Abstract. Laccase has been produced in a solid state fermentation (SSF) using white rot fungi and various lignocellulosic based substrates. White rot fungi used were Marasmius sp, Trametes hirsuta, Trametes versicolor and Phanerochaete crysosporium. The solid substrates employed in this research were collected from agriculture waste which were empty fruit bunches (EFB), rice straw, corn cob, and rice husk. The objective of this research was to determine the most promising fungus, the best solid substrate and the optimal conditions for the production of laccase. The results showed that Marasmius sp. on all solid substrates displayed higher laccase activity than that of any other strain of white rot fungi. Marasmius sp. and solid substrate of rice straw demonstrated the highest laccase activity of 1116.11 U/L on day 10. Three significant factors, i.e. pH, temperature and yeast extract concentration were studied by response surface method on laccase production using Marasmius sp and rice straw. The optimized conditions were pH, temperature and yeast extract concentration of 4.9, 31ºC and 0.36 g/L respectively. The fermentation of Marasmius sp. in SSF on agricultural waste shows a great potential for the production of laccase.
Natural fiber-reinforced composites can reduce the use of synthetic fibers and resins, making them more environmentally friendly. Bamboo fiber is a long fiber from non woody plant with a shorter growing season than wood. A study has been conducted to investigate the potential of bamboos, which are endemic in West Java, namely Tali bamboo (G. apus), Temen bamboo (G. pseudoarundinacea) and Haur bamboo/Green ampel (B. vulgaris v. Green), as sound absorber composite materials. Bamboo contains 21% - 22 % lignin, 44% - 53% alpha cellulose, 21% - 23% hemicelluloses, which makes it a potential pulp feedstock. Because of the adhesive nature of lignin, it is necessary to produce a pulp with a Kappa number of about 30 (+ 5% lignin). In accordance with bamboo characteristics, Tali bamboo requires less amount of cooking chemicals due to its lower contents of extractive substances and lignin, whereas Temen bamboo and especially Haur bamboo require more chemicals. Therefore, tali bamboo was chosen to produce pulp by Kraft cooking process. Subsequently, bamboo fiber was prepared by soda cooking process at the same conditions. Later on, some trial experiments with epoxy resin were performed to make sound absorber composites. The results show that at the reference frequency (5000 Hz) the pulp and bamboo fiber composites provide the maximum sound absorption coefficients (α) of 0.28 and 0.77, respectively. Hence, the composite meets the minimum standard of sound absorption coefficient of ISO 11654:1997 (α = 0.25). Moreover, the composite of epoxy and bamboo fiber is light (specific gravity <1) with an ability to reduce 97% of the sound at 2500 Hz.Keywords : fiber and pulp bamboo, nonwood, sound absorber composite, sound absorption coefficien ABSTRAK Komposit berpenguat serat alam, dapat mengurangi pemakaian serat sintetis dan resin, sehingga lebih ramah lingkungan. Serat bambu termasuk serat panjang non kayu dengan masa tanam lebih singkat dibanding kayu. Penelitian terhadap bambu endemik Jawa Barat, yaitu bambu Tali (G. apus), Temen (G. pseudoarundinacea) dan Haur/Ampel hijau (B. vulgaris v. green), dilakukan untuk mengetahui potensinya sebagai komposit peredam suara. Dari hasil uji diketahui bahwa bambu tersebut mengandung lignin 21% - 22%, selulosa alfa 44% - 53% dan hemiselulosa 21% - 23%, serta merupakan serat panjang yang berpotensi untuk menghasilkan pulp yang baik. Lignin pada pulp untuk bahan komposit masih diperlukan, sehubungan dengan sifatnya sebagai perekat, sehingga dilakukan penelitian untuk menghasilkan pulp bambu dengan bilangan Kappa sekitar 30 (lignin + 5%). Atas dasar karakteristiknya, pemasakan bambu Tali akan memerlukan zat kimia yang terendah karena kandungan zat ekstraktif dan lignin yang lebih rendah, sedangkan bambu Temen dan terutama Haur sebaliknya memerlukan zat kimia yang lebih tinggi. Oleh karenanya dipilih bambu Tali untuk dilanjutkan pada pembuatan pulp dengan pemasakan proses Kraft dan untuk mendapatkan seratnya dilakukan pemasakan dengan proses soda pada kondisi sama, yang kemudian dilakukan uji coba pembuatan komposit peredam suara dengan resin epoksi. Dari hasil uji diketahui bahwa pada frekuensi acuan (5000 Hz) komposit pulp dan serat bambu memberikan koefisien serap bunyi maksimum (α) sebesar 0,28 dan 0,77, berarti dapat memenuhi standar minimal koefisien serap bunyi sesuai ISO 11654:1997 (α = 0,25), terutama komposit epoksi/serat bambu, karena mampu meredam suara sampai 97% pada frekuensi 2500 Hz, dan lebih ringan (berat jenisnya < 1).Kata kunci: serat dan pulp bambu, non kayu, komposit peredam suara, koefisien serap bunyi
White rot fungi have an ability to degrade lignin by employing lignin-degrading enzymes i.e Lignin Peroxidase, Manganese Peroxidase and Laccase. Therefore, the fungi can be utilized on the pretreatment of biomass in pulp making (biopulping) and biobleaching. In this study, the pretreatment using White Rot Fungi of Marasmius sp. has been conducted on the the Oil Palm Empty Fruit Bunches (EFBs). Marasmius sp. has been grown on EFBs for 30 days. The results showed that the lignin content could be removed by 35.94%. However, cellulose and hemicelluloses relatively did not show any changes in the EFBs. From the pulping process, the pretreatment exhibited the Kappa Number of 31.10. Compared to no pretreatment of white rot fungi, the Kappa Number obtained was 38.63. This result demonstrated a promising process for a green pulp making.
Jamur pelapuk putih, Marasmius sp. merupakan jamur yang menghasilkan enzim lakase dengan aktivitas tinggi. Lakase merupakan enzim ligninolitik yang dapat mendegradasi lignin. Kemampuan ini dapat digunakan untuk proses pengolahan awal bahan lignoselulosa pada pembuatan bioetanol. Produksi lakase dilakukan dalam labu dengan modus batch menggunakan fermentasi kultur padat. Optimisasi produksi enzim lakase dengan metode fermentasi padat dilakukan dengan rancangan percobaan faktorial penuh. Pengaruh ukuran partikel, kelembapan, dan konsentrasi Cu diuji dengan medium penyangga jerami dengan menambahkan gliserol dalam medium Kirk termodifikasi sebagai sumber karbon. Penelitian ini menunjukkan bahwa ukuran jerami tidak berpengaruh signifikan terhadap aktivitas enzim. Aktivitas enzim lakase maksimum terjadi pada saat kelembapan 61% dan konsentrasi Cu 0,1 mM dengan aktivitas enzim lakase/berat kering tertinggi mencapai 4,45 IU/g.
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