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Karakterisasi α-Amilase Bacillus firmus KH.9.4 Alkalotoleran dari Limbah Cair Tapioka Rachmania, Nisa; Iswati, Ruma; Imas, Tedja
Biota : Jurnal Ilmiah Ilmu-Ilmu Hayati Vol 9, No 3 (2004): October 2004
Publisher : Universitas Atma Jaya Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (200.421 KB) | DOI: 10.24002/biota.v9i3.2909

Abstract

Alkalotolerant bacteria identified as Bacillus firmus KH.9.4 was isolated from tapioca liquid waste from Kedung Halang, Bogor. The isolate showed optimum a-amylase activity after 15 hours of cultivation on liquid media. Optimum enzyme activity occurred at pH 6.0 and temperature 800C. Upon heat treatment at pH 6.0 and 800C the enzyme was still 100% active after 6 hours incubation without substrate. The enzyme activity was enhanced by supplement 10 mM MgSO4.7H2O. The presence of 1, 5, and 10 mM ethylenediaminetetraacetic acid demonstrated the inhibitory effect to this enzyme. Zymogram analysis revealed one translucent zone corresponding to soluble starch activities after 60 minutes of incubation at 400C in the 0.05 M phoshate buffer pH 7.0. Whereas SDS-PAGE analysis showed that there are 5 bands of proteins.
Karakterisasi α-Amilase Bacillus firmus KH.9.4 Alkalotoleran dari Limbah Cair Tapioka Nisa Rachmania; Ruma Iswati; Tedja Imas
Biota : Jurnal Ilmiah Ilmu-Ilmu Hayati Vol 9, No 3 (2004): October 2004
Publisher : Universitas Atma Jaya Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24002/biota.v9i3.2909

Abstract

Alkalotolerant bacteria identified as Bacillus firmus KH.9.4 was isolated from tapioca liquid waste from Kedung Halang, Bogor. The isolate showed optimum a-amylase activity after 15 hours of cultivation on liquid media. Optimum enzyme activity occurred at pH 6.0 and temperature 800C. Upon heat treatment at pH 6.0 and 800C the enzyme was still 100% active after 6 hours incubation without substrate. The enzyme activity was enhanced by supplement 10 mM MgSO4.7H2O. The presence of 1, 5, and 10 mM ethylenediaminetetraacetic acid demonstrated the inhibitory effect to this enzyme. Zymogram analysis revealed one translucent zone corresponding to soluble starch activities after 60 minutes of incubation at 400C in the 0.05 M phoshate buffer pH 7.0. Whereas SDS-PAGE analysis showed that there are 5 bands of proteins.
Characterization of Acid-Aluminium Sensitive Mutants of Soybean Symbiont Bradyrhizobium japonicum Generated by Transposon Mutagenesis ARIS TRI WAHYUDI; ANDINI PURNAWIJAYA; DINI NURDIANI; TEDJA IMAS
Microbiology Indonesia Vol. 1 No. 2 (2007): August 2007
Publisher : Indonesian Society for microbiology

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (61.648 KB) | DOI: 10.5454/mi.1.2.7

Abstract

Acid-aluminium sensitive mutants of symbiotic bacterium Bradyrhizobium japonicum BJ11 (designated as AAS11) and KDR15 (designated as AAS15) were constructed by mini-Tn5 transposon mutagenesis to study genes involved in acid-aluminium tolerance (AAT) in B. japonicum. Transposon delivery was carried out through conjugation between B. japonicum strains as recipients and Escherichia coli S17-1 (ë pir) carrying pUTmini- Tn5Km1 as a donor strain. The result showed that frequency of transconjugation was in the range of 6.7 x 10-7 to 7.1 x 10-6 cell per recipients. AAS11 and AAS15 mutants did not grow on Ayanaba media (pH 4.5) containing 50 μM Aluminium. These mutants remained able to form root nodules of Siratro (Macroptilium arthropurpureum) plants revealing genes interrupted by transposon which were responsible for acid-Al tolerance did not correlate with the nodulation genes. Strains tolerant to acid-aluminium and their mutants with a wild type sensitive to acidaluminium were characterized by accumulating phosphate and aluminium absorption. Compared to the wild type acid-aluminium tolerant B. japonicum, there was approximately a three- to eight-times decrease in phosphate accumulation and a five- to seven-times increase in aluminium absorption by these mutants. These results suggest that aluminium and phosphate contents in the bacterial cells may be involved in mechanisms of acid-Al tolerance of B. japonicum grown in acid-aluminium stress conditions.