Iman Rusmana

Use of chlorate as a selective inhibitor to distinguish membrane‐bound nitrate reductase (Nar) and periplasmic nitrate reductase (Nap) of dissimilative nitrate reducing bacteria in sediment

The use of chlorate as a selective inhibitor of dissimilative nitrate reduction was studied using pure cultures of Comamonas testosteroni (a denitrifier) and Klebsiella pneumoniae (a nitrate-ammonifier) isolated from estuarine sediment, and in sediment slurry. Pure culture experiments demonstrated that chlorate selectively inhibited membrane-bound nitrate reductase (Nar) activity, probably by blocking nitrate transporters (NarK). Sediment slurry experiments showed that chlorate inhibited nitrate reduction and N(2)O formation, but did not inhibit nitrite reduction and its N(2)O formation, indicating that chlorate selectively inhibited only the first step of nitrate reduction. Chlorite chemically oxidized nitrite to nitrate and could not be used as a selective inhibitor of nitrite metabolism, although chlorite apparently selectively inhibited formation of N(2)O from nitrite. Chlorate can be used as a specific inhibitor to distinguish between nitrate reduction by Nap or Nar in natural communities of microorganisms.

Fermentation Characteristics and Microbial Diversity of Tropical Grass-legumes Silages

Calliandra calothyrsus preserved in silage is an alternative method for improving the crude protein content of feeds for sustainable ruminant production. The aim of this research was to evaluate the quality of silage which contained different levels of C. calothyrsus by examining the fermentation characteristics and microbial diversity. Silage was made in a completely randomized design consisting of five treatments with three replications i.e.: R0, Pennisetum purpureum 100%; R1, P. purpureum 75%+C. calothyrsus 25%;, R2, P. purpureum 50%+C. calothyrsus 50%; R3, P. purpureum 25%+C. calothyrsus 75%; and R4, C. calothyrsus 100%. All silages were prepared using plastic jar silos (600 g) and incubated at room temperature for 30 days. Silages were analyzed for fermentation characteristics and microbial diversity. Increased levels of C. calothyrsus in silage had a significant effect (p<0.01) on the fermentation characteristics. The microbial diversity index decreased and activity was inhibited with increasing levels of C. calothyrsus. The microbial community indicated that there was a population of Lactobacillus plantarum, L. casei, L. brevis, Lactococcus lactis, Chryseobacterium sp., and uncultured bacteria. The result confirmed that silage with a combination of grass and C. calothyrsus had good fermentation characteristics and microbial communities were dominated by L. plantarum.

Bacteria as Greenhouse Gases Reducing Agents from Paddy Plantation

Betel nut ( Areca catechu ) was proven to have antihyperglycemic activity through increased PI3K pathway in the GLUT4 translocation in cells. However, research on the ethanol extract of betel nut in Indonesia is still limited. The main problem in this study was whether the ethanol extract of betel nut could improve glucose tolerance in a two-hour postprandial period and whether the ethanol extract of betel nut could induce GLUT4 translocation in skeletal muscle cells of mice induced hyperglycemia. Glucose tolerance test results showed that treatment of the ethanol extract of betel nut for 24 days with all doses tested: P50,100,150,200 and 250 mg/kg body weight could improve glucose tolerance in a two-hour postprandial period. The protein electrophoresis of that fasting and one hour postprandial state treatments resulted an increase in GLUT4/βActin density ratio of P250 group compared to negative and positive controls. In this case, GLUT4/βActin density ratio of P100,P200 and P250 were higher than that GLUT4/βActin density ratio of P50 and P150. Increased in GLUT4/βActin density ratio showed enhancement of the GLUT4 in skeletal muscle cells in fasting and one hour postprandial state after treated with ethanol extract of betel nut.Indonesia is one of the largest pepper producing countries in the world. One of the pepper-producing provinces in Indonesia is the Bangka Belitung Islands (Babel). However, the infection of Radopholus similis and Meloidogyne spp. which causes yellow disease becomes one of obstacles in pepper cultivation in Babel. Thus, alternative solution to overcome this yellow disease is by reducing the amount of nematode inoculum of R. similis and Meloidogyne spp. in soil. This study aimed to determine the effectiveness of the infusion of oyster mushrooms baglog waste enriched with molasses to control the population of R. similis and Meloidogyne spp. and to increase the population of rhizobacteria. Infusion of oyster mushrooms baglog waste was mixed with 1% of molasses and was poured into soil obtained from the pepper plant roots. The concentrations used were 10%, 20%, 30% and 50%. Population of phytonematode, rhizobacteria, proteolytic bacteria, and group of fluorescence bacteria were calculated before and 7 days after treatment. Results showed that the populations of R. similis and Meloidogyne spp. in the soil poured with the influsion of oyster mushroom baglog waste decreased by 29.11% ( R. similis ) and 24.61% ( Meloidogyne spp. ), compared to the before and control treatments. The suppression of nematode population was found to be the highest in the influsion treatment at concentration of 50%. Overall, treatment of all concentrations succeeded to increase the population of rhizobacteria, proteolytic bacteria, and group of fluorescence bacteria in soil. Moreover, the highest increase was found in soil treated with concentration of 50%. This study provided new information that the infusion application of oyster mushrooms baglog waste enriched with molasses had the potential to increase the population of rhizobacteria and suppress the amount of pathogens R. similis and Meloidogyne spp .

Profile in various organic soil depth shrimp pond, Tambak Inti Rakyat, Karawang

ABSTRACT Organic material in the bottom of the pond is part of the land is a complex and dynamic system, which is sourced from the rest of the feed, plants, and or animals found in the soil that continuously change shape, because it is influenced by biology, physics, and chemistry. This study was aimed to see the profile of organic material consisting of C, N, and C/N ratio and phosphate in different depths of pond with different culture systems. Observation were conducted at Tambak Inti Rakyat, Karawang in traditional, semi-intensive and intensive culture systems. Observation at mangrove area was also observed as control. Sediment samples at the inlet and outlet at three different depths (0‒5 cm, 5‒10 cm, and 10‒15 cm) was taken every 30 days to measure the content of C, N, C/N ratio, and total phosphate. During the 120 day maintenance period could be known that in all pond systems were used (traditional, semi-intensive, and intensive) the concentration of C-organic and organic-N on average was located in the bottom layer which is a layer of 10‒15 cm. The lack of human intervention from ground pond system, the more diverse the type and amount of organic material contained therein. Keywords: organic materials, subgrade, depth, aquaculture systems, long maintenance ABSTRAK Bahan organik di dasar tambak merupakan bagian dari tanah yang merupakan suatu sistem kompleks dan dinamis, yang bersumber dari sisa pakan, tanaman, dan atau binatang yang terdapat di dalam tanah yang terus menerus mengalami perubahan bentuk, karena dipengaruhi oleh faktor biologi, fisika, dan kimia. Penelitian ini bertujuan untuk melihat profil bahan organik yang terdiri dari C, N, dan C/N rasio serta fosfat pada kedalaman tambak yang berbeda dengan sistem budidaya yang berbeda pula. Pengamatan dilakukan di Tambak Inti Rakyat Karawang pada sistem budidaya tradisional, semi intensif, dan intensif. Pengamatan di daerah mangrove diamati pula sebagai kontrol. Sampel sedimen di inlet dan outlet pada tiga kedalaman yang berbeda (0‒5 cm, 5‒10 cm, dan 10‒15 cm) diambil setiap 30 hari sekali untuk diukur kandungan C, N, C/N rasio, dan total fosfatnya. Selama 120 hari masa pemeliharaan dapat diketahui bahwa pada semua sistem tambak yang digunakan (tradisional, semi intensif, dan intensif) nilai konsentrasi C-organik dan N-organik rata-rata terletak pada lapisan paling bawah yaitu lapisan 10‒15 cm. Minimnya campur tangan manusia dari tanah sistem tambak maka semakin beragam jenis dan jumlah dari bahan organik yang terkandung di dalamnya. Kata kunci: bahan organik, tanah dasar, kedalaman, sistem budidaya, lama pemeliharaan

Impact of tempeh supplementation on mucosal immunoglobulin A in Sprague-Dawley rats

Tempeh, a well-known Indonesian fermented food made from soybeans, results from mixed-culture fermentation using a diverse group of microorganisms. The presence of many nonviable microorganisms in cooked tempeh may trigger responses in the immune system. Thirty female Sprague-Dawley rats were fed a standard diet supplemented with either non-fermented soybeans or tempeh (uncooked or cooked), for 28 days. Gene expression of intestinal immunoglobulin A (IgA) was analyzed using semi-quantitative real-time PCR, and intestinal IgA was further quantified from the ileum wash using ELISA. There was no significant (p>0.05) difference in IgA gene expression between animals groups receiving feed supplemented with cooked or uncooked tempeh. However, a significant (p<0.05) difference was observed between animals receiving feed supplemented with tempeh and with non-fermented soybeans. Microbial cells in tempeh might increase IgA protein secretion.

Identification of nif D and nif H Genes of Methanotrophic Bacteria from Rice Field

Metanotrophic bacteria have ability to oxidize methane and fix atmospheric nitrogen, hence the bacteria has an important role as a nitrogen source provider on wetland area like rice fields. Nitrogen fixation process is catalyzed by the nitrogenase enzyme complex, encoded by nifD and nifH genes. However, characteristic of these genes from indigenous-methanotrophic bacteria still poorly understood. Hence, nifD and nifH genes of methanotrophic bacteria isolated from rice fields in Indonesia (BGM3, BGM9, SS1, SS3, SS10, ST18, SP3 and INP4) were identified and characterized. Detection of nifH and nifD genes was conducted by polymerase chain reaction (PCR) amplification. nifH and nifD gene sequences were analyzed using BLAST-X and phylogenetic trees were constructed using Neighbour Joining method. Based on nifH sequences analysis, SS1 closely related to Beijerinckia mobilis and SS3, SS10, ST 18 closely related to Beijerinckia indica subsp. indica ATCC 9039, while, BGM3, INP4, and BGM9 related to nifH of uncultured nitrogen-fixing bacterium. In other hand, sequence analysis of nifD gene showed that SS1, SS3, SS10, ST 18 closely related to B. indica subsp. indica ATCC 9039 and BGM3, BGM9, INP4 closely related to Xanthobacter autotrophicus Py2. Identification by 16 SrRNA indicated that SS1, SS3, SS10, and ST18 had closeness to Beijerinckia sp. P310-1, while INP4 closely related to Xanthobacter sp. M5C24.

Salmonella population in waste water treatment installation (IPAK) at Pulo Gebang DKI Jakarta

Human typhoid fever and gastro-enteritis caused by the genus Salmonella are world-wide health problems. The serogroups of this bateria can be wed as an indicator on the food and water safety of a country. In Indonesia especially in DKI Jakarta, there is a waste treatment area (IPAK) sewing as enyironmental control. Salmonella have been isolated from IPAK using Salmonella Shigella Agar Medium. Salmonella population have been tested using Kirby-Bauer method. The result show that 937o ofthe isolated strains are sensitive to chloramphenicol and 27Vo are sensitive to tetracycline. It is suggested that Salmonella control in those environments shouLd be taken more seriosly. However chloramphenicol have a possibility as a good choice of drug.