Publikationen AK Mikrobiologie / Biotechnologie, Abstracts

Berthe-Corti, L.; Bruns, A. and Hulsch, R. (1997) Semi-continuous-flow cultures with marine sediment suspensions containing non-polar carbon sources-culture control by pneumatic sediment suspension dosage system. Journal of Microbiological Methods 29: 129-137.

A system for the continuous cultivation of microorganisms in sediment/seawater suspensions containing hydrocarbon as carbon source has been developed. The culture vessels are supplied with a liquid nutrient (aqueous phase) containing the sediment (solid-phase) and the hydrocarbon (non-polar phase). If pumps were to be used for supplying this suspension to the fermenter, separation of the different phases (solid, aqueous, non-polar) could occur. We developed a technique with which dosage can be carried out without pumps by using glass tubes with a calibrated filling volume. A computer program is used for dosage control and documentation of the suspension flow-rate. Steady state continuous cultivation of the bacterial population of mud flat sediment from the German North Sea coast could be maintained for more than eight weeks. 

HULSCH, R. AND BERTHE-CORTI, L. (1997) Dosierung eines problematischen Mediums (Sedimentsuspension mit hydrophobem Kohlenwasserstoff) zur Führung kontinuierlicher Kulturen im Bioreaktor. atp - Automatisierungstechnische Praxis 11: 63-68.

A system for a computer aided dosing of sediment suspension with non polar hydrocarbon, a problematic medium, was developed. The dosage system is suited for running continuous chemostat cultures in a bioreactor in which the inflow and the outflow consist of a multiphase system (solid, aqueous, and apolar). to avoid blockage of tubes and phase separation, caused by slow flow rates, dosage by means of pumps has to be avoided. Therefore we devoleped a technique for dosage without pumping. Using calibrated glass tubes, well defined volumes of the suspension can be dosed by pulsing at variable frequencies from the storage tank into the bioreactor and from the bioreactor into the release vessel. The flow rate is so high that separation of the different phases is avoided. A computer program controls the process and allows the flow rate of the suspension to be documented. The dosage unit was installed for the cultivation of a mixed hexadecane degrading population in a suspension of mud flat of the German North Sea in a quasi chemostatic process. With this system continous cultures were kept in a steady state over a period of more than eight weeks. Growth and hexadecane degradation of the culture were monitored. 

KARSTENS, A. AND BERTHE-CORTI, L. (1997) Biological background to anaerobic treatment of wastewaters. Biogas forum: 4-12.

A summary of the advantages and disadvantages plus essential background conditions for anaerobic, biological purification of wastewater is presented here.  In addition, parameters for the analysis of various types of wastewater are shown.  These help to define the biodegradability and toxicity of wastewater and also indicate the remaining pollution and pathogenic content of the clarified wastewater.

BERTHE-CORTI, L., CONRADI, B., HULSCH, R. AND SINN, B. (1998) Geschlossenes Bioreaktorsystem zur mikrobiellen Behandlung stark kohlenwasserstoffbelasteter Industrieschlämme. In: BERTHE-CORTI, L., UFZ-Bericht: Workshop-Bericht: Bioremediation of polluted areas. Bd. 18, 82-91, UFZ - Umweltforschungszentrum, Leipzig - Halle.

Bei der Förderung von Rohöl sowie der Produktion von petrochemischen Produkten und deren Entsorgung fallen große Mengen an unterschiedlich zusammengesetzten kohlenwasserstoffhaltigen Schlämmen an. Bei der biologischen Sanierung dieser Schlämme in Mieten oder Bioreaktoren sowie bei der Deponierung werden Abgase freigesetzt, die zu einer erheblichen Belastung der Umwelt mit Kohlenwasserstoffen führen können (PAYNE und PHILIPS 1985, BARTHA 1986, MELCER et al. 1989, DOBBS 1990, SONG et al. 1990, CHANG und ALVAREZ-COHEN 1995, NARAYANAN et al. 1995). Daher wird die Prozessabluft von Mieten und Reaktoren in der Regel durch Bio- oder Aktivkohlefilter geleitet. Die Abluft dieser Filter bedarf einer perrnanenten Kontrolle. Wünschenswert wären Reinigungsprozesse mit geschlossenen Gaskreisläufen zur Vermeidung von potentiellen Umweltkontaminationen.
Das Kooperationsprojekt ENV 24 zwischen der Universidad Nacional de La Plata, Argentinien und der Universität Oldenburg, Deutschland hat Untersuchungen zur biologischen Sanierung von Kohlenwasserstoffschlämmen der petrochemischen Industrie zum Gegenstand.
An der Universität Oldenburg wurden in diesem Zusammenhang Untersuchungen zur aeroben Behandlung von petrochemischen Schlämmen in gerührten Schlammreaktoren durchgeführt. An der Universidad Nacional de La Plata erfolgten Untersuchungen zur biologischen Behandlung von Schlämmen im Boden. Bei beiden Behandlungsarten treten die leichtflüchtigen Bestandteile in die Gasphase über. Um eine Kontamination der Umwelt zu vermeiden, wurde daher ein Reaktorsystem mit geschlossenem Gaskreislauf entwickelt.
Dabei ist ausschlaggebend, daß dem System Sauerstoff zugeführt werden muß, soll der Kohlenwasserstoffabbau in ökonomisch vertretbaren Zeiträumen stattfinden. Dies hatte zur Folge, daß in der gasdichten Anlage der verbrauchte Sauerstoff ersetzt und das beim Abbau produzierte C02 entsorgt werden mußte. Für diese Funktion eignen sich insbesondere Algen, die C02 als C-Quelle nutzten und 02 als Stoffwechselprodukt bildeten. Flüchtige Kohlenwasserstoffe in der Gasphase der Anlage wurden durch mikrobielle Aktivität eliminiert.

BERTHE-CORTI, L., CONRADI, B., HULSCH, R., SINN, B. AND WIESEHAN, K. (1998) Microbial Cleaning of Waste Gas Containing Volatile Organic Compounds in a Bioreactor System with a Closed Gas Circuit. Acta Biotechnologica 18, 4: 292-304.

The cleaning of the exhaust gases of a bioreactor containing volatile hydrocarbons in a bioreactor system with a closed gas circuit is described.  The bioreactor system consisted of three different reactor types: a stirred tank which was filled with hydrocarbon-containing waste water to simulate the exhaust gases of a remediation process; a trickle-bed reactor for aerobic treatment of the exhaust gas from the stirr-ed tank; and a photoreactor containing an algae culture which assimilated CO₂ from the trickle-bed reactor and also produced O₂.  With this bioreactor system, it was possible to efficiently remove volatile organic compounds (VOC) from the waste gases.  Depending on the type of waste water investigated, elimination rates of 41% to 93% of BTEX (benzene, ethylbenzene, toluene, xylene) and 29% to 53% of VCH (volatile chlorinated hydrocarbons) were obtained.  Due to the photosynthesis of the algae in the system´s photoreactor, oxygen concentrations between 12% and 18% [v/v], equivalent to about 57% to 83% DOT, were obtained.  This concentration permitted the aerobic degradation to be carried out without having to add fresh air.  The trickle-bed reactor and the photoreactor worked continuously, whereas the waste water in the stirred bioreactor was replaced in different batches.  The accumulation of toxic compounds in the nutrient solutions of the trickle-bed (EC-50 >30 g/l) and of the photoreactor (EC-50 >35 g/l) was low.  Carbon dioxide concentrations in the gas flow were higher than in fresh air (1% to 3% [vol/vol]), but no long-term accumulation Of CO₂ occurred.  This means that the algae in the photoreactor were active enough to assimilate the CO₂ which had been produced.  They were also able to produce sufficient oxygen for aerobic hydrocarbon degradation.  The system described is a first step towards treating waste gases which result from the bioremediation of hydrocarbon-contaminated media in a closed gas circuit without any emission (e.g. VOC, CO₂, germs).

Berthe-Corti, L.; Jacobi, H.; Kleihauer, S. and Witte, I . (1998) Cytotoxicity and mutagenicity of a 2,4,6-trinitrotoluene (TNT) and hexogen contaminated soil in S. typhimurium and mammalian cells. Chemosphere 37(2): 209-218.

BRUNS, A.[ALKE] AND BERTHE-CORTI, L. (1998) In situ detection of bacteria in continuous-flow culture of seawater sediment suspensions with fluorescently labelled rRNA-directed oligonucleotide probes. Microbiology 144: 2783-2790.

rRNA-targeted and fluorescently labelled oligonucleotide probes were used to study the composition of natural bacterial populations in continuous-flow cultures of seawater sediment suspensions. The cultures were run as enrichment cultures with increasing dilution rates, and hexadecane as the sole carbon source. Total cell numbers were analysed by counting DAPI (4H,6-diamidino-2-phenylindole)-stained cells. To differentiate the population composition, oligonucleotide probes for eubacteria, for Cytophaga/Flavobacteria, and for four subclasses of the Proteobacteria (a, b, c and d) were used. About 40–80% of the DAPI-stained cells could be detected with the EUB338 probe. Moreover, it was possible to detect a shift in the composition of the natural bacterial population with increasing dilution rate of the continuous culture, from large amounts of Cytophaga/Flavobacteria to large numbers of members of the c-Proteobacteria. The cell recovery rate for bacteria labelled with specific oligonucleotide probes was analysed with defined cell numbers of Rhodospirillum rubrum, Comamonas testosteroni and Desulfovibrio vulgaris subsp. vulgaris introduced into the seawater sediment suspension, and was determined to be 13<9–33<5%. The standard deviation determined for this method applied to sediment suspensions was O 8<3%. The results suggest that the application of the in situ hybridization technique allows a good insight into the structure of populations growing in sediment suspensions.

MORELLI, I. S., VECCHIOLI, G. I., COSTANZA, O. R., DEL PANNO, M. T., GARRE‚ M. I., BERTHE-CORTI, L. AND PAINCEIRA, M. T. (1998) Charakterisierung der Toxizität komplexer Kohlenwasserstoffgemische. In: BERTHE-CORTI, L., UFZ-Bericht: Workshop-Bericht: Bioremediation of polluted areas. Bd. 18, 100-105, UFZ - Umweltforschungszentrum, Leipzig - Halle.

Die Einschätzung der Toxizität eines komplexen Kohlenwasserstoffgemisches basiert unter anderem auf der Kenntnis der Prozesse, in deren Verlauf das zu untersuchende Gemisch anfällt und auf der biologischen und chemischen Charakteristik des Gemisches (BROWN et al. 1983).
Es gibt weder biologischen Tests noch gibt es einzelne Spezies, mit denen die toxischen Effekte aller chemischen Verbindungen oder einer Substanzmischung detektiert werden können. Daher ist es notwendig Testbatterien einzusetzen. Viele Aspekte der Toxizität von Substanzgemischen sind mit Hilfe von bakteriellen Tests erfaßt worden, da die Anwendung dieser Tests sehr praktisch ist (Mikroorganismen haben einen kurzen Lebenszyklus und sind stabil und leicht zu kultivieren). Die Erfassung der toxischen Wirkung von Substanzgemischen auf Bakterien ist unerläßlich, da u.a. die bakterielle Aktivität eine grundlegende Voraussetzung für Biodegradationsprozesse ist.
In der vorliegenden Arbeit wird eine Batterie von Kurzzeittests vorgestellt, die es erlaubt, ausgewählte Aspekte der Toxizität der genannten Gemische zu bestimmen.

BERTHE-CORTI, L. AND BRUNS, A.[ALKE] (1999) The Impact of Oxygen Tension on Cell Density and Metabolic Diversity of Microbial Communities in Alkane Degrading Continous-Flow Cultures. Microb Ecol 37: 70-77.

The impact of the dissolved 0₂ tension (DOT) and the dilution rate on the metabolic diversity of an autochthonous hexadecane-degrading community in continuous-flow cultures containing hexadecane-coated intertidal sediment was determined in a set of experiments.  The DOT was kept constant within each culture at values of 80% (168 µmol O₂ L^-1) or 0.4% (0.84 µmol O₂ L^-1).  The dilution rate was increased from D = 0.012 h^-1 to D - 0.06 h^-1 To determine the culture activity, we analyzed the hexadecane degradation rate, the protein production rate, and the oxygen consumption rate.  The cell concentration of different metabolic groups was determined by colony forming units (CFU), and by most probable number (MPN).  The metabolic diversity was determined by the substrate utilization spectrum in Biolog GN microtiter plates.  The substrate utilization pattern of the cultures decreased considerably as D increased.  This effect was more pronounced at 0.4% of DOT than at 80% of DOT.  The MPN and CFU revealed that as D increased, only minor changes occurred in the community structure.  The hexadecane degradation rate, the protein production rate, and the oxygen consumption rate increased parallel to D independently of the DOT.  This means that the biocenosis at 0.4% of DOT was different from the biocenosis at 80% of DOT, although the metabolic activity of the cultures was unaffected by a 200-factor difference in the oxygen tension and revealed a considerable buffer capacity with respect to changes in DOT.

BERTHE-CORTI, L. AND EBENHÖH, W. (1999) A mathematical model of cell growth and alkane degradation in Wadden Sea sediment suspensions. Biosystems 4: 161-189.

In a series of 16 experiments, hexadecane in different concentrations was mixed with natural Wadden Sea sediments, and the degradation of the alkane was observed under controlled conditions (bioreactor). The aim of the experiments was to quantify the impact of the dissolved oxygen tension and the initial alkane concentration on degradation time and degradation completeness. A mathematical model was constructed which is able to reproduce reasonably well the observed-time series under all conditions: aerobic and nearly anaerobic, diluted and alkane-satu-rated. The model contains hypotheses on the chain of reactions; it attempts to bridge existing gaps in the understanding of the degradation process. © 1999 Elsevier Science Ireland Ltd. All rights reserved.

BRUNS, A.[ALKE] AND BERTHE-CORTI, L. (1999) Fundibacter jadensis gen. nov., sp. nov., a new slightly halophilic bacterium, isolated from intertidal sediment. Int J Syst Bacteriol 49: 441-448.

A moderately halophilic hydrocarbon-degrading bacterium was isolated from continuous cultures containing a suspension of intertidal sediment from theGerman North Sea coast with hexadecane as the sole carbon source. On thebasis of phenotypic characteristics, fatty acid analysis and 16S rDNA sequence analysis, it was considered to be a new species belonging to a new genus. It is a Gram-negative, aerobic, rod-shaped bacterium, whose cell size varies. It grows at concentrations of 0<5–15% (w/v) NaCl and utilizes a restricted spectrum of carbon sources. The G+C content of the DNA is 63<6 mol%. Comparative 16S rDNA studies show a clear affiliation of this bacterium to the gamma subclass of the class Proteobacteria. Comparison of phylogenetic data indicate that it is most closely related to Marinobacter hydrocarbonoclasticus (88<9% similarity in 16S rRNA gene sequence). Since it is impossible to find a sufficiently closely related species, we propose the name Fundibacter jadensis gen. nov., sp. nov. for the bacteria. The type strain is T9 ^T (=DSM 12178 ^T ).

MORELLI, I.S., VECCHIOLI, G.I., COSTANZA, O.R., SCHÄFER, R., BERTHE-CORTI, L. AND PAINCEIRA, M.T. (1999) Effect of storage on the toxic potential of hydrocarbon containing sludges. Environ Toxicol 14/2: 227-233.

In many cases, petroleum-derived sludges are stored in open air ponds.- In this condition, weathering may produce changes that can be important when choosing a treatment arid/or disposal method.  The effect of weathering on chemical and toxicological characteristics of sludges were studied in two different sludges, one from a petrochemical API-separator- (API2N) and the other from a refinery biological treatment unit.  Starting determinations were performed with end-of-the-pipe, composite samples. Determinations were repeated after a 6-month weathering period.  Physico-chemical characterizadon included pH, water content, extractable organics, and class fractionation into aliphatics, aromatics, and asphaltics.  Microbiological concentration was done by enumeration of viable bacteria in plate count agar and solid mineral medium with the sludge as. the only source of carbon and energy, and fungi in Cooke rose bengal agar.  For toxicological assessment a battery of bioassays was performed that included: Bacillus cereus spot test, Resazurine reduction test, Bioluminiscence test with Photobactetium, effects on viable soil bacteria counts, Latuca sativa seed germination and root elongation test The Ames test: (TA-98 with S9- microsomal activation) was used to assess genotoxicity changes.  Comparison of starting results of both sludges with those obtained after 6 months showed a minimal change in the chemical characteristics, a significant increase in the starting low level of bacteria in API2N, reduction in acute toxicity and increase in the mutagenic effect in the dimethyI sulfoxide (DMAO)-sludges fraction, but not in the DMSO-ethylether organic fraction in both sludges.

JEFFKE, T., JENDE, D., MÄTJE, C., EHLERS, R.-U. AND BERTHE-CORTI, L. (2000) Growth of Photorhabdus luminescens in batch and glucose fed-batch culture. Apl Microbiol Biotechnol 54: 326-330.

Photorhabdus luminescens, a bacterial symbiont of entomopathogenic biocontrol nematodes, was grown in batch and glucose fed-batch culture.  The cell density, bioluminescence, production of antibiotic substances, number of cells with inclusion bodies, glucose concentration and oxygen uptake rate were recorded.  The addition of 12.4 g l^-1 glucose prolonged the growth, and the yield almost doubled, from 6.85 g l^-1 to 12.45 g l^-1 dry mass.  The production of antibiotic substances increased by 140%.  Bioluminescence was higher in the batch culture.  A shift of P. luminescens to phase II variants was not detected.

Berthe-Corti. L. and Bruns, A.[Alke] (2001) Composition and Activity of Marine Alkane-Degrading Bacterial Communities in the Transition from Suboxic to Anoxic Conditions. Microbial Ecol 42: 46-55.

The impact of the oxygen supply rate (OSR) on the metabolic activity and on the composition of hexadecane-degrading bacterial communities in a quasi-anoxic milieu (nominal DOT = 0%) was studied in continuous cultures containing intertidal sediment. The dilution rate was kept constant at 0.035 h-1. The OSR was stepwise reduced from 3.5 mmol O2 L-1 h-1 to 0.06 mmol O2 L-1 h-1. Activity was determined by analyzing the respiration quotient (RQ) and the rates of hexadecane degradation (QHex), of hexadecane mineralization, and of protein production (PPR). The community composition and size were investigated by fluorescence in situ hybridization (FISH), by dilution plating (colony forming units or CFU), and by most probable number (MPN). The culture showed an aerobic hexadecane metabolism down to an OSR of 0.35 mmol O2 L-1 h-1. Below this OSR, anaerobic metabolism was initiated. The relationship among the RQ, PPR, QHex, and the OSR can be approximated by hyperbola (Michaelis–Menten kinetics). We suggest that the metabolic adaptation of the culture to low OSRs is due to regulation of protein expression and enzyme activity. Reducing the OSR resulted in minor but significant changes in the concentration of different physiological and phylogenetic groups. This means that, in addition to protein expression and activity regulation, the adaptation of the population to low OSRs is due to changes in the community composition.

Ebenhöh, W. and Berthe-Corti, L. (2001) Modelling of hexadecane degradation in continuous-flow cultures. Biosystems 59: 159-183.

Microorganisms of Wadden Sea sediments are able to degrade hydrocarbons in suspensions. (Berthe-Corti, L., Bruns, A., Hulsch, R., 1997. J. Microb. Methods 29, 129-137) have observed in continuous culture experiments that the growth rate of microorganisms increases roughly proportional to the dilution rate. The growth rate is nearly independent of the oxygen saturation down to about 0.5%. Even at very low oxygen supply, corresponding to an oxygen saturation far below 0.1%, growth takes place at a reduced rate. In this paper, a model is presented which can reproduce the results of these experiments. The model treats the following processes, selection of the active fraction of microorganisms growing on hexadecane, uptake of hexadecane and transformation into palmitate as a first metabolic step, synthesis of biomass, respiration and exudation. The processes are regulated by the substrate concentration, the internal palmitate quota, the exudates´ concentration and an inhibiting factor. For the experiments under very low oxygen conditions, the observed growth with reduced O(2)-consumption and CO(2)-production is modelled by assuming an anoxic metabolic pathway.

Müller, S.; Kiesel, B. and Berthe-Corti. L. (2001) Muricauda ruestringensis has a asymmetric cell cycle. Acta Biotechnol 21/4: 343-357.

Muricauda ruestringensis B 1 is a GRAM-negative, marine bacterium and a member of the Flavobacteriaceae family. It is characterized by long appendages, which appear at different stages of growth. At the outer end of these appendages there is a bulbous structure. Investigating the cell morphology of strain B 1 during batch growth revealed a high diversity of cell types and sizes. Apart from small rod-shaped cells and rods with appendages, there were large rods and spherical cells of different sizes as well as spherical cells which had firnbriae. To be able to study the cell cycle events, it was essential to monitor the population dynamics of the involved individuals. For this purpose, fluorochromising techniques, multi -parametric flow cytometry, image analysis and fluorescence microscopy were used. It was demonstrated that all cell types displayed a broad variation in DNA content; the precise number of chromosomes varied depending on the growth phase. The assortment was testified to hold 16S rDNA sequence identity. The cultures consisted of subpopulations whose density within a Percoll gradient varied considerably, ranging from 1.028 to 1.070. Consolidating the results of the morphological data, the chromosome content and the density of the subpopulations at different growth stages enabled us to construct an asymmetric cell cycle for the growth of strain B 1 under the specific culture conditions of our experiments.

Bruns, A.[Alke], Rhode, M. and Berthe-Corti, L. (2001) Muricauda ruestringensis gen. nov., sp. nov., a facultative anaerobic, appendaged bacterium from German North Sea intertidal sediment. I.J.S.E.M. 51: 1997-2006.

A Gram-negative, facultatively anaerobic bacterium with appendages was isolated from continuous cultures with a seawater-sediment suspension containing hexadecane as the sole carbon source. Although this organism was isolated from a hexadecane-degrading bacterial community, it was not able to degrade hexadecane. However, this bacterium was able to use different sugars and amino acids for growth, indicating that it probably ~its from the lysis or from products like surfactants of other cells in the community. 165 rDNA analysis demonstrated that the isolated strain is phylogenetically related to the family Flavobacteriaceae of the phylum ´Cytophaga-Flavobacterium-Bacteriodes´. Evidence based on phenotypic characteristics and 165 rDNA analysis supports the conclusion that this bacterium is distinct from its nearest relative. Zobellia uliginosa (90.72% similarity in 165 rRNA gene sequence), and from the other genera of the Flavobacteriaceae. It is therefore proposed that the isolated marine bacterium represents a novel taxon, designated Muricauda ruestringensis gen. nov., sp. nov. The type strain is strain BIT (= DSM 1325W = LIVIG 19739T).

Berthe-Corti, L. and Fetzner, S. (2002) Bacterial metabolism of n-alkanes and ammonia under oxic, suboxic and anoxic conditions. Acta Biotechnol. 22,3-4: 299-336.

A review. N-Alkanes are widespread in the biosphere. Due to the lack of functional groups, these alkanes exhibit low chem. reactivity. However, many microorganisms have evolved pathways to utilize n-alkanes as a growth substrate, and moreover, fortuitous alkane oxidn. may play an important role in alkane degrdn. This review discusses the ecol. of n-alkane-degrading and ammonia-oxidising bacteria with a focus on alkane metab. in the transition from oxic to anoxic conditions, the pathways of n-alkane and ammonium oxidn., and the enzymes catalyzing n-alkane and ammonia activation. N-Alkane degrading bacteria occur in oxic as well as strictly anoxic environments, and they live in very diverse habitats, including marine or fresh water, soils, sediments or aquifers. Aerobic ammonium-oxidising as well as methanotrophic bacteria are often found in stratified habitats such as biofilms and sediments. Aerobic pathways involving oxygenases that catalyze the initial activation of n-alkanes and ammonium are well known. However, anaerobic ammonium oxidn. as well as anaerobic utilization of hydrocarbons have been demonstrated only in the past decade and are the subject of current research efforts. Enzyme systems that catalyze aerobic alkane oxidn. involve a no. of well-characterised monooxygenases such as cytochrome P 450 monooxygenases, multi-component alkane monooxygenases (also known as o-hydroxylase systems), methane monooxygenases, and ammonia monooxygenase. Alternative enzymes, for example an n-alkyl hydroperoxide-forming dioxygenase, have also been postulated, but contrary to the monooxygenases, an n-alkane oxidising dioxygenase has not yet been biochem. characterised. The oxygenase components of sol. methane monooxygenase and alkane monooxygenase contain binuclear iron centers that mediate dioxygen activation, whereas particulate methane monooxygenase, ammonia monooxygenase, and presumably distinct butane monooxygenases are copper-contg. enzymes. Little is known about the impact of the oxygen concn.
on bacterial alkane degrdn., and it has not yet been investigated which pathways and enzymes are active in bacteria which utilize alkanes at suboxic or even quasi-anoxic conditions. Methane monooxygenase as well as ammonia monooxygenase have low half-satn. consts. for oxygen and, in addn., both have an ample substrate spectrum. Activation of n-alkanes by cooxidn. has been demonstrated for both types of enzymes. In suboxic to quasi-anoxic habitats, in which alkane, ammonium and methane oxidising bacteria as well as other organotrophic microorganisms live in close vicinity, a cooperative effect with respect to n-alkane degrdn. may occur. 

Bredemeier, R.; Hulsch, R.; Metzger, J., O.; and Berthe-Corti, L. (2003) Submersed Culture Production of Extracellular Wax Esters by the Marine Bacterium Fundibacter jadensis. Marine Biotechnology 5: 579 - 583.

Fundibacter jadensis strain T9, a marine gram-negative bacterium, was isolated from the intertidal sediment of the German North Sea coast by our group. The cells were able to produce considerable amounts of extracellular wax esters when cultivated with n-alkanes (hexadecane or tetradecane) as a carbon source. The dependence of wax ester production and the composition of the purified wax on different culture conditions (C:N:P ratio and dissolved oxygen tension) were tested. Our results show that wax ester production was not directly growth-linked. The C:N:P ratio had no significant influence on the yield of alkane-free purified wax. The dissolved oxygen tension affected the produced amount of the alkane-free purified wax and the composition of the purified wax; when lower than 2% it decreased the yield of purified wax and led to an altered wax ester composition. Tetradecane as a carbon source enhanced the spectrum of the wax ester composition.

Berthe-Corti, L., and Höpner, T. (2005) Geo-biological aspects of coastal oil pollution. Palaeogeography, Palaeoclimatology, Palaeoecology 219: 171-189. 

More than 10 years after the 1991 Gulf War oil spill on the Saudi-Arabian coast of the Arabian Gulf, natural remediation has only been partially successful. This fact demonstrates the importance of studying the preconditions for, and the process of, hydrocarbon degradation as well as the competing processes which prevent or slow them down. This paper deals with the preconditions of biodegradation: the presence of water, the availability of oxygen, the influence of temperature and the presence and type of degrading microorganisms. This paper discusses abiotic transformation as well as aerobic and anaerobic biodegradation. The importance of emulsification and hydrocarbon uptake into the degrading microorganisms is underlined. Competing processes include the conversion of liquid oil to viscous and finally solid material, the formation of solid sediment–oil mixtures and the clogging of sediment pores preventing oxygen from entering the pores. At first glance, the competing processes seem more “geological” while emulsification and hydrocarbon uptake seem more “biological”. However, since the necessary energy input (e.g., waves and turbulence) is “geo”(physical), it becomes clear, on the one hand, that the biological process requires geophysical energy input and, on the other hand, is inhibited by geological competition. Oil pollution as well as remediation progress affect the impacted environment since they leave undegradable residues and intermediates as well as microbial biomass and its conversion products. Sediments are enriched with organic matter, whose properties and behaviour are altered. Even inorganic matter may be formed during hydrocarbon biodegradation.