A strong tendency is currently emerging to remove not only serum but also any product of animal origin from animal cell culture media during production of recombinant proteins. This should facilitate downstream processing and improve biosafety. One way consists in the fortification of protein-free nutritive media with plant protein hydrolysates. To investigate the effects of plant peptones on mammalian cell cultivation and productivity, CHO 320 cells, a clone of CHO K1 cells genetically modified to secrete human interferon-gamma (IFN-gamma), were first adapted to cultivation in suspension in a protein-free medium. Both cell growth and IFN-gamma secretion were found to be equivalent to those reached in serum-containing medium. Eight plant peptones, selected on the basis of their content in free amino acids and oligopeptides, as well as molecular weight distribution of oligopeptides, were tested for their ability to improve culture parameters. These were improved in the presence of three peptones, all having an important fraction of oligopeptides ranging from 1 to 10 kDa and a small proportion of peptides higher than 10 kDa. These peptones do not seem to add significantly to the nutritive potential to basal protein-free nutritive medium. Nevertheless, supplementation of an oligopeptide-enriched wheat peptone improved cell growth by up to 30% and IFN-gamma production by up to 60% in shake-flask experiments. These results suggest that the use of plant peptones with potential growth factor-like or antiapoptotic bioactivities could improve mammalian cell cultivation in protein-free media while increasing the product biosafety.

Fungal biomasses are capable of treating metal-contaminated effluents with efficiencies several orders of magnitude superior to activated carbon (F-400) or the industrial resin Dowex-50. Additionally, fungal biomasses are susceptible to engineering improvements and regeneration of their capabilities. With regard to organic pollutants, excessive nutrients and dyes, fungi can remove them from wastewaters, leading to a decrease in their toxicities. However, the detoxification rates seem to be dependent on media and culture conditions. The postreatement by anaerobic bioprocesses of effluents that have been pretreated with fungi can lead to higher biogas than the original effluents. In addition to the degradation of organic pollutants, fungi produce added-value products such as enzymes (LiP, MnP, Lacc, amylase, etc.) and single-cell protein (SCP). Most research on fungal capacities to purify polluted effluents has been performed on a laboratory scale, hence there is a need to extend such research to pilot scale and to apply it to industrial processes.

The sorption and degradation of the chlorinated ethenes tetrachloroethene (PCE, 5 mg L -1 ) and trichloroethene (TCE, 10 mg L -1 ) were investigated in zero-valent iron systems (ZVI, 100 g L -1 ) in the presence of compounds common to contaminated groundwater with varying physicochemical properties. The potential competitors were chlorinated ethenes, monocyclic aromatic hydrocarbons, and humic acids. The effect of a complex matrix was tested with landfill contaminated groundwater. Nonlinear Freundlich isotherms adequately described chloroethene sorption to ZVI. In the presence of the more hydrophobic PCE (5 mg L -1 ), TCE sorption and degradation decreased by 33% and 30%, respectively, while TCE (10 mg L -1 ) decreased PCE degradation by 30%. In the presence of nonreactive hydrophobic hydrocarbons (i.e., benzene, toluene, and m-xylene at 100 mg L -1 ), TCE and PCE sorption decreased by 73% and 55%, respectively. The presence of the hydrocarbons had no effect on TCE degradation and increased PCE reduction rates by 50%, suggesting that the displacement of the chloroethenes from the sorption sites by the aromatic hydrocarbons enhanced the degradation rates. Humic acids did not interfere significantly with chloroethene sorption or with TCE degradation but lowered PCE degradation kinetics by 36% when present at high concentrations (100 mg L -1 ). The landfill groundwater with an organic carbon content of 109 mg L -1 C had no effect on chloroethene sorption but inhibited TCE and PCE degradation by 60% and 70%, respectively.

We report the development of a new serum-free medium based on the use of factorial experiments. At first, a variety of hydrolysates were screened using a fractional factorial approach with High-Five cells. From this experiment yeastolate ultrafiltrate was found to have, by far, the most important effect on cell growth. Furthermore, Primatone RL was found to remarkably prolong the stationary phase of Sf-9 and High-Five cell cultures. The optimal concentrations for yeastolate and Primatone were determined to be 0.6 and 0.5%, respectively, on the basis of a complete factorial experiment. This new medium, called YPR, supported good growth of both Sf-9 and High-Five cells in batch cultures, with maximal densities of 5.4 and 6.1 x 10(6) cells/ml, respectively. In addition, both cell lines achieved good growth in bioreactor batch culture and had a prolonged stationary phase of 3-4 d in YPR medium compared to Insect-XPRESS medium. The ability of the new medium to support recombinant protein expression was also tested by infecting Sf-9 or High-Five cells at high density (2 x 10(6) cells/ml) with a baculovirus expressing secreted placental alkaline phosphatase (SEAP). The maximum total SEAP concentration after 7 d was about 43 lU/ml (58 mg/L) and 28 lU/ml (39 mg/L) for High-Five and Sf-9 cells, respectively.