TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Method: In the method, at least one of the recombinant enzymes is heterologous with respect to the engineered cyanobacterium. The method further comprises isolating at least one n-alkane, n-alkene or n-alkanol from the engineered cyanobacterium or the culture medium. Preferred Components: The enzymes are encoded by: a plasmid; recombinant genes incorporated into the genome of the engineered cyanobacterium; genes which are present in multiple copies in the engineered cyanobacterium; or genes which are part of an operon, where the expression of the genes is controlled by a single promoter. EXAMPLE - Natural Synechococcus elongatus PCC7942-1593-Synechococcus elongatus PCC7942-1594 operonic sequence was PCR-amplified from the genomic DNA of Synechococcus elongatus PCC7942 and cloned into the pAQ1 homologous recombination vector pJB5 via Ndel and EcoRI. The resulting plasmid was denoted pJB823. The construct placed the Synechococcus elongatus PCC7942-1593-Synechococcus elongatus PCC79421594 operon under the transcriptional control of the constitutive aphll promoter. The sequence of pJB823 is provided as SEQ ID NO: 15 (comprising fully defined 7026 nucleobases as given in the specification). The intracellular hydrocarbon products of Escherichia coli K-12 EPI400 (RTM: Electrocompetent cells) harboring pJB823, JCC1076, were compared to those of EPI400 (RTM: Electrocompetent cells) harboring pJB5, the control strain JCC9a, by gas chromatography-mass spectrometry (GC-MS). Clonal cultures of JCC9a and JCC1076 were grown overnight at 37 degrees C in Luria broth containing glucose (2%), carbenicillin (100 mu g/ml), spectinomycin (50 mu g/ml), streptomycin (50 mu g/ml), and 1x copycutter induction solution. For each strain, saturated culture (15 ml) was collected by centrifugation. Cell pellets were washed thoroughly by three cycles of resuspension in milli-Q water (ultrapure laboratory grade water) and microcentrifugation, and then dewetted as much as possible by three cycles of microcentrifugation and aspiration. Cell pellets were then extracted by vortexing for 5 minutes in acetone (0.8 ml) containing butylated hydroxytoluene (100 mu g/ml) and ethyl arachidate (100 mu g/ml). Cell debris was pelleted by centrifugation and 700 mu l extractant was pipetted into a gas chromatography vial to give JCC9a and JCC1067 acetone samples containing hydrocarbons.