¹ Biotechnology Department, Faculty of Food Science & Biotechnology, University Putra Malaysia,
43400 Serdang, Selangor, MALAYSLA
² Department of Biotechnology, Graduate School of Engineering, Osaka University, 2 1 Yamadaoka,
Suita, Osaka 565, JAPAN

Received 31 October 2000 / Accepted 8 December 2001

Abstract.
The production of ethanol from sago starch was investigated using three genetically modified Saccharomyces cerevisiae strains, which are YKU 107 (expressing (a amylase), YKU 131 (expressing glucoamylase) and YKU 132 strains (expressing (a amylase and glucoamylase). Substrate utilization, biomass formation, and ethanol production were studied in media containing sago starch and glucose as carbon sources. For all the strains, the mmax in media containing glucose was much higher than that in media containing sago starch. The YKU 107, YKU 131 and YKU 132 strain could hydrolyzed 83.45%, 67.2% and 71.9% of sago starch, respectively. However, only the YKU 131 strain could produced significant amount of ethanol (2.16 gl^-1) from sago starch. The superiority of the YKU 131 strain as compared to YKU 107 and YKU 132 strains was found to be correlated with its glucoamylase secretion. The YKU 132 strain did not produce ethanol due to its negligible secretion of glucoamylase. The YKU 107 strain was superior in SCP production from sago starch, with the yield of 0.414 g/g.

Keywords: Sago starch, recombinant Saccharomyces cerevisiae, ethanol fermentation, a amylase, glucoamylase

¹Division of Microbiology and Immunology, Institute of Biological Sciences, Faculty of Science,
University Malaya, Kuala Lumpur, Malaysia
²School of Science and Technology, University Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia

Received 16 February 2001 / Accepted 4 September 2001

Abstract.
The isolation of forty eight strains of actinomycetes from eight soil samples was done with the conventional dilution plate method on Humic acid vitamin agar (HVA), Starch Casein agar and Sorenson's agar. HVA was found to be the best isolation medium as more strains of actinomycete could be isolated. Based on the aerial mycelium colour scheme, three colour groups were recognised. Representative isolates from each colour group were subjected to macrorestriction analysis with the pulsed field gel electrophoresis (PFGE). The different coloured strains exhibited low levels of similarity (Dice coefficient, F<0.50). Acetone extracts of the isolates were screened on mutant yeasts for Mitogen Activated Protein Kinase (MAPK) Kinase and MAPK Phosphatase inhibitor to find an indirect inhibitor of ras. However, no inhibitor was found but seven isolates exhibited toxic effect towards the yeasts. PFGE analysis of these isolates showed that two of isolates were identical. From the phenotypic and genotypic characteristics, the two isolates were shown to be of the same strain.

Keywords: morphology, PFGE, soil isolation, Streptomyces

¹Institute of Biological Science, Faculty of Science, 2Department of Medical Microbiology,
Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia

Received 21 September 2001 / Accepted 10 December 2001

Abstract.
Pulsed field gel electrophoresis (PFGE) despite being a highly reproducible and discriminatory method for molecular subtyping of many bacterial pathogens has been criticised for being time consuming. We have developed a modified, rapid PFGE method for Gram positive bacteria, in particular, Streptococccus spp. Our method can be completed in only 3 days' time as compared to the standard procedure which required Lip to 6 days. We successfully applied this method on clinical isolates of Streptococcus pneumoniae (50) and Group B Streptococcus (50) obtained from the University of Malaya Medical Center with comparable results. The method for DNA preparation was reproducible when repeated analysis was carried out. The rapid method has the ability to process a large number of isolates in less time than the standard method. This will definitely enhance the rapid and accurate analysis of outbreaks of nosocomial or community acquired Streptococcal infections.

Keywords: Rapid protocol, PFGE, Streptococcus spp.

Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia

Received 2 August 2001 / Accepted 5 September 2001

Abstract.
Pulsed field conditions specific for Pasteurella multocida B:2 have been optimised to obtain a good separation resolution. Restriction enzyme, NotI, was the most suitable as it generates discernible number of bands. Other optimised electrophoretic conditions were: 1.5% agarose gel concentration, 200 V, ramped pulsed time of 1-25 s and a run time of 26 h. This research is important for fast and accurate characterisation of this bacterial strain following an outbreak in Malaysia.

Keywords: Pasteurella multocida, PFGE, restriction enzymes