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Articles by issue : Vol 7, No 2 (2013): June 2013
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Articles
Selection of Methods for Microbiological Extraction of Chitin from Shrimp Shells

JUNIANTO, JUNIANTO, WAHYUNTARI, BUDIASIH, SETYAHADI, SISWA

Microbiology Indonesia Vol 7, No 2 (2013): June 2013
Publisher : Indonesian Society for microbiology

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Abstract

Chitin extraction from shrimp shells involves two processing steps that are demineralization followed by deproteination process. Lactobacillus acidophilus FNCC 116 and Bacillus licheniformis F11.1 were used in demineralization and deproteination respectively. The overall objectives of this experiment were to determine fermentation systems which resulted in the highest mineral and protein removal. The demineralization experiments consisted of three different batch fermentation designs: batch fermentation (Am ); subsequent batch fermentation 1, in which 100% medium was replaced with fresh medium after 24 h fermentation (Bm ); and subsequent batch fermentation 2, in which 50% medium was replaced with the same amount of fresh medium after 24 h fermentation (Cm ). The demineralization was conducted at 30±2 °C, 50 rpm for 60 h. The deproteination experiments consisted of 3 different batch fermentation designs: batch fermentation 1, inoculum was added once at the beginning of the fermentation (A p); batch fermentation 2, inoculum was added twice, at the beginning and after 24 h fermentation (Bp ); and subsequent batch fermentation, 100% medium was replaced with fresh medium after 24 h fermentation (Cp ). The deproteination was carried out at 55 °C, pH 7.8-8.0, aeration 2.3 vvm, and agitation 275 rpm for 96 h. The experimental results showed that in the demineralization process, fermentation design B gave the highest ash removal. Ash removed in the fermentation design A , B , and C was 97.19, 99.69, and 97.69%, respectively. The protein removed in the fermentation design A , B , and C was 94.42, 94.51, and 95.37%, respectively.

Enzymatic and Acid Hydrolysis of Sago Starch for Preparation of Ethanol Production

SUNARYANTO, ROFIQ ( Center of Biotechnology BPPT, Kawasan PUSPIPTEK Serpong, Tangerang Selatan 15314,Banten , Indonesia ) , HANDAYANI, BERTI HARIASIH ( Deparment of Biology, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Jalan Raya Bandung- Sumedang KM 21 Jatinangor , Sumedang 45363, West Java, Indonesia ) , SAFITRI, RATU ( Deparment of Biology, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Jalan Raya Bandung- Sumedang KM 21 Jatinangor , Sumedang 45363, West Java, Indonesia )

Microbiology Indonesia Vol 7, No 2 (2013): June 2013
Publisher : Indonesian Society for microbiology

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Abstract

A series of studies on the hydrolysis of Sago starch for ethanol fermentation had been conducted. Hydrolysis of sago starch was carried out using sulfuric acid 2.5% and amylase(s) enzymes. The concentrations of sago starch used in this experiment were  5, 10, 15, 20, and 30% (w/v). The highest hydrolyzate  containing reducing sugar was used as substrate for ethanol fermentation by Saccharomyces cerevisiae FNCC 3012. The results indicated  that hydrolysis using 2.5% sulfuric acid for 120 min at 121 °C produced 6.6%  (w/v)  reducing sugar and hydrolysis using α-amylase and Dextrozyme DX produced more reducing sugar, 7% (w/v) and 17.1% (w/v), respectively. The fermentation of hydrolyzed sago starch by S. cerevisiae FNCC 3012 produced ethanol 7.98% (v/v).

Mutagenic Improvement of Xylanase Production from Xylanolytic Bacteria and its Phylogenetic Analysis

HANIM, CHUSNUL, YUSIATI, LIES MIRA, CAHYANTO, MUHAMMAD NUR, WIBOWO, ALI

Microbiology Indonesia Vol 7, No 2 (2013): June 2013
Publisher : Indonesian Society for microbiology

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Abstract

This study was conducted to obtain xylanolytic mutants that have higher xylanase activity than their wildtype counterparts. A mutant with the best xylanolytic activity was selected and identified based on its 16S rRNA sequence. Its optimum growth condition was also characterized and its phylogenetic relations to other xylanolytic bacteria were analzsed. Wild type xylanolytic alkalophlic bacteria were grown in medium containing xylan as a substrate. Mutation was performed using ethidium bromide (EtBr) or ethyl methanesulfonate (EMS) atconcentrations 50, 100, and 150 mg mL-1 and times of exposure 30, 60, 90, and 120 min for each treatment. Twenty two mutants were obtained from EtBr and 24 mutants from EMS mutageneses. The mutants were analyzed for their capability to secrete xylanase into xylan medium containing xylose or glucose or glycerol. Growth optimizations of the mutant were done in media with pH range 6-11 and temperature range 30 to 60 °C. Mutant number 19, which was obtained by treatment using 50 mg mL-1 EMS for 120 min, had the highest xylanase activity (15.057 U g-1). This activity was obtained at optimum growth conditions: pH 9.5 and temperature 55 °C. Chromosomal DNA of this mutant was extracted and amplified by PCR using 16S rRNA gene specific primers. The amplified fragments were sequenced by dideoxynucleotide chain terminator method. The phylogenetic analysis based on 16S rRNA gene sequence showed that mutant 19 was closed to an anaerobic xylanase producing bacteria.

Nitrous Oxide Reduction Activity of Denitrifying Ochrobactrum anthropi Isolated from Rice Field

SETYANINGSIH, RATNA ( Department of Biology, Faculty of Mathematics and Natural Sciences, Universitas Sebelas Maret, Jalan Ir Sutami 36A Kentingan, Surakarta 57126, Indonesia ) , RUSMANA, IMAN ( Department of Biology, Faculty of Mathematics and Natural Sciences, Institut Pertanian Bogor, Darmaga Campus, Bogor 16680, Indonesia ) , SETYANTO, PRIHASTO ( Balai Penelitian Lingkungan Pertanian, Jalan Jakenan-Jaken Km 05, Jakenan, Pati 59182, Indonesia ) , SUWANTO, ANTONIUS ( Department of Biology, Faculty of Mathematics and Natural Sciences, Institut Pertanian Bogor, Darmaga Campus, Bogor 16680, Indonesia )

Microbiology Indonesia Vol 7, No 2 (2013): June 2013
Publisher : Indonesian Society for microbiology

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Abstract

Nitrous oxide (N2O) is one of the principal greenhouse gases. Differences in soil microbial community composition affect N2O emission. Ochrobactrum anthropi BL1 and BLN1 isolated from rice field in Tangerang, Banten, Indonesia can grow on and reduce N2O.  This study investigated  the patterns of N2O reduction activity and growth of O. anthropi BL1 and BLN1 on denitrification media and also examined the ability of BLN1 strain to reduce N2O in flooded rice soil. Nitrous oxide reduction activity and growth of strains BL1 and BLN1 occurred simultaneously, indicating that the bacteria used N2O for growth. BL1 and BLN1 showed the same specific growth rate, but the N2O reduction rate of BLN1 was higher than that of BL1. Increase of the N2O concentration in the surface water of flooded soil without BLN1 isolate six hours after the addition of NO3- was significantly greater than the surface water from soil that had been inoculated with the isolate.

Cloning and Expression of Serotype-2 Simian Betaretrovirus Reverse Transcriptase Gene Isolated from Indonesian Cynomolgus Monkey in Escherichia coli

SAEPULOH, UUS ( PRC IPB ) , ISKANDRIATI, DIAH, HOETAMA, FUNGKEY, MARIYA, SELA SEPTIMA, SOLIHIN, DEDY DURYADI, PAMUNGKAS, JOKO, SAJUTHI, DONDIN

Microbiology Indonesia Vol 7, No 2 (2013): June 2013
Publisher : Indonesian Society for microbiology

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Abstract

In this study, we isolated the simian betaretrovirus serotype-2 (SRV-2) reverse transcriptase (RT) gene from infected Indonesian cynomolgus monkey (Macaca fascicularis). The gene was then cloned in Escherichia coli expression system. The SRV-2 RT gene is located between nucleotides 3284-4925 in the polyprotein (Pol) region encodes 547 amino acids. Analysis of expression using SDS-PAGE and western blot techniques showed a specific band of 64.9 kDa, indicating SRV-2 RT recombinant enzyme. Purification of SRV-2 RT recombinant enzyme produced 312 μg mL-1 protein with 7.1 U μL-1 enzyme activities. Application of this recombinant enzyme in reverse transcription-PCR (RT-PCR) of β-globin and β-actin genes produced DNA fragments of 206 and 350 bp, indicating amplification of β-globin and β-actin genes, respectively. Therefore, the expressed SRV-2 RT enzyme was proven to be functional, although the activity was low.