Reduced viscosity mutants of Trichoderma reesei with improved industrial fermentation characteristics

Morphological mutants of Trichoderma reesei were isolated following chemical or insertional mutagenesis. The mutant strains were shown to have reduced viscosity under industrially-relevant fermentation conditions and to have maintained high specific productivity of secreted protein. This allowed higher biomass concentration to be maintained during the production phase and, consequently, increased volumetric productivity of secreted protein. The causative mutations were traced to four individual genes (designated sfb3, ssb7, seb1 and mpg1). We showed that two of the morphological mutations could be combined in a single strain to further reduce viscosity and enable a 100 per cent increase in volumetric productivity.

Productivity of the plum (Prunus domestica L.) cultivars and elite forms in the conditions of the Right-Bank Lisosteppe of Ukraine

The authors present the assessment of the yield, vigor and productivity of the plum cultivars and elite forms in the conditions of the Right-Bank Lisosteppe of Ukraine. The researches were carried out during 2018-2020 at the L.P. Symyrenko Research Station of Pomology of the Institute of Horticulture of NAAS of Ukraine. 14 cultivars bred at the mentioned institution were studied as well as 9 elite forms. The significant differences were revealed as concerns the trees vigor and crown habitus. According to the vigour cvs and elite forms were divided into groups as follows: low-holed (with the crown volume up to 15 m3), in particular, Oda, Nenka, Herman, 12516, 8124, 8143; middle-growing (15-20 m3) – Record, Zamanchyva, Dobra, Stanley, Bluefree, President, 9605, 7756, 9996; vigorous (over 20 m3) – Reinclaude Karbysheva, Čačanska Najbolja, Yantarna Mliivska, Tophit, Shtuthart, 8087, 7794, 8110. According to its results concerning the productivity, level early-ripening cultivars Nenka, Oda and Herman (14.2-15.1 t/ha) distinguished themselves, in the group of medium-ripening ones – Čačanska Najbolja, Yantarna Mliivska, Zamanchyva, Dobra and the elite form 12516 (15.6-16.5 t/ha), among late-ripening cultivars – Bluefree and the hybrids 8124 and 8143 with a yield of 16.3-16.4 t/ha. The same cultivars are characterized with high specific productivity, which reflects the density of the crop per unit of the crown volume, the area of its horizontal projection and the cross section of the trunk – 2.7-3.9 kg/m3, 5.2-6.6 kg/m2 and 0.12-0.20 kg/dm2 respectively. The optimum density of the placement of the trees with the different vigor of the rootstock myrobalan plum with the orbicular small sized crown was established applying the method of the mathematical modelling, in particular for low-growing cultivars -1111 trees/ha, middle-growing varieties – 667 trees/ha, vigorous strains – 555 trees/ha.

Cereal extrusion with steam recuperation process

The extrusion process advantage of agricultural raw materials processing into food and feed over traditional technologies is the high specific productivity, energy efficiency and versatility of use. The presence of a large number of control factors and influence on the raw materials quality, such as operating parameters and structural elements, make extrusion a difficult reproducible process when scaling or moving from one installation to another. But this aspect is the reason for the maximum flexibility of extrusion systems and the possibility of their continuous improvement. One of the ways for the extrusion technology development is the improvement of equipment and design solutions in the field of energy saving. Investigations of the thermoplastic extrusion process of wheat grinding with the application of the recovery of steam heat generated by a special configuration of screw elements and its degassing with the feeding into the processed material were carried out in the work. The modernized extruder Werner & Phleiderer Continua 37, supplemented by a developed recuperative unit and a steam line, was used to achieve this goal. An assessment of changes in energy consumption during steam recovery was carried out. The physicochemical properties of the experimental and control samples of wheat grain extrudates obtained under various operating conditions were investigated and determined. It was found out that the steam recovery mode is a statistically significant reason for increasing the humidity of the extruded product from 3.8 to 5.0 bulk density - by 15% relative to the mode without recovery. A decrease in the explosion coefficient and the water-holding capacity of the extrudates during operation in the regenerative mode of extrusion was noticed. The presented method with additional thermal effects on the processed raw materials allows us to expand the technological capabilities of the process of thermoplastic extrusion in obtaining products of various functional and technological purposes.

Inductive Cold Crucible Melting and Characterization of Uranium and Thorium Bearing Murataite Ceramics

Murataite-based ceramics containing 10 wt.% either UO2 or ThO2 were produced by inductive cold crucible melting (ICCM) at operating frequencies of 1.76 MHz and 5.28 MHz and examined using X-ray diffraction and scanning and transmission electron microscopy. High specific productivity was achieved. Average melting ratio was 8.3 kW×h/kg. We identified three distinct murataite polytypes in the U-bearing ceramics: a five- (5C), eight- (8C), and three-fold (3C) fluorite unit cell composing respectively the core, intermediate and rim zones of the grains. In contrast, in the Th-bearing ceramic one of the polytypes with eight-fold (8C) fluorite unit cell was found to be prevailing over two others (5C and 3C). Computer simulation of the major reflection due to the murataite phase in the Th-bearing sample also exhibits superposition of peaks due to three distinct polytypes but one of them (8C) is predominant. The core zone of the murataite in the U-bearing specimens is characterized by UO2 concentrations as high as 12.1 wt%, which successively diminishes in concentration through the intermediate zone to the rim, the latter of which contains 5.2 wt% UO2. Thorium distribution within the murataite crystals is more uniform. The other phases found in the ceramics are crichtonite, rutile and traces of perovskite, Fe/Mn titanate ilmenite/pyrophanite, zirconolite, and vitreous phase. The difference in phase composition and actinide partitioning in the ceramics is influenced by synthesis conditions. Thus, application of large-scale cold crucibles is a prospective route for the development of industrial-scale process and technology for ceramization of actinide-bearing HLW. The advantage of this method is production of zoned crystals with the highest concentrations of actinides and rare earth elements in the core, effectively isolating these elements from potential leach solutions.