Among bacterial expression system, Escherichia coli was the popular and widely used expression host due to its high rate expression trait. However, overexpression of recombinant protein in E. coli often found as inclusion bodies. While formation of inclusion bodies is beneficial in protein isolation from other cellular components, most of recombinant proteins from inclusion bodies are misfolded which have lost their biological activity. Protein refolding allows misfolded protein to rearrange into their native conformation which exhibit its biological activity, thus protein refolding become a pivotal step to recover active protein. However, protein refolding was affected by various factors; hence, screening of refolding condition was required to meet the optimal result. As a consequence, rapid and efficient characterization method is required to monitor the refolding performance. In this review, we will briefly give an overview about protein refolding method, chemical additives in protein refolding, and also provide insight in structural characterization to evaluate refolding performance.

The human epidermal growth factor (hEGF) is widely used clinically as a wound healer, as it has a vital role in stimulating cell proliferation, differentiation, and migration. Consequently, the large-scale production of recombinant hEGF in E. coli has been developed to meet the high demand for hEGF clinically. However, intracellular proteins in E. coli, especially small proteins like hEGF, are degraded by proteases. To overcome this issue, hEGF was fused with CBD-Ssp DnaB to construct a fusion protein CBD-Ssp DnaB-hEGF. This study was conducted to obtain refolded hEGF from the inclusion bodies of CBD-Ssp DnaB-hEGF. The experiment was carried out using E. coli BL21(DE3) containing plasmid pD861-CBD-Ssp DnaB-hEGF. The CBD-Ssp DnaB-hEGF gene was constructed by fusing CBD-Ssp DnaB and hEGF gene and then was optimized. The method was started with E. coli transformation, CBD-Ssp DnaB-hEGF expression, inclusion bodies solubilization, refolding, and simultaneous cleavage to release hEGF. The CBD-Ssp DnaB-hEGF was expressed as inclusion bodies, which can then be purified by washing with Triton X-100 and 1 M urea. The inclusion bodies were solubilized in 8 M urea, the solubilized CBD-Ssp DnaB-hEGF was reformed by dialysis, and then hEGF was spliced by shifting the pH from 8.5 to 6.0 to yield a concentration of 0.163 mg/ml. Therefore, we concluded that hEGF was obtained from the solubilized CBD-Ssp DnaB-hEGF from inclusion bodies produced by E. coli BL21(DE3).

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Informasi tentang herpetofauna di Punggualas, Taman Nasional Sebangau telah dilakukan pada tahun 2015. Tujuan dari penelitian ini adalah untuk menginventarisasi jenis-jenis herpetofauna setelah empat tahun dari data terakhir di Punggualas, Taman Nasional Sebangau. Metode yang digunakan dalam penelitian ini adalah Visual Encountered Survey (VES) selama empat hari di sepanjang transek Kahiu dan Metarius. Hasil penelitian menunjukkan bahwa terdapat 11 spesies yang terinventarisasi yang terdiri dari delapan spesies reptile (7 famili) dan tiga spesies amfibi (3 famili). Temuan ini lebih sedikit dibandingkan literatur pada tahun 2015 yaitu sebanyak 33 spesies yang terdiri dari 17 spesies reptile (13 famili) dan 16 spesies amfibi (4 famili). Hal ini dikarenakan perbedaan luas daerah pengamatan, lama pengamatan, metode, jumlah orang pengamat, dan tingkat keahlian pengamat. Lima spesies ditemukan pada penelitian ini yang belum ditemukan pada tahun 2015 yaitu Homalopsis buccata, Ahaetulla prasina, Cyrtodactylus sp., Siebenrockiella crassicollis, dan Notochelys platynota. Terkait dengan status, 28 spesies herpetofauna berstatus Least Concern, tiga spesies berstatus Vulnerable, dan satu spesies berstatus Near Threatened. Enam spesies lainnya belum memiliki status konservasi di IUCN Red List. Perlu dilakukan penelitian berikutnya tentang jumlah populasi dan pengamatan pada daerah yang lebih luas.

Pada kajian ini, penulis bermaksud untuk mengetahui pengaruh proses pretreatment resistive heating pada proses pembuatan furfural dari bahan alang-alang dan juga untuk mengetahui karakter furfural yang dihasilkan. Rancangan percobaan terdiri dari 2 faktor, faktor 1 yaitu konsentrasi NaOH (0,01; 0,05; 0,09 M) dan faktor 2 yaitu suhu pretreatment (65, 75, 85 °C). Hasil penelitian menunjukan bahwa pretreatment pemanasan resistive dapat menghasilkan rendemen furfural yang lebih banyak dibanding dengan rendemen tanpa pretreatment dan juga konsentrasi NaOH dan suhu pretreatment berpengaruh terhadap jumlah rendemen furfural hasil hidrolisis. Perlakuan terbaik diperoleh pada kombinasi perlakuan suhu pemanasan 65°C dengan konsentrasi NaOH  0,01 M, yaitu didapatkan rata-rata rendemen furfural sebanyak 7,34%. Karakterisasi melalui pengukuran massa jenis, kromotografi lapis tipis (KLT), spektrofotometri UV-Vis, spektrofotometri FTIR, dan gas chromatography (GC) menunjukan bahwa karakter furfural yang didapat memiliki kemiripan dengan furfural standar.Kata kunci: Alang-alang, Furfural, Pretreatment, Resistive, Lignoselulosa