¹Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, 43400 Selangor, Malaysia
²Faculty of Food Science and Biotechnology, Universiti Putra Malaysia, Serdang, 43400 Selangor, Malaysia

Received 16 August 2001 / Accepted 8 December 2001

Abstract.
Dichelobacter nodosus serogroup B is the most predominant serogroup in Malaysia and was found to be distinct from the prototype strains. In the present study, we investigate the relationship between fimbriae from different strains isolated in Malaysia and the prototype strains. None of the local isolates had identical sequence with the prototype strain. Isolates exhibited 94 to 97% of amino acid similarities (identities and conserved changes) to D. nodosus prototype strains. Unique sequences for local isolates arc the NQA sequence at AP61, isoleucine at AP67 and threonine at AP 79. There is no substitution in the hypervariable region API 17 124 in all isolates. These results strengthen the suggestion that this region is the common determinant fro the B serogroup. Most importantly, the data in the study is essential for future development of specific vaccine against footrot disease in Malaysia.

Keywords: footrot, Dichelobacter nodosus, sheep, fimbriae

¹School of BioSciences and Biotechnology, Faculty of Science and Technology,
Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia;
²Institute of Molecular Biosciences, Massey University, Palmerston North, New Zealand

Received 19 November 2001 / Accepted 12 December 2001

Abstract.
The cutinase gene (cutA) has been identified from a genomic DNA library of the plant pathogenic fungus Glomerella cingulata ICMP 11061. Nucleotide sequence data revealed that this gene codes for a putative 224-amino acid protein encoded by two exons of 189 bp and 486 bp, separated by an intron of 52 bp. The presence of the 52 bp intron was confirmed after comparison with the cutinase cDNA sequence obtained using RT PCR of cutin induced cells. The DNA segments from positions-120 to-112 and from positions-101 to-95 relative to the start codon are potential segments for cutinase transcription start and transcription factor binding sites, respectively. The presumptive TATA box is mapped at-116 from the initiation of translation site. Potential adenylation sites are mapped at segments 228 to 231 and 257 to 259 downstream from the stop signal. The cutinase gene is present in a single copy in the genome of G. cingulata and the putative protein product is between 24 and 99 per cent identical at the amino acid level to other fungal cutinases. The three dimensional protein structure of G. cingulata cutinase as determined by protein homology modeling showed that the protein is ellipsoidal and has a central ß sheet consisting of five parallel strands surrounded by 5 helices. The amino acid residues potentially participating in the catalytic triad and oxyanion hole have been determined and are located at one extremity of the protein.

Keywords: Cutinase gene, Glomerella cingulata

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

A.M. Yazid^1*, M. Shuhaimi¹, A.M. Ali², M.H. Ghazali², J. Normah¹, A.B. Fatimah³,
N.A. Nur Atiqah4 and A. Reezal3

¹Department of Food Technology, ²Department of Biotechnology, ³Department of food Science, Faculty of Food Science and
Biotechnology, Universiti Putra Malaysia, 43400 Serdang, Selangor,
⁴Department of Paediatrics, Kuala Lumpur Hospital, Jalan Pahang, 50586 Kuala Lumpur, Malaysia

(Received 10 April 1999 / Accepted 29 July 1999)

Abstract.
The ability of eighteen strains of genus Bifidobacterium spp. to survive in a simulated gastric pH and tolerance to bile acids exposure was investigated. Four strains namely, B. bifidum (ATCC 35914), B. adolescentis (ATCC 11146), B. breve (ATCC 15698) and B. infantis (ATCC 27920) showed excellent growth following 90 min exposure to extreme acidic condition (pH 2.5). Strains B. breve (ATCC 15701) and B. adolescentis (ATCC 15706) showed good acid tolerance and another 2 strains (B. adolescentis ATCC 15705 and B. longum ATCC 15707) possessed moderate ability to tolerate exposure to low pH. The remaining 10 strains did not survive the extreme acid condition. The ability to grow in the presence of bile acids was variable among strains. Four strains (B. longum ATCC 15707 and ATCC 15708, B. adolescentis ATCC 11146 and B. asteroides ATCC 25910) showed good tolerance and another 5 strains (B. breve ATCC 15700 and 15701, B. asteroides ATCC 25909, B. bifidum ATCC 35914 and B. infantis ATCC 27920) showed moderate tolerance and the rest were sensitive to bile acids. No correlation was observed between the ability to survive extreme acidic condition and the ability to grow in the presence of bile. The strains that possess excellent acid tolerance were not necessarily tolerant to bile, and vice versa.

Keywords: Bifidobacteria, tolerance, pH, bile acids