The Occurrence of 3-Hydroxy-3-methylglutaryl CoA Reductase (NADPH) in the latex of regularly-tapped Hevea brasiliensis

The enzyme 3-hydroxy-3-methylglutaryl CoA reductase (NADPH) from the latex of mature trees of Hevea brasiliensis was studied. It was found to be mainly associated with the bottom fraction of centrifuged latex (42,000 g), although appreciable activity was also detected in the Frey-Wyssling zone. The bottom fraction enzyme has a specific requirement for NADPH as the cofactor and its pH optimum was 6.6 - 6.9 in 0.1 M phosphate buffer. The Arrhenius plot of the enzyme was linear within the temperature range of 12 - 40°C and the Arrhenius activation energy was estimated to be 57.3 kJ/mol (13.7 kcal/mol). The enzyme was very unstable when the latex was collected and centrifuged at ambient temperature. A 30% loss of activity also occurred when the bottom fraction was stored at -15° C for 24 hr. Pre-incubation of the enzyme at 30°C for up to 1 hr resulted in a 90% loss of activity and this was not prevented by washing the bottom fraction or by the addition of either bovine serum albumin (1 %, w/v) or NADPH (2 mM) or dithiothreitol (10 mM) to the assay mixture. Enzyme activity in the washed bottom fraction was saturated at 300 11M R&-HMG CoA and the K m and Vmax were 56 11M and 6.10 pkat/mg protein respectively

Separation of (3.14C) 3-Hydroxy.3-methylglutaric acid from (3_14C) 3-Hydroxy-3-methylglutaryl CoA using Sephadex G-15 column chromatography

A new method has been developed for the separation of (3- 14C) 3-Hydroxy-3-methylglutaric acid from a (3-14C) 3-Hydroxy-3-methylglutaryl CoA preparation using Sephadex G-15 column chromatography. This method is simple, rapid and is useful in studies where the preparation of (3_ 14C) 3-Hyd1'oxy-3-methylglutaryl CoA is required to bef1'eef1'Om (3_ 14C) 3-Hydroxy-3-methylgluta1'ic acid contamination

Innovativeness in Thai family SMEs: An exploratory case study

Over the past decade, academic research has revealed innovativeness to be one of the core components effecting SME performance. This research aims to study the linkage between innovativeness and “familiness” in family SMEs. The paper employs a qualitative approach and exploratory case studies, in collecting data on three categories of firms manufacturing, trading and servicing companies in order to identify how “familiness” effects the innovativeness of their family SMEs. To identify how “familiness” either accelerates or decelerates innovativeness in family SMEs, we adopted the F-PEC scale as a tool to study the connection between family and business values and also the impact of family commitments to the company. We found that power, experience and culture accelerate innovativeness in family SMEs. The paper illustrates the important role of family in firm innovativeness and how this can bring competitive advantage and success to family SMEs

Expression of a thermostable xylanase gene from Bacillus coagulans ST-6 in Lactococcus lactis

Aims: The aim of the study is to evaluate whether xylanase can be used as a potential reporter gene for cloning and expression studies in Lactococcus. Methods and Results: The 750 bp xylanase gene was amplified and subcloned into the unique NheI restriction enzyme site of pMG36e and subsequently transformed into competent Escherichia coli XLI-blue MRF cells and Lactococcus lactis cells. Bacterial culture containing pMG36e-Xy has an enzyme activity of 390 μg xylose ml−1 culture 30 min−1, respectively, when compared with 40 μg xylose ml−1 culture 30 min−1 for the negative control (plasmidless strain). Conclusions: The thermostable xylanase gene was successfully expressed in both E. coli and L. lactis. The activity of xylanase can be easily detected by the formation of visible clearing zones around the transformed colonies on Remazol Brilliant Blue-Xylan (RBB-Xylan) agar media. However, there were some significant differences in the optimum growth temperature and plasmid stability in the new clones. Significance and Impact of the Study: The constructed reporter vector has the potential to be used as a reporter system for Lactococcus as well as E. coli, and it is an addition to the pool of lactococcal vector systems