Propagation and Preservation Techniques of Trichoderma asperellum T13 and Aspergillus niger A1 Indigenous Inoculants.

Abstract

Indigenous isolates Trichoderma asperellum T13 and Aspergillus niger A1 have been tested in laboratory for their beneficial characteristics such as antagonistic action against Ganoderma boninense, causal agent of main oil palm disease, and phosphate solubilizing activity (respectively). Pre-inoculation trial on solid media gave an optimum condition of two hours of sinking in hot water followed by addition of 5 mL of aquadest prior to autoclave sterilization. The result was based on spores counting and visualization, mycelia production and easiness of spore harvesting. Trial on optimization of propagation media has been carried out during 6 days incubation in room temperature, in semi-transparant polyethylene bag for solid media and Erlenmeyer flask for liquid media. The best solid and liquid media for T. asperellum T13 were millet (5.34 x 1010 cfu/mL) and T3-4 (3.10 x 1010 cfu/mL) and for A. niger A1 were red rice (3.03 x 1010 cfu/mL) and A5 (1.59 x 1010 cfu/mL). Ultra Performance Liquid Chromatography (UPLC) measurement of organic acids and phytohormones showed the capacity for both fungi to produce these two metabolites. The low amount produced could be caused by non optimum trial conditions. The optimum centrifugation speeds for concentrating T. asperellum T13 and A.niger A1 spores were 10,000 g and 6,000 g (respectively). Trial to select the best solid and liquid carrier media has been carried out in semi-transparent polyethylene bag for solid media in dark place at 28oC and screwed essay tubes in refrigerator at 4oC during 42 days preservation. The lowest drop in viability rate that represented the best carrier media for T. asperellum T13 were 67.2% in compost, 82.14% in 0.85% NaCl/ 0.5% CMC and for A. niger A1 were 1.04% in cocopeat, 33.33% in 10% glycerol. No significant decrease observed in chitinase and phosphate solubilizing activities during five weeks preservation in both spores. The irregular pattern of soluble phosphate was probably caused by the use of phosphate by the fungi and possible repetitive chelation of free phosphate by other cations in media. The result showed that the agricultural wastes such as compost and coco peat could be used as good carrier media for bio-products.

Trichoderma asperellum T13 dan Aspergillus niger A1 merupakan kapang indigenus kebun kelapa sawit yang telah diuji kemampuan penghambatan cendawan patogen Ganoderma boninense dan pelarutan fosfatnya secara laboratorium, maupun uji di pembibitan. Penelitian ini terdiri dari tiga kegiatan, yaitu: (1) karakterisasi media perbanyakan dan bahan pembawa spora T.asperellum T13 dan A.niger A1, (2) perbanyakan spora kedua kapang dalam media padat dan cair, dan (3) penyimpanan spora masing-masing kapang dan keduanya dalam bahan pembawa padat dan cair. Analisis karakteristik media dilakukan dengan metode Analisis Komponen Utama, sedangkan penentuan media dan bahan pembawa terbaik menggunakan Analisis Sidik Ragam Anova yang dilanjutkan dengan uji Least Significance Difference (LSD) pada taraf 5%. Hasil penelitian menunjukkan kondisi prainokulasi adalah perendaman selama dua jam dengan penambahan 5 mL akuades sebelum disterilisasi dengan autoklaf. Hasil ditentukan berdasarkan penghitungan dan pengamatan spora secara visual, produksi miselia dan kemudahan panen spora berdasarkan skoring. Perlakuan optimisasi media perbanyakan dilakukan selama inkubasi enam hari dalam suhu ruang menggunakan kantong plastik untuk media padat dan labu Erlenmeyer untuk media cair. Media padat dan cair terbaik untuk T. asperellum T13 adalah millet (5,34 x 1010 spk/mL) danT3-4 (3,10 x 1010 spk/mL) sedangkann untuk A. niger A1 adalah beras merah (3,03 x 1010 spk/mL) dan A5 (1,59 x 1010 spk/mL).