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The membrane-bound formaldehyde dehydrogenase from Methylococcus capsulatus Bath is a homotetramer consisting of 49,500 dalton each subunits. The enzyme oxidizes formaldehyde to formate and uses pyrroloquinoline quinone as its redox cofactor.

Research was conducted to examine the structural gene and polypeptide for high-molecular-mass multi-c-heme cytochromes from Methylococcus capsulatus Bath. Electron paramagnetic resonance spectrum and degenerate oligonucleotide probe were used to prove the presence of multiple low spin and to identify a DNA fragment from M. capsulatus, respectively. Results indicate that cytochrome C5530 and the gene products of ORF3 and ORF1 belong to a novel class of c-type cytochrome.

P460 cytochromes catalyze the oxidation of hydroxylamine to nitrite. A degenerate oligonucleotide probe was synthesized using the N-terminal amino acid sequence of cytochrome P460 and applied in the identification of a DNA fragment from M. capsulatus Bath that contains cyp, the gene encoding cytochrome P460. The overall sequence similarity of the P460 cytochromes from M. capsulatus Bath and N. europaea was low, even though short regions conserved residues are found in both proteins. Both terminals have a C-terminal, c-heme binding motif and a conserved lysine residue.

The gene cycA encoding the tetraheme cytochrome c554 of Nitrosomonas europaea is present in three copies per genome and the cytochrome c554 represents a new class of tetraheme c cytochromes. Southern blot sequence probes reveal that the gene cluster consists of hao, cycA and ORF2 genes and organization of these genes for three proteins results in ammonia oxidation in N. europaea.

The sequence of the entire hao gene cluster that exists as a single copy in the genome of Nitrosococcus oceani and compare it to the hao gene clusters of Nitrosospira multiforms and Nitrosomonas europaea is presented. The analyses of gene cluster organization and phylogenetic analyses of the protein sequences encoded by genes in the hao gene cluster are described.

Many studies have identified the potential of rainwater harvesting (RWH) systems to simultaneously augment potable water supply and reduce delivery of uncontrolled stormwater flows to downstream drainage networks. Potentially, such systems could also play a role in the controlled delivery of water to urban streams in ways which mimic baseflows. The performance of RWH systems to achieve these three objectives could be enhanced using Real-Time Control (RTC) technology to receive rainfall forecasts and initiate pre-storm release in real time, although few studies have explored such potential. We used continuous simulation to model the ability of a range of allotment-scale RWH systems to simultaneously deliver: (i) water supply; (ii) stormwater retention; and (iii) baseflow restoration. We compared the performance of RWH systems with RTC technology to conventional RWH systems and also systems designed with a passive baseflow release, rather than the active (RTC) configuration. We found that RWH systems employing RTC technology were generally superior in simultaneously achieving water supply, stormwater retention and baseflow restoration benefits compared with the other types of system tested. The active operation provided by RTC allows the system to perform optimally across a wider range of climatic conditions, but needs to be carefully designed. We conclude that the active release mechanism employing RTC technology exhibits great promise; its ability to provide centralised control and failure detection also opens the possibility of delivering a more reliable rainwater harvesting system, which can be readily adapted to varying climate over both the short and long term. [ABSTRACT FROM AUTHOR]