ABSTRACTThe growth character and nitrification activity of nitrifying cultures (N-Sw). Theculture of nitrifiers (N-Sw) was obtained from acclimated sludge of sawit palm oil industrywastewater. The growth and nitrification activity of those cultures were investigated.The result shows that the growth and nitrification activity attained optimum at pH 7-8,and temperature of 30 0C. The culture of nitrifiers was still growing at pH 5, but thenitrification activity was not detected. The growth of nitrifiers and the nitrification activitywas inhibited at 40 0C. The ammonium conversion rate reached 0,088-0,090 mg NNH4+/L/hour/g biomass. The rate of ammonium conversion in the bioreactor increasedto 0.630 mg N-NH4+/L/hour/g biomass as the pH maintained at 7.5-8 and dissolvedoxygen at 3-4 mg/l O2.Key words: nitrifying culture, ammonium, ammonium convertion rate
Banana wilt disease caused by Fusarium oxysporum f.sp.cubense is considered as one of the most destructive diseases on banana plants in the tropical region. Biological control agents (BCA?s) have become a promising solution to overcome this disease. The objective of this study was to find potential BCA?s for wilt disease of banana plants. Bacteria and actinomycetes were isolated from banana?s rhizosphere in Lampung and Cianjur. As much as 64 actinomycetes and 142 bacteria isolates were obtained. Antagonistic test against F. oxysporum f. sp. cubense of those isolates showed that 21 bacteria and 10 actinomycete isolates have abilities to inhibit F. oxysporum f. sp. cubense. Actinomycetes showed relatively higher inhibition against F. oxysporum f. sp. cubense compared to bacteria. Isolates which have positive antagonistic activities against F. oxysporum f. sp. cubense were then tested for their protease, chitinase, and selulase activities qualitatively on specific medium. All actinomycetes which were tested had chitinase enzyme activities, while only 5 bacterial isolates had chitinase activities. On the other hand, 13 bacterial isolates showed protease activities and only 1 actinomycete showed protease activity. Two bacterial isolates (L.II.4.ND and L.A.I-5.DW) and 3 actinomycetes (L.A.I.DW, L.3.1.DW and Ci.I.A5.DW) which showed high inhibition against F. oxysporum f. sp. cubense and lyses enzymes activities were identified based on 16S rRNA genes. Analysis based on GenBank data, those isolates have 99% homology to Klebsiella pneumonia (L.II.4.ND), Burkholderia sp. (L.A.I-5.DW), Streptomyces sp. (L.A.I.DW), Streptomyces sp. (L.3.1.DW) and Streptomyces sp. (Ci.I.A5.DW).
Untuk mendukung suatu sistem pertanian yang berkelanjutan, praktek pertanian organic dilakukan pada kultivasi kacang tanah. Pada penelitian ini, pengkombinasian antara penggunaan bakteri pelarut fosfat (Pseudomonas sp.), bakteri penambat nitrogen (Rhizobium spp.), dan fungi pendegradasi selulosa (Trichoderma sp. dan Aspergillussp.) digunakan untuk inokulan. Kompos berupa bahan hijauan daun dan limbah kotoran ternak kemudian diformulasikan dengan inokulan untuk digunakan sebagai pupuk hayati. Kompos-matang dan kompos-setengah-matang fermentasi digunakan untuk pengkayaan hara tanah. Penggunaan kompos setengah matang merupakanpraktek semi-on-site-composting di dalam upaya menstimulasi pertum-buhan tanaman. Pengaruh perlakuan pada penelitian ini dievaluasi melalui pertum-buhan tanaman dan hasil polong. Tidak didapat perbedaan yang signifikan di antara perlakuan pupuk hayati, namun seluruh perlakuan memperlihatkan perbedaan yang nyata terhadap kontrol.Oleh sebab itu, praktek pengunaan kompos setengah matang mampu mempersingkat persiapan tanam dan dapat diterapkan pada kultivasi kacang tanah. Penggunaan kompos separuh matang hasil penelitian ini dapat dipraktekan di dalam pengembangan tehnik kultivasi untuk mendukung sistem pertanian berkelanjutan. Kata kunci : pupuk hayati, semi-on-site-composting, sistem pertanian berkelanjutan, Arachis hypogea L. AbstractIn order to support a sustainable agriculture system, an organic farming purpose had been carried out all through groundnut cultivation. In this experiment, the combination of phosphate solubilizing bacteria (Pseudomonas sp.), fixing nitrogen bacteria (Rhizobium spp.), and fungal degrading cellulose (Trichoderma sp. and Aspergillus sp.) were used as inoculant. Organic substrate as a green manure compost and cattle waste was mixing with the inoculant to utilize into biofertilizer improvement. Full and half fermented compost materials designed for soil augmentation. Half fermented compost materials exploited to semi-on-site-composting practice in appropriate to fuel plant growth. Result of the treatment evaluated through plant growth and the pods yield. There have not significant different among biofertilizer handling, and all have the exclusion to the control. As due
Experiment using organic fertilizer and microbial community to support the growth of Tectona grandis L.f in the cyanide contaminated-soil has been conducted in gold tailing pond Cikotok. Microbes used in this experiment were mixed of cyanide degradingbacteria,Nitrogen fixing-bacteria, and Phosphat solubilizing-bacteria. The results show that the microbes given in the Tectona grandis L.f plantation was significantly supporting the growth of the plants and reduced cyanide from the contaminated soil, but did not influence the microbe population of the soil.Key word: Phytoremediation, Cyanide, Tectona grandis L.f.
Potensi bakteri denitrifikasi dalam mendegradasi senyawa Carbaryl dalam kondisi anaerobik dipelajari. Penelitian diawali dengan aklimatisasi kultur mikroba yang berasaldari tanah pertanian tercemar pestisida di daerah Lembang dan Dieng, dalam media denitrifikasi yang mengandung Carbaryl. Dari hasil aklimatisasi diperoleh 3 kultur mikrobadenitrifikasi (CL, CD dan D3) yang mengindikasikan mampu tumbuh pada media yang mengandung 1000 ppm Carbaryl. Hasil isolasi dari ketiga kultur tersebut diperoleh 10 isolat bakteri murni. Enam isolat bakteri (CL1, CL2, CD1, CD2, D3.1, D3.2) diuji aktivitas denitrifikasi dan kemampuan degradasi Carbaryl pada kondisi anaerobik. Hasilpengujian menunjukkan bahwa keenam isolat bakteri mampu tumbuh dan melakukan aktivitas denitrifikasi serta memperlihatkan indikasi mampu mendegradasi Carbaryl,dengan terbentuknya senyawa 1-Naphtol. Reaksi denitrifikasi dan degradasi Carbaryl berlangsung secara simultan. Ada dua pola perubahan Carbaryl oleh bakteri denitrifikasi yang diuji, yaitu bakteri denitrifikasi yang hanya mampu merombak Carbaryl menjadi 1-Naphthol dan bakteri denitrifikasi yang dapat merombak Carbaryl menjadi 1-Naphthol dan senyawa tertentu lainnya (belum terdeteksi).
ABSTRACTPlant Growth Promoting Rhizobacteria (PGPR) are a group of bacteria known to influence plant growth by direct or indirect mechanisms. In search of efficient PGPR which potential as biofertilizers, a total of 26 isolates of rhizobacteria were isolated from various plant rhizosphere. These 26 isolates were screened through in vitro methods for PGPR properties like phosphate solubilization, siderophore, IAA and amonia production, and catalase activity. The result revealed that 9 isolates showed positive activities for phosphate solubilization 17 isolates for IAA production 18 isolates for siderophores 19 isolates for ammonia production and all of the isolates have catalase activities . Only four isolates (Az.KT.CSC, Az.D.8B, Az.D.8A and Az.Lo.10B) exhibited multiple plant growth promoting traits viz., phosphate solubilization, siderophore, IAA, amonia production, and catalase activity. Ten isolates that have different characters were further investigated for quantitative analysis of IAA production, HCN production and its effect on germination and seedling growth of Zea mays. The range of IAA production was 3,12â 134,27 ppm, among ten isolates, Az.D.8B isolate produced the highest IAA (134,27 ppm). Production of HCN was detected in eight isolates. Four isolates positively affected the germination of Zea mays seeds. Highest root elongation was recorded when seeds were treated with Az.Lo.5 isolate. Whereas, the highest chlorophyl content and plant high were recorded when seeds were treated with Az.B.8B isolate.Keywords: N-fixing bacteria, PGPR, IAA, siderophore, catalase
Ultisols are potential for growing soybean However, the soils are considered as acid soils having pH <5,5 hindering availability of several nutrients to support plant growth. The problem can be overcome by application of fertilizers and soil amendment fertilization. This study that was aimed to elucidate the effects of application of PGPR (Plant Growth Promoting Rhizobacteria), lime, and compost on soybean growth on an ultisol of Bogor, used RALF (Factorial Complete Random Design) with 2 factors. The first factor was planting medium with 2 levels (Soil + Compost) and (Soil + Lime) and second factor of PGPR formula with 5 levels (F0 control, F1 soybean bacteria formula, F2 bacterial formula of Root and Tuber Crops Institute, F3 bacterial formula of beans, and F4 formula bacteria of other plant). The results showed that soil + compost treatment had more effect on soil biochemical and plant growth than lime + soil. The treatment of soybean bacteria formula (F1) was most effective in increasing ammonium, nitrate and total population of bacteria. The treatment of bacterial formula of Root and Tuber Crops Institute (F2) had an effect of soil plant growth.
ABSTRACTNitrite Oxidation by Heterotrophic Bacteria Under Aerobic Condition. The nitrite transformingactivities of heterotrophic bacteria from isolates from agriculture soil, Lampung were studiedunder aerobic conditions. Among the 9 bacterial isolates tested, almost all are reported haveability to consume of nitrite, but none of the bacterial isolates formed significant nitrate in themedium. NOB H1 (Bacillus licheniformis), is denitrification-negative, consumed 16. 4 mg/L ofnitrites with the accumulation of 4.45 mg/L nitrates. While, NOB H8 (Pseudomonas sp.) isdenitrification-positive, consumed 49. 64 mg/L of nitrite with the accumulation of 3.34 mg/Lnitrates. Nitrite oxidations of both isolates NOB H1 and NOB H8 took place during stationeryphase to the dead phase. Growth pattern of both isolates NOB H1 and NOB H8 were sigmoidwith generation time of 1.69 and 2.19 hour, respectivelyKey words: heterotrophicbacteria; nitrite oxidation; denitrification
Efficiency of biodegradation of organic carbon and ammonium of sawit palm oil industry wastewater was investigated by using batch reactor with fluidized porous support particles.Two bioreactors, each had an effective volume of 3.0 L, were operated in parallel. Bioreactor-l is a batch reactor with fluidized porous support particles and bioreactor-ll is a suspended growth reactor.The wastewater consisting of 1500-2000 mg/L COD and 50-60 mg/L nitrogen was fed by fill and draw mode with one cycle per day,where 1.5 L treated water was drawn before adding the new wastewater.Efficiency of COD degradation and nitrification were calculated by measuring concentration of COD, ammonium-N, nitrite-N and nitrate-N.The experimental results showed that efficiency of COD degradation and nitrification tend to be higher in the bioreactor-l than in the bioreactor II.The highest efficiency of COD degradation in the reactor-l was 83.7% and in the bioreactor-ll was 63.44 %.The highest efficiency of nitrification in the bioreactor-l and bioreactor-ll was 76.72% and 56%, respectively.Ammonium removal occurred in the bioreactor might not only by biological nitrification, but also by other phisical or chemical processes.
The addition of zeolite into the mix culture of nitrifying bacteria N-Sw was investigated in order to improve the nitrification activity. In this experiment, the ammonium conversion was investigated by zeolite as a sole agent and also mixed with nitrifying culture N-Sw.The mix culture of nitrifying bacteria N-Sw was developed from the sludge of wastewater treatment of palm oil industry, which acclimated by ammonium sulfate for about one year. The result show that the nitrification efficiency on the treatment using nitrifying culture N-Sw was 30.76%, the ammonium elimination rate was 7.46 mg N-NH /L/hour.The addition of 10 g/l zeolite, increase both the nitrification efficiency (64.58%), and the ammonium elimination rate (14.0 mg N-NH /L/hour).The nitrification efficiency increased to be 100% on the second and third day operation, and the ammonium elimination rate was increased to be 22.4â22.9 mg N-NH /L/hour. From this experiment indicated that the role of zeolite on the improving the nitrification activity was as an absorbent of ammonium.