Judul: Enzymatic Deinking Of Pulp From Laser Print Paper
Abstrak: The objective of this research is to evaluate the physical and chemical properties of pulp from waste laser print paper. The waste paper was pretreated with 1 % lipase (based on oven-dried pulp) for repulping. After repulping, pulp slurry was floated at two conditions : alkaline flotation and acidic flotation. The result of the research shows that brightness increased in the added lipase, reach the maximum brightness after flotation by increased ash content. Residual ink area and particle size distribution decreased in the lipase addition. Furthermore, they can increase deinkability factor. The enzymatic deinking can change cellulose structure with the formation of carboxyl groups and increasing index of crystallinity. The Water Retention Value (WRV) with centrifuge method at 3000 G, increased in the added lipase with existence of carboxyl groups. Lipase and acidic treatment can increase the viscosity of pulp. Enzymatic treatment can increase strength properties of deinked pulp.
Keyword: 

Judul: Isolasi lakase dari jamur pelapuk putih PSM01 dengan teknik kromatografi penukar ion dan filtrasi gel
Abstrak: Aplikasi enzim dalam industri pulp dan kertas mulai berkembang pesat sejak pertengahan tahun 1980, terutama dalam proses pemutihan pulp kraft atau sulfat (Bajpai, 1999). Pemutihan pulp berarti penghilangan residu lignin dari pulp kimia yang bertujuan untuk meningkatkan derajat keputihan. kertas dan memperbaiki mutu kertas Proses penghilangan pulp sulfat hanya menghilangkan sekitar 90% lignin, sedangkan residu lignin 10% akan tertinggal dalam pulp berupa senyawaan dengan struktur terkonyugasi seperti kuinon, katekol kompleks, kalkon, dan stilbena. Senyawaan ini akan menyebabkan pulp berwarna kecoklatan. Awalnya penghilangan residu lignin dilakukan secara kimiawi dengan proses klorinasi, dilanjutkan dengan ekstraksi alkalin (Loras, 1980). Klorin berikatan dengan lignin dan komponen pulp lainnya membentuk substansi organik klorin yang bersifat toksik, mutagen, dan karsinogenik dengan kadar lignin yang tinggi (Ander et al., 1977; Eriksson et al., 1979). Limbah pulp ini mencemarkan lingkungan dan perlu diolah kembali dengan cara delignifikasi oksigen, memperpanjang waktu pemasakan pulp, atau mengganti klorin dengan ozon atau hidrogen peroksida. Cara tersebut dapat menghilangkan klorin dalam pemutihan pulp sulfat, tapi kurang efektif karena memerlukan berbagai proses modifikasi dan biayanya mahal. Penelitian mulai beralih kepada pemutihan pulp sulfat secara biologis dengan memanfaatkan mikroorganisme secara langsung. Kirk & Chang (1981) melaporkan bahwa jamur pelapuk putih sebagai produsen enzim pendegradasi lignin sangat efektif digunakan dalam proses delignifikasi pulp sulfat. Tetapi pemanfaatan jamur secara langsung dalam proses tersebut memerlukan waktu selama 5 hari, sedangkan proses klorinasi di pabrik pulp dan kertas hanya berlangsung selama 18 jam sehingga kapasitas produksinya lebih sedikit ....
Keyword: 

Judul: Distribution and Diversity of Ectoparasite Mites on Geckos in Indonesia
Abstrak: Data on the diversity and dispersal of parasitic mites on house geckos in Indonesia are very scarce. In this work, the distribution and diversity of mites living on three species of house geckos, namely Cosymbotus platyurus, Hemidactylus frenatus, and H. garnotii collected throughout Indonesia, has been elaborated. Geckos and mites were captured and immediately preserved in 70% ethanol. Whole mount of the mites was prepared by clearing in lactophenol followed by mounting on polyvinyl lactophenol solutions. The SEM preparation was conducted to examine the detail morphological characters of the mites. The results showed that among 448 individuals of geckos, 221 geckos were infected by Geckobia mites. Prevalences of C. platyurus, H. frenatus, and H. garnotii infested by mites were 14.8%, 50.69%, and 79.6%, respectively. Three different spesies of Geckobia (G1, G2, and G3) could be differentiated; and based on similarities of their morphological characters to ones described in published literatures, Geckobia G2 is Geckobia glebosum and Geckobia G3 is Geckobia bataviensis while G1 could not be identified to the species level. The highest mean intensity of Geckobia G1 infestation was found on H. garnotii (I=7.0), G. glebosum infestation on H. frenatus (I=3.5), and G. bataviensis infestation on H. garnotii (I=11.8). In general, C. platyurus was infested by the least number of mites. Geckobia G1 were found living on the skin folds on the claws, G. glebosum were found mainly on the body and thigh, and G. bataviensis were found on almost all parts of the host’s body. Geckobia mites are distributed randomly throughout Indonesian Archipelago, following the pattern of distribution of their hosts. So it is concluded that Geckobia G1, G. glebosum, and G. bataviensis are sympatric.
Keyword: