Regulating ehrlich and demethiolation pathways for alcohols production by the expression of ubiquitin-protein ligase gene HUWE1.

Ehrlich and demethiolation pathways as two competing branches converted amino acid into alcohols. Controlling both pathways offers considerable potential for industrial applications including alcohols overproduction, flavor-quality control and developing new flavors. While how to regulate ehrlich and demethiolation pathways is still not applicable.

Screening of the key volatile organic compounds of Tuber melanosporum fermentation by aroma sensory evaluation combination with principle component analysis.

Aroma results from the interplay of volatile organic compounds (VOCs) and the attributes of microbial-producing aromas are significantly affected by fermentation conditions. Among the VOCs, only a few of them contribute to aroma. Thus, screening and identification of the key VOCs is critical for microbial-producing aroma.

Aroma improvement by repeated freeze-thaw treatment during Tuber melanosporum fermentation.

The aroma attributes of sulfurous, mushroom and earthy are the most important characteristics of the aroma of Tuber melanosporum. However, these three aroma attributes are absent in the T. melanosporum fermentation system.

Current progress on truffle submerged fermentation: a promising alternative to its fruiting bodies.

Truffle (Tuber spp.), also known as "underground gold," is popular in various cuisines because of its unique and characteristic aroma. Currently, truffle fruiting bodies are mostly obtained from nature and semi-artificial cultivation.

Metabolism of L-methionine linked to the biosynthesis of volatile organic sulfur-containing compounds during the submerged fermentation of Tuber melanosporum.

Tuber melanosporum, known as the black diamond of cuisine, is highly appreciated for its unique and characteristic aroma, which is mainly due to its volatile organic sulfur-containing compounds (VOSCs). In this work, by adding 5 g/L L-methionine to the fermentation medium, the activities of aminotransferase and α-ketoacid decarboxylase were significantly enhanced by 103 and 250%, respectively, while the activities of alcohol dehydrogenase and demethiolase were decreased by 277 and 39%. Then, the six VOSCs, i.

Ranking the significance of fermentation conditions on the volatile organic compounds of Tuber melanosporum fermentation system by combination of head-space solid phase microextraction and chromatographic fingerprint similarity analysis.

Tuber melanosporum is highly appreciated in culinary contexts due to its unique and characteristic aroma. T. melanosporum fermentation has been established as a promising alternative for fruiting bodies to produce volatile organic compounds (VOCs).

Actinobacillus succinogenes ATCC 55618 fermentation medium optimization for the production of succinic acid by response surface methodology.

As a potential intermediary feedstock, succinic acid takes an important place in bulk chemical productions. For the first time, a method combining Plackett-Burman design (PBD), steepest ascent method (SA), and Box-Behnken design (BBD) was developed to optimize Actinobacillus succinogenes ATCC 55618 fermentation medium. First, glucose, yeast extract, and MgCO(3) were identified to be key medium components by PBD.

Evaluation of aroma active compounds in Tuber fruiting bodies by gas chromatography-olfactometry in combination with aroma reconstitution and omission test.

The aroma active compounds of three Tuber fruiting bodies (i.e., Tuber himalayense, Tuber indicum, and Tuber sinense) were firstly systematically evaluated by instrumental gas chromatography-olfactometry combining with quantitative analysis, aroma reconstitution, and omission tests.

Lycopene production from synthetic medium by Blakeslea trispora NRRL 2895 (+) and 2896 (-) in a stirred-tank fermenter.

The dissolved oxygen tension of 20% of air saturation, pH-shift from 4.0 to 5.5 on day 3, and a moderate shear stress (calculated as an impeller tip speed, V(tip) = 0.

Optimization of the mated fermentation process for the production of lycopene by Blakeslea trispora NRRL 2895 (+) and NRRL 2896 (-).

The mated fermentation process for the production of lycopene by Blakeslea trispora NRRL 2895 (+) and NRRL 2896 (-) was systematically optimized in shake flasks. The ratio of the (+) to (-) strains, the lycopene cyclase inhibitors piperidine and creatinine, the trisporic acid structural analog abscisic acid, the 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) precursor leucine, and the mevalonate kinase enhancer penicillin were all identified as key factors affecting lycopene biosynthesis. With an optimal ratio of 5:1 for the (+) to (-) strains and the addition of 6 g/L creatinine on day 3, the highest lycopene production was 98.

Quantitative analysis for the effect of plant oil and fatty acid on Tuber melanosporum culture by uniform design combined with partial least squares regression.

Uniform design and partial least squares regression were adopted to quantitatively analyze the effects of plant oil and fatty acid as well as their addition amount and addition time on the performance of Tuber melanosporum submerged fermentation. The regression models showed the optimal scheme was the addition of 1.2 mL soybean oil on day 9, which was validated by experiment.

Tuber melanosporum fermentation medium optimization by Plackett-Burman design coupled with Draper-Lin small composite design and desirability function.

A novel method using Plackett-Burman design (PBD) coupled with Draper-Lin small composite design (SCD) and desirability function (DF) was developed to optimize Tuber melanosporum fermentation medium. Firstly, sucrose, yeast extract, peptone and Mg(2+) were identified to be key medium components by PBD. Secondly, in order to evaluate the relationships between responses and the identified key components, mathematical models were developed by SCD.

Fed-batch fermentation of Tuber melanosporum for the hyperproduction of mycelia and bioactive Tuber polysaccharides.

For the first time, a fed-batch fermentation process of Tuber melanosporum was developed for the efficient production of bioactive mycelia and Tuber polysaccharides. Each 1.67 g/L of peptone and 8.

Quantitative response of cell growth and Tuber polysaccharides biosynthesis by medicinal mushroom Chinese truffle Tuber sinense to metal ion in culture medium.

During the submerged fermentation of medicinal mushroom Chinese truffle Tuber sinense, there was no significant effect of metal ion on the cell growth and the production of intracellular polysaccharides, while metal ion and its concentration significantly affected the production of extracellular polysaccharides (EPS). By using the approach of "one-variable-at-a-time", 50 mM Mg2+ was identified to be the most favorable for EPS production, and the next was 10 mM K+. A mathematical model, constructed by response surface methodology combination with full factorial design, was applied to study the synergic effect of Mg2+ and K+.