Abdul Aziz Darwis
Fakultas Teknologi Pertanian, Institut Pertanian Bogor, Kampus Darmaga, Bogor 16680

Published : 6 Documents
Articles

Found 6 Documents
Search

Penggandaan Skala Produksi Bioinsektisida Bacillus thuringiensis var. israelensis untuk Membasmi Jentik Nyamuk Aedes aegypti Rahayuningsih, Mulyorini; Syamsu, Khaswar; Darwis, Abdul Aziz; Purnawati, Rini
Jurnal Ilmu Pertanian Indonesia Vol 12, No 2 (2007): Jurnal Ilmu Pertanian Indonesia
Publisher : Institut Pertanian Bogor

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

The objective of this research is to study the scaling up of bionsecticide production from Bacillus thuringiensisvar. israelensisusing onggok (a cassava by-product) as a carbon source. The insecticide produced was used to eradicate Aedes aegypti larvae. The product was a crystal protein produced during bacterial sporulation. Scaling up from laboratory to pilot plant scale was done using two methods, i.e. constant agitation power per unit volume (Pg/V) and constant oxygen transfer coefficient (kLa). The results showed that yield of product per substrate (Yp/s) of Pg/V based product with the value of 3.52 ± 0.02 spora per gram substrates was higher than Yp/s of  kLa based product with the value of 2.96 spora per gram substrate.  Logarithmic value of viable spore count (log of VSC) was also higher, i.e. 7.23 ± 0.30 for Pg/V based product as compared to 7.17 ± 0.20 for kLa based product. Substrate efficiency was also higher in Pg/V based (92.47%) than kLa based (64.87%). LC50 of Pg/V based product was lower (0.49 μg/ml) meaning that it was more toxic than kLa based product (0.62 μg/ml). Amino acid content of Pg/V based product was also higher than kLa based product. Constant Pg/V method was suggested as a based on the scaling up of bioinsecticide production of B. thuringiensis israe/ensison industrial scale. Keywords: bioinsecticide, Bacillus thuringiensisvar. israelensis, kLa, Pg/V, LC50, viable spore count
The Influence Of Reactant Ratio (Eupcalyptus Lignin – Sodium Bisulfite) And Initial Ph Towards Characteristcs Of Sodium Lignosulfonate Syahbirin, Gustini; Darwis, ABDUL Aziz; Suryani, Ani; Syafii, Wasrin
Jurnal Teknologi Industri Pertanian Vol 19, No 2 (2009): Jurnal Teknologi Industri Pertanian
Publisher : Jurnal Teknologi Industri Pertanian

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Eucalyptus lignin was isolated from kraft black liquor through by acidification using H2SO4. Sulfonation of eucalyptus lignin produced sodium lignosulfonate (SLS) which can be used as dispersants, and emulsifier. In this research, sulfonation was carried out towards lignin with mass ratio of eucalyptus lignin-NaHSO3 (b/b) of 1:0.4, 1:0.5, and 1:0.6, and initial pH of 5, 6, 7, 8. Studies on the effect of various ratio of eucalyptus lignin versus NaHSO3 (1 based on w/w) and initial pH of 5,6,and 7 for the sulfonation reaction showed an  increasing yield and improved purity of SLS obtained.  However, no significant result was observed on the application of initial pH  7 and 8 toward increasing of SLS yield and purity.  The highest SLS  yield of 83.8% with  purity of 82.9% was obtained under condition of initial pH at 7 and the mass ratio of eupcayptus lignin over NaHSO3 was 1:0.5.  The resulted SLS was light brown, water soluble, with  pH level between 6.3 and 7.24, and released sulfur-like odor.Key words: lignin, kraft black liquor,  sodium lignosulfonate.
Analysis of Reducing Sugars on Hydrolysis of Cassava Starch by a Thermostable a-Amylasefrom Bacillus stearothemophilus TII 12 Lestari, Puji; Darwis, Abdul Aziz; Syamsu, Khaswar; Richana, Nur; Damardjati, Djoko Said
Jurnal Mikrobiologi Indonesia Vol 6, No 1 (2001): JURNAL MIKROBIOLOGI INDONESIA
Publisher : Jurnal Mikrobiologi Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

The product of a-amylase hydrolysis was evaluated for their application In sugar syrup Industry. The objectives ofthis experiment were to determine the enzyme production of Bacillus stearothermophilus TH,2 in a five liter bioreactorand to analyze its hydrolysis product on cassava starch using thin layer chromatography and high performance liquidchromatography. The bacterium was cultured in the bloreactor for 48 hours, and then the biomass, enzyme activity,protein and reducing sugar contents in the filtrate were evaluated In the course of cultivation. The strain secreted anextraceiiuiar a-amylase in the optimal condition at pH 6.5, 5O´C, agitation of 300 rpm and aeration of 1.5 vvm for 24hours. The highest activity of a.amylase and reducing sugar content of 1 068.87 U/mI and 4.48 g/l respectively wereobtained after 24 hours incubation. Hydrolysis products by the crude enzyme on cassava starch were evaluated atdifferent Incubation time. In the course of incubation the content of glucose, dextrin, maltose and oligosaccharideswere increasing. After 24 hours the concentration of glucose and maltose reached 51 970 and 10 090 ppm respectively.Based on the enzymatic products, we concluded that thermostabie a.amylsse produced by B. slearothermophilus was aaendo-a-amylase.
Penggandaan Skala Produksi Bioinsektisida Bacillus thuringiensis var. israelensis untuk Membasmi Jentik Nyamuk Aedes aegypti Rahayuningsih, Mulyorini; Syamsu, Khaswar; Darwis, Abdul Aziz; Purnawati, Rini
Jurnal Ilmu Pertanian Indonesia Vol 12, No 2 (2007): Jurnal Ilmu Pertanian Indonesia
Publisher : Institut Pertanian Bogor

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

The objective of this research is to study the scaling up of bionsecticide production from Bacillus thuringiensisvar. israelensisusing onggok (a cassava by-product) as a carbon source. The insecticide produced was used to eradicate Aedes aegypti larvae. The product was a crystal protein produced during bacterial sporulation. Scaling up from laboratory to pilot plant scale was done using two methods, i.e. constant agitation power per unit volume (Pg/V) and constant oxygen transfer coefficient (kLa). The results showed that yield of product per substrate (Yp/s) of Pg/V based product with the value of 3.52 ± 0.02 spora per gram substrates was higher than Yp/s of  kLa based product with the value of 2.96 spora per gram substrate.  Logarithmic value of viable spore count (log of VSC) was also higher, i.e. 7.23 ± 0.30 for Pg/V based product as compared to 7.17 ± 0.20 for kLa based product. Substrate efficiency was also higher in Pg/V based (92.47%) than kLa based (64.87%). LC50 of Pg/V based product was lower (0.49 ?g/ml) meaning that it was more toxic than kLa based product (0.62 ?g/ml). Amino acid content of Pg/V based product was also higher than kLa based product. Constant Pg/V method was suggested as a based on the scaling up of bioinsecticide production of B. thuringiensis israe/ensison industrial scale. Keywords: bioinsecticide, Bacillus thuringiensisvar. israelensis, kLa, Pg/V, LC50, viable spore count
Purifikasi dan Karakterisasi α-amilase Termostabil dari Bacillus stearothermophilus TII-12 Lestari, Puji; Richana, Nur; Darwis, Abdul Aziz; Syamsu, Khaswar; Murdiyatmo, Untung
Jurnal AgroBiogen Vol 7, No 1 (2011): April
Publisher : Balai Besar Penelitian dan Pengembangan Bioteknologi dan Sumber Daya Genetik Pertanian

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Purification and Characterization of Thermostableα-amylase from Bacillus stearothermophilus TII-12. PujiLestari, Nur Richana, Abdul A. Darwis, Khaswar Syamsu,and Untung Murdiyatmo. Thermostable α-amylase is apotential enzyme employed in the starch processing andwidely used in food industries, but this enzyme is stillimported. The local enzyme production would be moreeconomist and useful for its broad applications. Here wereport α-amylase from indigenous bacteria TII-12 which waspurified and characterized, as well as analyzed its hydrolysisproduct on cassava starch. The enzyme of Bacillusstearothermophilus TII-12 partially purified by ultrafiltration,acetone precipitation and gel filtration (Sephadex G-100)showed the reduced total activity, total protein and yield, butincreased the specific activity. The enzyme had a Km of 1,06mg/ml and Vmax of 1,21 mol/min, with optimal activity at pH 7and 90oC. An apparent molecular mass was of 192.932,8Dalton, as estimated by Native-Polyacrylamide Agarose Gelelectrophoresis. Its activity was inhibited by the divalentcation chelator such as EDTA and CuSO4 but activated bycalcium ion. Hydrolysis products of this enzyme on cassavastarch were glucose, dextrin, maltose and oligosaccharides.After 24 hours of hydrolysis, the concentration of glucoseand maltose reached 51.970 and 10.090 ppm, respectively.The thermostable α-amylase of TII-12 is an endo-α-amylaseand prospective to be applied on starch liquefaction withhigh temperature process.
The Influence Of Reactant Ratio (Eupcalyptus Lignin – Sodium Bisulfite) And Initial Ph Towards Characteristcs Of Sodium Lignosulfonate Syahbirin, Gustini; Darwis, ABDUL Aziz; Suryani, Ani; Syafii, Wasrin
Journal of Agroindustrial Technology Vol 19, No 2 (2009): Jurnal Teknologi Industri Pertanian
Publisher : Department of Agroindustrial Technology, Bogor Agricultural University

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Eucalyptus lignin was isolated from kraft black liquor through by acidification using H2SO4. Sulfonation of eucalyptus lignin produced sodium lignosulfonate (SLS) which can be used as dispersants, and emulsifier. In this research, sulfonation was carried out towards lignin with mass ratio of eucalyptus lignin-NaHSO3 (b/b) of 1:0.4, 1:0.5, and 1:0.6, and initial pH of 5, 6, 7, 8. Studies on the effect of various ratio of eucalyptus lignin versus NaHSO3 (1 based on w/w) and initial pH of 5,6,and 7 for the sulfonation reaction showed an  increasing yield and improved purity of SLS obtained.  However, no significant result was observed on the application of initial pH  7 and 8 toward increasing of SLS yield and purity.  The highest SLS  yield of 83.8% with  purity of 82.9% was obtained under condition of initial pH at 7 and the mass ratio of eupcayptus lignin over NaHSO3 was 1:0.5.  The resulted SLS was light brown, water soluble, with  pH level between 6.3 and 7.24, and released sulfur-like odor.Key words: lignin, kraft black liquor,  sodium lignosulfonate.