Judul: Biodegradasi Oksidatif Styrofoam oleh Kapang Pelapuk Putih dan Bakteri.
Abstrak: Limbah styrofoam tersusun atas banyak monomer stirena yang mengalami polimerisasi. Sejauh ini penelitian dalam biodegradasi styrofoam hanya pada bakteri Pseudomonas sp.. Enzim ligninolitik berasal dari kapang pelapuk putih berpotensi dalam mendegradasi styrofoam. Kapang pelapuk putih yang digunakan adalah NG007, WM01, dan BIOM3. Bakteri yang digunakan Pseudomonas aeruginosa, Serratia marcescens, dan Basillus subtilis. Tujuan dari penelitian ini adalah menemukan galur kapang pelapuk putih dan bakteri yang paling resistan, dan mampu dalam mendegradasi styrofoam dengan baik. Tingkat resistensi terhadap styrofoam adalah kapang NG007 (Pestalotiopsis sp.) dan bakteri Pseudomonas aeruginosa setelah inkubasi 7 hari, dengan suhu ±25℃. Degradasi larutan styrofoam pada media cair kapang NG007 sebesar 74.43 % dan bakteri Pseudomonas aeruginosa sebesar 63.43 % yang paling mampu dalam mendegradasi styrofoam setelah inkubasi 30 hari, dengan suhu ±25℃. Bakteri Pseudomonas aeruginosa dan kapang NG007 (Pestalotiopsis sp.) hasil SEM menunjukkan adanya perubahan struktur lapisan berupa pembesaran lubanglubang pada rongga styrofoam setelah inkubasi 30 hari, dengan suhu ±25℃.
Keyword: enzim ligninolitik, NG007, Pseudomonas aeruginosa, styrofoam

Judul: Characterization and Biodegradation of Polyblend (Styrofoam-Starch) with Polylactid acid (PLA) as Biocompatizer.
Abstrak: Styrofoam is a kind of polystyrene which can not be naturally decomposed. The increasing amount of using styrofoam causes environment pollution. In facing this problem, modification of recyclable styrofoam is needed to produce degradable plastic. Starch can be a solution because it is a polymer that can be biologically decomposed. The mixture of starch to the styrofoam composite creates biodegradable plastic. Unfortunately, various polarity of styrofoam and starch is difficult to mixed homogenously, so we need polylactic acid (PLA) as the biocompatizer. Styrofoam and starch of four different concentrations of PLA, 5, 10, 15, and 20%. Film with the highest homogeneity was given by 80:20 concentration of styrofoam and starch combination with 20 % of PLA addition. The more PLA, the more homogenous of film we got. Film with the highest homogeneity produced substantial weight reduction which about 10%. The film that has been produced was amorphous since it had wide melting point, 155 °C to 185 °C. Infrared spectrum film showed the existence of C-O ester on 1184 cm-1 region. Ester functional group indicated that the film could be biodegraded. The infrared spectrum of the film did not show new functional groups, so we concluded that the film was a product of physical mixture between styrofoam and starch.
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Judul: Quantitative Trait Loci Mapping for Trait in Categorical Scale
Abstrak: Genes or regions on chromosome underlying a quantitative trait are called Quantitative Trait Loci (QTL). Characterizing genes controlling quantitative trait on their position in chromosome and their effect on trait is through a process called QTL mapping. In estimating the QTL position and its effect, QTL mapping basically utilize the association between QTL and DNA markers. However, many important traits are obtained in categorical scale, such as resistance from certain disease. From a theoretical point of view, QTL mapping method assuming continuous trait could not be applied to categorical trait. This research was focusing on the assessment of the performance of Maximum Likelihood (ML) and Regression (REG) approach employed in QTL mapping as well as the performance of Lander and Botstein (LB) and Piepho method in determining critical value in testing the existence of QTL for binary and ordinal trait by means of simulation study. The simulation study to evaluate the performance of ML and REG approach was conducted by taking into account several factors that may affecting the performance of both approaches. The factors are: (1) marker density; (2) QTL effect; (3) sample size; (4) shape of phenotypic distribution; (5) number of categories; and (6) number of QTL. Moreover, the simulation study for evaluating LB and Piepho method in determining critical value was conducted by generating distribution of the test statistic under null hypothesis. From simulation study, it was obtained that LB and Piepho method showing similar performance in determining critical value in testing the existence of QTL for binary and ordinal trait. The simulation study also indicating that both methods could be used in determining critical value in QTL mapping analysis for binary trait as well as for ordinal trait if the REG approach is used but not if ML approach is used due to their poor performance. In assessing the performance of ML and REG approach in QTL mapping analysis for binary trait, the two approaches showing comparable performance; whereas for ordinal trait REG approach showing poor performance compared with ML approach in estimating thresholds. As a result, in QTL mapping analysis, ML and REG approach could be used when dealing with binary trait, whereas ML approach is suggested when dealing with ordinal trait.
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