LIPID PRODUCING MICROALGAE FROM SEVERAL ECOSYSTEMS IN WEST AND CENTRAL JAVA, INDONESIA

This study is aimed to get lipid producing microalgae as feedstock for biofuel production. The microalgae were isolated from 355 collected water samples which  represented many distinct ecosystems such as paddy fields, rivers, agricultural dams, ponds, swampy areas and unique ecosystem of volcano and mud-volcano craters in West- and Central Java, Indonesia. A total of  267 strains of microalgae were isolated from the samples of which  221 strains of them have capability to produce lipid. There were four promising strains that produce lipid between 14.7 – 45.7 percent dry weight in optimal condition that were identified as Chlamydomonas sp. KO-7267 and PK-7195, Chlorella sp. KS-7300 and Desmodesmus sp. BK-7291.   Keywords: microalgae, lipid, biofuel, Indonesian ecosystem

Pertumbuhan dan Hasil Tanaman Jagung Manis pada Berbagai Populasi Gulma Chloris barbata (Poaceae)

Purpletop chloris (Chloris barbata Sw.) is a dominant weed on maize field in East Nusa Tenggara (ENT), but study on the effect onto maize is rare. The study evaluated the effect of C. barbata on growth and yield of sweet corn. The seed of C. barbata was obtained from farmer field in Kupang Regency, ENT. Experiment was conducted in October 2019 to January 2020 at Cikabayan Experimental IPB Farm, Bogor-Indonesia using a randomized complete block design with five replications. Sweet corn seeds were planted at polybag sized 30 cm x 30 cm filled with 5 kg media with five levels of C. barbata seeds, i.e., 0 (clean weeding), 15, 30, 45, and 60. The results showed that C. barbata suppressed the growth and yield of sweet corn. It suppressed the height and dry weight (DW) at 4 weeks after planting (WAP) where the population of 15 individuals decreased plant height and 30 individuals suppressed the total DW at 8 WAP. A population of 15 individuals reduced stem diameter, leaf area and width, leaf color, and total DW, while the leaf number and its length were significantly reduced by the treatment of 30 individuals per polybag. The weight of the corn with and without husk, and the length of the cobs reduced by the treatment of 45 individuals, i.e., 48.3%, 49.0%, and 77.7% relative to the control, respectively. Inhibition mechanism of C. barbata on sweet corn growth and yield needs further research. Keywords: allelopathy, competition, corn, East Nusa Tenggara, purpletop chlorisRumput cakar ayam (Chloris barbata Sw.) merupakan gulma dominan pada pertanaman jagung di Nusa Tenggara Timur (NTT) yang masih jarang diteliti. Penelitian bertujuan mempelajari pengaruh populasi C. barbata pada tanaman jagung manis. Penelitian dilakukan pada Oktober 2019 sampai Januari 2020 di Kebun IPB Cikabayan, Bogor, Indonesia menggunakan rancangan acak kelompok dengan lima ulangan. Benih jagung ditanam pada lima populasi C. barbata yaitu 0 (tanpa gulma), 15, 30, 45, dan 60 individu per polibag berukuran 30 cm x 30 cm yang diisi media 5 kg. Biji gulma diperoleh dari lahan petani di Kabupaten Kupang, NTT. Hasil penelitian menunjukkan bahwa gulma memengaruhi pertumbuhan dan hasil tanaman jagung. Kehadiran gulma menekan tinggi dan bobot kering (BK) tanaman jagung mulai 4 minggu setelah tanam (MST). Pada 4 MST, populasi 15 individu menekan tinggi tanaman dan 30 individu menekan BK total tanaman jagung. Populasi 15 individu menekan diameter batang, luas dan lebar daun, kehijauan daun, dan BK total tanaman jagung, sedangkan jumlah dan panjang daun menurun oleh perlakuan 30 individu pada 8 MST. Bobot tongkol dengan dan tanpa klobot, serta panjang tongkol berkurang oleh perlakuan 45 individu per polibag yakni menjadi sebesar 48.3%, 49.0%, dan 77.7% relatif terhadap kontrol. Perlu penelitian lebih lanjut mekanisme penghambatan C. barbata pada tanaman jagung. Kata kunci: alelopati, jagung, kompetisi, Nusa Tenggara Timur, rumput cakar aya

KAJIAN RISIKO LINGKUNGAN UNTUK PENGGUNAAN AGEN HAYATI DI BIDANG PERTANIAN

In Indonesia, the biological agents have been widely used in the agriculture for reducing chemical fertilizers uses, for controlling plant pest and pathogens, and for increasing rate of composting process. The application of biological agents is especially important in the organic agriculture practices. The agents consist of microorganisms both fungi and bacteria, and in some extent are also viruses, that part of them are imported from other countries. Based on their characteristics, any biological agents that are released into the environment can pose potential problems to the environment or the ecology.  There is a Ministerial Decree that require an environmental risk assessment (ERA) for getting a permission of an importation of biological agents. Unfortunately, there is not any guidance to conduct ERA of biological agents. This paper reviews ERA and using of the approach to do a risk assessment of biological agents that will be used in agriculture

The Diversity and Abundance of Springtail (Collembola) on Forests and Smallholder in Jambi

Harapan forests is the first restoration forest in Indonesia, includes several different ecosystems. Different ecosystems have different characteristic to affect the diversity and abundance of Collembola. In the ecosystem, Collembola have an important role in biocontrol, decomposition, soil nutrient distribution, stimulation of soil microbial activity and as an alternative feed for predators. This study was aimed to investigate the diversity and abundance of Collembola in four ecosystems at Harapan forest, i.e. secondary forest, rubber forest, rubber smallholder and oil palm smallholder. To achieve the objective, soil samples were taken at 48 observation points in the four ecosystem. The soil samples were then extracted by Kempson Extractor. The diversity and abundance of Collembola in four ecosystems were categorized as medium to high. The total of individual and population of Collembola in the secondary and rubber forest ecosystems were likely to be higher than in the rubber and oil palm smallholders. This study had also identified four orders, 14 families and 31 genera of Collembola, where Isotomiella and Proisotoma dominated the genus of Collembola in the four ecosystems. [How to Cite: Widrializa, R Widyastuti, DA Santosa and G Djajakirana. 2015. The Diversity and Abundance of Springtail (Collembola) on Forests and Smallholder in Jambi. J Trop Soils 20: 173-180. Doi: 10.5400/jts.2015.20.3.173]

Application of Biological Nitrogen Fixation Cyanobacteria To Paddy Plant Cultivated Under Deep-Water Culture System

 The Biological Nitrogen Fixing (BNF) cyanobacteria can reduce atmospheric nitrogen into ammonium. This ability makes BNF cyanobacteria a potential eco-friendly N-source for soil-planted pad-dy. Apart from a few success stories of BNF cyanobacteria applica-tion in the rice field, its role as an ammonium producer is still an open question. There is also a possibility that indeed cyanobacteria biomass which provides nitrogen through the biological decomposing process. This study aimed to analyze the influence of three strains BNF cyanobacteria on paddy grown in the Deep-Water Culture (DWC) hydroponic system. Yoshida Nutrient Solution was used as a growth medium with the application of 0, 45.7, and 91.4 gL-1 of ammonium nitrate (NH4NO3) with five replications. The result showed that inter-action between cyanobacteria and nitrogen significantly influenced the total nitrogen of paddy plant, but not the paddy plant height, the num-ber of tillers, and biomass. Cyanobacterial filaments were found most-ly attached to the paddy root rather than floated in the DWC system. Paddy treated with cyanobacteria had more lateral root than control. The result suggested that cyanobacteria support paddy growth indi-rectly through nitrogen deposition in plant tissue and root development.

Halotolerant Plant Growth-Promoting Bacteria Colonization of Agronomic Crops Under Saline Stress

The ability of a plant growth-promoting bacteria (PGPB) strain to colonize the roots and tissues of inoculated plants is important for their successful use in agricultural practices. The purpose of this study was to determine how effective 15 indigenous halotolerant PGPB were at colonizing three different agronomic crops via seed inoculation. Using standard Hoagland’s media and Hoagland’s media amended with 100 mM NaCl, we tested 15 gfp-tagged halotolerant bacterial isolates for their ability to colonize rice, maize, and soybean seedlings. The quantitative dilution plating method and fluorescent microscopy were used to determine the colonization degree of gfp-tagged halotolerant PGPB isolates in the rhizoplane zone and in the inner tissue of the seedlings at 21 days after germination. All halotolerant PGPB isolates colonized the rhizoplane zone of all seedlings. In both standard and 100 mM NaCl amended Hoagland’s media, isolates E194-3, D183-4, and E101-1 showed the highest colonization in rice, maize, and soybean seedlings, respectively. The ability of halotolerant PGPB isolates to colonize agronomic crops was found to vary depending on bacterial isolates, plant species, plant tissues, and NaCl concentration. Keywords: inoculation, colonization, halotolerant, endophyte, rhizoplan

KEANEKARAGAMAN ENZIM INVERTASE, PENGEMBANGAN STRAIN UNGGUL DAN TEKNOLOGI PRODUKSINYA

Invertase Diversity, Novel Strain and Production Technology DevelopmentInvertase or β-fructofuranosidase (E.C.3.2.1.2.6) have been a valuable enzyme in food industry, so that research about enhancing invertase activity on an industrial scale has been reported massively. So far, the production of the invertase enzyme is highly dependent on the potential activity of the invertase enzyme derived from microorganisms. The development of enzyme production technology is also a concern in invertase research to obtain an efficient and inexpensive production system. So far, various developments in enzyme production technology and enzyme utilization have been carried out, including various innovations in immobilizing and increasing the stabilization of the invertase enzyme during the production process. The development of superior strains and enzyme production technology continues amid the discovery of the latest approaches such as genetic engineering, protein modification, and nanotechnology. This paper aims to discuss invertase variation from various organisms, its correlation to novel microbial strain development to increase invertase production and invertase enzyme production technologies development including immobilization technology and stabilization of invertase enzymes.Keywords: β-fructofuranosidase, ezyme production, fermentation, immobilitation, invertase geneABSTRAKInvertase atau β-fructofuranosidase (E.C.3.2.1.2.6) merupakan enzim yang sangat penting dalam dunia industri pangan sehingga berbagai optimasi aktivitas enzim untuk produksi dalam skala industri terus dilakukan. Produksi enzim invertase hingga sejauh ini sangat bergantung oleh potensi aktivitas enzim invertase yang diambil dari mikroorganisme. Selain itu, pengembangan teknologi produksi juga menjadi perhatian dalam pengembangan produksi dan pemanfaatan enzim untuk mendapatkan sistem produksi yang efisien dan murah. Sejauh ini berbagai pengembangan teknologi produksi enzim dan pemanfaatan enzim telah dilakukan, diantaranya dengan berbagai inovasi dalam melakukan imobilisasi dan peningkatan stabilisasi enzim invertase selama proses produksi. Pengembangan strain unggul dan teknologi produksi enzim terus dilakukan di tengah ditemukannya pendekatan-pendekatan terkini seperti rekayasa genentika, modifikasi protein, dan teknologi nano. Artikel ini bertujuan untuk membahas variasi enzim invertase dari berbagai organisme, korelasi pengembangan strain mikrobia unggul terhadap peningkatan produksi enzim invertase, dan perkembangan teknologi produksi enzim invertase meliputi teknologi imobilisasi dan stabilisasi enzim invertase

Kelimpahan Vegetasi dan Simpanan Biji Gulma pada Pertanaman Jagung Berbeda Sejarah Pola Tanam di Lahan Kering

Weed management is an important aspect in the dry land; however, weed resides in dry land like East Nusa Tenggara is rarely reported. The study aimed to evaluate weed species and its seed bank on maize fields from the different history of cropping patterns in order to develop effective weed control. The research was conducted in April-June 2019 at farmer fields at Kupang District, East Nusa Tenggara, Indonesia. Weeds were evaluated from four maize fields experienced a different history of cropping pattern (L1, L2, L3, and L4), and its seed bank from the depth of 0-10, 11-20, 21-30, and 31-40 cm were evaluated using seedling emergence method. The evaluation revealed 13 species at which 4 species exclusively were found in vegetation analysis, 2 species in the seed bank and 7 species in both vegetation and seed bank analysis. Dominant weed at podzolic L2 and L3 that experienced fallow for two months was Chloris barbata, while without fallow of podzolic L1 and grumusol L4 were Digitaria adscendens and Mazus japonicus, respectively. Cropping history and soil depths affected weed density, but depths of 0-20 cm had the highest density irrespective preceding the cropping pattern. Research implies both vegetation and seed bank analysis should be addressed and integrated in weed management. Keywords: dry land, fallow, weed management, East Nusa Tenggara, vegetation analysi

DINAMIKA KELIMPAHAN ORIBATIDA PADA AREA PERKEBUNAN KELAPA SAWIT DI KECAMATAN BAJUBANG BATANGHARI JAMBI

Oribatids are one of the important fauna groups in the soil. They have an important role in the decomposition of organic matter in the soil. The objection of this research was to study population dynamics of Oribatids through determining the abundance and diversity of Oribatids and to know the effect of environmental factors on Oribatids in oil palm plantation at Bajubang, Batanghari, Jambi. Soil and litter samples were taken from four different locations (25 m x 25 m) and from each location three samples were taken from litter lanes and open lanes, respectively (the size was 16 x 16 cm with a depth of soil is 5 cm). The samples were extracted using Kempson extractor. Identification of Oribatids was done to the family level and the diversity of Oribatids was measured using Shannon’s diversity index. The population dynamic of Oribatids showed a fluctuation in the sampling period. When rainfall increased >200 mm did not follow by increasing abundance and diversity (number of the family) of Oribatid mites. When rainfall between 100 – 200 mm was the optimal condition for Oribatids so abundance and diversity (the number of the family) of Oribatids increased. But, when rainfall <100 mm especially in February 2014 (the lowest rainfall 1 mm), abundance and diversity (number of the family) of Oribatids was lowest (330 individual m-2; 7 families) compared to another month. It was assumed that Oribatids may migrate into the deep soil to avoid a harsh environmental condition. Abundance and diversity (number of the family) of oribatids were significantly higher in litter lanes (4,560 individual m-2; 25 families) than in open lanes (1,570 individual m-2; 14 families). The availability of litter in the litter lanes was higher than in open lanes. In this research, There are 3 families that most abundance and always found on the sampling period, they are Scheloribatidae, Mycobatidae and Galumniidae. Keywords: Abundance, diversity, oil palm plantation, Oribatids, soil faunaOribatida merupakan salah satu kelompok fauna yang penting di dalam tanah. Mereka memiliki peran dalam dekomposisi bahan organik di tanah. Tujuan penelitian ini untuk mempelajari dinamika populasi Oribatida dengan mengukur kelimpahan dan keanekaragaman Oribatida pada area perkebunan kelapa sawit dan mengetahui pengaruh faktor lingkungan terhadap Oribatida pada area perkebunan kelapa sawit di Kecamatan Bajubang, Batanghari, Jambi. Contoh tanah dan serasah diambil dari empat lokasi yang berbeda (25 m x 25 m) dan dari setiap lokasi diambil masing - masing tiga contoh tanah pada gawangan serasah dan gawangan hidup (berukuran 16 x 16 cm, kedalaman 5 cm). Sampel tersebut diekstrak menggunakan Kempson Extractor. Identifikasi Oribatida dilakukan sampai tingkat famili dan indeks keanekaragamannya ditentukan menurut Shannon’s diversity index. Dinamika populasi Oribatida di area perkebunan kelapa sawit menunjukkan adanya fluktuasi pada periode pengambilan sampel. Fluktuasi tersebut bergantung dengan curah hujan setiap bulannya. Ketika curah hujan meningkat >200 mm tidak diikuti dengan peningkatan kelimpahan dan keanekaragaman Oribatida. Ketika curah hujan antara 100 – 200 mm merupakan kondisi yang optimal bagi Oribatida sehingga kelimpahan dan keanekaragamannya meningkat. Namun, ketika curah hujan < 100 mm khususnya pada bulan Februari 2014 (curah hujan terendah 1 mm), kelimpahan dan keanekaragaman Oribatida (330 individu m-2; 7 famili) terendah dibandingkan bulan lainnya. Oribatida diduga mengalami perpindahan ke lapisan tanah yang lebih dalam untuk menghindari kondisi lingkungan yang tidak menguntungkan di permukaan tanah. Kelimpahan dan keanekaragaman Oribatida (jumlah famili) secara signifikan lebih tinggi di Gawangan serasah (4,560 individu m-2; 25 famili) dibandingkan di gawangan hidup (1,570 individu m-2; 14 famili). Ketersediaan serasah di gawangan serasah lebih tinggi dibandingkan di gawangan hidup. Di dalam penelitian ini, terdapat 3 famili yang paling melimpah dan selalu ditemukan selama periode pengambilan sampel yaitu Scheloribatidae, Mycobatidae dan Galumniidae. Kata kunci: Kelimpahan, keanekaragaman, perkebunan kelapa Sawit, Oribatida, fauna tana

Exploration and characterization of exopolysaccharide-producing bacteria from soil in West Kalimantan for improving sandy soil aggregation

Exopolysaccharide (EPS) is a complex mix of macro-molecular electrolyte contained in the outer cells of bacteria excreted as mucus and has a role in soil aggregation. This study aims to obtain bacteria that have a high potential for exopolysaccharide-producing bacteria. A total of 112 isolates of exopolysaccharide-producing bacteria were isolated from rubber soil rhizosphere, secondary forest, and shrubs in PT. Hutan Ketapang Industri is the result of isolation on ATCC no.14 medium. Based on the observations of a morphological colony of these isolates, most of them similarities of color and shape but only 25 colonies are different isolates were obtained based on colony morphology. However, only 10 isolates formed a thick mucus or slimy when cultured on MacConcey agar. the results show that obtained three isolates of exopolysaccharide-producing bacteria have a higher value of the dry weight i.e. isolates RB292 (7.53 mg/mL) followed by RB51 (7.55 mg/mL), and RB241 (1.75 mg/mL) with 2% sucrose. Isolates RB51 and RB292 increasing significantly soil aggregate stability at 2% dosage of organic matter with soil aggregate stability index from 30.61% to 47.87% and 45.79%. Homology of the isolates with known bacteria i.e. isolate RB51 was 98.86% homolog with Klebsiella sp. LW-13, isolate RB241 was 98.65% homolog with Klebsiella pneumonia strain DSM 30104 and isolate RB292 was 98.83% homolog with Burkholderia anthina strain MYSP11