Microbial production of L-lysine: a review.

Microbial production of L-lysine has been reviewed with 251 references. The review includes different lysine producing microorganisms, their optimum cultural conditions, yield, assay and process of product recovery. It includes a discussion on the pathway of aspartate family of amino acid's biosynthesis in bacteria and its regulation. Achievements in this regard made through genetic engineering have also been included.

Methionine production by microorganisms.

Microbial production of methionine is reviewed with 73 references. The review describes different methionine-producing organisms, as well as analog-resistant regulatory mutants, their optimum cultural conditions and yields. The pathways of methionine biosynthesis and their regulation are discussed.

5-Nitrofuran derivatives of fatty acid hydrazides induce differentiation in human myeloid leukaemic cell lines.

Compounds formed by 5-nitrofuran with hydrazides of formic, acetic and propionic acids, hereafter respectively known as SBF, SBA and SBP have been used to evaluate the differentiation-inducing properties on two established myeloid leukaemic cell lines ML-2 and EOL-1. SBP is found to be the most effective as an antineoplastic agent amongst the three. Induction of differentiation observed are in the order SBP > SBA > SBF, as assessed by morphology, NBT-reducing activity and surface marker antigens of the treated cells. Induction of differentiation of ML-2 and EOL-1 cells by the most effective compound, SBP (3 microM), is accompanied by perturbation of the cell cycle, with most of the cells accumulating in the G0-G1, phase. Inhibition of DNA synthesis occurs while protein and RNA synthesis remain practically unchanged.

Microbial production of L-tyrosine: a review.

Microbial production of L-tyrosine by direct fermentation and by enzymatic methods has been reviewed. Achievements in this regard made through recombinant DNA techniques have also been included. The review also includes biosynthesis and regulation of tyrosine.

Biosynthesis of lysine in plants: the putative role of meso-diaminopimelate dehydrogenase.

Extracts from Chlamydomonas, corn, soybean and tobacco were tested for enzymes of the lysine biosynthetic pathway. Dihydrodipicolinic acid (DHD) synthase, DHD reductase, diaminopimelate (DAP) epimerase and DAP decarboxylase were present in all. However, in contrast to the report of Wenko et al., meso-DAP dehydrogenase could not be detected in extracts prepared from soybean. Moreover, it was not found in Chlamydomonas, corn and tobacco as well. In order to set an upper limit to the amount of meso-DAP dehydrogenase that might be present, reconstruction experiments were performed with soybean and corn extracts in which the conversion of dihydrodipicolinate to lysine was made dependent on the addition of limited amounts of the meso-DAP dehydrogenase purified from Bacillus sphaericus. The presence of DAP epimerase and the absence of meso-DAP dehydrogenase indicates that the meso-DAP dehydrogenase abbreviated pathway for lysine synthesis is not operative in plants.

Microbial production of L-tryptophan: a review.

Microbial production of L-tryptophan has been reviewed with 172 references. The review includes different tryptophan producing microorganisms, their optimal cultural conditions, yields, assay and process of recovery. It also includes a discussion on the pathway of tryptophan biosynthesis and its regulation. Achievements in this regard made through genetic engineering have also been included.

L-phenylalanine production by double auxotrophic mutants of Arthrobacter globiformis.

A number of tryptophan-plus-tyrosine double auxotrophs have been isolated from a glutamate producing Arthrobacter globiformis excreting L-phenylalanine by two-step mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine. For the three potent mutants tested the medium of Alföldi was found to be the best. The optimum tryptophan, tyrosine and biotin concentrations for phenylalanine production of these mutants were 0.5 mmol/L, 0.1 mmol/L and 5 micrograms/L, respectively. At these levels strain TT-39 yielded 2.6 g phenylalanine per L of medium in flask culture with glucose (350 mmol/L) and NH4Cl (60 mmol/L).

Microbial production of L-phenylalanine: a review.

Microbial production of L-phenylalanine by direct fermentation and by substrate conversion has been reviewed. The review also includes a discussion on different other methods for phenylalanine production, their advantages and disadvantages with mutants and genetically tailored strains. Biosynthesis of phenylalanine, its regulation in hyperproducing strains and recovery of phenylalanine has been discussed in brief.

Studies on the antineoplasticity of Schiff bases containing 5-nitrofuran and pyrimidine.

Antineoplastic properties of different Schiff bases obtained by the interaction of 5-nitrofuran with substituted pyrimidines have been examined both in vitro and in vivo. In vitro studies on L 5178Y/asparaginase sensitive, HL 60 and P 388 cell lines and in vivo studies on the P 388 cell line indicate that all the compounds are potential antineoplastic agents. However, 2-(5-nitro-2-furfurylidene-amino)-pyrimidine (SBP1) is the most effective, and 2-(5-nitro-2-furfurylidene-amino)-6-hydroxypyrimidine (SBP3) is the least effective agent. Doubling time, rates of protein and DNA synthesis inhibition and LD50 values-1,000 mg/kg body weight for SBP1 and 1,275 mg/kg body weight for 2-(5-nitro-2-furfurylidene-amino)-4- methylpyrimidine (SBP2)- in the oral route support the activity and use of SBP1 and SBP2 as future anticancer agents.

Lysine production from hydrocarbon by Micrococcus varians 2Fa.

A bacterium isolated from Assam (India) soil was found to accumulale l-lysine from hydrocarbon and was identified as a strain of Micrococcus varians. The strain is able to grow and accumulate lysine in a purely synthetic medium though supplementation of the synthetic medium with casamino acids significantly improves the yield. The yield of l-lysine under optimal conditions was found to be 2.6 g X 1(-1) of the compound isolated in crystalline form.

Valine production from hydrocarbon by Micrococcus varians.

A bacterium isolated from Assam (India) soil was found to accumulate L-valine in the growth medium and was identified as Micrococcus varians. The strain grew and accumulated valine in a purely synthetic medium, but supplementation with either casamino acids or yeast extract or with both, improved the yield. The entire fermentation period could be divided into a growth phase and a production (phase which could be prolonged by adjustment of pH to neutral range. Among the different hydrocarbon and nitrogen sources tested straight run gas-oil and ammonium sulphate, respectively, were found most suitable. Antibiotics inhibited growth but stimulated extracellular valine accumulation. Vitamins stimulated growth and valine yield and an inoculum level of 10% was found to be optimal. The yield of L-valine under optimal conditions was 2.95 g/L.

A glutamic acid producing Streptomyces sp.

Following the bioautographic technique, a strain of Streptomyces sp. has been isolated producing L-glutamic acid. The strain in able to grow and produce glutamate in mineral salt medium, but supplementation with yeast extract improved the yield.

Excretion of peptides by Rhodosporidium torudoides.

Strains of Rhodospordium torloides produced two peptides into the culture filtrate. Peptide I contained 6 amino acids and peptide II contained 5 amino acids. The peptides however, are, not homologous to the alpha-factor, and become assimilated at a later phase of growth.