Judul: Perubahan Struktur Fenantrena Selama Proses Biodegradasi oleh Bakteri Bacillus altitudinis
Abstrak: Polycyclic aromatic hydrocarbons (PAHs) are toxic, mutagenic, and carcinogenic pollutants that are present in environment. Some bacterial species have ability to metabolize these compounds and use them as energy sources for their growth. Bacillus altitudinis was used to degrade phenanthrene, a three-ring aromatic PAH. The maximum degradation rate (14%) was obtained when Bacillus altitudinis was cultured for 28 days after the addition of 50 ppm phenanthrene to the liquid medium. Furthermore, the degradation was affected by addition of Tween 80 as surfactants. The observation parameters were total plate count (TPC) and pH. The value TPC increased for 28 days cultivation and pH value increased too from 6 to 8 during the 28 days cultivation. The mechanism of degradation was determined through identification of metabolites, the possible pathway of phenanthrene degradation is via phthalic acid. It has been proofed by a mass spectrum of phthalic acid at retention time of 7.607 with match quality of 72.
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Judul: Biodegradation of Polyaromatic Hydrocarbons using Phellinus noxius BRB 11 Isolated from Berbak-Sembilang Biosphere Reserve, Indonesia
Abstrak: Microbial biodegradation of Polyaromatic Hydrocarbons (PAHs) mixture is an eco-friendly practice that requires the exploration of efficient bio-degraders. In this study, three fungal species i.e., Phellinus noxius BRB 11, Leiotrametes menziesii BRB 73, and Ceriporia lacerata BRB 81, were screened out for phenanthrene (PHE) degradation. MnP and laccase of each fungus was analysed using microplate reader while PHE degradation was analysed by gas chromatography. The capability of the selected fungus was then performed in the following four single PAHs treatments i.e., PHE, anthracene (ANT), and Benzo (a)pyrene (BaP), and their mixtures i.e., PHE–ANT, PHE–BaP, ANT–BaP, ANT– PHE–BaP. PHE (100 ppm) final concentration was subjected to only crude laccase enzymes of the selected fungus, and with the addition of 1-Hydroxybenzotriazole (1-HBT), 2,2,6,6-Tetramethylpiperidinyloxy (TEMPO), and Violuric acid (VA) as mediators. These mediators were used in 0.1, 0.3, 0.5, 1, 2, 3, and 4 mM concentration. Toxicity evaluation of degraded and non-degraded PAHs was performed using Vigna radiata and Artemia salina. The results showed that the enzymatic activity was high in BRB 11, and PHE biodegradation results from BRB 11, BRB 73 and BRB 81 i.e. 95%, 24%, and 26%, respectively. Further research was performed using the selected fungus, P. noxius BRB 11. In the single and mixture PAHs degradation experiment, all PAHs except for ANT was degraded above 90%. While BaP was degraded higher than its single degradation. During the degradation, ten metabolites were detected by GCMS and bio-detoxification was observed in all the treated samples. Among mediators used, TEMPO was the most efficient mediator with highest degradation rate on 0.1 mM until 2 mM concentration. PHE degradation was high at 0.1 mM of all mediator concentration, but starts decreasing as 1-HBT and VA mediators approached to higher concentrations. Laccase treated PAH was less toxic to Vigna radiata and Artemia salina than control. This study suggests that Phellinus noxius BRB 11 could be used as a potent PAHs degrader from the environment.
Keyword: Anthracene (ANT), and benzo (a)pyrene (BaP), phenanthren (PHE), degradation, laccase, mediators, Phellinus noxius BRB11, toxicity

Judul: Integration of Islamic Stock Markets of OIC Countries Before and During the Russia-Ukraine War Crisis
Abstrak: Pasar saham yang terintegrasi memberikan dampak negatif seperti percepatan co-movement (pergerakan bersama) yang rentan terhadap guncangan ekonomi, maupun krisis pasar global ke pasar domestik. Salah satu krisis yang terjadi pada tahun 2022 adalah perang Rusia-Ukraina yang berdampak pada pasar saham, termasuk pada saham syariah yang dipercaya lebih tahan terhadap guncangan krisis global. Penelitian ini bertujuan untuk meneliti perkembangan, integrasi dan respon lima pasar saham syariah negara OKI pada perang Rusia-Ukraina. Metode yang digunakan adalah VAR/VECM pada indeks DJIMMT25, SPSADS, SPSUAEDS, JII, DJIMT, SPBMIR, dan SPBMIU. Hasil penelitian menunjukkan pergerakan yang sama pada pasar saham UAE dan Arab Saudi, sedangkan Turki mengalami tren positif selama perang. Pasar saham syariah negara OKI selama periode perang Rusia-Ukraina terkointegrasi, sementara pasar saham Malaysia memengaruhi pasar saham syariah empat negara OKI lainnya. Hasil IRF menunjukkan terdapat efek permanen pada volatilitas pasar saham syariah negara OKI akibat guncangan yang diberikan. Namun, respon volatilitas relatif kecil karena kontribusi guncangan lebih didominasi oleh pasar saham itu sendiri, An integrated stock market has negative impacts, such as accelerating co-movement, which is vulnerable to economic shocks and global market crises on the domestic market. One of the crises in 2022 was the Russia-Ukraine war which impacted the stock market, including Sharia stocks which were believed to be more resistant to the shocks of the global crisis. This study examines the development, integration, and response of OIC countries five Islamic stock markets in the Russia-Ukraine war. The method used is VAR/VECM on the DJIMMT25, SPSADS, SPSUUAEDS, JII, DJIMT, SPBMIR, and SPBMIU indices. The results show the same movement in the UAE and Saudi Arabia stock markets, while Turkey experienced a positive trend during the war. The Islamic stock market of the OIC countries during the Russia-Ukraine war was cointegrated. In contrast, the Malaysian stock market influenced the Islamic stock markets of the other four OIC countries. The IRF results show a permanent effect on the volatility of the Islamic stock market in OKI countries due to the shocks given. However, the volatility response is relatively small because the stock market itself dominates the contribution of shocks.
Keyword: co-movement, OIC, Rusia-Ukraine war, sharia stock market integration