ISOLASI DAN IDENTIFIKASI BAKTERI PENAMBAT NITROGEN UNTUK PEMBUATAN BIOFERTILIZER

Nitrogen is a macro nutrient needed by plants. Generally, people use inorganic fertilizers to fulfill nitrogen nutrients in plants. The problem then is, the continuous use of synthetic nitrogen fertilizers has a direct negative impact on the soil and a derivative impact on human health. The use of microorganisms, in this case bacteria, to provide nitrogen to plants can be done by isolating it and making it a biological fertilizer agent. Nitrogen fixing bacteria was isolated on the land of the oil palm plantation of PT Astra Agro Lestari. The isolated nitrogen-fixing bacteria were then tested quantitatively for their ability to fix nitrogen. The bacteria with the highest nitrogen fixing ability were then identified by sequencing their DNA nucleotide bases so that the bacterial strains were identified. The result is that there are 13 bacteria that are able to fix nitrogen with the codes J1, J3, Q5, L1, L11, J31, D1, M6, M5, R1, P2, J4 and C7. The quantitative test shows that bacteria with code D1 are the best at fixing nitrogen in the form of NH4, namely 0.27 ppm. The results of D1 bacterial DNA nucleotide base sequencing showed that the putitive Bacillus aerius strain 24K with identical values ​​and query cover reach   &nbsp

Screening and Identification of Mushrooms Growth Promoting Bacteria on Straw Mushrooms (Volvariella volvacea)

This research aimed to identify the indigenous Mushroom Growth Promoting Bacteria (MGPB) bacteria that can increase the growth of Volvariella volvacea. The research began by isolating indigenous MGPB from planting media of straw mushrooms in Karawang, Indonesia. The screening was performed to select bacterial isolates that can promote the highest growth of mushrooms by dual culture method on PDA media. There were 10 of the 58 highest bacterial isolates that have a positive effect on the vegetative growth of mushrooms. The 23K bacterial isolate was the most significant increase in mycelium growth compared to other isolates and bacteria-induced controls. A bacterial isolate 25K by gene analysis was identified by 16S rRNA (518F primer (5’- CCA-GCA-GCC-GCG-GTA-ATA-CG -3’) and 800R primer (5’- TAC-CAG-GGT-ATC-TAA-TCC -3’). The result from gene analysis shows that there are ~1550 base pairs products. BLAST analysis and phylogenetic tree adjustment results show that the closest diversity of this bacterial isolate 25K is Bacillus thuringiensis serovar konkukian str. 92-27 (equality value = 99%)

ANTIFUNGAL PHYTOPHTHORA PALMIVORA FROM CLOVE BUDS (SYZYGIUM AROMATICUM L.)

Objective: Clove buds (Syzygiumaromaticum) have been reported as a natural fungicide and could be an alternative fungicide for Phytophthorapalmivora one of pathogenic fungi in Cacao plantations. The aim of this research was to evaluate an antifungal Phytophthora of the essential oil, extract, fraction, bioactive compounds from clove buds.Methods: Successive extractions of clove buds were performed by maceration with n-hexane, ethyl acetate and methanol. Fractionation and purification were performed using vacuum liquid chromatography and column chromatography. Identification of the isolated compounds was performed by thin layer chromatography (TLC), gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Agar well diffusion method was used as the assay method and then the percentage radial growth inhibition of Phytophthoramy celium was calculated on the fifth days.Results: At 10 mg/ml, the n-hexane extract showed the highest inhibition 90.00 %, followed by ethyl acetate extract, essential oil and methanol extract with 78.00 %, 72.72 %, and 29.17 % inhibition, respectively. Two active fractions from vacuum liquid chromatography (VLC) of n-hexane extract were obtained with 49.29 % (F-2), and 90.00 % (F-5) inhibition, respectively at 5 mg/ml. Two active subfractions were obtained from column chromatography with inhibition 8.79 % (F-A) and 89.01 % (F-B), at 5 mg/ml. The thin layer chromatography (TLC) and gas chromatography (GC) showed that F-B consists of one of a compound having the same Rf and Rt values that of a eugenolauthentic marker. The gas chromatography-mass spectrometry (GC-MS) data showed that the major compound in F-A was caryophyllene (M 204), and F-B was eugenol (F-B1) (M 164) and acetyl eugenol (F-B2) (M 206).Conclusion: Eugenol and eugenol acetate were the main active compounds effective in inhibiting as antifungal P. palmivora.Â

ISOLASI DAN IDENTIFIKASI BAKTERI PELARUT FOSFAT DARI TANAH RHIZSOSFER KELAPA SAWIT (Eleis guineensis)

Bakteri sebagai salah satu agent penyubur tanah, masih sangat minim diketahui petani. Kenyataannya bakteri mampu menyediakan unsur hara makro yang dibutuhkan oleh tanaman, contohnya fosfat. Fosfat di tanah umumnya dalam bentuk terikat, baik yang berbentuk anorganik (Ca-P, Fe-P dan Al-P) maupun organik (asam nukleat dan fosfolipida). Mengeksresikan asam organik, merupakan cara umum bakteri untuk melarutkan fosfat terikat khususnya yang anorganik. Isolasi bakteri pelarut fosfat dilakukan di tanah rhizosper Kelapa Sawit (Eleis guineensis) PT Astra Agro Lestari dengan menggunakan media pikovskaya yang di dalamnya terdapat kalsium fosfat (Ca-P).  Hasilnya ada 6 bakteri yaitu A2, B5, C7, F1, F2, dan K1 yang mampu melarutkan kalsium fosfat (Ca-P). Uji kuantitatif dengan menggunakan spektrofotometer 410 nm, pada supernatant pikovskaya cair menunjukkan bakteri A2 mampu melarutkan fosfat 20,40 ppm paling baik jika dibandingkan dengan bakteri, C7= 7,69 ppm, F1= 5,77 ppm, F2= 5,53 ppm, B5= 1.19 ppm dan K1= 0,46 ppm. Identifikasi partial sequences 16s rRNA menunjukkan bakteri A2 putative Amycolatopsis albidoflavus

Assessment of double screening programmes via solid substrate fermentation (SSF) in a flask system and identification of lovastatin potential producer

Local economical substrates namely rice bran and unprocessed brown rice was applied into fermentation condition to produce a potent secondary metabolite compound, lovastatin. A basis condition of fermentation viz. 70% (v/w) of moisture content (adjusted to pH 6.0), 1x107 spore/ml of inoculum size, mixture of 1:1 substrates and 7 days of incubation period, was applied into SSF system. During a preliminary test, all of 72 fungi disclosed positive dark spot onto the thin layer chromatography plate (TLC). In order to verify the existence of lovastatin, the secondary screening which involving high performance liquid chromatography (HPLC) was conducted. Out of 72, only 71 fungi were detected as lovastatin producers and the highest production was stated from SAR I isolate with 68.72±0.84 mg lovastatin/g dry substrate and 0.87±0.03 mg glucosamine/g dry substrate of fungal growth. SAR I isolate was identified via colony and microscopic morphologies. Through the observations, SAR I isolate was identical to Aspergillus nige

Upaya Kultivasi Jamur Morel (Morchella esculenta (L.) Pers.) dari Kawasan Lembang, Jawa Barat dan Optimasi Pertumbuhannya dengan Menggunakan Media Pati

Jamur morel (Morchella esculenta (L.) Pers.) memiliki nilai gizi yang baik dan bernilai jual tinggi dari segi industri kuliner. Di Indonesia, jamur ini telah ditemukan di kawasan Gunung Rinjani, Nusa Tenggara Barat, dan di kawasan Lembang, Jawa Barat, yang menjadi spesimen dalam penelitian ini. Penelitian ini bertujuan untuk mencoba menginokulasi jamur morel pada media kultur murni, media bibit induk, dan media tanam. Kemudian pertumbuhan miselia dan laju tumbuhnya diamati pada media karbohidrat yang dibuat dari tepung terigu, beras, maizena, dan tapioka pada cawan Petri. Kultur murni dengan menggunakan media agar dekstrosa kentang di cawan Petri telah membuahkan hasil, sebagaimana jamur morel telah membentuk miselia dan sklerotia pada media kultur. Hasil positif juga ditemukan pada tahap lanjutan, yaitu kultur bibit induk dengan media buah kapuk dan dedak. Akan tetapi, upaya kultur di baglog berisi media tanah kompos belum membuahkan hasil, sehingga perlu diteliti lebih lanjut dan dilakukan optimasi. Pada percobaan optimasi media karbohidrat, miselia jamur morel tumbuh paling baik pada media tepung terigu, kemudian tepung beras, dan paling sedikit pada tepung maizena. Miselia tidak tumbuh pada media tepung tapioka

Pre-treatment and Suitable Reagent Enabled a Reliable and Consistent for Molecular Detection of Fusarium oxysporum f. sp. cubense Tropical Race 4 (Foc4)

Fusarium wilt which is caused by the soil-borne fungus, Fusarium oxysporum f.sp. cubense (Foc), is one of important diseases in banana plant. Foc tropical race 4 (Foc4) is the most pathogenic race which could infect various banana cultivars including Cavendish cultivar which was previously considered as resistant cultivar. Molecular detection of Foc using PCR analysis is indispensable to determine the race of Foc. We demonstrate a faster DNA isolation procedure described in previous method by substituting sodium acetate precipitation with ammonium acetate precipitation without affecting the result. Based on our experience, some fungal genomes were troublesome to be amplified. We suggested pre-treatment step prior to amplification procedure by incubating fungal DNA in 65°C for 10 minutes for any samples of fungal genome, including stubborn samples, before mixing into PCR mix reagent. PCR reagents should be tested for stubborn samples since some of the reagents were unable to amplify the desired DNA fragment. Pre-treatment and the choice of robust PCR reagent should be taken into consideration for a reliable and consistent Foc4 molecular detection result

What Should be Mastered by Elementary, Junior and Senior High School Teachers Related to the Concept of Evolution?

Content knowledge is one of the competencies to be mastered by a teacher. Teachers who master content thoroughly and understand the limitations in teaching content to students at different levels are professionals. Online interviews were conducted, and questionnaires were distributed to 9 participants consisting of 3 elementary school teachers, 3 junior high school science teachers, and 3 senior high school biology teachers. This qualitative research aimed to investigate the depth of evolution content that must be mastered by teachers at every level of elementary, junior, and senior high schools. The answers from the participants were analyzed qualitatively using a grounded theory research design. It is known that the three kinds of teachers have different depths of the evolution material from one to the others. Elementary school teachers should master the concept of evolution in the form of signs of an evolutionary process that can be found by students in everyday life. In addition to being required to master elementary school materials, junior high school teachers should master the theories of evolution as well. For senior high school teachers, they are required to have a wider and deeper mastery of the material that includes the meaning, theories, clues, and mechanism of evolution

Characterization of Plant Growth Promoting Rhizobacteria (PGPR) on Capcissum annum

Plant Growth Promoting Bacteria Rhizobacteria (PGPR) is one of the potential bacteria to enhance of Capsicum annuum through inhabitation the growth of pathogenic fungi. This study aimed to characterize PGPR in chili plants (Capsicum annuum). PGPR was isolated from the soil habitat of the red chili plant in Cilegon, Indonesia. Screening was then carried out with the dual culture method on Petri dishes and tested through in vivo method on the red chili plant. The selected bacteria were characterized morphologically, biochemically, and physiologically. The results revealed that there were 14 single isolates of bacteria from the roots of the red chili plants. The five single bacterial isolates, namely Azostobacter, Azospirillum, Pseudomonas, Serratia, and Beijerinckia have good potential as PGPR based on multiple culture screening by producing clear zones and positively effect the growth of chili plants

Endophytic Fungi from Four Indonesian Medicinal Plants and Their Inhibitory Effect on Plant Pathogenic Fusarium oxysporum

The medicinal plants Centella asiatica, Curcuma xanthorrhiza, Guazuma ulmifolia, and Hydrocotyle verticillata are widely used  in Indonesian traditional medicine, but little is known about their associated endophytic fungi. This research aimed to study the diversity of endophytic fungi derived from functional parts of these plants and to evaluate their potential as antifungal agents against the plant pathogenic fungus Fusarium oxysporum. A total of 17 isolates of endophytic fungi were obtained: nine from leaves of G. ulmifolia, three each from leaves of C. asiatica and H. verticillata, and two from rhizomes of C. xanthorrhiza. The genus Colletotrichum was found in all plants studied, but each plant was associated with different species. Colletotrichum aeschynomenes was associated with C. xanthorrhiza, C. siamense was associated with C. asiatica, and C. tropicale was associated with G. ulmifolia and H. verticillata. The species Curvularia affinis, Diaporthe tectonae, Lasiodiplodia mahajangana, Parengyodontium album, Talaromyces trachyspermus, and Speiropsis pedatospora were found only in G. ulmifolia; while Didymella coffeae-arabicae and Muyocopron laterale were found only in H. verticillata. The endophytic fungi showed inhibition activity against F. oxysporum with inhibition values of 6.0-78.9%, T. trachyspermus JBd10 and C. affinis JBd14 gave the highest inhibition activity