Comparing a mindfulness- and CBT-based guided self-help Internet- and mobile-based intervention against a waiting list control condition as treatment for adults with frequent cannabis use: a randomized controlled trial of CANreduce 3.0.

BACKGROUND: Though Internet- and mobile-based interventions (IMIs) and mindfulness-based interventions (generally delivered in-situ) appear effective for people with substance use disorders, IMIs incorporating mindfulness are largely missing, including those targeting frequent cannabis use. METHODS: This paper details the protocol for a three-arm randomized controlled trial comparing a mindfulness-based self-help IMI (arm 1) and cognitive-behavioral therapy (CBT)-based self-help IMI (arm 2) versus being on a waiting list (arm 3) in their effectiveness reducing cannabis use in frequent cannabis users. Predictors of retention, adherence and treatment outcomes will be identified and similarities between the two active intervention arms explored. Both active interventions last six weeks and consist of eight modules designed to reduce cannabis use and common mental health symptoms. With a targeted sample size of n = 210 per treatment arm, data will be collected at baseline immediately before program use is initiated; at six weeks, immediately after program completion; and at three and six months post baseline assessment to assess the retention of any gains achieved during treatment. The primary outcome will be number of days of cannabis use over the preceding 30 days. Secondary outcomes will include further measures of cannabis use and use of other substances, changes in mental health symptoms and mindfulness, client satisfaction, intervention retention and adherence, and adverse effects. Data analysis will follow ITT principles and primarily employ (generalized) linear mixed models. DISCUSSION: This RCT will provide important insights into the effectiveness of an IMI integrating mindfulness to reduce cannabis use in frequent cannabis users. TRIAL REGISTRATION: International Standard Randomized Controlled Trial Number Registry: ISRCTN14971662 ; date of registration: 09/09/2021.

Biotransformation of glycerol to dihydroxyacetone by recombinant Gluconobacter oxydans DSM 2343.

The genus Gluconobacter is well known for its rapid and incomplete oxidation of a wide range of substrates. Therefore, Gluconobacter oxydans especially is used for several biotechnological applications, e.g., the efficient oxidation of glycerol to dihydroxyacetone (DHA). For this reaction, G. oxydans is equipped with a membrane-bound glycerol dehydrogenase that is also described to oxidize sorbitol, gluconate, and arabitol. Here, we demonstrated the impact of sldAB overexpression on glycerol oxidation: Beside a beneficial effect on the transcript level of the sldB gene, the growth on glycerol as a carbon source was significantly improved in the overexpression strains (OD 2.8 to 2.9) compared to the control strains (OD 2.8 to 2.9). Furthermore, the DHA formation rate, as well as the final DHA concentration, was affected so that up to 350 mM of DHA was accumulated by the overexpression strains when 550 mM glycerol was supplied (control strain: 200 to 280 mM DHA). Finally, we investigated the effect on sldAB overexpression on the G. oxydans transcriptome and identified two genes involved in glycerol metabolism, as well as a regulator of the LysR family.

Modification of the membrane-bound glucose oxidation system in Gluconobacter oxydans significantly increases gluconate and 5-keto-D-gluconic acid accumulation.

Gluconobacter oxydans DSM 2343 (ATCC 621H)catalyzes the oxidation of glucose to gluconic acid and subsequently to 5-keto-D-gluconic acid (5-KGA), a precursor of the industrially important L-(+)-tartaric acid. To further increase 5-KGA production in G. oxydans, the mutant strain MF1 was used. In this strain the membrane-bound gluconate-2-dehydrogenase activity, responsible for formation of the undesired by-product 2-keto-D-gluconic acid, is disrupted. Therefore, high amounts of 5-KGA accumulate in the culture medium. G. oxydans MF1 was equipped with plasmids allowing the overexpression of the membrane-bound enzymes involved in 5-KGA formation. Overexpression was confirmed on the transcript and enzymatic level. Furthermore, the resulting strains overproducing the membrane-bound glucose dehydrogenase showed an increased gluconic acid formation, whereas the overproduction of gluconate-5-dehydrogenase resulted in an increase in 5-KGA of up to 230 mM. Therefore, these newly developed recombinant strains provide a basis for further improving the biotransformation process for 5-KGA production.

High-yield 5-keto-D-gluconic acid formation is mediated by soluble and membrane-bound gluconate-5-dehydrogenases of Gluconobacter oxydans.

Gluconobacter oxydans DSM 2343 is known to catalyze the oxidation of glucose to gluconic acid, and subsequently, to 2-keto-D-gluconic acid (2-KGA) and 5-keto-D-gluconic acid (5-KGA), by membrane-bound and soluble dehydrogenases. In G. oxydans MF1, in which the membrane-bound gluconate-2-dehydrogenase complex was inactivated, formation of the undesired 2-KGA was absent. This mutant strain uniquely accumulates high amounts of 5-KGA in the culture medium. To increase the production rate of 5-KGA, which can be converted to industrially important L-(+)-tartaric acid, we equipped G. oxydans MF1 with plasmids allowing the overproduction of the soluble and the membrane-bound 5-KGA-forming enzyme. Whereas the overproduction of the soluble gluconate:NADP 5-oxidoreductase resulted in the accumulation of up to 200 mM 5-KGA, the detected 5-KGA accumulation was even higher when the gene coding for the membrane-bound gluconate-5-dehydrogenase was overexpressed (240 to 295 mM 5-KGA). These results provide a basis for designing a biotransformation process for the conversion of glucose to 5-KGA using the membrane-bound as well as the soluble enzyme system.

The use of microorganisms in L-ascorbic acid production.

L-Ascorbic acid has been industrially produced for around 70 years. Over the past two decades, several innovative bioconversion systems have been proposed in order to simplify the long time market-dominating Reichstein method, a largely chemical synthesis by which still a considerable part of L-ascorbic acid is produced. Here, we describe the current state of biotechnological alternatives using bacteria, yeasts, and microalgae. We also discuss the potential for direct production of l-ascorbic acid exploiting novel bacterial pathways. The advantages of these novel approaches competing with current chemical and biotechnological processes are outlined.

A Gluconobacter oxydans mutant converting glucose almost quantitatively to 5-keto-D-gluconic acid.

Gluconobacter oxydans converts glucose to gluconic acid and subsequently to 2-keto-D-gluconic acid (2-KGA) and 5-keto-D-gluconic acid (5-KGA) by membrane-bound periplasmic pyrroloquinoline quinone-dependent and flavin-dependent dehydrogenases. The product pattern obtained with several strains differed significantly. To increase the production of 5-KGA, which can be converted to industrially important L-(+)-tartaric acid, growth parameters were optimized. Whereas resting cells of G. oxydans ATCC 621H converted about 11% of the available glucose to 2-KGA and 6% to 5-KGA, with growing cells and improved growth under defined conditions (pH 5, 10% pO2, 0.05% pCO2) a conversion yield of about 45% 5-KGA from the available glucose was achieved. As the accumulation of the by-product 2-KGA is highly disadvantageous for an industrial application of G. oxydans, a mutant was generated in which the membrane-bound gluconate-2-dehydrogenase complex was inactivated. This mutant, MF1, grew in a similar way to the wild type, but formation of the undesired 2-KGA was not observed. Under improved growth conditions, mutant MF1 converted the available glucose almost completely (84%) into 5-KGA. Therefore, this newly developed recombinant strain is suitable for the industrial production of 5-KGA.

Cell cycle-dependent expression of an essential SMC-like protein and dynamic chromosome localization in the archaeon Halobacterium salinarum.

The genome of Halobacterium salinarum encodes four proteins of the structural maintenance of chromosomes (SMC) protein superfamily. Two proteins form a novel subfamily and are named 'SMC-like proteins of H. salinarum' (Sph1 and Sph2). Northern blot analyses revealed that sph1 and hp24, the adjacent gene, are solely transcribed in exponentially growing, but not in stationary phase, cells. A synchronization procedure was developed, which makes use of the DNA polymerase inhibitor aphidicolin and leads to highly synchronous cultures. It allowed us for the first time to study cell cycle-dependent transcription in an archaeon. The sph1 transcript was found to be highly cell cycle regulated, with its maximal accumulation around the time of septum formation. The Sph1 protein level was also elevated at that time, but a basal protein level was found throughout the cell cycle. The hp24 transcript was sharply upregulated about 1 h before sph1 and had already declined at the time of sph1 induction. These and additional transcript patterns revealed that precisely controlled transcriptional regulation is involved in haloarchaeal cell cycle progression. A DNA staining protocol was developed, which opened the possibility of following the dynamic intracellular localization of haloarchaeal nucleoids using synchronized cultures. After an initial dispersed localization, the nucleoid is condensed at mid-cell. Subsequently, DNA is rapidly transported to the 1/4 and 3/4 positions. All staining patterns were also observed in untreated exponentially growing cells, excluding synchronization artifacts. The Sph1 concentration is elevated when segregation of the new chromosomes is nearly complete; therefore, it is proposed to play a role in a late step of replication, e.g. DNA repair, similar to eukaryotic Rad18 proteins.

Monitoring apple flavor by use of quartz microbalances.

"Electronic noses", i.e. arrays of differently coated quartz microbalances (QMB), have been used for selective detection of, and discrimination between, volatile organic compounds (VOC) formed during the post-harvest ripening of apples. The flavor components to be differentiated are chemically rather similar carbonyl compounds, chiefly aldehydes and esters. Because their relative ratios change during the post-harvest ripening period, appropriately selected sensor-active layers lead to characteristic patterns of the sensor responses which can be analyzed via pattern-recognition methods. This enables qualitative and quantitative identification of individual components whereby the post-harvest ripening of apples and other fruits can be monitored. Different kinds of apple differ in type and concentration of individual carbonyl compounds.