In industrial fermentation of L-glutamic acid with cane molasses as the main carbon source, productivity increased when sucrose inversion was done first. Sucrose could be hydrolyzed by yeast invertase immobilized in alginate. As a first step, a pilot-scale apparatus was tried. Na-alginate that contained invertase was pressed out, gelled with a Ca²⁺ solution, and then cut to give cylindrical particles with immobilized enzyme. Optimum conditions were investigated. The length of particles with immobilized enzyme was proportional to the flow rate of Na-alginate and inversely proportional to the speed at which the cutting blades revolved. A speed of revolution less than the critical value (600 rpm, for this apparatus) gave highly stable production. Room temperature was suitable and cane molasses could be used for gelling. A flow rate of 80l/h and a speed of revolution of 500 rpm gave particles with immobilized enzyme 4mm long with a diameter of 1.4mm. The immobilized enzyme had the same activity as the enzyme prepared on the laboratory scale and it retained activity for at least 30 days during a performance test.

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Use of converted sugar in L-glutamuc acid fermentation increases productivity. Cane molasses was used instead of sucrose as the main carbon source in a pilot-plant study done with yeast invertase trapped in Na-alginate and a pair of agitation-type reactors each with a capacity of 35-1. Two-step continuous reaction gave a conversion ratio of 95% when the initial sugar concentration was 550g/l, the enzyme packing ratio was 30%, the mean retention time was 7h, and the temperature was 50°C. Problems did not occur on this increased scale. The retention time that would give a conversion ratio of 95% in reactors of this size calculated with the Michaelis-Menten equation from experimental results obtained with a 100-ml reactor agreed with the experimental value obtained with the 35-1 reactors.

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The crude extract from Cassia mimosoides L. var. nomame Makino significantly inhibited lipase activity. In this paper, lipase inhibitors in the above plant were studied. The lipase activity was assayed in a homogeneous mixture of water and organic solvents with lipase B-detergent complexes soluble in organic solvents. A component that inhibited the activity was purified and identified as pheophorbide a. The effects of various chlorophyll derivatives and related substances on the lipase activity in various reaction mixtures were also studied. Substances containing a porphyrin ring inhibited the activity in the mixture of water and organic solvents and in water when porcine pancreas lipase and 4-methylumbelliferyl oleate were used. The metal complex of chlorophyllin strongly inhibited the activity in water alone. The effects of proteins on the inhibition caused by chlorophyllin were examined by comparison with epigallocatechin gallate (EgCg), an inhibitor that is phenolic. The inhibition caused by chlorophyllin was so decreased less than the inhibition caused by the phenolic inhibitor when casein was present. Chlorophyllin activated the lipase activity when bovine serum albumin was present, but the phenolic inhibitor did not have this effect. These results suggest that the mechanism of the inhibition by chlorophyllin is different from that of the phenolic inhibitor.

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To develop a method to inhibit the growth of fibroblasts that contaminate primary cultures of human cancer cells, we examined the effects of dextran sulfate in the medium when human cancer cells and fibroblasts were cultured. Dextran sulfate of the molecular weight of 8000, 15, 000, 50, 000, and 500, 000 was used. The dextran sulfate of the molecular weight of 500, 000 inhibited the growth of MRC-5 fibroblasts most strongly of all molecular weights tested. The same dextran sulfate inhibited the growth of six other human fibroblast cell lines concentration-dependently. Its inhibition of the nine human cancer cell lines tested was slight. The cytoplasm of the seven fibroblast cell lines became hypertrophic in a concentration-dependent way when dextran sulfate was present. When human cancer cells obtained from forty-two surgical specimens were cultured with 10 μg/ml dextran sulfate, the growth of the fibroblasts in the stroma of the cancer was suppressed, and the cancer cells grew. These results suggest that culture media containing dextran sulfate can be used for the selective culture of human cancer cells.

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