acinetobacter sp. and Sphingomonas sp. This study showed that these two newly isolated bacteria may be suitable for the disposal of tobacco waste and the reduction of nicotine in tobacco leaves.     

Preferential utilization of petroleum oil hydrocarbon components by microbial consortia reflects degradation pattern in aliphatic–aromatic hydrocarbon binary mixtures

In this study, the abilities of two microbial consortia (Y and F) to degrade aliphatic–aromatic hydrocarbon mixtures were investigated. Y consortium preferentially degraded the aromatic hydrocarbon fractions in kerosene, while F consortium preferentially degraded the aliphatic hydrocarbon fractions. Degradation experiments were performed under aerobic conditions in sealed bottles containing liquid medium and n-octane or n-decane as representative aliphatic hydrocarbons or toluene, ethylbenzene or p-xylene as representative aromatic hydrocarbons (all at 100 mg/l). Results demonstrated that the Y consortium degraded p-xylene more rapidly than n-octane. It degraded toluene, ethylbenzene and p-xylene more rapidly than decane. In comparison, the F consortium degraded n-octane more rapidly than toluene, ethylbenzene or p-xylene, and n-decane more rapidly than toluene, ethylbenzene or p-xylene. 16S rRNA gene sequencing revealed that the Y consortium was dominated by Betaproteobacteria and the F consortium by Gammaproteobacteria, and in particular Pseudomonas. This could account for their metabolic differences. The substrate preferences of the two consortia showed that the aliphatic–aromatic hydrocarbon binary mixtures, especially the n-decane–toluene/ethylbenzene/p-xylene pairs, reflected their degradation ability of complex hydrocarbon compounds such as kerosene. This suggests that aliphatic–aromatic binary systems could be used as a tool to rapidly determine the degradation preferences of a microbial consortium.