[BI019] Molecular Cloning And Characterisation Of The 5 -Untranslated Region And Promoters In Human Peroxisome Proliferator-Activated Receptor Alpha (hPPARα).

The peroxisome proliferator activated receptors (PPARs) are members of the nuclear hormone receptor gene superfamily of ligandactivated transcription factors [Issemann and Green, 1990]

Construction of integration vector for nitrogen fixing genes (nif) regulation studies of Paenibacillus macerans

Nitrogen is very important to living organism because nitrogen is one of the components for proteins and nucleic acids. Nitrogen is one of the limiting factors in agriculture

Regulation studies of phaC(C1 and C2) genes in Pseudomonas sp. USM 4-55

Among the various biodegradable plastics available, polyhydroxyalkanoates (PHAs) attract a lot of attention because these polymers are produced by bacteria and have thermoplastic properties. They are biodegradable, biocompatible, moisture resistant, versatile, have long shelf life and are made from renewable source materials (Pouton et al., 1996)

Gene expression patterns of Glaciozyma antarctica PI12 in response to cold, and freeze stress

Psychrophilic yeast, Glaciozyma antarctica PI12 was isolated from the sea ice in the Southern Ocean. Several recent studies have revealed some of the strategies employed by G. antarctica PI12 to grow and survive at low temperatures, but those information are still limited. Hence this project was carried out to sequence the whole transcriptome to generate additional information on the cold-adaptation strategies of G. antarctica PI12. The yeast grown optimally in Saccharomyces cerevisiae minimal medium at 12 °C was subsequently exposed to cold-shock at 0 °C and freeze-shock at −12 °C for 6 h and 24 h. RNA from those cells were extracted, sequenced, and analyzed. Interestingly, the results showed that G. antarctica PI12 remained metabolically active at −12 °C. Two hundred and five genes were differentially expressed in the cells. Among them, 107 genes were upregulated while 98 genes were downregulated. In the first 6 h after the cells were exposed to cold- and freeze-shocks, CCR4-NOT (carbon catabolite repressed 4 - negative on TATA-less) core subunit cdc36, DNA repair protein Rad8, Elongation factor 1-gamma, 26s proteosome subunit 45, and Homocitrate synthase genes were commonly upregulated to perform several immediate and important tasks to ensure the cells survived. Apart from that, there were also genes upregulated and downregulated uniquely at 6 h and 24 h to facilitate the cells to adjust to the new temperatures. After overcoming the stress of the cold- and freeze-shocks for 24 h, the cells acclimatized to those temperatures and became metabolically active again, and the cell cycles related genes were up-regulated

Microscopic observation of a root-adhering factor Avin_16040 in Azotobacter vinelandii and Escherichia coli during association with rice root

Microbial adherence to plant root is the initial step in a beneficial plant-microbe interaction. Quantitative RT-PCR analysis deduced the Avin_16040 gene showed upregulated expression when Azotobacter vinelandii was adhered to the rice root. By transforming the full-length Avin_16040 gene into a heterologous host Escherichia coli, the recombinant clones displayed filamentous cell shapes in contrast to the rod-shape of wild type cells. Besides full-length gene insert, some E. coli clones were detected to contain truncated Avin_16040 gene inserts but still shape-shifted to filamentous cells. Further analysis by DNA sequencing revealed the shape-shifting E. coli clones contained 3’-end truncated Avin_16040 gene, while E. coli clones containing the 5’-end truncated Avin_16040 gene remained rod-shaped. The cell surface topographies of A. vinelandii and E. coli cells in the presence and absence of Avin_16040 gene and in association with rice root adherence were analysed using atomic force microscopy

Molecular cloning and characterisation of the 5’-untranslated region and promoters in human peroxisome proliferator-activated receptor alpha (hPPARα)

The peroxisome proliferator activated receptors (PPARs) are members of the nuclear hormone receptor gene superfamily of ligandactivated transcription factors [Issemann and Green, 1990]

Characterisation of polyhydroxyalkanoate production by mutant Azotobacter vinelandii

The production of PHA by Azotobacter vinelandii was characterised in different types of mineral medium including DSMZAzotobacter medium, Ashby’s medium, Burk’s medium and Minimal Medium PHA (MMPHA). A deletion mutant of Azotobacter vinelandii, designated as ΔAvin_16040 was able to accumulate 3-folds higher PHA which was 0.48 ± 0.02 g/L compared to the wild type strain which was 0.11 ± 0.03 g/L in a modified DSMZ-Azotobacter medium. Although this bacterial strain is able to fix nitrogen, addition of urea as external nitrogen source into the medium had increased both its biomass and PHA production. Among the various medium types, MMPHA showed the highest biomass and PHA yields of 3.5 ± 0.1 g/L and 1.50 ± 0.03 g/L, respectively. Higher PHA concentration of 1.74 ± 0.05 g/L was obtained in this medium by increasing the sucrose concentration from 20 g/L to 25 g/L

Biosynthetic production of human growth hormone gene in methylotrophic yeast, Pichia pastoris

Human growth hormone (hGH) is secreted from the anterior pituitary gland and exerts a wide variety of functions such as, IGF-1 production, protein synthesis, glucose metabolism, lipolysis, lipogenesis, and cell proliferation/differentiation (Isaksson et al., 1985; Press, 1988; Thorner and Vance, 1988; Strobl and Thomas, 1994)

Unveiling the multifaceted microbial strategies: Insights into ecological adaptations and interactions

Microorganisms, such as spanning bacteria, archaea and fungi, were ubiquitous and played pivotal roles in shaping ecosystems. This review offered a comprehensive investigation into the multifaceted strategies employed by microorganisms to thrive and adapt within complex ecological niches. Key themes explored in this review encompassed microbial defence mechanisms, biofilm formation, quorum sensing and altruistic behaviours. Microbial defence mechanisms were scrutinized, with a focus on bacteriocin production. Despite the costs associated with production, bacteriocins served as potent weapons that selectively targeted closely related strains, reducing competition and conferring indirect benefits to the producer's genetic kin. Biofilm formation, a critical facet of microbial survival, was discussed in detail. These structured microbial communities encased in self-secreted extracellular matrices provided structural support and protection, demonstrating their significance in diverse ecological contexts. The review further delved into the evolutionary implications of quorum sensing and altruism within microbial communities. Quorum sensing, a mechanism that allowed population density-dependent communication and cooperation, was revealed as essential for microbial survival. In conclusion, this review enhanced our understanding of the intricate strategies microorganisms employed for survival, adaptation and competition in intricate ecosystems. By shedding light on these mechanisms, it advanced our comprehension of microbial community dynamics and their indispensable roles in diverse environments

Cloning and characterization of polyhydroxyalkanoate (PHA) genes from Pseudomonas sp. isolated from Antarctica

Pseudomonas strains accumulate mediumchain-length poly(R)-3-hydroxyalkanoate (PHA) as carbon and energy source under conditions of limiting nutrients in the presence of an excess of carbon source (Fidler et al., 1992)