Characterization of thermostable aminoacylase from Geobacillus sp. strain SZN

Aminoacylase (EC 3.5.1.14) hydrolyzes N–acetylated amino acids to produce amino acids. Although thermostable aminoacylase has been commercially produced since 2004, here was a knowledge gap in the field of understanding aminoacylase thermostability from a structural point of view. This study investigated the physical and structural properties of the purified thermostable aminoacylase SZN. The spectropolarimetry data for structural determination has indicated a gradual decrease of α-helix from 36 to 27.6%, followed by tremendous disorientation of the structure at the transition of temperatures from 60 to 70°C (27.6 to 19.5%). In contrast, the percentage of β-sheet has increased steadily over the tested temperatures. The α-helix, where notable metal binding and catalytic residues are located, was totally weakened at temperatures above 70°C, thus resulted in loss of activity. The loss of the α-helical structure could further explain drastic deterioration of activity at temperatures beyond 70°C. The activity of aminoacylase SZN was enhanced by divalent metal ions, such as Mn2+ and Cu2+, and inhibited by detergent Triton-X-100. As a conclusion, the isolated aminoacylase SZN was characterized as a thermostable enzyme based on the α-helical structure integrity and functional stability in high temperatures. This enzyme could be used as an alternative enzyme for bioindustries in view of its activity enhancement in high temperatures and stability in various tested inhibitors

RETOOLING SCIENCE TEACHING ON STABILITY TOPIC FOR STEM EDUCATION: MALAYSIAN CASE STUDY

By 2020, Malaysia needs to develop its workforce capacity in order to obtain the 500,000 STEM human capital requirement for the New Key Economic Areas (NKEAs). Therefore, an effort of retooling teaching and learning of science teachers is a part of the planning in catalyst STEM human capital. Science teachers require refreshment in teaching and learning approach of pedagogy to enhance the student understanding in the subject matter and stability topic is chose as the initial idea to attract the student interest in STEM activities. This study aims to introduce a teaching aid Arts and Stability Card (A&S Card) to help teachers to diversify the teaching concept of stability science through A&S Card. 300 science teachers across the 10 districts from Perak state, provided their perceptions upon the modules via questionnaire in two parts: a pedagogical approach to teaching and learning, and training suitability. The reliability test of Chronbach’s Alpha to the pedagogical approach to teaching and learning scored 0.868 while training suitability obtained 0.874, which fall under the very good category of reliability results. The mean result score of 4.29 and 4.17 to the pedagogical approach to teaching and learning, and training suitability, where the results indicate A&S Card module and training were successfully conducted. Besides, this module also contains the value of creativity and innovation to build a fun learning in a science subject and the concept can be replicated for other science subject

Population structure and warfarin resistance in the brown rat, (Rattus norvegicus) in the English countryside

The brown rat, Rattus norvegicus is a relatively recent addition to the English fauna. However it is currently one of the most important vertebrate pest species. Anticoagulant rodenticides are the major control method used for the last 50 years. Widespread use of the rodenticide has led to evolution of resistance leading to problems controlling brown rat populations. One thus far ignored aspect of resistance biology is the population structure of the brown rat. In this research mitochondrial DNA and microsatellite DNA were used to elucidate the population structure of the brown rat at different scales in the English countryside. I also report on the type and the distribution of different warfarin resistant mutations in the English rural population.;Mitochondrial DNA data suggests a structured population at county level and the English brown rat population as a whole appears not to be at equilibrium. The relative lack of diversity in the mitochondrial DNA sequences examined can be explained by a founder effect and a subsequent spatial expansion. However, the microsatellite data shows much more mixing of populations at county level, even more clearly at the farm level. I discuss two possible explanations for this discrepancy; small effective population size of mitochondrial genomes and the greater movement of males compared to female rats.;Through mutation analysis we found 3 types of mutations in the exon 3 region of the VKORC1 gene among our brown rat populations. One mutation type is almost ubiquitous being found in almost all counties. We also found a geographical pattern to the different mutation distribution. As these mutations are also found in other parts of Europe, we suggest that they have entered England through different ports from different parts of the Continent which would explain the geographical structure of the mutations