Effect of growth temperature on lipid fatty acids of four fungi (Aspergillus niger,Neurospora crassa,Penicillium chrysogenum,andTrichoderma reesei)

The effect of growth temperature on the lipid fatty acid composition was studied over a temperature range from 35 to 10° C with 5° C intervals in four exponentially growing fungi: Aspergillus niger, Neurospora crassa, Penicillium chrysogenum, and Trichoderma reesei. Fatty acid unsaturation increased in A. niger, P. chrysogenum, and T. reesei when the temperature was lowered to 20–15, 20, and 26–20° C, respectively. In A. niger and T. reesei, this was due to the increase in linolenic acid content. In P. chrysogenum, the linolenic acid content increased concomitantly with a more pronounced decrease in the less-unsaturated fatty acid, oleic acid, and in palmitic and linoleic acids; consequently, the fatty acid content decreased as the temperature was lowered to 20° C. In T. reesei, when the growth temperature was reduced below 26–20° C, fatty acid unsaturation decreased since the mycelial linolenic acid content decreased. In A. niger and P. chrysogenum, the mycelial fatty acid content increased greatly at temperatures below 20–15° C. In contrast, in N. crassa, fatty acid unsaturation was nearly temperature-independent, although palmitic and linoleic acid contents clearly decreased when the temperature was lowered between 26 and 20° C; concomitantly, the growth rate decreased. Therefore, large differences in the effects of growth temperature on mycelial fatty acids were observed among various fungal species. However, the similarities found may indicate common regulatory mechanisms causing the responses. Received: 1 March 1995 / Accepted: 8 May 1995     

Three new species of penicillium

Three new species of microfungi belonging to the genus Penicillium Link ex Fries are described and illustrated. All but one have been isolated from the atmosphere of las Palmas, capital city of the island of Gran Canaria (Canary Islands, Spain). They clearly differ from all species of the genus described so far and are, therefore, described and proposed as new species: Penicillium hispanicum sp. nov., Penicillium grancanariae sp. nov., and Penicillium palmensis sp. nov.     

Polyol accumulation by two filamentous fungi grown at different concentrations of NaCl

The accumulation of polyols by Aspergillus niger (van Tiegh) strain S 1 and Penicillium chrysogenum (Thom) strain S 30 was followed during growth in media of different concentrations of NaCl. The major polyols found were glycerol, erythritol and mannitol. The total polyol pool increased in both organisms in response to raised salinity, and the proportion of glycerol and erythritol was markedly enhanced at high salinity.     

Four new species of Penicillium isolated from the air

Four new species of Penicillium Link ex Fries are described and illustrated. All of them but one have been isolated from the atmosphere in Madrid, Spain. They clearly differ from all species of the genus described so far and are, therefore, described and proposed as new taxa: Penicillium aurantio-flammiferum sp. nov., Penicillium gallaicum sp. nov., Penicillium granatense sp. nov., and Penicillium ilerdanum sp. nov.     

2-Heptanone Production by Spores of Penicillium roquefortii in a Water-Organic Solvent Two-Phase System

The production of 2-heptanone from octanoic acid may be performed by free and entrapped spores of Penicillium roquefortii in a water-organic solvent two phase system.

An industrial, isoparafflnic solvent, i.e. Hydrosol IP 230 O.S., which may be considered as tetradecane, is well suited for the process. Activities nearly double those achieved with aqueous systems are observed using an initial fatty acid content in the organic layer close to 100 mM and a ratio of the volume of the organic phase to the total volume of the medium of 0.88. The presence of the solvent allows a better recovery of the metabolite by lowering its activity coefficient.

Fed-batch experiments performed in an aerated, stirred reactor show that the bioconversion may proceed in the two-phase system for at least 300 h. These conditions allow conversion of 750 mM (108 g · 1^-1) fatty acid, and production of 600 mM (68.5 g · 1^-1) 2-heptanone.     

Decreased production ofpara-hydroxypenicillin V in penicillin V fermentations

Summary Penicillin V (phenoxymethyl penicillin) is produced by industrial strains ofPenicillium chrysogenum in the presence of phenoxyacetic acid (POAc), a side-chain precursor for the penicillin V molecule. The wild-type strain ofP. chrysogenum produces an undesirable penicillin byproduct,para-hydroxypenicillin V (p-OH penicillin V), in addition to penicillin V, viapara-hydroxylation of POAc and subsequent incorporation of thep-OH phenoxyacetic acid into the penicillin molecule. Most of thep-OH penicillin V is produced late in cycle when the POAc concentration in the medium is nearly depleted. The level ofp-OH penicillin V produced by the control strain ranges up to 10–15% of the total penicillins produced. 3-Phenoxypropionic acid andp-bromophenylacetic acid partially inhibit the formation ofp-OH penicillin V with a minimal effect on penicillin V productivity. Mutants deficient in their ability to hydroxylate POAc were found to produce lower levels ofp-OH penicillin V. Multi-step mutation and screening, starting with the wild-type strain, have culminated in isolation of mutants which producep-OH penicillin V as 1% of the total penicillins with no adverse effect on penicillin V productivity.     

On the effect of glucono-δ-lactone on the yeast Pichia polymorpha

Investigation has been made into the action of glucono--lactone on living cells of Pichia polymorpha in relation to the uptake of D-(U-¹⁴C) glucose, and the incorporation of (2-¹⁴C) uracil and L-(U-¹⁴C)-threonine into RNA and protein respectively. Other factors such as the action of glucono--lactone on cell morphology and on enzymic synthesis have also been studied. The action of this compound on -glucanase has been found to take place in the hydrolytic power and not in the synthesis.     

Regulation of specific activity of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase in Penicillium chrysogenum

Abstract The specific activity of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase changed when Penicillium chrysogenum was grown on different carbon sources. In the presence of 2% lactose, the activities of these enzymes were approximately 25–35% lower than those in media containing 2% glucose or 2% fructose. We assume that an increase in cAMP concentration was responsible for the observed decreases in the enzyme activities, because a higher cAMP concentration could be detected when the mycelium was grown in a medium containing solely lactose as carbon source. The likely role played by cAMP in the regulation was also demonstrated by the addition of either cAMP or caffeine to the medium.     

Simplicissin,a New Pollen Growth Inhibitor Produced by the Fungus,Penicillium cf. simplidssimum (Oudemans) Thorn No. 410

A new pollen growth inhibitor, named simplicissin, was isolated from Penicillium cf. simplicissimum (Oudemans) Thorn No. 410, and its structure was established by spectroscopic methods including 2D NMR. The biological activities of the compound were examined by the bioassay methods involving tea pollen together with lettuce seedlings. The compound inhibited the growth of the tea pollen tube by 45% at a concentration of 3 mg/liter and showed complete inhibition at 10mg/liter.