Characterisation of PAMP-PRR interaction and the immune response in Nile tilapia

The innate immune system is the first line of host defense against invading pathogens across the entire animal kingdom. Pathogen recognition and effective response are essential to survive in a microbe-rich environment that often characterizes certain types of tilapia aquaculture. In this thesis, we developed a platform to study the innate immune response of the Nile tilapia (Oreochromis niloticus). Specifically, a macrophage model system was characterised and used to explore PAMP-PRR interactions. Moreover, the basal expression of targeted innate immunity gene was measured in different tissues of tilpia, cultured under different aquaculture environments. The macrophage primary cell culture was used to characterize PAMP-PRR interactions after stimulation with upPGN or dsRNA at the level of mRNA transcription of cytokines and antiviral related genes using absolute qPCR and secreted prostaglandins in the cell supernatant. A phylogenetic study of the target genes revealed conservation of Nile tilapia innate immunity genes across different species and all extant teleosts. Head kidney derived macrophages from Nile tilapia were optimally cultured and stimulated with PAMPs over specific time periods. Results revealed moderate levels of secreted PGE2 in culture media but no change upon PGN stimulation. Cytokine mRNAs were generally upregulated although high levels of mRNAs were found in basal state cells. Granulomas were observed during cell culture suggestive of chronic infection with intracellular parasites. Mycobacterium detection using PCR based method was able to detect mycobacterium DNA in macrophages and tissues samples of Nile tilapia (Oreochromis niloticus). The qPCR tools developed were used to examine the tissue-specific gene expression in tilapia cultured in Thailand. Data suggests that red hybrid tilapia (O.niloticus X O. mossambicus) are potentially more sensitive to culture conditions, particularly in polyculture husbandry systems in comparison to Nile tilapia (Oreochromis niloticus)

Thermoelectric properties of Thallium Lanthanoid Tellurides, Tl10-xLnxTe6, 0.25 x 1.32, Ln = La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Er

Thermoelectrics can convert heat energy into electrical energy (Seebeck effect) and vice-versa (Peltier effect) without any sort of pollution. That is because there are no moving parts that can cause noise pollution and no liberation of gas or chemical residue that could degrade the environment. On the contrary, application of the thermoelectric concept will help to deal with two main global issues, the increasing demand for energy with all the developments (increasing number of vehicles on the road, construction of more building, urbanisation of rural areas in developing countries etc.) and the drastic climate changes which are a result of those developments. The application of thermoelectrics in Peltier coolers has already helped to decrease the ozone depletion problem by replacing the CFC’s in the refrigerators. The Seebeck effect could help fulfil the increasing global demand for fuel and decrease significantly greenhouse gases if applied to exhaust systems of vehicles to convert the lost heat energy into useful electricity. The efficiency of thermoelectrics depends on the dimensionless figure of merit, ZT (ZT=T (S^2 σ)⁄κ, T = temperature, S = Seebeck coefficient, σ = electrical conductivity, κ = thermal conductivity); the higher the ZT value, the higher will be the efficiency. The best suited materials for thermoelectric are semiconductors as they have a compromised high S and high , however, depends on the materials themselves, some have low and some have high. Lots of research has been done on reduction of of semiconductors with good electronic properties. This research is about investigating the structure and the thermoelectric properties of thallium lanthanoid tellurides. Thallium lanthanoid tellurides might be promising thermoelectrics exhibiting small , as selected thallium-based tellurides have outstanding properties. The ZT values of both Tl9AgTe5 and Tl9BiTe6 are 1.2 at 700 K and 500 K respectively; the state-of-the-art thermoelectric materials, SiGe, Bi2Te3 and LAST have a ZT value of ~ 0.5 at temperatures greater than 900 K, 0.6 at RT and ~ 1.7 at 700 K respectively. The low of ~ 0.4 W/(mK) is responsible for the good ZT value of Tl9BiTe6 and Tl9AgTe5. However, thallium based semiconductors might never be commercialized due to the toxicity of Tl element. Nevertheless, from a scientific point of view, the study of the thallium lanthoid tellurides, Tl10-xLnxTe6, will still contribute in understanding the relation between the structure, stoichiometry and the properties of these thallium based semiconductors. In the present study, thallium lanthanide tellurides, Tl10-xLnxTe6, Ln = La, Nd, Gd, Tb, Dy, Ho, Er; 0.25 ≤ x ≤ 1.32 are investigated. All the thallium lanthanoid tellurides are isostructural to Tl9BiTe6, adopting the space group I4/mcm with mixed occupancy of Tl+/Ln3+ at the 4c site. Substitution of Tl by Ln at the 4c site in the Tl10Te6 structure, changes the lattice parameters and unit cell volume of the compounds as expected. The unit cell volume increases as the lanthanide content increases within a particular phase (more of the f-block Ln elements incorporated in the structure) and decreases across the lanthanides series for a specific stoichiometry (across the Ln series, atomic size decreases due to lanthanide contraction). Thermoelectric property measurements on sintered pellet showed that the Seebeck coefficient, S, increase as the lanthanide content increases for a particular phase (carrier concentration in the compound decreases as more Ln is incorporated). On the other hand, electrical conductivity, , (due to decrease in carrier concentration) and thermal conductivity, , (due to decrease in carrier concentration, increase in mass fluctuation and lattice vibration) decrease as the lanthanide content increase. The opposite trend is true for Tl10-xLnxTe6, x 1, across the lanthanide series, S decreases whereas and increase. Consequently, the dimensionless figures of merit increase within a particular phase but decreases across the lanthanide series, the highest ZT value of ~ 0.20 was obtained for Tl9LaTe6 and Tl8.98Nd1.02(6)Te6 at 553 K. Moreover, thermoelectric properties were studied on a hot-pressed pellet of Tl9LaTe6. The Seebeck coefficient for the cold-pressed and the hot-pressed pellets were almost same for the whole temperature range studied. A slight increase in the values for hot-pressed compared to the data of the sintered pellet was observed for the same temperature range. Similarly, values for the hot-pressed pellet were higher that of the cold-pressed pellet. The higher electrical and thermal conductivity of the hot pressed pellet with respect to the sintered pellet is due to improved compactness. The highest ZT for the hot-pressed pellet was ~ 0.32 around 555 K. The second part of the project was to study the thermoelectric and magnetic properties on the Ce, Sm and Pr compounds of the Tl10-xLnxTe6 family. The thermoelectric properties of those compounds with temperature were in agreement to the observations made for other compounds studied in this thesis. As temperature increases, S increases while decreases, was basically temperature independent as for the rest of this study. However, the study of the thermoelectric properties of compounds of Ce, Pr and Sm phases did not correlate with the rest of the thallium lanthanoid tellurides both within the phases and across the lanthanide series. The unit cell volume of Tl9CeTe6 was found to be unexpectedly smaller compared to the general decreasing tend ain the unit cell volume of Tl9LnTe6, across the Ln series. On the contrary, the unit cell volume of Tl9PrTe6 was found to be unexpectedly bigger compared to the general decreasing tend in the unit cell volume of Tl9LnTe6, across the Ln series. The physical properties of Tl9CeTe6 and Tl9PrTe6 compounds were anomalous as well, with respect to the rest of the Tl9LnTe6 series. There is a general increase in S from Tl9CeTe6 to Tl9SmTe6 compounds instead of a decreasing trend. Instead of an increasing tendency in the and values across the Tl9LnTe6 series, both parameters decrease from Tl9CeTe6 to Tl9SmTe6. Curie-Weiss Law and Modified Curie-Weiss Law were applied to their magnetic property measurement data. The magnetic property measurements revealed a magnetic moment of 2.02 eff/B for Tl9CeTe6 which is lower than the expected value of 2.54 eff/B. This points out towards the possibility of some Ce4+ in the structure unlike the Tl9PrTe6 compounds which had only Pr3+ ion in the structure. The magnetic data of Tl9SmTe6 was not conclusive as there was a temperature dependence of the magnetic field. This study therefore reveals that the thallium lanthanoid tellurides, Tl10-xLnxTe6, 0.25 x 1.32, Ln = La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Er, do have low ( 3 W/(mK)), especially when x ~ 1 ( 0.5 W/(mK)). The best ZT of this series is ~ 0.20 around 550 K exhibited by Tl9LnTe6, Ln = La, Nd, Sm compounds. The hot-pressed sample of Tl9LaTe6 exhibited a ZT value of ~0.32 in the around 550 K

Yeast diversity associated with the phylloplane of corn plants cultivated in Thailand

RTA5480009 RTA6080004 PHD/0025/2556The ecology and diversity of phylloplane yeasts is less well understood in tropical regions than in temperate ones. Therefore, we investigated the yeast diversity associated with the phylloplane of corn, an economically important crop in Thailand, by a culture-dependent method. Thirty-six leaf samples were collected and 217 yeast strains were isolated by plating leaf-washings. The strains were grouped by PCR-fingerprinting and representative strains were identified by analysis of the D1/D2 domain of the large subunit rRNA gene. In total, 212 strains were identified within 10 species in the Ascomycota and 32 species in the Basidiomycota. Five strains represented potential new species in the Basidiomycota, one strain was recently described as Papiliotrema plantarum, and four strains belonged to the genera Vishniacozyma and Rhodotorula. A higher number of strains in the Basidiomycota (81.6%) was obtained. Hannaella sinensis was the species with the highest occurrence. Principal coordinates analysis ordinations of yeast communities revealed that there were no differences in the similarity of the sampling sites. The estimation of the expected species richness showed that the observed species richness was lower than expected. This work indicated that a majority of yeast associated with the phylloplane of corn plant belongs to the phylum Basidiomycota.publishersversionpublishe

Social Quality and Democratic Citizenship of Students of Rajabhat Maha Sarakham University

A studyof social quality and citizenship of Rajabhat Maha Sarakham University students sought to 1) study citizenship of students from Rajabhat Maha Sarakham University, 2) study social quality factors related to citizenship of Rajabhat Maha Sarakham University students and 3) propose citizenship development guidelines of Rajabhat Maha Sarakham University students using quantitative research methods. A questionnaire was used as a tool for data collection. The results showed that most of the samples were female (62.5%). Most of them were aged 19-20 years (43.7%). Most of them were students of the faculty is Humanities and Social Sciences. (42.0%), with first-year students (38.0%) and with income between 6,001-10,000 baht (52.5 %). It was found that the overall level of citizenship of the students was ( =2.85, S.D.=0.857). The social quality factors related to student citizenship were as follows: 1) social solidarity variables and students’ citizenship level variables were a statistically significant relationship at 0.05 level, 2) the social capital conversion variable and the student citizenship level variable were statistically significant at the 0.05 leveland 3) the networking level variableof social factors and the degree of citizenship of the students were statistically significantly related at the 0.05 level. Citizenship development approach used the following factors of social quality .-1) principles of building good relationships between groups of students, 2) principles of eliminating conflicts of interests, 3) principles of ideology and values of diligence, patience, cooperation, honesty and self-reliance, 4) continuing education and citizenship training to encourage students to have knowledge and ideas and help students to be more self-confident to behave as a good citizens, and 5) teamwork principles that can be used to seek cooperation in developing the student society to realize citizenship

A Kluyveromyces marxianus 2-deoxyglucose-resistant mutant with enhanced activity of xylose utilization

Thermotolerant ethanologenic yeast Kluyveromyces marxianus is capable of fermenting various sugars including xylose but glucose represses to hamper the utilization of other sugars. To acquire glucose repression-defective strains, 33 isolates as 2-deoxyglucose (2-DOG)-resistant mutants were acquired from about 100 colonies grown on plates containing 2-DOG, which were derived from an efficient strain DMKU 3-1042. According to the characteristics of sugar consumption abilities and cell growth and ethanol accumulation along with cultivation time, they were classified into three groups. The first group (3 isolates) utilized glucose and xylose in similar patterns along with cultivation to those of the parental strain, presumably due to reduction of the uptake of 2-DOG or enhancement of its export. The second group (29 isolates) showed greatly delayed utilization of glucose, presumably by reduction of the uptake or initial catabolism of glucose. The last group, only one isolate, showed enhanced utilization ability of xylose in the presence of glucose. Further analysis revealed that the isolate had a single nucleotide mutation to cause amino acid substitution (G270S) in RAG5 encoding hexokinase and exhibited very low activity of the enzyme. The possible mechanism of defectiveness of glucose repression in the mutant is discussed in this paper. [Int Microbiol 18(4):235-244 (2015)]Keywords: Kluyveromyces marxianus · glucose repression · 2-deoxyglucose-resistant mutants · ethanol fermentation on xylose · thermotolerant yeas

Utilization capability of sucrose, raffinose and inulin and its less-sensitiveness to glucose repression in thermotolerant yeast Kluyveromyces marxianus DMKU 3-1042

Kluyveromyces marxianus possesses a useful potential to assimilate a wide variety of substrates at a high temperature, but the negative effect by coexisting glucose is critical for utilization of biomass containing various sugars. Such a negative effect on the activity of inulinase, which is the sole enzyme to hydrolyze sucrose, raffinose and inulin, has been demonstrated in K. marxianus without analysis at the gene level. To clarify the utilization capability of sucrose, raffinose and inulin and the glucose effect on inulinase in K. marxianus DMKU 3-1042, its growth and metabolite profiles on these sugars were examined with or without glucose under a static condition, in which glucose repression evidently occurs. Consumption of sucrose was not influenced by glucose or 2-deoxyglucose. On the other hand, raffinose and inulin consumption was hampered by glucose at 30°C but hardly hampered at 45°C. Unlike Saccharomyces cerevisiae, increase in glucose concentration had no effect on sucrose utilization. These sugar-specific glucose effects were consistent with the level of inulinase activity but not with that of the KmINU1 transcript, which was repressed in the presence of glucose via KmMig1p. This inconsistency may be due to sufficient activity of inulinase even when glucose is present. Our results encourage us to apply K. marxianus DMKU 3-1042 to high-temperature ethanol fermentation with biomass containing these sugars with glucose

Potential of Thermotolerant Ethanologenic Yeasts Isolated from ASEAN Countries and Their Application in High- Temperature Fermentation

Thermotolerant ethanologenic yeasts receive attention as alternative bio-ethanol producers to traditionally used yeast, Saccharomyces cerevisiae. Their utilization is expected to provide several benefits for bio-ethanol production due to their characteristics and robustness. They have been isolated from a wide variety of environments in a number of ASEAN countries: Thailand, Vietnam, Laos, and Indonesia. One of these yeasts, Kluyveromyces marxianus has been investigated regarding characteristics. Some strains efficiently utilize xylose, which is a main component of the 2nd generation biomass. In addition, the genetic basis of K. marxianus has been revealed by genomic sequencing and is exploited for further improvement of the strains by thermal adaptation or gene engineering techniques. Moreover, the glucose repression of K. marxianus and its mechanisms has been investigated. Results suggest that K. marxianus is an alternative to S. cerevisiae in next-generation bio-ethanol production industry. Indeed, we have succeeded to apply K. marxianus for bio-ethanol production in a newly developed process, which combines high-temperature fermentation with simultaneous fermentation and distillation under low pressure. This chapter aims to provide valuable information on thermotolerant ethanologenic yeasts and their application, which may direct the economic bioproduction of ethanol and other useful materials in the future

Tracking alternative versions of the galactose gene network in the genus Saccharomyces and their expansion after domestication

406564/2022-1 , and CNPq process numbers 0457499/2014-1 , 313088/2020-9 , and 408733/2021 , and Fundação do Amparo a Pesquisa do Estado de Minas Gerais ( FAPEMIG , process numbers APQ-01525-14 and APQ-02552-15 ). Field work in West Africa by L. Jespersen was supported by DANIDA , the Danish International Development Assistance. Publisher Copyright: © 2024 The AuthorsWhen Saccharomyces cerevisiae grows on mixtures of glucose and galactose, galactose utilization is repressed by glucose, and induction of the GAL gene network only occurs when glucose is exhausted. Contrary to reference GAL alleles, alternative alleles support faster growth on galactose, thus enabling distinct galactose utilization strategies maintained by balancing selection. Here, we report on new wild populations of Saccharomyces cerevisiae harboring alternative GAL versions and, for the first time, of Saccharomyces paradoxus alternative alleles. We also show that the non-functional GAL version found earlier in Saccharomyces kudriavzevii is phylogenetically related to the alternative versions, which constitutes a case of trans-specific maintenance of highly divergent alleles. Strains harboring the different GAL network variants show different levels of alleviation of glucose repression and growth proficiency on galactose. We propose that domestication involved specialization toward thriving in milk from a generalist ancestor partially adapted to galactose consumption in the plant niche.publishersversionpublishe