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"Microbial communities usually have mixed populations, only in uniqueenvironmental situations do microorganisms live entirely alone. Thus many types of interactions are possible among the members of an ecosystem?s community. In general, the constant association of different organisms in an ecosystem is referred to as symbiosis, with the associates being called symbionts. One type of a symbiosis is antagonism. Antagonism is a symbiotic relationship in whichone population of microorganisms has a harmful effect on the growth of another microbial population (Batzing 2002: 696). A number of microorganisms (bacteria, yeasts, fungi) which effectivelycontrol postharvest pathogens have been identified as antagonists (Mari and Guizzardi 1998:60). A variety of microbial antagonists were reported to control several different pathogens on various fruits. The organism that suppresses the pest or pathogen is referred to as the biological control agent (BCA) (Pal & Mcspadden Gardener 2006: 1). Biological control may in simple terms be defined as the use of one living organism to control another (Druvefors 2004: 4).Often antagonists are isolated on the surface of plants; this natural presence makes them more likely to succeed because of their colonization ability and environmental adaptation (Mari and Guizzardi 1998:60). The use of yeasts as antagonists appears to be quite promising, although the mechanism has not yet been fully elucidated. Some antagonist yeasts have been reported as biocontrol agent of fungal pathogen on fruits. Zhao et al. (2008: 115--116) reported that tomato fruit treated with Pichia guillermondii had an infection rate of 25% which was caused by Rhizopus nigricans, which wassignificantly lower than the control (41.67%). Kalogiannis et al. (2006: 72) reported that Rhodotorula glutinis Y-44 significantly reduced disease incidence caused by Botrytis cinerea on tomato by 52%, compared to the untreated control. Zhang et al. (2004: 84) reported that the application of Cryptococcus laurentii resulted in low average decay incidence caused by B. cinerea in fruit by 7.1%, compared with 40% in the water-treated control fruit. University of Indonesia Culture Collection (UICC) collected epiphytic yeasts from plant samples of Cibodas Botanical Garden, and moulds from decayed tomatoes and infected plants. The ability of the epiphytic yeasts as biocontrol agents against tomato spoilage-causing moulds has not beenreported. This study consists of two parts. Part 1 is The Antagonistic Ability of Epiphytic Yeasts of Cibodas Botanical Garden on Tomato Plant Infected-Causing Moulds. Part 2 is The Potential of Candida sp. UICC Y-328 as a Biocontrol Agent of Aspergillus ochraceus on Postharvest Tomatoes.The purposes of this study were to investigate the ability of six species of epiphytic yeasts in inhibiting the growth of tomato plant infected-causing moulds, and the potential of Candida sp. UICC Y-328 as a biocontrol agent in reducing postharvest tomato spoilage caused by Asp. ochraceus. The media used for growing the yeasts was Yeast Malt Agar (YMA), and maintenance for fungi was Potato Dextose Agar (PDA). The media used for antagonistic test were PDA and Potato Dextrose Broth (PDB). Antagonistic test by strip method was carried out by using the concentrations of yeast cells at (0.7--4.45) x 108 CFU/ml, and Asp. ochraceus at (7.0--8.1) x 107 CFU/ml, Asp. terreus Thom at (7.7--8.6) x 107 CFU/ml andDrechslera sp. at (0.45--3.5) x 105 CFU/ml. The yeast cells were inoculated 4 hours earlier before inoculation of mould spores on PDA in Petri dishes. Results showed that Candida sp. UICC Y-328 has highest percentage of colony reduction of Asp. ochraceus (56.45%), followed by Metschnikowia reukaufii UICC Y-351 on reducing colonies of Asp. terreus and Drechslera sp. (25.42% and 51.28%, respectively) during 6-day incubation. Antagonistic test by co-culture method was carried out by using the concentrations of yeast cells at (0.7--4.45) x 108 CFU/ml, and Asp. ochraceus at (6.0--8.6) x 107 CFU/ml, Asp. terreus at (4.6--9.5) x 107 CFU/ml. The yeast cells were inoculated 8 hours earlier before inoculation of mould spores on PDB. Results showed that Candida sp. UICC Y-328 reduced the size of conidial heads(5.52%) and hyphae (8.29%) of Asp. ochraceus, at 3-day incubation.Cryptococcus laurentii UICC Y-379 reduced the size of conidial heads and hyphae of Asp. ochraceus (15.07% and 11.60% respectively) and Asp.terreus (12.35% and 24.47% respectively) at 3-day incubation. Antagonistic test by slide culture method showed that the yeast cells of four strains (Candida rancensis UICC Y-326, Cr. laurentii UICC Y-319, Cr. laurentii UICC Y-379,and M. reukaufii UICC Y-351) attached to hyphae of Drechslera sp. after 3- and 4-day incubation.Cells of Candida sp. UICC Y-328 attached to hyphae of Drechslera sp. after 4-day incubation. Cells of Cr. laurentii UICC Y-385 was not able to attach to hyphae of Drechslera sp. Candida sp. UICC Y-328 was potential in reducing the growth of Asp. ochraceus, and was investigated further for its potential as a biocontrol agent. Wounds on postharvest tomatoes were inoculated with 25 µl of yeast cellsuspension and 25 µl of mould spore suspension. The yeast cells wereinoculated 24 hours earlier before inoculation of mould spores on wounds of tomatoes. Biocontrol study showed that incidence of spoilage in postharvest tomatoes which were wounded and inoculated with Candida sp. UICC Y-328 and Asp. ochraceus, were reduced by 20% after 15-day incubation at room temperature. All postharvest tomatoes which were wounded and inoculated with Asp. ochraceus as control, were spoiled (100%). Synthetic fungicide Dithane M-45 at a concentration of 0.08% reduced spoilage incidence by 70%. Candida sp.UICC Y-328 was not effective as biofungicide in reducing spoilage incidence."

"Sektor kelapa sawit (Elaeis guineensis Jacq.) berperan penting dalam perekonomian nasional, tetapi terancam oleh infeksi Ganoderma boninense yang menyebabkan penyakit Busuk Pangkal Batang (BPB). Salah satu upaya pengendalian penyebaran fungi fitopatogen yaitu menggunakan bakteri antagonis. Penelitian ini bertujuan untuk menguji potensi antagonis ko-kultur Bacillus siamensis LDR dan Stenotrophomonas maltophilia G17 terhadap Ganoderma boninense melalui uji antagonis dan antibiosis. Uji antagonis dilakukan menggunakan metode dual culture berupa pour plate dan disc delayed culture pada medium. Filtrat ko-kultur yang difermentasi selama 5 dan 7 hari pada Nutrient Broth (NB) dan NB dengan tambahan glukosa digunakan untuk uji antibiosis menggunakan metode agar well diffusion dan pour plate. Uji antagonis maupun uji antibiosis dilakukan pada medium Plate Count Agar (PCA) dan Potato Dextrose Agar (PDA). Potensi antagonis dan antibiosis ko-kultur bakteri terhadap fungi diukur berdasarkan diameter pertumbuhan fungi yang menunjukkan hambatan menggunakan rumus Growth Inhibition Rate (GIR). Hasil uji antagonis menunjukkan hambatan pertumbuhan fungi mencapai 69.63% ± 2,46% pada metode disc delayed culture sedangkan pada metode pour plate mencapai 100%. Sementara, filtrat hasil fermentasi ko-kultur bakteri berusia 5 hari dan 7 hari menghasilkan senyawa antifungi yang menghambat pertumbuhan fungi uji dengan GIR mencapai 100% pada metode pour plate dan 48,20% ± 2,23% pada metode agar well diffusion. Filtrat hasil fermentasi selama 5 hari menunjukkan performa antibiosis yang lebih baik. Sementara, penambahan glukosa pada proses fermentasi tidak meningkatkan performa antibiosis. Selanjutnya, perlu dilakukan identifikasi senyawa antifungi yang dihasilkan oleh ko-kultur B. siamensis LDR dan S. maltophilia G17.

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The oil palm sector (Elaeis guineensis Jacq.) plays a crucial role in the national economy but is threatened by Ganoderma boninense, causing Basal Stem Rot (BSR). One strategy to control the spread of this phytopathogenic fungus is to employ antagonistic bacteria. This research aims to assess the antagonistic potential of co-cultured Bacillus siamensis LDR and Stenotrophomonas maltophilia G17 against G. boninense through antagonism and antibiosis assays. Antagonism assays were conducted using pour plate and disc delayed culture methods. Fermented co-culture filtrates (5 and 7-day) in Nutrient Broth (NB) and NB supplemented with glucose were utilized for antibiosis assays, using agar well diffusion and pour plate methods. Both assays were conducted on Plate Count Agar (PCA) and Potato Dextrose Agar (PDA) media. Potency of bacterial co-culture against G. boninense were evaluated based on the inhibition diameter of fungal growth, calculated using the Growth Inhibition Rate (GIR) formula. The antagonism assay results showed fungal growth inhibition of 69.63% ± 2.46% with the disc delayed culture, while the pour plate achieved 100% inhibition. Meanwhile, the filtrate from the 5 and 7-day fermented bacterial co-culture produced antifungal compounds that inhibited fungal growth by 100% using the pour plate and 48.20% ± 2.23% using the agar well diffusion. The 5-day fermented filtrate showed better antibiosis performance. The addition of glucose during the fermentation process did not enhance antibiosis performance. Further identification of antifungal compounds produced by the B. siamensis LDR and S. maltophilia G17 co-culture is needed."

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Bacillus spp. berpotensi sebagai agen biokontrol untuk meminimalisir kontaminasi mikroorganisme. Tujuan dari penelitian ini adalah untuk mengetahui aktivitas antagonistis sel dan filtrat Bacillus siamensis LDR terhadap beberapa spesies kapang. Purifikasi dan karakterisasi morfologi dilakukan pada medium PDA. Uji aktivitas antagonistis dilakukan dengan metode dual kultur dan uji antibiosis dilakukan dengan menggunakan filtrat fermentasi B. siamensis LDR yang diperoleh dari panen hari ke-12 dan ke-14. Persentase inhibisi ditentukan berdasarkan perhitungan pertumbuhan radial dan biomassa kapang yang diberi perlakuan, dibandingkan dengan kontrol. Hasil uji antagonistis menunjukkan bahwa Fusarium oxysporum, Aspergillus flavus AHM, dan Aspergillus clavatus ABH berhasil dihambat sebesar 35,92%, 42.75%, 27.18% pada teknik dual disc dan sebesar 92.94%, 87.15%, 85.45% pada teknik pour plate disc. Hasil uji antibiosis menunjukkan inhibisi F. oxysporum, A. flavus AHM, dan A. clavatus ABH lebih tinggi pada filtrat 14 hari, yaitu 41.84—41,94%, 34,83—36,04%, 63.27—63,81% pada medium PDA dan 53,15—76,37%, -151— -11.01, 88.87—90.36% pada medium PDB. Sel dan filtrat B. siamensis LDR memiliki aktivitas antagonistis terhadap Fusarium oxysporum, Aspergillus flavus AHM, dan Aspergillus clavatus ABH dengan ketidakstabilan aktivitas antibiosis terhadap A. flavus AHM, secara in vitro.

 

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Bacillus spp. are potential biocontrol agent to reduce crop contamination by microorganism. Aim of this research is to screen antagonistic activity of B. siamensis LDR cells and filtrate against few species of filamentous fungi. Purification and morphological characterization were done on PDA. Screening of antagonistic activity was done by antagonistic assay using dual culture method and antibiosis assay using 12 and 14 days fermentation filtrate of B. siamensis LDR. Percentage of inhibition were determined by comparing radial growth and biomass of treated fungi to untreated fungi as control. Result of antagonistic assay showed Fusarium oxysporum, Aspergillus flavus AHM, and Aspergillus clavatus ABH were inhibited for 35,92%, 42.75%, 27.18% by using dual disc technique and 92.94%, 87.15%, 85.45% by using pour plate disc technique, respectively. Result of antibiosis assay showed the highest inhibition activity against F. oxysporum, A. flavus AHM, A. clavatus ABH was found in 14 days fermentation filtrate, which were 41.84—41,94%, 34,83—36,04%, 63.27—63,81% on PDA and 53,15—76,37%, -151— -11.01, 88.87—90.36% on PDB, respectively. Therefore, B. siamensis LDR cell and filtrate has antagonistic activity against Fusarium oxysporum, Aspergillus flavus AHM and Aspergillus clavatus ABH, despite of unstable antibiosis activity against A. flavus AHM, in vitro.

 

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"ABSTRACTBiological control of postharvest diseases of fruits and vegetables byantagonistic microorganism seems increasingly promising to replace the use of synthetic fungicides which are subjected to some limitation due to development of fungicides-resistant strain of the pathogens and risk for consumers and the environment (Lima et al, 1999). Several species of yeast have been reported to reduce postharvest fungal decay on fruits. One of the antagonistic yeast that has been use as commercial biocontrol is Metchnikowia fructicola in Shemerm product (Vero et al., 2002) Yeast Rhodotomla has been studied for the postharvest biologicalcontrol various mould pathogens on various fruit (Castoria et al., 1997).University of Indonesia Culture Collection (UICC) have Rhodotorula spp.strains from plants of Cibodas Botanical Garden, and moulds frompostharvest decayed-tomatoes and plants. The ability of these yeast strains as biocontrol agents against has not been reported.This thesis consists of two parts. Part 1 is entitled The antagonisticActivity of Rhodotorula spp. from Cibodas Botanical Garden Against Tomato Plant Infected-Causing Moulds. Part 2 is entitled The Potential of Rhodotorula sp. UICC Y-381 as Biocontrol Agent of Aspergillus ochraoeus on Postharvest Tomatoes. The objectives of this research are to obtain a potential Rhodotorula sp. with antagonistic activity against tomato infected-causing moulds, and to obtain infoimation on the ability of Rhodotorula sp. UICC Y- 381 as a biocontrol agent in reducing the severity of decay by Aspergillus ochraceus. The research was carried out in Laboratory of Microbiology, Department of Biology, and Center of Excellence Indigenous Biological Resources-Genome Studies (CoE IBR-GS), Faculty of Mathematics and Natural Sciences, from July 2008-July 2009.Yeast Malt Agar (YMA) was used for yeast growth medium, and PotatoDextrose Agar (PDA) was used for maintenance of fungi. The media PDA and Potato Dextrose Agar (PDB) were used for antagonistic test.Six strains of Rhodotorula spp. (Rhodotorula sp. UICC Y-318,Rhodotorula sp. UICC Y-325, Rhodotorula sp. UICC Y-332, Rhodotorula sp. UICC Y-381, Rhodotomla sp. UICC Y-384, and Rhodotorula sp. UICC Y-386) were investigated as antagonistic yeasts against Aspergillus ochraceus D1.2.2.SSM3, A. terreus D2.2.MC, and Drechslera sp. D1.3.MC. The yeasts were obtained from plants of Cibodas Botanical Garden, and the moulds were obtained from decayed tomatoes and infected plants, belonging to the University of Indonesia Culture Collection (UICC). Antagonistic test by strip method was carried out by usingconcentration of yeast cells at (1 .2-5.2) x 10° CFU/ml, and A. ochraceusD1.2.2.SSM3 at 4.7 x 10? CFU/ml, A. terreus D2.2.Mc at 3.2 x 10° CFU/ml,and Drechslera sp. D1.3.MC at 5.2 x 10? CFU/ml. Inoculation of the yeastcells on PDA was carried out 4 hours earlier before inoculation of mouldspores on petri dishes. Results showed that highest percentage reduction of mould colonies was shown by Rhodotorula sp. UICC Y- 325 againstDrechslera sp. (28.12%-72.14%), followed by Rhodotorufa sp. UlCC Y-381 against A. ochraoeus (54.28%-72.46%), and Rhodotoruta sp. Y-318 against A. terreus (21.76% - 58.10%) during 6-day incubation.Antagonistic test by co-culture method was carried out by usingconcentration of yeast cells at (1 .58-5.59) x 10° CFU/ml, and Aspergillus ochraceus D1.2.2.SSM3 at 7 x 10? cFU/ml, A. terreus D2.2.MC at 1.5 x 10? CFU/ml. Inoculation of the yeast cells on PDB was carried out 8 hours earlier before inoculation of mould spores on broth medium. Results showed that highest percentage reduction of conidial heads and hyphal width was shown by Rhodotorula sp. UICC Y-381 against A. ochraceus (9.45% and 12.43%; 7.10% and 7.51 %, after 2- and 3-day incubation, respectively). Rhodotorula sp. UICC Y-332 reduced conidial heads of A. terreus (10.17% and 9.60% after 2- and 3-day incubation) but, was not able to reduce hyphal width of A. terreus. Microscopic observation by slide culture method on PDA showed that there was attachment of Rhodotorula spp. cells to the hyphae of Drechslera sp., however, Rhodotorula spp. UICC Y-386 attached more intensively and colonized the hyphae.The ability of Rhodotorula sp. UICC Y-381, which was isolated fromplant leaves, as a biocontrol agent against postharvest tomato fruit decay- causing mould Aspergillus ochraceus D1 .2.2.SSM3 was evaluated. Observation was carried out for 15 days at 25°C - 27°C. Results showed that Rhodotorula sp. UICC Y-381 was able to reduce the severity of decay by A.ochraceus with 100% reduction until day-12, when compared to control. The synthetic fungicide Dithane M-45 at a concentration of 0.08% reduced the severity of decay to 100% until 15-day incubation."

"Penelitian ini dimaksudkan untuk mengeksplorasi Pilkada Makassar yang merupakan satu-satunya pilkada calon tunggal yang berakhir dengan kekalahan calon tunggal. Pasangan calon tunggal yang kalah bukan petahana maupun kerabat petahana. Pertanyaan penelitian adalah mengapa terjadi pilkada calon tunggal dan pasangan calon tunggal kalah serta bagaimana dinamika kompetisi yang terjadi? Penelitian dilakukan dengan metode kualitatif, menggunakan teori boundary control Edward Gibson (2012) dan antagonistic cooperation Heinrich Best (2010) serta otonomi elit Etzioni-Halevy (1993). Argumen penelitian adalah terjadi kerja sama antagonistik antar elit serta dinamika boundary control antara petahana walikota dan penantang yang menyebabkan pilkada menjadi kompetisi calon tunggal dan pasangan calon tunggal kalah. Pilkada calon tunggal terjadi karena keberhasilan nasionalisasi oleh penantang melalui pelibatan elit nasional. Terdapat dua mekanisme pelibatan elit nasional yaitu melalui party-led transitions dan center-led transitions. Petahana hanya berhasil merespon party-led transitions dengan mendaftar melalui jalur perseorangan. Petahana tidak dapat bertahan menghadapi center-led transitions sehingga didiskualifikasi. Setelah pilkada calon tunggal terjadi, petahana melakukan penguatan (boundary strengthening) melalui parokialisasi kekuasaan, sebagai respons terhadap gugatan hukum lawan yang menyebabkannya didiskualifikasi. Parokialisasi kekuasaan terjadi berupa penguatan birokrasi dan RT/RW serta mobilisasi isu ke ruang publik secara maksimal. Saat bersamaan pasangan calon tunggal gagal mempertahankan boundary opening dengan lemahnya citra figur. Koalisi pasangan calon tunggal lemah dalam mengantisipasi banyaknya kepentingan strategis pada kolom kosong seperti proyeksi elit untuk pilkada berikutnya, munculnya sentimen negatif terhadap korporasi politik, protes atas party-led transitions dalam penetapan calon serta respon terhadap dinamika politik berdasar nilai budaya lokal. Pilkada Makassar terdiri dari dua fase interaksi elit yang melibatkan elit lokal, elit nasional dan elit partai politik berupa mekanisme penguatan diri dan pelemahan terhadap lawan.

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Makassar local election was the only one single-candidate election which the candidate failed to win the election. The failed single-candidate were not an incumbent nor had relationship with the incumbent. The research questions are: Why did the single candidate election happen, why did the single-candidate could be failed and how did the dynamic competition among elites The research was conducted by qualitative method using Edward Gibson`s (2012) boundary control theory, antagonistic cooperation theory of Heinrich Best (2010) and elite autonomy theory of Etzioni-Halevy (1993). The research argument is there were elites antagonistic cooperations as well as dynamic of boundary control between incumbent of mayor and his competitors which caused the election turned into single-candidate election then ended up with the failed of single-candidate. The single-candidate election caused by the success of opposition nationalization carried out by national elites. There were two transitions which national elites involved i.e. through party-led transitions and center-led transitions. The incumbent did the boundary strengthening after the party-led transitions by registered as a candidate independently (without political party stripe). The incumbent failed to do boundary strengthening after the center-led transitions which caused him to be disqualified from the election. As the single-candidate election ensued, the incumbent did boundary strengthening by parochialization of power in response to the opposition`s lawsuit that had caused him been disqualified. Parochialization of power consisted of the strengthening of bureaucracy, RT/RW, as well as the mobilization of issues to the public. At the same time the single candidate failed to maintain their boundary opening with the weakness of candidates in political experiences. The coallition could not anticipated many important interests of its opponent (kolom kosong) such as many elites strategies for the next election, negative sentiment of political corporation, protest over party-led transitions and respons to political dynamic based on local culture. Makassar local election consists of two elit interaction phases which involved of local elites, national elites, and political party elites such as self-strengthening and weakening against the opponent."