Penapisan Kapang Asal Lahan Sulfat Masam Kalimantan Selatan Sebagai Penghasil Enzim Ekstraseluler

Kalimantan acid sulphate land has the potential to be developed into productive land, with good land optimization. Utilization of rhizosphere microorganism diversity, especially mold can potentially provide a solution in optimizing agricultural land, namely the ability to produce extracellular enzymes. This study aims to determine the potential of mold originating from acid sulphate fields in producing extracellular enzymes (pectinase, chitinase, glucanase, cellulase, and phosphatase). The study was conducted in June-July 2019 at the Microbiology Laboratory, Indonesian Center for Agricultural Biotechnology and Genetic Resources Research and Development. Screening  of extracellular enzyme-producing fungi was carried out on selection media. The results obtained by some isolates have the ability to produce extracellular enzymes. Indications of the ability of mold to produce extracellular enzymes are the presence of clear zones in the selection medium. In pectinase, chitinase and glucanase testing all isolates showed negative results. Potential isolates in producing extracellular enzymes include Penicillium sp. Paddy 4.1 (cellulolytic index 2.43),  Clonostachys sp. KRMT 17.9 and Penicillium singorense KLK 13.7 (proteolytic indices 3.97 and 3,00, respectively). The difference in index values ​​indicates the variation in the level of enzyme activity.Lahan sulfat masam kalimantan berpotensi untuk dikembangkan menjadi lahan yang produktif, dengan pengoptimalan lahan yang baik. Pemanfaatan keanekaragaman mikroorganisme rhizosfer, khususnya kapang dapat berpotensi memberikan solusi dalam pengoptimalan lahan pertanian, yaitu dengan kemampuan menghasilkan enzim-enzim ekstraseluler. Penelitian ini bertujuan untuk mengetahui potensi kapang asal lahan sulfat masam dalam menghasilkan enzim extraseluler (pektinase, kitinase, glukanase, selulase, dan fosfatase). Penelitian dilakukan pada bulan Juni-Juli 2019 di Laboratorium Mikrobiologi, Balai Besar Penelitian dan Pengembangan Bioteknologi dan Sumberdaya Genetik Pertanian, Bogor. Penapisan kapang penghasil enzim ekstraseluler dilakukan pada media  seleksi. Hasil penelitian diperoleh beberapa isolat memiliki kemampuan dalam menghasilkan enzim ekstraseluler. Indikasi adanya kemampuan kapang dalam menghasilkan enzim ekstraseluler yaitu adanya zona bening pada medium seleksi. Pada pengujian pektinase, kitinase dan glukanase semua isolat menunjukan hasil yang negatif. Isolat yang potensial dalam menghasilkan enzim ekstraseluler diantaranya Penicillium sp. Padi 4.1 (indeks selulolitik 2.43),  Clonostachys sp. KRMT 17.9 dan  Penicillium singorense KLK 13.7 (masing-masing indeks proteolitik 3.97 dan 3,00). Perbedaan nilai indeks menunjukan adanya variasi tingkat aktivitas enzim. &nbsp

Aktivitas Antifungi Formula Kitosan-Tripolifosfat Terhadap Infeksi Colletotrichum spp. Pada Cabai

Colletotrichum spp. penyebab penyakit antraknosa banyak menginfeksi tanaman cabai, sehingga perlu dikendalikan dengan agen hayati ramah lingkungan. Tujuan penelitian ini adalah untuk menguji aktivitas antifungi campuran formulasi berbagai konsentrasi kitosan (K) (0.2%, 0.3% dan 0.5%) hasil ekstraksi kitinase isolat E65 dan NaTPP (0.1%) pada ratio [5:2] terhadap penghambatan  pertumbuhan jamur Colletotrichum spp. pada cabai. Daya hambat formulasi K-TPP terhadap pertumbuhan Colletotrichum spp. masing-masing dilakukan dengan metode in vitro (pada media PDA) dan in vivo (pada buah cabai). Konsentrasi K (0.5%) : TPP (0.1%) pada rasio [5:2], menunjukkan daya hambat paling tinggi terhadap infeksi Colletotrichum spp. Penelitian lanjutan perlu dilakukan terhadap aktivitas antifungi berbagai formulasi dan konsentrasi K-TPP lainnya terhadap cabai di lapangan

ANALISIS AKTIVITAS NITROGENASE DAN GEN NIFH ISOLAT BAKTERI RHIZOSFER TANAMAN PADI DARI LAHAN SAWAH PESISIR JAWA BARAT

AbstrakPenambatan nitrogen oleh bakteri rhizosfer dapat dimanfaatkan untuk menyiasati dampak salinitas pada tanah sawah pesisir. Kemampuan tersebut disebabkan oleh aktivitas nitrogenase yang disandikan gen nifH pada komponen II. Penelitian  ini bertujuan  menganalisis aktivitas nitrogenase pada kondisi salin dan mengidentifikasi gen nifH. Sebanyak 50 isolat bakteri rhizosfer asal tanah sawah pesisir daerah Eretan dan Patimban, Jawa Barat telah dianalisis. Lima isolat yang menunjukkan aktivitas nitrogenase pada kondisi salin adalah Er B1 3, Er B1 4, Er B1 9, Er B2 10, dan Ptb B1 4. Gen nifH kelima sampel diidentifikasi menggunakan PCR menghasilkan amplikon berukuran ~360 bp. Aktivitas nitrogenase tertinggi berdasarkan Analisis Reduksi Asetilen (ARA) diperoleh pada isolat Er B2 10 yang memiliki kekerabatan terdekat dengan bakteri Providencia sp. Hasil yang diperoleh membuktikan bahwa beberapa bakteri asal sawah pesisir dapat menambat nitrogen pada kondisi salin.AbstractThe ability of nitrogen fixation by rhizosphere bacteria could be used to decrease salinity impact in coastal paddy field, due to nitrogenase capability, encoded by a nifH gene in component II. The objectives of this research are to analyze nitrogenase activity in saline condition and identify the presense of the nifH gene. A total of 50 isolates of the rhizosphere bacteria coastal from wetland areas of Eretan and Patimban, West Java, has been isolated and being analyzed. Among them, five isolates i.e. Er B1 3, ER B1 4, Er B1 9, Er B2 10 and Ptb B1 4, showed the nitrogenase activity under saline condition. The polymerase chain reaction (PCR) of the nifH gene from those five samples resulted in the amplicon size of  ~360 bp. The highest activity of nitrogenase assessed by acetylene reduction assay (ARA) was shown by Er B2 10 which closely related to bacteria of Providencia sp. The obtained result showed that several bacteria from coastal paddy field were able to conduct nitrogen fixation under saline stress

DIVERSITY OF EXTRACELLULAR ENZYMES PRODUCED BY ENDOPHYTIC FUNGUS ORIGINATED FROM Centella asiatica (L.) Urban

Asiatic Pennyworth (Centella asiatica) is a medicinal plant known to be symbiotic with various types of endophytic fungi. There are extensively studied as a source of new bioactive compounds, including extracellular enzymes. This study aimed to characterize enzymes produced by 40 endophytic fungi from C. asiatica. This research was conducted at the Microbiology Laboratory, Indonesian Center for Agricultural Biotechnology and Genetic Resources Research and Development Bogor and the Microbiology Laboratory, PLT UIN Syarif Hidayatullah Jakarta in February to April 2019. Seven enzymes screened were asparaginase, amylase, cellulase, pectinase, protease, glucanase, and laccase on Potato Dextrose Agar enriched with a specific substrate. The results showed that the number and type of enzymes produced by the fungi varied.  Phanerochaete chrysosporium MB02, Fusarium falciforme MB07, Trichaptum sp.MB11, Fusariumkeratoplasticum MB12, Penicillium capsulatum MB15, Phomamultirostrata MB16, Fusarium oxysporum MB17, and Mycochaetophora gentianae MB21 produced the highest enzyme number, i.e., six types of enzymes.  Colletotrichum tabaci MB14 produced the highest index value for asparaginase (index 2.65), Fusarium keratoplasticum MB12, Colletotrichum tabaci MB14, and Phoma multirostrata MB16 for amylase (index 2.00); Peroneutypa scoparia MM10 for cellulase (index 4.10); Colletotrichum karstii MM02 for pectinase (index4.12); C. tabaci MB14 for protease (index 4.37); Acrocalymma vagum MB04 for glucanase (index 1.68); and Fusarium solani MM03 for laccase (index 0.22). Colletotrichum tabaci MB14 was superior because it produced the highest of 3 enzymes (asparaginase, amylase, and protease).  Further study is required to find optimal conditions for each enzyme production for industrial purposes.Keywords: Asiatic Pennyworth, extracellular enzyme, in vitro production Abstrak KERAGAMAN ENZIM EKSTRASELULER DIHASILKAN OLEH JAMUR ENDOFIT ASAL Centella asiatica (L.) UrbanTanaman Pegagan (Centella asiatica) adalah tanaman obat yang dikenal bersimbiosis dengan berbagai jenis jamur endofit. Jamur endofit dipelajari secara ekstensif sebagai sumber senyawa bioaktif baru, termasuk enzim ekstraseluler. Enzim asparaginase, amilase, selulase, pektinase, protease, glukanase, dan lakase digunakan dalam industri. Penelitian ini bertujuan untuk mengkarakterisasi beberapa produksi enzim dari 40 jamur endofit dari C. asiatica. Penelitian dilakukan di Laboratorium Mikrobiologi, Balai Besar Penelitian dan Pengembangan Bioteknologi dan Sumberdaya Genetik Pertanian Bogor dan Laboratorium Mikrobiologi, PLT UIN Syarif Hidayatullah Jakarta pada bulan Februari hingga April 2019. Skrining enzim asparaginase, amilase, selulase, pektinase, protease, glukanase, dan lakase dilakukan pada medium Potato Dextrose Agar yang diperkaya dengan substrat tertentu. Hasil penelitian menunjukkan bahwa jumlah dan jenis enzim yang dihasilkan oleh jamur bervariasi. Phanerochaete chrysosporium MB02, Fusarium falciforme MB07, Trichaptum sp. MB11, Fusarium keratoplasticum MB12, Penicillium capsulatum MB15, Phoma multirostrata MB16, Fusarium oxysporum MB17, dan Mycochaetophora gentianae MB21 menghasilkan jumlah enzim tertinggi (6 jenis enzim). Berdasarkan enzim yang diproduksi (nilai indeks), Colletotrichum tabaci MB14 menghasilkan asparaginase tertinggi (indeks 2,65), Fusarium keratoplasticum MB12, Colletotrichum tabaci MB14, dan Phoma multirostrata MB16 untuk amilase (indeks 2,00); Peroneutypa scoparia MM10 untuk selulase (indeks 4.10); Colletotrichum karstii MM02 untuk pektinase (indeks 4.12); C. tabaci MB14 untuk protease (indeks 4.37); Acrocalymma vagum MB04 untuk glukanase (indeks 1,68); dan Fusarium solani MM03 untuk lakase (indeks 0,22). Colletotrichum tabaci MB14 merupakan isolat yang unggul penghasil 3 jenis enzim tertinggi (asparaginase, amilase, dan protease).  Perlu dilakukan penelitian lebih lanjut untuk menganalisis secara kuantitatif produksi enzim ekstraseluler yang dihasilkan dan prospeknya untuk keperluan industri.Kata kunci:  Enzim ekstraseluler, pegagan, produksi in vitro

SPECIES AND FUNCTIONAL DIVERSITY OF RHIZOBACTERIA OF RICE PLANT IN THE COASTAL SOILS OF INDONESIA

Rhizobacteria are important components of soil and directly or indirectly influence the soils quality and plant growth for maintaining adequate plant nutrition and reducing the negative environmental effects of fertilizers. Applying high dose of chemical fertilizers in most of rice fields in the coastal areas could reduce the quality of the soil in the long time. There are few studies addressed to verify the species and functional diversity of cultivable rhizobacteria associated with rice plant in the coastal soils. The objective of the study was to verify the species and functional diversity of rhizobacteria isolated from the coastal soils of two rice production areas of Subang and Indramayu, West Java. Special focus was given to verify phosphate solubilization, nitrogen fixation, IAA and cellulase production of the selected 78 strains of rice rhizobacteria isolated from the coastal paddy field, as well as taxonomical analyses based on 16S rRNA. The results showed that among 78 bacterial isolates from the coastal paddy field, mostly were belonging to the Firmicutes, most of them affiliated with genera Bacillus, 75 strains produced IAA, 32 strains fixed nitrogen, 37 strains solubilized phosphate and 33 strains produced cellulase. Several strains of the rhizobacteria were capable of producing plant growth promoting substances (PGPR), alone or in combination, such as IAA, fixing nitrogen,  solubilizing phosphate, and producing cellulase. Taking all of these diverse PGPR characteristics into account, it is clear that the 78 identified isolates have great potential for improving saline soils of the coastal paddy fields in Indonesia

GROWTH IMPROVEMENT OF TOMATO WITH THE APPLICATION OF BACTERIAL ISOLATES PRODUCING INDOLE ACETIC ACID (IAA) AND PHOSPHATE SOLUBILIZER

Soil bacteria have important roles in biogeochemical cycle for soil fertility and have been manipulated for ecologically-friendly crop production.  The search for beneficial association between microbes and plants for promoting growth and health should be studied for tomato growth improvement. The study aimed to  evaluate 19 microbial isolates which produced indole acetic acid (IAA) affecting growth and development of tomato (Palupi variety), and  molecularly identify the most effective isolates in improving tomato growth based on 16s rDNA sequences. The experiment was conducted in pots using a complete randomized design with three replications. The parameters observed included plant height, plant dry weight, root length, root dry weight, and fruit fresh weight.  The isolates that significantly improved tomato growth were molecularly identified using 16s rRNA sequence. The phenotypic properties such as IAA content and phosphate solubilizing index (PI) of the superior isolates were determined. Results showed that the application of bacterial isolates on tomato significantly increased plant dry weight and fruit yield. From 19 isolates tested, Aj 3.7.1.14 significantly increased plant dry weight, root length, and fruit yield. This isolate produced IAA of about 14.77 ppm and PI of 1.86.  Molecular analysis on Aj 3.7.1.14 demonstrated that the isolate had 89% similarity to Pseudomonas fragi. The identified P. fragi was found to be the most effective isolate for improving tomato growth and fruit yield. Another isolate, Bacillus amyloliquefaciens was found to promote root length, root dry weight, and fruit yield. These isolates are potential to be further investigated for field trial

Characterization of Lipopolysaccharides of Bradyrhizobium japonicum KDR 15 Heavy Metal Tolerant

The lipopolysaccharide (LPS) of Bradyrhizobium japonicum KDR 15 heavy metal tolerant strain was isolated by miniphenol-water extraction and yielded LPS in phenol and water phase. The LPS KDR 15 was further characterized by sodium dodecyl sulfate-polyacrilamide gel electrophoresis (SDS PAGE) and showed many bands distributed from an area of high until low molecular weight (LPS IA, IB, and II). Composition analysis of the LPS had been done after acetic acid 1% hydrolysis. The polysaccharide portion consist of glucose, sucrose, galactose, mannose, xylose, arabinose, rhamnose, ribose, glucosamine, and 3-deoksi-D-manno-oktulosonat (KDO). Lipid A portion consisted of C16:0 and C18:1. The LPS also contained 0.02% of protein and 1.7% of phosphate. The presence of functional groups that shows negative charge densities such as phosphate and carboxyl within LPS KDR 15 assumed to be a potentially binding sites for accumulating heavy metals. Key words: Bradyrhizobium japonicum, heavy metal tolerant, lipopolysaccharide

Biosintesis nanopartikel perak (AgNP) menggunakan Bacillus firmus E65 dan aktivitasnya terhadap mikroba patogen

Silver (Ag) in ionic form is toxic to microbial cells, but is environmentally friendly and safe for humans. This study aims to synthesize silver nanoparticles (AgNP) using Gram-positive bacterial isolate (B. firmus E65) as a bioreductor and to test its activity as an antimicrobial against Eschericia coli, Xanthomonas oryzae pv. oryzae (Xoo) and the fungus Colletotrichum gloeosporioides under in-vitro assays. AgNP was obtained by adding bacterial culture supernatant B. firmus E-65 to 5mM AgNO3 solution. The formation of AgNP was observed by changing the color of the solution after incubation at 37 °C for 72 hours. The UV-Vis spectrophotometer measurement to AgNP solution showed a maximum wavelength of 425 nm. The particle size of AgNP was 252.1 nm with intensity of 98.90 %. The result of bioassay against E. coli showed the greatest inhibition at 50 % AgNP (degree of inhibition (DI) =96.15 %), followed by 25 % AgNP (DI=76.92 %), and 12.5 % AgNP (DI=53.84 %). The bioassay against Xoo showed the greatest degree of inhibition was at AgNP 50 % (DI=92.85 %), followed by 25 % AgNP  and 12.5 % AgNP (DI=85.71 %). Meanwhile bioassay against C.gloeosporioides, the greatest inhibition  was observed at 25 % AgNP (DI=94.35 %), followed by 50 % AgNP (DI=91.9 %)

Isolasi dan Karakterisasi Aktinomisetes Penghasil Antibakteri Enteropatogen Escherichia coli K1.1, Pseudomonas pseudomallei 02 05, dan Listeria monocytogenes 5407

Isolation and Characterization of Actinomycetes ProducingAntibacterial Compound into EnteropatogenikEscherichia coli K1.1, Pseudomonas pseudomallei 02 05and Listeria monocytogenes 5407. Dwi N. Susilowati,Ratih D. Hastuti, and Erny Yuniarti. The resistance ofbacterial pathogens to some antibacterial agents and sideeffects of the antibacterial usage demanded discovery ofnew effective, safe, and active antibacterial compounds.Some pathogenic bacteria, such as enteropathogen Escherichiacoli (EPEC) that cause diarrhoea on children andinfants, Pseudomonas pseudomallei that cause melioidosison human and animal, and Listeria monocytogenes thatcause listeriosis on newly born babies mortality and death ofpregnant woman. Actinomycetes is the largest bacterialgroup that produce antibiotics. More than 10,000 antibacterialcompounds had been discovered, two-third ofthem were produced by this bacterial group. A study wasdone to isolate and characterize Actinomycetes producingantibacterial compounds effective against EPEC K1.1 and P.pseudomallei 02 05. Soil samples were taken from 39locations in Indonesia and 115 actinomycetes isolates wereobtained. Two of the isolates, i.e., isolate A3.5 that waseffective against P. pseudomallei 02 05 and isolate F6.1 thatwas effective against EPEC K1.1 evaluated further. Theisolate A3.5 had an optimum time 72 hours to produce antibacterialcompound, while F6.1 took 96 hours. The antibacterialcompounds produced by both isolates were dissolvein the a 70% ethyl acetate solution, but not in a 40oCwarm methanol solution because it is very dissolved. Theantibacterial compound extracted from the isolate A3.5 hada similar effectiveness to antibiotics bacithracyn 10 unit andneomycin 30 g. On the other hand, the antibacterialcompound extracted from isolate F6.1 had a similar effectivenessto antibiotics colistin 10 g and doxyciclin 30 g.Further identification of the isolates suggested that both ofthem belongs to the genera Streptomyces