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Fatty acid butyl esters were synthesized from sunflower oil with 1-butanol using a homogeneous Rhizomucor miehei lipase in a biphasic organic (triglyceride, 1-butanol, hexane)– water (with enzyme) system in a continuous setup consisting of a cascade of a stirred tank reactor and a continuous centrifugal contactor separator (CCCS), the latter being used for integrated reaction and liquid–liquid separation. A fatty acid butyl ester yield up to 93% was obtained in the cascade when operated in a once-through mode. The cascade was run for 8 h without operational issues. Enzyme recycling was studied by reintroduction of the water phase from the CCCS outlet to the stirred tank reactor. Product yield decreased over time to an average of 50% of the initial value, likely due to accumulation of 1-butanol in water phase, loss of enzyme due to agglomeration, and the formation of a separate enzyme layer.

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Biodiesel is produced through the transesterification process in the presence of alcohol and a catalyst that catalyzes the conversion of triglycerides to esters and glycerol compounds. A more optimal product conversion can be achieved using enzymes, such as lipase. Lipase is reported to be produced in osmophilic yeasts due to the low water content in their natural habitats. Wild forest honey is one of the osmophilic natural habitats in Indonesia. However, lipase-producing yeast has not been reported in the Indonesian honey. In this study, we screened the lipase-producing yeasts isolated from wild forest honey collected from Central Sulawesi. The production profile and activity of lipase were determined at different pH values and temperatures. One promising yeast was isolated from the honey, which was identified as Zygosaccharomyces mellis SG 1.2 based on ITS sequence. The maximum lipase production (24.56 ± 1.30 U/mg biomass) was achieved by culturing the strain in a medium containing 2% olive oil as a carbon source at pH 7 and 30℃ for 40 h. The optimum pH and temperature for lipase activity were 6 and 55℃, respectively. The enzyme maintained 80% of its activity upon incubation at 25℃ for 4 h. However, the enzyme activity decreased by more than 50% upon incubation at 35 and 40℃ for 2 h. This is the first study to report the lipase producing capability of Z. mellis. Further studies are needed to optimize the enzyme production.

Lipase-producing fungi have been isolated from environments containing lipids. The non-dairy creamer industrial waste has a high amount of lipids so it is a potential source for the isolation of lipase-producing fungi. However, the study of fungi that secrete lipase from this industrial waste has not been reported. The purpose of this study was to obtain lipase-producing filamentous fungi from non-dairy creamer industrial waste. Mineral salt and potato dextrose agar were used as media for the isolation process. The qualitative screening was conducted using phenol red agar medium and the quantitative screening using broth medium containing glucose and olive oil. Isolates producing the highest amounts of lipase were identified with molecular methods. We found that 5 out of 19 isolated filamentous fungi are lipase producers. Further analysis showed that isolate Ms.11 produced the highest amount of lipase compared to others. Based on ITS sequence Ms.11 was identified as Aspergillus aculeatus. The lipase activity in medium containing 1% glucose + 1% olive oil at pH 7.0 and 30℃ after 96 and 120 h of incubation was 5.13 ± 0.30 U/ml and 5.22 ± 0.59 U/ml, respectively. The optimum lipase activity was found at pH 7.0, 30℃ and using methanol or ethanol in the reaction tube. Lipase was more stable at 20−30℃ and maintained 85% of its activity. It was concluded that isolate Ms.11 is a potential source of lipase that catalyzes transesterification reactions. Further studies are required to optimize lipase production to make the strain suitable for industry purposes.

This study aimed to evaluate the block system implementation in Permata Harapan Vocational High School based on (1) understanding and apply the block system conducted by teaching staff, (2) understanding of block system implementation by students, (3) availability of facilities and infrastructure at Permata Harapan Vocational High School to support good student competence. This research was a descriptive study. Data was collected by using a questionnaire method based on the CIPP evaluation model (context, input, process, product). The subjects of this study were 50 students in grade X and XI Permata Harapan School and several officials high school. The description of the data carried out by considering the frequency distribution and determining the Level of Respondent Achievement (TPR) in each component and indicator which compared with the criteria. The results showed that the scores were based on an understanding of the implementation of the block system using the CIPP evaluation method which included in moderate category and reached 68.65% percent, with details of each aspect: (1) the context aspect was 81.94%, (2) 63.89% of input aspects, (3) 67.70% of process aspects, (4) 71.52% of product aspects. Based on the discussion results of observation and documentation, the average achievement of all aspects was 82.47%. So, the implementation of the block system at SMK Permata Harapan has been in good classification but it still needs improvement in various aspects so that the goal of implementing the block system can be achieved perfectly.

Limbah pengolahan udang merupakan salah satu sumber enzim pendegradasi kitin (enzim kitinolitik) potensial. Tulisan ini melaporkan sebagian hasil rangkaian riset mengenai pencarian sumber enzim Kitinolitik dari lingkungan laut, khususnya dari limbah industri perikanan. Tujuan dari riset ini adalah mengisolasi bakteri kitinolitik dan limbah pengolahan udang, mengetahui kondisi optimum untuk memproduksi enzim tarsebut dan mengidentifikasi bakteri terbaik penghasil enzim tersebut. Penapisan diakukan dengan mengevaluasi indeks kitinolitik pada medium kitin padat (2%) dan mengukur aktivitas kitinolitik pada medium minimal (MSM) cair yang diperkaya koloidal kitin 0,5%. Optimasi produksi enzim dilakukan dengan mangkultur isolat pada berbagai pH, suhu, dan substrat menggunakan penangas air bersuhu 37ºC dengan agitasi 100 rpm. Sejumlah 106 isolat berhasil diisolasi, dan di antaranya isolat KPU 218 yang memiliki aktivitas kitinolitik tertinggi (0,134 ± 0,004 U/mg) dalam waktu tercepat (24 jam). Kondisi optimum untuk memproduksi enzim tersebut adalah pH 5, suhu 25ºC dengan substrat koloidal kitin dan waktu produksi 30 jam. Hasil identifikasi berdasarkan 16S-rDNA menunjukkan bahwa isolat KPU 218 memiliki kemiripan 87% dengan Acinetobacter sp.