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Peranan Serasah Terhadap Sumbangan N dan P pada Agroekosistem Kopi EVIZAL, RUSDI; TOHARI, TOHARI; PRIJAMBADA, IRFAN D.; WIDADA, JAKA
AGROTROP Vol. 2, No. 2 November 2012
Publisher : AGROTROP

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (71.575 KB)

Abstract

Litter is the main source of organic matter and nutrient entrance in shade grown coffee agroecosystems.Shade trees provide ecological and economic benefits in coffee agro-ecosystems thatindicate the key factor for sustainable coffee production. This study examined the role of litter onnutrient (N and P) returning in coffee agro-ecosystems. The experimental plots of Coffea canephorawere constucted at benchmark site of Conservation and Sustainable Management of Below-GroundBiodiversity (CSM-BGBD), in Sumberjaya Subdistrict, West Lampung, Indonesia, during 2007-2010.Types of shade trees to be examined were legume shade trees of Gliricidae sepium and Erythrinasububrams, non-legume tree of Michelia champaca, and no shade tree. The results showed that: (1)kind of shading determined litter productivity of coffee agro-ecosystems. Litter productivity of coffeeagro-ecosystems with shade trees increased coffee bean yield, (2) litter was an important source of Nand P that returned into the soil. Amount of nitrogen from litter biomass has linier effect on coffee beanyield.
Biochemical properties of crude extracellular proteases from Chromohalobacter salexigens BKL5 and Micrococcus luteus 11A Achmad, Ayu Ashari; Rohman, M. Saifur; Prijambada, Irfan D.
Indonesian Journal of Biotechnology Vol 21, No 1 (2016)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijbiotech.26705

Abstract

In this work, we have reported an enzymatic activity and biochemical properties of extracellular proteases from Chromohalobacter salexigens BKL5 and Micrococcus luteus 11A. C. salexigens BKL5 and M. luteus 11A were previously isolated from Bledug Kuwu mud volcano and dietary industry wastewater treatment, respectively. Both bacterial strains were able to produce extracellular proteases, when grown on minimal agar medium supplemented with 1% of skim milk. Proteolytic indexes of C. salexigens BKL5 and M. luteus 11A were 2.5±0.14 and 2.9±0.42, respectively. Both extracellular proteases exhibited optimum enzymatic activity at pH 7, with specific activity of C. salexigens BKL5 was 13.3% higher than that of M. luteus 11A. Optimum temperature for enzymatic activity of both proteases was 45°C. Metal cofactor preferences assay showed that extracellular protease from C. salexigens BKL5 preferred Zn2+, meanwhile extracellular protease from M. luteus 11A mainly preferred Ca2+ ion. Metal cofactor preferences assay also suggested that crude extracellular protease from C. salexigens BKL5 was categorized as metalloprotease, meanwhile crude extracellular protease of M. luteus 11A was common neutral protease. The enzymatic stability assay against various salt concentrations showed that crude extracellular protease from C. salexigens BKL5 was more stable than that of M. luteus 11A.
Pengaruh Campuran Onggok, Sekam, Pati dan Bahan Humat terhadap Pertumbuhan Aspergillus niger dan Kemampuannya dalam Melarutkan Fosfat Sastro, Yudi; Widianto, Donny; Prijambada, Irfan D.
Majalah Ilmiah Biologi BIOSFERA: A Scientific Journal Vol 23, No 3 (2006)
Publisher : Fakultas Biologi | Universitas Jenderal Soedirman

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.mib.2006.23.3.173

Abstract

The aims of this study were to investigate the effects of the mixture of tapioca waste, rice bran, starch (BOC), and humic substance (BH) on Aspergillus niger growth and its phosphate solubilizing capability. The experiment was conducted in Erlenmeyer flask containing 200 ml Pikovskaya liquid media and incubated on shaker with 100 rotaries per minute for nine days.  The Christmas Island phosphate rock was used as phosphate source.  Aspergillus niger YD 17 was taken from the Laboratory of Microbiology, Faculty of Agriculture, Gadjah Mada University. The experiment was arranged using factorial completely randomized design with three-replications (3x4x3). The level of BOC (i.e. 0, 2, and 4 g.l-1 media)   and BH   (i.e. 0, 1, 2, and 3 ml.l-1) were applied as experimental factors. Dry weight of mycelia and the soluble phosphate in media were parameters of Aspergillus niger growth. The results showed that BOC and BH increased the Aspergillus niger growth and its phosphate solubilizing capability (P£0.05). Four-gram of BOC and 3 ml of BH per litter of media were the best level for Aspergillus niger growth, while 4 g of BOC and 2 ml of BH was the best level for phosphorus solubilization capability.
ISOLASI DAN KARAKTERISASI BAKTERI PENDENITRIFIKASI YANG DIISOLASI DARI LUMPUR KAWASAN MANGROVE Triyanto, Triyanto; Isnansetyo, Alim; Prijambada, Irfan D.; Widada, Jaka; Kembaren, Duranta D.
Jurnal Perikanan Universitas Gadjah Mada Vol 10, No 1 (2008)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jfs.8912

Abstract

The aim of this research is to isolate denitrifying bacteria which have the highest activity to reduce nitrate. The sources of the denitrifying bacteria were mangrove sediment collected from Cilacap Regency, Central Java and Indramayu Regency, West Java. Basalt medium containing KNO3 as a source of nitrogen was used for isolating the denitrifying bacteria. Double layer agar was used for making anaerob condition. Fourty-one isolates were obtained at the first step of the isolation, 29 of them have nitrate reduction activity at a range of 0.77-95.62%. Three isolates, i.e. D19.2, DR2.1 and D27.3 having the highest activity were selected for further examination. The selected isolates were characterized and identified. Characterization includes colony and cell morphology, Gram staining, motility, spore staining and biochemical tests as catalase and oxidase. Identification was done by using profile matching to Bergey’s Manual of Determinative Bacteriology. The results indicate that isolate D19.2 and D27.3 have similarities to the characters of genus Listeria, whereas isolate DR2.1 has similarities to the characters of genus Propionibacterium. All of the selected isolates were able to grow in a medium having NaCl concentration at a range of 0.5-3.5% and pH range of 5-8. Observation of nitrate reduction ability of the isolates during five days incubation shows that isolate DR2.1 has the highest denitrifying activity. The selected isolates can be used as bioremediation agents for controlling nitrate pollution in brackish water pond.
ISOLASI, KARAKTERISASI DAN UJI INFEKSI BAKTERI PROTEOLITIK DARI LUMPUR KAWASAN HUTAN BAKAU Triyanto, Triyanto; Isnansetyo, Alim; Prijambada, Irfan D.; Widada, Jaka; Tarmiawati, Afi
Jurnal Perikanan Universitas Gadjah Mada Vol 11, No 1 (2009)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jfs.2966

Abstract

This research was aimed to isolate proteolytic bacteria that have high ability to hydrolize protein. The sources of bacterial samples were collected from mangrove sediment in Indramayu and Cilacap Regency. Collwel SWYE Modification Agar medium and Skim Milk Agar Medium, which contain pepton and casein, were used for isolating the bacteria. Forty isolates having proteolitic activity were obtained. Three isolates, i.e. Ps.23.1, Ps.27.3 and Ps.23.2, having the highest activity were selected. The selected isolates were able to grow at pH range of 5 to 8. They were also able to grow at NaCl concentration of 0.5-3.5%. Intramuscular injection test on white shrimp (Lithopenaeus vannamei) shows that Ps.23.1 and Ps.23.2 were not pathogenic to shrimp. On the other hand, Ps.27.3 was indicated to cause disease on shrimp. These results indicated that isolates Ps.23.1 and Ps.23.2 potentially can be used as inoculant for bioremedation of brackish water pond. Isolate Ps.23.1 was characterized to be an aerobic, nonmotile, short rod, gram negative bacteria having catalase and oxidase activities. It produced yellowish, circulair, entire colonies. Isolate Ps.23.2 was characterized to be an aerobic, motile, rod, spore forming, gram positive bacteria having catalase and oxidase activities.