Vol. 17 No. 4 (2010): December 2010

The excessive number of free radicals in human body could increase lipid peroxides and causes a variety of degenerative diseases. Piper crocatum is a plant containing natural chemicals that may have an antioxidant ability to inhibit fatty acid oxidation and reduce free radicals, however, there is no published scientific reports up to now. Therefore, the objective of this research is to study the ability of ethanol extract of P. crocatum as an antioxidant. The leaves of P. crocatum (25 g) were extracted with 100 ml of 70% ethanol. Antioxidant activity was measured by thiobarbituric acid method and compared with 2,2-diphenil-1-picryl hydrazyl method with α-tocopherol as the standard antioxidant. The results showed that the extract of 200 ppm inhibited fatty acids oxidation by 80.40% and IC50 for free radical scavenging was 85.82 ppm. There was no significant different (α = 0.05) inhibition of unsaturated fatty acids oxidation between the sample and α-tocopherol at 200 ppm. This study suggested that the leaves extract of P. crocatum has a potential natural antioxidant.

Bioremediation of petroleum sludge was conducted by using land-farming method in micro scale and by applying an indigenous bacteria Bacillus megaterium. The samples were from PT. Pertamina Musi Banyuasin district of South Sumatra. The research aim was to evaluate the performance of the bacteria in degrading petroleum sludge. The rate of the biodegradation process was determined by using differential method and the data analyses show that the reaction order is 0.74. Then, the rate of biodegradation constant was determined by using an integral method assuming that the biodegradation process was a first reaction order. From the calculation, it was revealed that the biodegradation reaction constant was 0.0204/day. The bioremediation-kinetics model is y = -0.0204X + 2.0365, and by using this model the bioremediation process could be ended after 99.83 days. The qualitative analysis was carried out by using GC-MS to investigate the components of compounds changed during the bioremediation process. The results show that the B. megaterium could degrade 99.32% of alkane compounds.

Huge areas of diverse tropical forest are lost or degraded every year with dramatic consequences for biodiversity. Human activities such as deforestation, fragmentation, over-exploitation, and monoculture practices are the main drivers of tropical forest biodiversity loss.  Investigating of these threats with focusses on changes in species richness or species diversity will be able to minimize any impact of human activities at the early stage in a certain region. Therefore, to know the impact of human activities to dynamic of insect communities in Gunung Salak, West Java, we measured moth diversity and their structure within communities by comparing the index diversity, species richness and species composition across five different habitat types. The results showed that the habitat changes due to human activities had changed not only to the moth diversity but also to their structure within communities. The number of moth species decreased significantly as well as the number of lower taxa (family) in the disturbed forest (secondary forest, Agathis forest, and transition area) within ranges: 20-50 and 10-20%.  The composition of the two main families, Geometridae and Noctuidae also showed a major change, family Geometridae decreased within ranges 10-50% in the disturbed area but Noctuidae increased up to 50% in those areas. Indeed, habitat lost due to human activities such as illegal logging, change of land use and land clearing is the main threats to decrease on macro-moth diversity and change their structures within communities.

Genotype identification of Sengon (Paraseriathes falcataria (L.) Nielsen needs accurate and reliable method for identification. Sixteen individuals of P. falcataria from Okinawa, Japan were used as materials for selecting polymorphic RAPD fragments and for developing SCAR marker whereas confirmation of polymorphisms of the SCARs was conducted using 24 materials from Candiroto Seed Orchard, Indonesia. Forty-eight polymorphic fragments were obtained from screening in 288 RAPD primers. Forty-six out of 48 SCAR primers were successfully developed. Examination of the newly-designed of SCAR primer using 24 P. falcataria from Candiroto Seed Orchard, Indonesia found 5 polymorphic SCAR primers. These five SCARs are considered as useful marker for genotype and clone identification within P. falcataria.

Three isolates among 138 sponge-associated bacteria were isolated from Waigeo Island, Raja Ampat West Papua Province, Indonesia, have been shown protease inhibitory activity against subtilisin (serine protease), thermolysin (metalloprotease), and crude extract from pathogenic bacteria (Eschericia coli enteropathogenic/EPEC K.1.1, Staphylococcus aureus, and Pseudomonas aeruginosa). Those three isolates were designated as sponge associated bacteria SAB S-12, SAB S-21, and SAB S-17. A simple casein and Sea Water Complete (SWC) double layer agar method was used to screen the bacteria against pathogenic bacteria producing protease, i.e. EPEC K.1.1, S. aureus, and P. aeruginosa. Among them, SAB S-12 isolate showed no inhibitory zone indicated. The isolate had the highest inhibitory activity against subtilisin and crude extract enzyme of pathogenic bacteria, the inhibitory activity was 91.6 and 98.9%, respectively. In addition, the SAB S-21 isolate had the highest inhibitory activity against thermolysin, it was 70.4%. The optimum pH and temperature for protease inhibition of the three isolates was at pH 7.0-8.0 and 40-50 oC respectively. Based on 16S rRNA gene sequence, the closest related with SAB S-12, SAB-17, and SAB-21 isolates was Providencia sp. (92% identity), Paracoccus sp. (86% identity), and Bacillus sp. (% identity), respectively.

Cinchona alkaloids are in extensive uses, not only for drugs but also for soft drink industries. They are harvested from the bark of trees Cinchona spp. after certain ages and therefore are available over a limited time. Cell culture is an alternative way to continuously produce such secondary metabolites in a much shorter time. Various substances were added in the normal growth media to promote quinoline alkaloids production by cell cultures of Cinchona ledgeriana. At the sixth week of culture, quinine and cinchonine contents were suppressed by paclobutrazol (PBZ), abscisic acid (ABA), or even by precursor tryptophan, while cinchonidine content was enhanced by 0.2 mg/l tryptophan to 43 fold of that produced by untreated cells (2.8% dry weight). At the seventh week of culture, the production of quinine and quinidine started to grow whereas the production of cinchonine and cinchonidine tended to decrease. An addition of 5 mg/l PBZ to culture media yielded the highest level of total quinine/quinidine after seven weeks, e.g. quinine 11 times more abundant and quinidine 23 fold higher compared to the untreated cells. Particularly the level of quinine which is the most demanded for medical and industrial purposes still need to be improved to approach to or even higher than that of extracted from the conventional source.

One method to obtain genetic information is the diallel cross analysis. The objective of this study was to eavluate the genetic parameters of six inbred pepper (Capsicum annuum L.) using full diallel crosses. The experiment was conducted at IPB Experiment Field, Cikabayan, Darmaga. The design was randomized complete block design (RCBD) using three replications as blocks. Data from generation F1 and parents were analyzed using the Hayman Method. Results indicated that no epistatic effects were significant for all the traits assessed. Additive genetic effects were larger than the dominant effects for yield per plant, fruit length, and  diameter fruit traits. Dominant genetic effects were larger than the additive effects for fruit weight traits. Narrow-sense and broad-sense heritability were high for all the traits assessed. The character of the yield per plant, fruit weight and fruit diameter shows that there were more dominant genes in the parents. There were more recessive genes in parents for the fruit length character. IPB C7 parent was the most recessive genes containing control characters in the yield per plant. In the new improved varieties of high yielding, IPB C7 could be crossed with IPB C9. Employing individual or mass selection breeding should be successful in developing high-productivity lines in this population.

A xylanase gene, xynA, has been cloned from thermophilic strain Geobacillus stearothermophilus, which was isolated from marine Tanjung Api, Indonesia. The polymerase chain reaction product of 1266 bp of xynA gene consisted of 1221 bp open reading frame and encoded 407 amino acids including 30 residues of signal peptide. The sequence exhibited highest identity of 98.7% in the level of amino acid, with an extracellular endo-1,4-β-xylanase from G. stearothermophilus T-6 (E-GSX T-6) of the glycoside hydrolase family 10 (GH10). A comparative study between the local strain G. stearothermophilus (GSX L) and E-GSX T-6 on homology of amino acid sequence indicated five differents amino acids in the gene. They were Threonine/Alanine (T/A), Asparagine/Aspartate (N/D), Lysine/Asparagine (K/N), Isoleucine/Methionine (I/M), Serine/Threonine (S/T) at the position 220, 227, 228, 233, and 245, respectively. Protein structural analysis of those differences suggested that those amino acids may play role in biochemical properties such as enzyme stability, in particular its thermostability.

High utilization of fossil fuel increases the level of carbon dioxide in the atmosphere and results in global warming phenomenon. These things establish the world’s thought to look for the other alternative energy that can reduce the use of fossil fuel even to be replaced by the substitute. Recently, Indonesia has been doing the research of microalgae as a feedstock of an alternative biofuel. Fatty acid content that microalgae have is also high to produce biofuel. The steps used in this research is a 7 days cultivation, harvesting, extraction using hexane, and fatty acid identification using Gas Chromatography of microalgae species. Fatty acid component in some species such as Chlorella sp., Scenedesmus sp., Nannochloropsis sp., and Isochrysis sp. is between 0.21-29.5%; 0.11-25.16%; 0.30-42.32%; 2.06-37.63%, respectively, based on dry weight calculation. The high content of fatty acid in some species of microalgae showed the potential to be the feedstock of producing biofuel in overcoming the limited utilization from petroleum (fossil fuel) presently.