THE EFFECTIVENESS OF PHYSICAL AND ALKALI HYDROTHERMAL PRETREATMENT <br> IN IMPROVING ENZYME SUSCEPTIBILITY OF SWEET SORGHUM BAGASSE

Abstract

Sweet sorghum bagasse (SSB) obtained after juice extraction is a potential feedstock for fermentable sugars production that can be further fermented to different kinds of products, such as ethanol or lactic acid. The proper particle size resulted from phsyical pretreatment and different pretreatment processes including water, alkali, hydrothermal, and alkali hydrothermal for improving enzyme susceptibility of SSB have been investigated. After grinding to particle sizes of <250 μm, 250-420 μm, and, > 420 μm the sweet sorghum bagasse was washed to eliminate residual soluble sugars present in the bagasse. Dosages of cellulase enzyme used in saccharification were 60 and 100 FPU/g substrate, respectively. The results showed that SSB with particle sizes of 250-420 μm had the highest cellulose (38.33%) and hemicellulose content (31.80%). Although the yield of reducing sugar of 250-420 μm size particles was lower than that of smaller particle (<250 μm), the former was more economical in the energy consumption for milling process. The yields of reducing sugar obtained from enzymatic hydrolysis of alkali hydrothermal pretreated sweet sorghum bagasse were 1.5 and 0.5 times higher than that from untreated sweet sorghum bagasse at enzyme loading of 100 and 60 FPU/g substrate, respectively. Furthermore, alkali hydrothermal pretreatment was able to remove as much as 85% of lignin. Morphological analysis using SEM (Scanning Electron Microscope) showed that samples treated with alkali hydrothermal have more pores and distorted bundles than that of untreated sweet sorghum bagasse. Meanwhile, XRD (Xray diffraction) analysis showed that pretreated samples had a higher crystallinity and smaller crystallite size than untreated sweet sorghum bagasse, which might be due to removal of amorphous lignin components.

Integration of Multiple Fundamental Instrumental Analyses to Understand the Key Factors for Enhancing Enzymatic Saccharification of Oil Palm (Elaeis guineensis) Empty Fruit Bunch by Aqueous Pretreatments

“…were consistent with a previous study conducted by Pramasari et al (2017) which inferred that the crystallite size imposed no significant influence on the performance of enzymatic saccharification. Apart from that, it should be noted that there is a paucity of research examining the effect of crystalline size on the trend of enzymatic saccharification glucose yield at present.…”

Design and performance of amphiphilic lignin derivatives in enzymatic hydrolysis of sweet sorghum bagasse for bioethanol production

“…The cellulose content of SSB is greater than 40%, which makes SSB a promising material to convert as bioethanol (Fatriasari et al 2015). Therefore, many scientists have conducted research on the pretreatment of SSB using chemical (Jiang et al 2019), physical, (Pramasari et al 2017) and enzymatic applications (Yesuf and Liang 2014;Partida-Sedas et al 2016). To enhance the reducing sugar, additives such as 2- [4-(2,4,4-trimethylpentan-2-yl)phenoxy]ethanol (Triton-X) (Eriksson et al 2002), polyoxyethylene sorbitan monooleate (Tween) (Wang et al 2018;Nababan et al 2020), bovine serum albumin, Brij-35 (Rocha-Martín et al 2017), and lignin derivative products resulting from the reaction of lignin with polyethylene glycol (Lin et al 2015;Chen et al 2016;Fatriasari et al 2020a,b) were added during the enzymatic process.…”

PRODUKSI BIOETANOL DARI BAGAS SORGUM MANIS MELALUI SAKARIFIKASI DAN FERMENTASI SIMULTAN (SSF) KONVENSIONAL MENGGUNAKAN Trichoderma reesei dan Saccharomyces cerevisiae

“…Hal ini tergantung pada agen kimia yang digunakan (misalnya asam, alkali) serta kondisi perlakuan yang diterapkan (Wu et al 2011). Delignifikasi bagas sorgum manis menggunakan alkali hidrotermal dan hidrogen peroksida dinilai cukup efektif untuk meningkatkan aksesibilitas selulosa dan mampu menurunkan lignin hingga 85% (Pramasari et al 2017).…”