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Screening for Natural Producers Capable of Producing 1,3-Propanediol from Glycerol Andriani, Dian; Kusharyoto, Wien; Prasetya, Bambang; Willke, Thomas; Vorlop, Klaus Dieter
Annales Bogorienses Vol. 14 No. 1 (2010): Annales Bogorienses
Publisher : BRIN

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Abstract

Glycerol is a renewable resource found as the main by-product in the transesterification of triglycerides and fat saponification. Due to the increased production of plant oils, especially palm oil in developing countries, and their larger use by the oleochemical industry, glycerol surpluses are on the world market and this may result in a decrease in glycerol price. As a consequence, biotechnological processes have been developed to convert this substrate into value-added products, such as 1,3-propanediol (1,3-PD). The microbial production of 1,3-PD could be competitive to chemical routes assuming that it is based on cheap raw material and an optimised process. In the screening for 1,3 PD–producing bacteria, raw glycerol as by-product from rapeseed oil processing unit was used as a carbon source compared with commercial glycerol. By using increasing concentration of both glycerols from 50 to 150 g/l, two potential bacteria were obtained from soil samples. BMP-1 was obtained from an enrichment culture using 50 g/l commercial glycerol, while BMR-1 was obtained from an enrichment culture using 100 g/l raw glycerol. The highest conversion yield obtained using the isolate BMP-1 was around 0.62 g 1,3-PD formed per mol glycerol consumed, and 0.73 mol 1,3-PD formed per mol glycerol using the isolate BMR-1. No bacteria were obtained from cultures using 150 g/l commercial and raw glycerol, respectively, which indicated that higher concentration of glycerol has inhibition effect. 
Optimization of Culture Conditions for Production of β-Mannanase by Strain Nonomuraea sp. ID06-379 using Submerged Substrate Fermentation Ratnakomala, Shanti; Yopi, Yopi; Suhartono, Maggy Thenawidjaja; Meryandini, Anja; Prasetya, Bambang
Annales Bogorienses Vol. 18 No. 2 (2014): Annales Bogorienses
Publisher : BRIN

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Abstract

The objective of this study was to investigate the effect of media compositions on the production of β-mannanase by Nonomuraea sp. ID06-379. The study was focused on the influence of carbon, nitrogen, phosphorus and detergents on β-mannanase synthesis through manipulating media compositions on production medium. The results indicated that for carbon sources, locus bean gum (0.745 ± 0.036 U/ml) showed maximum mannanase activity. Malt extract was the best nitrogen source for producing β-mannanase (1.075 ± 0.006 U/ml), (NH4)2HPO4 as phosphate source (1.733 ± 0.026 U/ml) and Tween 80 (1.145 ± 0.003 U/ml) as surfactants effect on increasing permeability of bacterial cell membrane, enhancing membrane transport and excretion of extracellular enzymes into the production media. The results showed that 1% malt extract, 0.5% locus bean gum and 0.05% (NH4)2HPO4 were good substances for nitrogen source, carbon source and phosphate respectively. The highest production of β-mannanase by Nonomuraea sp. ID06-379 (5.33 U/mg) was reached in the medium optimization (Vogel’s minimal medium) contained the following ingredients: 0.5% locus bean gum, 1% malt extract and 0.05% (NH4)2HPO4, under submerged fermentation with shaking at 120 rpm and 28C for 2 days incubation.
Fiber Disruption of Betung Bamboo (Dendrocalamus asper) by Combined Fungal and Microwave Pretreatment Fatriasari, Widya; Syafii, Wasrin; Wistara, Nyoman; Syamsu, Khaswar; Prasetya, Bambang; Anita, S Heris; Risanto, Lucky
BIOTROPIA Vol. 22 No. 2 (2015): BIOTROPIA Vol. 22 No. 2 December 2015
Publisher : SEAMEO BIOTROP

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1200.375 KB) | DOI: 10.11598/btb.2015.22.2.363

Abstract

Combined microwave pretreatment is an effective method to modify carbohydrate and lignin structures of fungal and lignocellulosic materials, thereby improving the hydrolysis process for bioethanol conversion. This study aimed to evaluate the structural changes in carbohydrate and lignin components of betung bamboo following a combined biological–microwave pretreatment. Based on previous findings, a 30-day incubation using 5% and 10% (w/v) inoculum loading of the white-rot fungus Trametes versicolor—which showed the highest delignification selectivity—was selected as the fungal pretreatment. Microwave irradiation was then applied for 5, 10, and 12.5 minutes at 330 W. Characterization of structural changes was conducted using FTIR spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). FTIR analysis revealed that the combined pretreatment affected only the intensity of absorption bands without altering the functional groups. A decline in peak intensity occurred at 1,736 cm⁻¹ (C=O in xylan), 1,373 cm⁻¹ (C–H deformation in cellulose and hemicellulose), 1,165 cm⁻¹ (C–O–C vibration in cellulose and hemicellulose), and 895 cm⁻¹ (β-glycosidic linkage in cellulose). The pretreatment reduced hydrogen bonding in cellulose and weakened lignin–carbohydrate linkages associated with bamboo cellulose crystallinity. A slight increase in crystallinity index was observed due to cleavage of the amorphous fraction. SEM imaging confirmed the disruption of fiber structure, showing increasing degradation with longer microwave exposure durations.