Biopreservative nisin: its application to fishery products

The need for safe food products amid increasingly perceived widespread use of various foodadditives which are sometimes hazardous to health. Preservative is one of food additives intendedto extend the shelf life of food products. The preservative produced by lactic acid bacteria isbacteriocin. Nisin, one of bacteriocin produced by LAB Lactococcus lactis,is considered safeand allowed its use in many countries, including Indonesia. This preservative is widely used forfood products due to its ability in inhibiting bacteria, especially Gram-positive bacteria such asClostridium botulinum, Staphylococcus aureus, Streptococcus hemolyticus, Listeriamonocytogenes, Bacillus stearothermophilus, and Bacillus subtilis.Nisin works actively at lowpH and can be used singly or in combination with other preservation treatments. Based on itsphysico chemical properties and bioactivity, the use of nisin in fishery products is more suitable infermentation process as well as fish canned in acidic medium such as tomato sauce

PENGARUH DEASETILASI DAN ALKALINASI TERHADAP KARAKTERISTIK KARBOKSIMETIL KITOSAN

Carboxymethyl chitosan (CMCts) is one of the chitosan derivatives produced by the carboxymethylation process of chitosan. Compared to chitosan which is soluble in weak acid, the CMCts is soluble in water and it becomes more desirable in many applications both in pharmaceutical and food industries. Chitosan as the raw material of CMCts was made from chitin deacetylation. The reasearch aimed to study the effect of chitin deacetylation methods and concentrations of sodium hydroxide in the alkalination process on the characteristics of CMCts produced. Three deacetylation processes were applied in the production of chitosan, i.e. treatment with 60% NaOH at 70oC for 2 and 3 days, and treatment with 60% NaOH at ambient for 5 days. Whereas, the alkalination process was conducted using NaOH at the concentrations of 20, 30, 40 and 50%. The carboxymethylation of chitosan was carried out using monochloroacetic acid with the ratio of chitosan to monochloroacetic acid of 1 : 1.5 (w/w) at 50oC for an hour. The results showed that the CMCts produced had solubilitiy of 27.0 to 98,1% and viscosity of 28 to 265 cPs. Based on the solubility and viscosity, the best treatment was found on using chitosan which had been deacetylated with 60% NaOH at 70oC for 3 days followed by alkalination using NaOH of 30% before carboxymethylation. The treatment resulted CMCts with water solubility 98.1%, viscosity 265 cPs and yield 72.2%

PENGARUH KONSENTRASI ASAM MONOKLORO ASETAT DALAM PROSES KARBOKSIMETILASI KITOSAN TERHADAP KARBOKSIMETIL KITOSAN YANG DIHASILKAN

Percobaan pembuatan karboksimetil kitosan (CMCts) telah dilakukan dengan variasi jumlah asam monokloro asetat. Rasio kitosan : asam monokloro asetat yang digunakan selama eterifikasil:0,9; 1:1,1; 1:1,3 dan 1:1,5(b/b). Eterifikasi dilakukan pada suhu 90oC selama 4 jam. Hasil percobaan menunjukkan bahwa jumlah asam monokloro asetat sangat berpengaruhterhadap kualitas dan kuantitas CMCts yang dihasilkan

PENGARUH JUMLAH MONOKLORO ASETAT TERHADAP KARAKTERISTIK KARBOKSIMETIL KITOSAN DARI KITOSAN CANGKANG DAN KAKI RAJUNGAN

Riset ini bertujuan untuk mengetahui pengaruh jenis limbah raiungan cangkang/punggung dan kaki) sebagai bahan baku kitosan dan rasio kitosan-monokloro asetat pada proses karboksimetilasi terhadap karakteristik karboksimetil kitosan yang dihasilkan

Identification of Protease-Producing Bacteria Isolated from Banyuwedang, Bali, and Characterization of its Protease

Proteases or peptidases is known as a largest group of hydrolytic enzymes and have been applied in various industries such as food, pharmacy, leather, detergent and waste treatment. Although they are also produced by plants and animals, microbes remain the main source of proteases in the world market which mostly derived from Bacillus sp. Aims of this research were to identify isolate BII-1 and study its protease. Analysis of 16Sr RNA sequencing showed the identity of BII-1 as Bacillus subtilis (99% similarity with the same species in GenBank). It was found that protease from BII-1 exhibited optimal temperature and pH of 50 oC and 8-9, respectively. It was activated by Li2+, Na2+, Mg2+ and K+. The degenerated primer for protease gene was designed, and a partial protease gene was amplified from BII-1. The sequencing result showed that this amplified gene shared 100 and 99% similarity with those from Geobacillus thermophiles and Bacillus subtilis in the GenBank, respectively. Keywords: protease, bacteria, Bacillus subtilis, Geobacillus thermophylu

Identification of SGS 1609 Cellulolytic Bacteria Isolated from Sargassum spec. and Characterization of The Cellulase Produced

Bacterial isolate from seaweed designated as SGS 1609 was previously found to be able to produce cellulase represented by formation of clear zone on solid medium containing carboxymethylcellulose (CMC). This research was conducted to identify the isolate and determine optimum production time as well as characterize the cellulase produced. The isolate was identified using  16s-rRNA gene analysis. Cellulase production was conducted by cultivating the isolate in the liquid medium containing CMC followed by centrifuging to get supernatant as the crude enzyme. The enzyme was then concentrated using ammonium sulfate precipitation and ultra filtration. The concentrated enzyme having higher activity produced from the concentration process was then characterized  to determine its optimum pH and temperature, heat stabilization, metal ions effect and substrate specificity. The result showed that the SGS 1609 isolate was identified as Serratia marcescens with 99%  similarity. The isolate produced cellulase optimally at 4 days incubation. Ultra filtration produced higher enzyme activity compared to NH4-sulfate precipitation. The enzyme concentrated by ultra filtration worked optimally at the  pH of 7, temperature of 50 oC, stable at the temperature of 60 oC for 240 minutes and was increased its activity by Ca2+ and Mg2+ ions. On the other hand, the enzyme was inhibited by Fe3+, Zn2+ and Na+ ions, but was not relatively affected by K+ and EDTA. The use of conventional agar producer waste  treated with 6% NaOH gave highest activity compared to other substrates

Food additives and effect of thickness on fish crackers quality

Investigation on the effects of the use of 0.2% food additives (sodium bicarbonate, sodium polyphosphate and ammonium bicarbonate) on the cracker quality has been conducted. Crackers were made from sago and fortified with 25% offish meat (Congresox talabon). Cracker thickness studied were 2, 3 and 4 mm. The cracker quality was evaluated in terms of expansion volume and crispiness. The results showed that crackers with sodium bicarbonate addition and 2 mm thickness had the highest volumetric expansion and crispiness followed by sodium polyphosphate and ammonium bicarbonate

Chemical Composition and Fatty Acid Profile of Some Indonesian Sea Cucumbers

Indonesia has a great sea cucumber resource which is useful as functional food. Even though much information about the biopotency of sea cucumbers have been published, however, studies on nutrition value of Indonesian sea cucumbers are still beneficial due to the great diversity and uniqueness of each species. The present work was  intended to obtain information about chemical composition and fatty acid profile of 4 (four) types of sea cucumbers which are frequently found in Halmahera water, North Maluku (Molucca),  one  of  sea  cucumbers  producing area  in Indonesia. The samples coded as  H-03, H-04, H-05 and H-10, were identified as Bohadschia  argus, Holothuria  fuscogilva, Thelenota  ananas, and Actinophyga lecanora. All sea cucumbers showed high protein content, more than 60% (drybase/db), except for T. ananas which had the lowest protein content (48.26% db). As for fats, T. ananas showed the highest amount (2.35%db) with dominated saturated fatty acids (SFA). On the other side, A. lecanora showed higher value of PUFA compared to SFA and MUFA.  Palmitic acid (C16:0) was the most abundant SFA in the most samples with the amount of 0.49–4.9 mg/g sample. Among PUFA, eicosapentaenoic acid/EPA (C20:5n3) was detected, and eicosatrienoic acid (C20:3n6) was relatively higher than the others. The ratio of w6/w3 fatty acid was 1.2–3.2 showing that total w6 fatty acid was higher than total w3 fatty acid. However, this value is safe enough to protect against chronic and degenerative diseases

Penapisan dan Identifikasi Bakteri Penghasil Agarase dari Sampel Sedimen Laut Bara Caddi, Sulawesi Selatan

Agarase adalah enzim yang mampu menghidrolisis agar menjadi oligoagar yang sudah banyak diaplikasikan dalam industri kesehatan dan kosmetik. Bakteri laut merupakan mikroba yang paling banyak dilaporkan sebagai sumber untuk isolasi bakteri penghasil agarase. Penelitian ini bertujuan untuk melakukan penapisan, isolasi, dan identifikasi bakteri penghasil agarase dari sedimen laut. Sampel sedimen diambil dari pantai Pulau Bara Caddi, Sulawesi Selatan. Penapisan dilakukan menggunakan media air laut yang ditambahkan tripton 0,5%, ekstrak ragi 0,1%, dan agar 2%. Identifikasi dilakukan dengan amplifikasi gen 16S rRNA. Sebanyak 45 isolat berhasil dimurnikan, 16 diantaranya merupakan bakteri penghasil agarase. Pola zona bening yang terbentuk terlihat berbeda-beda, hal ini diduga disebabkan oleh perbedaan jenis agarase yang dihasilkan oleh masing-masing isolat. Hasil penelitian menunjukkan bahwa terdapat 4 genera bakteri yang memiliki kemiripan yang tinggi dengan 16 isolat bakteri penghasil agarase yang terdapat pada sampel sedimen yaitu Vibrio, Alteromonas, Salinivibrio, dan Marinobacter. Vibrio merupakan genus yang paling dominan diikuti oleh Alteromonas dan hanya satu isolat yang menunjukkan kesamaan dengan Salinivibrio dan Marinobacter. ABSTRACT Agarase is an enzyme that hydrolyze agar into agaro oligosaccharide which have been applied in health and cosmetic industries. Marine bacteria are the most widely reported microbes as a source for isolation of agarase-producing bacteria. This work was aimed to screen, isolate, and identify the agarase-producing bacteria from marine sediment. The sediment samples were collected from the sea around Bara Caddi Island, South Sulawesi. The screening of agarase-producing bacteria was carried out using seawater media containing 0.5% tryptone, 0.1 % yeast extract with 2 % agar. The identification of the bacteria obtained was carried out by amplification of the 16S rRNA gene. A total of 45 isolates were successfully purified, 16 of which were agarase-producing bacteria. The clear zone formed on solid medium by some isolates showed different pattern which may be caused by the type of agarase produced by each isolate. The results showed that there were 4 genera of bacteria which similar to the 16 isolates agarase-producing bacteria found in sediment samples i.e. Vibrio, Alteromonas, Salinivibrio, and Marinobacter. Vibrio is the most dominant genus followed by Alteromonas and only one isolate showed similarity to Salinivibrio and Marinobacter

Bacterial Diversity of a Microbial Mat from Hot Spring at Wartawan Beach, Lampung and Its Potential as a Source of Hydrogenases

Biohydrogen produced from thermophilic hydrogenases is an ideal and clean energy sources. As the biggest tectonic area in the world, Indonesia is potential for thermophile isolation. The aims of this study were to analyze the bacterial diversity of a microbial mat from hot spring at Wartawan beach, Lampung and to analyze the potency of microbial mat for hydrogenases, using clone library method. The diversity of 16S rRNA showed that the microbial mat sample contained 9 phyla of bacteria, and dominated by Cyanobacteria and Proteobacteria. These phyla indicate that the bacterial community of the microbial mat consisted of phototrophic and heterotrophic groups. In addition, a microbial mat of Wartawan beach environment might be influenced by marine environment and hydrothermal vent which was indicated by detection of both associated bacteria. The diversity of hydrogenase genes using NiFe hydrogenase (NiFe) and FeFe hydrogenase (FeFe) genes showed that Cyanobacteria was specifically related to NiFe, while Firmicutes was associated with FeFe. Proteobacteria and Bacteroidetes, however, were detected for both genes. The detected hydrogenase genes indicate that the microbial mat from hot spring at Wartawan beach is a promising source for hydrogenases isolation and further applications for biohydrogen production as a renewable energy