The hydrogen evolution from ethanol, n-propanol, n-butanol, malate and mixed substrates containing these compounds by Rhodopseudomonas sp. No. 7 was examined. A small amount of bicarbonate was necessary for the commencement of the hydrogen evolution in an alcoholglutamate medium by the bacterium grown in an alcohol-NH⁺₄ medium. Bicarbonate added to the medium was a concentration of less than one-tenth of that required for the maximum growth in the alcohol-NH⁺₄ medium. Once the cells had acquired the ability of hydrogen evolution, they continued to evolve hydrogen regardless of the presence or absence of bicarbonate. The rate and the yield of the evolution were improved in a medium containing both an alcohol and malate. These substrates were not preferentially but simultaneously consumed in the mixed medium. The alcohols and malate were effective for the evolution when the electron donors were used at low concentrations and when the incubation temperature was elevated to 40°C, respectively. The yield and the rate of the evolution at 40°C were 70% and 80μl/mg cell/hr, respectively. The bacterium incubated in a medium containing an alcohol exhibited a higher level of glutamine synthetase than that in the malate-medium.

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A novel pullulanase-amylase complex enzyme, which hydrolyzes pullulan into maltotriose as well as starch into maltose and maltotriose as the main products, was found in the culture filtrate of a strain of Bacillus subtilis newly isolated from soil. The enzyme was purified to almost complete homogeneity by means of calcium phosphate gel adsorption, DEAE-Sepharose column chromatography and Bio-gel A-1.5m filtration. The optimum pH of the pullulanase activity was observed at around 7.0 to 7.5, with a discernible shoulder around pH 5.0. While the optimum pH of the amylase activity was 6-7. The optimum temperatures of the pullulanase and amylase activities were about 60°C and about 50°C, respectively. The molecular weight was estimated to be about 450, 000 by the gel filtration method. The enzyme could be used for the production of glucose from starch with glucoamylase and the production of a new type of syrup containing a relatively high amount of maltotriose, 50-55%, from starch.

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Dialkoxy-, trialkoxy-, dialkoxyvinyl-, and trialkoxyvinylbenzenes were investigated for chemosterilant and toxic acitivity on Planococcus citri. The alkoxyvinylbenzenes were toxic; they reduced the egg production of the test insect. Dialkoxyvinylbenzenes decreased the number of eggs laid by females, but the chemosterilizing activity of the trialkoxy derivatives was not strong.
Larvae treated with 0.1% 1, 5-diisopropoxy-4-vinylbenzene (6), 17% survived. The surviving females were strongly retarded in their growth (which was 56% of normal) and their egg production was reduced by 70%. Some of the small adults (43% of the surviving females) failed to form an ovisac and did not lay eggs at all.

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The volume of air accompanying flour particles was determined through the measurement of the apparent density and compared with the volume of micropores, smaller than 30nm in diameter, of the flour particles, which was measured by the Cranston-Inkley method. Weak wheat flour had the largest amount of accompanying air, strong wheat flour an intermediate amount, and rice flour the least. Most of the air accompanying the wheat flours was held in pores larger than 30nm in diameter, while most of the air accompanying the rice flour was held in pores smaller than 30nm in diameter. From the viewpoint of the expansion of dough, the condition of the wheat flours was much better than that of the rice flour.

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The effects of sifting, drying, lipid extraction, oxidation with benzoyl peroxide and aging on the amounts of air accompanying particles of weak and strong wheat flours and a rice flour were investigated. The drying and the lipid extraction were effective in increasing the amount of accompanying air, and the combination of drying and lipid extraction was the most effective. The additional accompanying air due to these treatments was found to be held in a space larger than 30nm in diameter inside the flour particles. The increase in air accompanying flour particles may improve the characteristics of flours used in baking and extrusion cooking.

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A thermostable lipase from Humicola lanuginosa No. 3 was purified by means of acetone precipitation and successive chromatographies on Sephadex G-75, DEAE Sepharose CL-6B and hydroxyapatite columns. The enzyme was purified about 150-fold with a yield of 15.0% and a specific activity of about 3000 U/mg protein. The purified enzyme showed a single protein band on polyacrylamide gel electrophoresis. Its molecular weight was estimated to be 39, 000 on both sodium dodecyl sulfate polyacrylamide gel electrophoresis and gel filtration on Sephadex G-100, suggesting that the enzyme was a monomer. Its isoelectric point was pH 6.6. The optimum pH and temperature were 7.0 and 45°C, respectively. The enzyme was stable over a pH range of 5 to 9 (45°C, 24hr), and its activity was maintained at 60°C for about 20 hr. The activity was inhibited by Co²⁺, Cu²⁺, Ni²⁺, Hg²⁺ and Sn²⁺, and slightly affected by Zn²⁺, Mg²⁺, EDTA and sodium dodecyl sulfate. The Km value for trilaurin (45°C) was 14.2mg/ml. The enzyme was specific for substrates containing a C12 fatty acid component. Analysis of hydrolyzates of triolein and olive oil after the lipase reaction revealed that Humicola lanuginosa No. 3 produced a 1, 3 positional specific lipolytic enzyme.

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The entrapment of non-proteolytic enzymes inside human plasma α₂-macroglobulin (α₂M) was attempted using Serratia superoxide dismutase (SOD) and horseradish peroxidase (HRP). HRP was easily entrapped within α₂M in the presence of Serratia protease (TSP), but SOD was not under the same conditions. SOD was enclosed in α₂M molecule by conjugation with TSP. The antigenicities of these enzymes were completely masked with α₂M, but both enzyme-α₂M complexes had the enzyme activities.

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In contrast to the situation in shoots and stems of mulberry (Morus alba L.), for nitrogen reserves soluble nitrogen predominated in bark and wood of the main roots, especially arginine, followed by asparagine. The small roots also played a part in storage of nitrogen, with protein nitrogen predominating. Accumulation of nitrogen in the roots started in October (bark and wood of the main roots) and November (small roots) and still continued in midwinter, increasing until January (small roots and wood) and late February (bark). The nitrogen levels in bark and wood of the main roots then levelled off notably during bud break and leafing-out, while during the same period those in small roots decreased slightly. The results are discussed in relation to tree growth in winter, and storage and metabolism of nitrogen in the tree during the winter and new growth in spring.

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The gene directing the synthesis of the β-1, 4-endoglucanase (1, 4-D-glucan glucohydrase) (EC 3.2.1.4) of Ruminococcus albus F-40 was cloned in Escherichia coli C600. The recombinant plasmid pRA1 contained a 3.6 kilobase pair(kb)-Hind III fragment derived from R. albus. Forty-five percent of the cellulase activity encoded by pRA1 was detected in the periplasmic space and the remaining 55% was in the inner cellular fraction. The optimum pH and temperature of the cloned enzyme were pH 5.7 and 37°C, respectively. The enzyme could digest carboxymethyl cellulose (CMC) and lichenan, but it was inactive for laminarin, xylan, and cellobiose.

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A fungus was isolated from soil as a cellulolytic enzyme-producing microorganism. This wild strain, named fungal strain Y-94, secreted a large amount of cellulolytic enzyme components consisting of 0.8 units of avicelase, 9.2 units of carboxymethyl cellulose (CMC)-hydrolyzing enzyme (CMCase) and 2.0 units of β-glucosidase per ml of culture broth on cultivation in Mandels medium for 7 to 10 days at 30°C, and also produced in the culture filtrate various other polysaccharidehydrolyzing enzymes such as xylanase, β-1, 3-glucanase, amylase, etc. Higher productivity of the cellulolytic enzymes (avicelase, 6.5 units/ml; CMCase, 82 units/ml; β-glucosidase, 25 units/ml; and filter paper units (F.P.U.), ^* 5.0 units/ml) was obtained by altering the medium composition. The maximum production of the cellulolytic enzymes was observed when this strain was cultured in a medium containing 4% cellulose powder, 1% peptone, 0.6% KNO₃, 0.2% urea, 1.2% KH₂PO₄, 0.16% KCl, 0.12% MgSO₄•7H₂O, 0.001% ZnSO₄•7H₂O, 0.001% MnSO₄•6H₂O, 0.001% CuSO₄•7H₂O and 0.1% Tween 80 or polyethylene glycol 1000, pH 4.0, under the same culture conditions.

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Capsaicin (CAP), a pungent principle of hot red pepper, enhances energy metabolism in rats fed a high fat diet. In this study, the site of action of CAP in rats was investigated in vivo with the serum glucose level as an index of energy metabolism. Administration of CAP (4 mg/kg, ip) caused a significant increase in the serum glucose level. Treatment with hexamethonium bromide (5 mg/kg, ip) and atropine sulfate (1 mg/kg, ip) did not affect the serum glucose response to CAP. Rats treated with 6-hydroxydopamine hydrobromide (30 mg/kg, ip) or reserpinie (5 mg/kg/day for 5 days) also responded to CAP. Adrenodemedullation, however, completely prevented the response to CAP, and injection of epinephrine into the adrenodemedullated rats significantly increased the serum glucose level. These results suggest that the CAP-induced enhancement of the energy metabolism in rats occurs via the secretion of catecholamine from the adrenal medulla.

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Photobromination of 1, 5-anhydropentofuranoses and subsequent metal deuteride reduction of the resulting 5-exo-bromides gave C-5 chirally deuteratcd 1, 5-anhydropentofuranoses. The stereochemistry of the reduction is discussed in terms of the effects of substituents at C-2 and C-3 of 1, 5-anhydropento-furanoses.

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A 3.2kb chromosomal DNA fragment encoding homoserine dehydrogenase (HD) of Brevibacterium lactofermentum M-15, a L-threonine and L-lysine producing mutant, was cloned into the unique Pstl site of vector plasmid pAJ1844. Strain M-15 was transformed with the obtained recombinant plasmid pAJ210. The transformant, AJ12021, showed 2-fold higher HD activity and accumulated a 1.4-fold higher amount of L-threonine (maximally 25.0 g/liter) than in the case of the host strain, M-15, respectively. The correlation between the amino acid production and the regulation of enzyme activities was discussed.

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The homoserine kinase (HK) gene was cloned from Brevibacterium lactofermentum M-15, a threonine-producing mutant. Then, a trimethoprim-resistant hybrid plasmid pAJ212 expressing the HK gene was constructed. A threonine-producing recombinant strain harboring pAJ210, a chloramphenicol-resistant plasmid on which homoserine dehydrogenase (HD) gene was cloned, was transformed further with the obtained HK-expressing plasmid pAJ212. Plasmids pAJ210 and pAJ212 were compatible in B. lactofermentum because these two plasmids were derived from two different cryptic plasmids, pHM1519 and pAM330 respectively. Co-existence of the cloned HD and HK genes in M-15 resulted in more than a 30% increase of threonine production (33 g/liter) and a decrease of the by-products (lysine and homoserine) as compared with M-15 carrying HD recombinant plasmid alone. The activities of HD and HK in the strain harboring both HD- and HK-recombinant plasmids were elevated markedly by gene dosage effect, which brought about the apparent increase in threonine production.

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NADP-Specific G6P dehydrogenase was partially purified from Brevibacterium flavum. Its activity, with an optimum pH of 7.5, was stabilized by KC1 or Mg²⁺ and inhibited by diamide, a sulfhydryl reagent. It was also inhibited by oxaloacetate, FBP, PRPP, acetyl-CoA, Ru5P, xylulose 5-phosphate and NADPH. Among them, oxaloacetate showed the strongest inhibition. The concentration of oxaloacetate giving 50% inhibition was 0.09 mm. The inhibitions by oxaloacetate, FBP, PRPP, and NADPH were non-competitive, mixed, and competitive for both the substrates, respectively. Oxaloacetate in combination with FBP, PRPP, or Ru5P inhibited the activity cumulatively. The sensitivities to the oxaloacetate, FBP, and PRPP inhibitions were lost on ammonium sulfate treatment, whereas that to NADPH inhibition was not affected at all. The inhibition by oxaloacetate was specific to glutamate-producing bacteria belonging to the genera, Brevibacterium and Corynebacterium, in contrast to those by FBP and PRPP, which were found in almost all bacteria tested. G6P dehydrogenase in B. flavum was induced by glucose when it was cultured on acetate, succinate, or glutamate.

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The changes in enzyme activities in embryonic axes of soybean seeds during germination were investigated. After 48 hr of germination, the activities of 6-phosphogluconate, glucose-6-phosphate, and L-isocitrate dehydrogenases were 2-4 times as high those of embryonic axes from dry seeds. The activities of L-glutamate and meso-D-diaminopimelate dehydrogenases and of L-isocitritase, however, were still low. The activities of L-malate dehydrogenase and acid phosphatase increased strikingly after germination, and the activities of the germinated axes were about 80 (at 48 hr) and 27 (at 40 hr) times, respectively, those of embryonic axes from dry seeds. The elevated activity of acid phosphatase was due to de novo synthesis of enzyme protein in the embryonic axes, not to activation of the enzyme protein, or to transfer of the enzyme protein from germinating cotyledons. Acid phosphatase activity in embryonic axes increased in a very early stage of protein synthesis in the axes. The pronounced increase in L-malate dehydrogenase activity was mainly due to activation of the enzyme protein by imbibition, not to de novo synthesis of enzyme protein, or to transfer of ths enzyme protein from germinating cotyledons.

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The effects of pH, ionic strength, temperature, and degree of polymerization of procyanidins isolated from Rhaphiolepis umbellata on the formation of procyanidin-protein complexes were investigated. The results suggested that the formation of the complexes was strongly influenced by pH, and no insoluble complex was detected above pH 10.5, that the affinity of procyanidins for proteins was proportional to the degree of polymerization of procyanidins, and dimers and higher oligomers of procyanidins could form insoluble complexes with proteins, and that the structural isomers of dimers or trimers of procyanidins also had higher affinities for proteins, forming insoluble complexes.

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The production of catechol from benzene by a mutant strain of Pseudomonas, defective in catechol catabolism, was examined under various conditions. The catechol producing activity was the highest when the growing medium contained succinate as a growing substrate, benzene as a inducer and high level of phosphate. Under the optimum conditions, 3.1 mg/ml of catechol was produced from 5 mg/ml of benzene through the reaction with resting cells.
In addition, whole cells of the mutant were immobilized with carrageenan, urethane prepolymer, polyacrylamide and DEAE-cellulose, and their ability to produce catechol was examined.

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A Brevibacterium flavum mutant lacking pyruvate kinase, No. 70, grew on glucose, fructose and sucrose as well as the original wild strain did, but was unable to grow on ribose or gluconate unless pyruvate was added. Mutants that required pyruvate for growth on ribose were derived directly from the wild strain. Many of them were completely or partially defective in pyruvate kinase activity. These pyruvate kinase mutants were also unable to grow on gluconate. A phosphoenolpyruvate (PEP): sugar phosphotransferase system (PTS) was found in B. flavum, which catalyzed the formation of pyruvate and sugar phosphate from PEP and sugar. The system required Mg²⁺, acted on glucose, fructose, mannose, glucosamine and 2-deoxyglucose, and existed in the cells grown on any of the carbon sources tested. Cells grown on fructose, mannitol and sucrose, however, exhibited higher PTS activities on fructose than those grown on others. Glucose PTS activity was about 20-fold stronger than that of glucokinase. Other sugar metabolic enzymes, inducible mannitol dehydrogenase, gluconokinase, ribokinase and maltase, as well as constitutive invertase were also detected. Oxaloacetate decarboxylase and malic enzyme, which also catalyzed the pyruvate formation, were found in B. flavum, but the latter activity was very low in cells grown on glucose. The levels of these enzymes in pyruvate kinase mutants unable to grow on ribose or gluconate derived from the wild strain were almost identical to those in the wild-type strain.

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An investigation was carried out on Okinawan plants to find antibacterial compounds against a human skin bacterium, Staphylococcus epidermidis, which causes acne vulgaris. A medicinal plant, Elaeagnus glabra, showed significant activity, and (-)-epigallocatechin (27) was isolated from the plant as an antibacterial constituent against the bacterium. Twenty-six flavonoids related to 27 were tested for the activity, galangin (7) being the most active species. Although a structure-activity study was attempted, no clear structural factor was deduced.

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A butyryl-CoA synthetase (EC 6.2.1.2) was obtained from Paecilomyces varioti AHU 9417 in a highly purified form, which appeared to be homogeneous on polyacrylamide gel electrophoresis in the absence and presence of sodium dodecyl sulfate (SDS). The purified enzyme exhibited molecular weights of 145, 000 for the native enzyme and 74, 000 for the subunit. This enzyme required both monovalent and divalent cations for the reaction. The enzyme was active toward saturated fatty acids with 3 to 5 carbon atoms, and butyrate was the best substrate. The reaction mechanism of the enzyme was also investigated and was found to conform to a Bi-Uni-Uni-Bi ping-pong mechanism, in which the order of addition and evolution of substrates and products was ATP, butyrate, PPi, CoA, butyryl-CoA (or AMP) and AMP (or butyryl-CoA). Butyryl-CoA and AMP were evolved at random or at the same time.

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A serine proteinase inhibitor was isolated from carp, Cyprinus carpio, ordinary muscle by ammonium sulfate fractionation, heat treatment, column chromatography on DEAE-Sephadex A-50, gel nitration on Sephadex G-150, and preparative polyacrylamide gel electrophoresis. The final purified preparation of the inhibitor was' homogeneous as judged by polyacrylamide gel electrophoresis. The molecular weight of the inhibitor was about 100, 000 by gel filtration on Sephadex G-100, and 56, 000 by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis after reduction with 2-mercaptoethanol. The inhibitor was stable over the range of pH 7.0 - 9.5 at 5°C for 15hr, but unstable below pH 4.5. The isoelectric point was about 5.3. Trypsin, α-chymotrypsin, and elastase were strongly inhibited by the inhibitor. Subtilisin BPN' and pronase were slightly inhibited, but pepsin, papain, and thermolysin were not inhibited. E•I complex from the inhibitor and elastase was stable to denaturing and reducing reagents such as SDS and 2-mercaptoethanol. On the basis of the properties described above, the proteinase inhibitor is most similar to the α₁-proteinase inhibitor of human serum.

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A hydrophobic peptide of 17 residues, β-CN (f193-209), and a hydrophilic peptide of 25 residues, β-CN (f1-25), were isolated from enzyme hydrolyzates of bovine β-casein. The emulsifying activity (EA) of both peptides was low at a neutral pH. In the acidic or alkaline condition, however, β-CN (f193-209) showed high EA values. β-CN (f1-25) also showed high EA values at acidic pHs. These peptides are shown to be more surface active at pH 3 than at pH 7.

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Dehydroacetic acid (DHA) gave rise to some mutagenic substances on irradiation with ultraviolet (UV) light. Mutagenicity was detected toward Salmonella typhimurium TA 100 without the S-9 mix. A decrease in the absorbance maximum at 307 nm of DHA was accompanied by a simultaneous increase in total carbonyls and a slight decrease in pH. The mutagenicity of the substances derived from DHA was reduced by the addition of reducing agents, which suggested that the mutagenic substances might be carbonyl compounds. From the results of analysis of carbonyl compounds by GC-mass spectrometry and determination of their mutagenicities in the UV-irradiated DHA sample, it was confirmed that the mutagenicity of the sample was mainly due to 2-pentenal.

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A bacterium which grows in a medium containing D-serine as a sole nitrogen source has been isolated from soil and identified as Aeromonas caviae. The bacterium had a high enzyme activity catalyzing racemization of various amino acids. The enzyme, purified to homogeneity by polyacrylamide gel electrophoresis and ultracentrifugation, has a molecular weight of about 76, 000, and is composed of two subunits identical in molecular weight (40, 000). The results of enantiomeric analysis of the reaction product and kinetic examination of the reaction indicate that the enzyme catalyzes the complete racemization of substrates. The enzyme has absorption maxima at 280 and 420nm, and contains 2mol of pyridoxal 5'-phosphate per mol of enzyme. The holoenzyme is resolved to the apoenzyme by treatment with hydroxylamine, and reconstituted by the addition of pyridoxal 5'-phosphate. The very broad substrate specificity of the A. caviae amino acid racemase is comparable to that of the Pseudomonas striata enzyme. However, they share no common antigenic determinants.

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The lipase (EC. 3.1.1.3) of Pseudomonas fragi 22.39 B was purified by acidification of the culture supernatant, ammonium sulfate fractionation, and column chromatography on DEAE-Toyopearl 650m and DEAE-Sepharose CL-6B. The recovery of activity was about 48%. The purified lipase was homogeneous electrophoretically and its molecular weight was 33, 000. The optimum pH and temperature for hydrolysis of olive oil emulsion were 9.0 and 65°C, respectively. The enzyme was stable up to 51°C at pH 9.0 for 24hr and in a pH range from 6.5 to 10.5 at 30°C for 24 hr. The lipase was inhibited by Zn²⁺, Fe²⁺, Fe³⁺ and cationic surfactants such as cetyltrimethylammonium bromide.

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Starch phosphorylase was purified from either freshly harvested or stored roots of sweet potato (Ipomoea batatas (L.) Lam. cv Tainon 65). Both enzyme preparations in their native state showed on polyacrylamide gel electrophoresis a cluster of about six closely located activity bands, which had common antigenic determinants as they were simultaneously probed by monoclonal antibodies. The molecules of enzymes from stored roots were smaller than those from fresh roots. However, the two enzyme preparations had completely fused precipitin lines in double diffusion assays with an antiserum raised against the fresh root preparation. One large subunit and several small ones were found for both enzyme preparations. The small subunits appeared to be the degradation products of the large ones as revealed by peptide mapping and immunoblotting. Immunofluorescence microscopy showed that the enzyme was present in the amyloplasts and cell walls of root storage parenchyma.

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Myosin filaments were prepared by either dialysis or rapid dilution to give a final condition of 0.1 M KCl and pH 6.0, in the presence or absence of C-protein. The average length of myosin filaments prepared by dialysis was much longer than that by dilution whether C-protein is present or absent. C-protein reduced the diameters of both filaments but no significant effects on the filament length were observed. All of the myosin filament suspensions formed gels upon heating, but C-protein alone did not. The strengths of thermal gels of myosin filaments prepared by dialysis were much higher than those-by dilution. In addition, a fine strand-like network structure was formed in the gel from dialyzed myosin, but diluted myosin formed a rather coarse network structure. C-protein lowered the strengths of thermal gels of myosin filaments, especially that prepared by dialysis. These results suggest that the rheological properties of thermal gels of myosin filaments at low ionic strength depend on the structure of myosin filaments before heating. The longer and thicker the filaments, the stronger the heat-induced gels.

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2-[1-(1-Alkylamino)alkylidene]-1, 3-dicarbonyl compounds were synthesized as photosynthetic electron transport (PET) inhibitors because of their structural resemblance to the potent new PET inhibitors "cyanoacrylates". Their functionalities were different from those of other classic photosystem II (PS II) inhibitors, and these compounds inhibited PET at the reducing side of PS II. In this paper, the synthetic approaches to these compounds are discussed.

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The stereochemistry of some dihydrofurano-isoflavones previously isolated from white lupin roots, or obtained following fungal metabolism of prenylated isoflavones, was investigated using CD spectroscopy. The osmate ester/pyridine complex of dextrorotatory lupinisoflavone A (1) exhibited a positive CD Cotton effect at 480nm, indicating a side-structure configuration (S at C-2''), opposite to that of natural rotenone (9), which afforded a negative Cotton effect at 474nm (R-configuration at C-2' on the side structure [ring E]). The stereochemistry of the laevorotatory luteone metabolite BC-1 (2) and lupinisoflavone D (4) (both R-configuration at C-2'') was similarly determined after converting to the corresponding dehydrate (10) or trimethyl-dehydrate (1b, 10a).

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Both 2, 3-erythro- and 2, 3-threo-isomers of aplidiasphingosine were synthesized. By examining their ¹³C NMR spectra, 2, 3-threo- and 13, 14-erythro-relative configurations are proposed for aplidiasphingosine.

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Euglena gracilis strain Z produced liquid wax esters when it was incubated anaerobically in the presence of unsaturated fatty acids after aerobic cultivation for 3 days on a glucose-peptone medium. On anaerobic incubation for 6 days with the supplementation of 1 % of oleic acid, linoleic acid, α-linolenic acid or ricinoleic acid, 6.9-8.4g/liter of wax esters was accumulated in the cells. The yields increased to about 50% of the dry cell weight, and all of the wax esters were in the liquid state at room temperature. Gas-liquid chromatographic analysis showed that the unsaturated fatty acids provided not only the acyl moiety of the wax esters but also the alkoxy one, which was formed through reduction to the corresponding fatty alcohols and then incorporated into the wax esters.

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5-Fluorotryptophan (5FT), indolmycin (IM), 4-fluorotryptophan and 7-azatryptophan were found on screening to be tryptophan antagonists among various chemically synthesized and naturally occurring tryptophan analogues for the isolation of L-tryptophan (L-Trp) producing mutants of Bacillus subtilis K.
From among 5FT resistant mutants, potent L-Trp producers were obtained using an improved isolation medium. Growth of the isolated 5FT-resistant L-Trp producer, AJ 11709, was inhibited by IM. From among 5FT and IM resistant mutants, the best strain, AJ 11979, which produced 9.0g/liter of L-Trp from 13% glucose on 120hr cultivation, was selected.

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