Growth of plant cell cultures is demonstrated in an uncontrolled, simple, and inexpensive plastic-lined vessel. Sustained specific growth rates of 0.22 day-1 for Hyoscyamus muticus cell suspension cultures are achieved in a low-cost gas-sparged bioreactor configuration (6.5 L working volume, wv) which is comparable to an "optimized" 5 L wv mechanically agitated fermentor. In an effort to reduce bioreactor costs, the need for an autoclavable vessel was eliminated. Sterilization is achieved by separate autoclaving of the plastic liner and by gas-phase sterilization using ethylene oxide. The initial run sterilized with ethylene oxide displayed a long lag, apparently due to residual sterilant gas. Because ethylene oxide could eliminate costs associated with autoclave rated vessels, a quantitative basis for aeration time was developed by experimental measurements and modeling of diffusion in the polymer liner. Operational techniques to eliminate toxicity are implemented to grow 0.2 kg dry weight of plant cells in 13 days in a 40 L (28.5 L wv) air-lift bioreactor without autoclave sterilization. The biomass yields for all reactors were statistically indistinguishable from shake flask culture.

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The fatty acid profile of kenaf (Hibiscus cannabinus L.) seed oil has been the subject of several previous reports in the literature. These reports vary considerably regarding the presence and amounts of specific fatty acids, notably (12,13-epoxy-9(Z)-octadecenoic (epoxyoleic) acid, but also cyclic (cyclopropene and cyclopropane) fatty acids. To clarify this matter, two kenaf seed oils (from the Cubano and Dowling varieties of kenaf) were investigated regarding their fatty acid profiles. Both contain epoxyoleic acid, the Cubano sample around 2 % and the Dowling sample 5-6 % depending on processing. The cyclic fatty acids malvalic and dihydrosterculic were identified in amounts around 1 %. Trace amounts of sterculic acid were observed as were minor amounts of C17:1 fatty acids. The results are discussed in the context of the fatty acid profiles of other hibiscus seed oils.

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A two-step process assisted by microwave irradiation was used to produce kenaf oil methyl ester. The first stage made use of sulfuric acid catalyst to convert free fatty acids into methyl ester, while the second made use of potassium hydroxide catalyst under microwave irradiation to transesterify the triglycerides. The four major experimental variables considered in the latter step were catalyst concentration, alcohol-oil molar ratio, reaction temperature and reaction time. The results were analyzed statistically for the effect of those variable parameters on the reaction conversion. Optimum conversion of about 94% was obtained at the optimum values of variables 0.55% KOH catalyst, 4.5:1 methanol-oil molar ratio, 57.5oC and 6.5 minutes reaction time. The analyses on the biodiesel produced by this method proved to be acceptable in comparison to ASTM biodiesel standard.