Pauli Kiel

Mutagenicity of fume particles from metal arc welding on stainless steel in the Salmonella/microsome test

Mutagenic activity of fume particles produced by metal arc welding on stainless steel (ss) is demonstrated by using the Salmonella/microsome mutagenicity test described by Ames et al., with strain TA100 (base-pair substitution) and TA98 (frame-shift reversion). Results of a representative but limited selection of processes and materials show that mutagenic activity is a function of process and process parameters. Welding on stainless steel produces particles that are mutagenic, whereas welding on mild steel (ms) produces particles that are not. Manual metal arc (MMA) welding on stainless steel produces particles of higher mutagenic activity than does metal inert gas (MIG) welding, and fume particles produced by MIG welding under short-arc transfer. Further studies of welding fumes (both particles and gases) must be performed to determine process parameters of significance for the mutagenic activity.

Integrated utilisation of green biomass in the green biorefinery.

Abstract Grass, clover and alfalfa are used for production of fodder pellets. In the green crop drying factories in the northern countries the drying is combined with pressing of the green crops resulting in production of large volumes of plant juices, green and brown juice. In order to get rid of these enormous amounts of plant juice, representing an environmental threat, it is our aim to convert the simple drying industry to a whole crop utilisation factory, a green biorefinery, where the plant juice can be used as raw material in a fermentation process. As the plant juice is very unstable, it has been necessary to develop a method for both conservation and utilisation of the juice. The plant juice is converted to a nice universal fermentation medium by lactic acid bacteria. A number of lactic acid producing strains have been tested. Among the most productive strains, Lactobacillus paracasei ssp. paracasei P4155 is found to be the most effective in utilising fructans and citric acid. Most carbohydrates and organic acids in the juice can be converted to lactic acid by two homofermentative lactobacilli. The highest lactic acid yield and productivity is reached when using not-heat sterilised brown or green juice as the fermentation medium. The amount of free amino acids in the juice is increased and the content of vitamins and other important growth factors kept unspoiled by the lactic acid fermentation. The fermented juice can be stored as it is or evaporated to a concentrated form and used in fermentation industries for production of amino acids, organic acids, enzymes etc.

Mutagenic action of methyl 2-cyanoacrylate vapor

Alkyl 2-cyanoacrylate adhesives were tested for mutagenicity in Salmonella typhimurium strains TA98, TA100, TA1535 and TA1538. Both a normal spot test and a spot test specially designed to test volatile compounds were used. The adhesives were also tested in the plate incorporation assay. These investigations showed that methyl 2-cyanoacrylate adhesives are mutagenic in strain TA100. The spot test for volatile compounds showed that it is the vapors from the methyl 2-cyanoacrylate monomer that are responsible for the mutagenic effect. One can conclude that working with methyl 2-cyanoacrylate adhesives entails exposure to vapors with a mutagenic effect and may therefore pose a carcinogenic hazard. Because the adhesives are used in industry, their mutagenic effect has a special importance in work environment.

Agricultural Residues and Cereals as Fermentation Media

In many traditional industrial processes based on biomass, the production only takes place in the harvest season and the products are main products such as starch, sugar, green pellets, potato chips etc. plus a residue used as fertilizer or animal feed stuff. From economical and environmental points of view such processes are not very rational. A yearround, integrated production with more biotechnologically-based products would seem more reasonable.

Microorganisms for Biorefining of Green Biomass

Traditional green crops such as grass, clover, alfalfa as well as new (halophytic) green biomass of Salicornia have great potential to be utilised in the concept of the green biorefinery, where the first step is a wet fractionation of the biomass to yield a sugar- and protein-rich juice and a lignocellulosic pulp fraction.